Device and method for processing of data flow, having sequence of packets and information of synchronisation related to packets

FIELD: information technologies.

SUBSTANCE: device (3400) for processing of coded data flow (3401), comprising a decoding module (3402) to generate decoded data flow (3403) from coded data flow (3401), detection module (3404) for detection of information on position of at least one intra-coded frame in coded data flow (3403) and substitution module (3405) for substitution on the basis of detected information on position of coded data flow (3401) parts with according parts of decoded data flow (3403).

EFFECT: increased efficiency, speed of data flow processing by means of selective substitution of only that data in data flow, which is required for further use of data flow.

28 cl, 37 dwg

 

The technical FIELD TO WHICH the INVENTION RELATES.

The invention relates to a device for processing an encrypted data stream.

In addition, the invention relates to a method of processing encrypted data stream.

In addition, the invention relates to a device for processing a data stream having a sequence of packets and timing information related to the packages.

The invention also relates to a method of processing a data stream having a sequence of packets and timing information related to the packages.

In addition, the invention relates to a program element.

In addition, the invention relates to a machine-readable medium.

PRIOR art

Electronic entertainment devices are becoming increasingly important. In particular, increasing the number of users buying audio/video players based on the hard drive and other equipment for entertainment.

Since the reduction of memory is important in the field of audio/video players, audio and video data is often stored in a compressed form and for security reasons in encrypted form.

MPEG2 is the standard for the generic coding of motion pictures and related audio and creates in geopathic of data frames, that can be placed in a particular order, called the structure group of pictures (GOP). The bit stream standard MPEG2 composed of a sequence of frames of data, coding of the image. Three ways of encoding images are internal encoding (I-picture), coding with direct prediction (P-picture) and encoding with bi-directional prediction (B-picture). Coded internal encoding (intra-kodirovanie) frame (I-frame) refers to a single image and contains the relevant data. The frame with the direct prediction (P-frame) requires information about previous I-frame or P-frame. Frame with bi-directional prediction (B-frame) depends on the information about the previous or the next I-frame or P-frame.

In the device media playback in addition to the normal play mode, in which media content is reproduced at the normal speed, the interesting feature is the provision of special playback mode in which the media content is playing a modified way, for example with increased speed ("fast forward").

However, for the formation of the stream for the special playback mode may require complex data processing.

WO 03/107664 A1 discloses a method is a device for processing a stream which contains encrypted information, which detect the beginning and the ends of the I-frames. In response to the detection check whether the corresponding encrypted packet.

OBJECTIVE AND summary of the INVENTION

The task of the invention consists in the processing of a data stream in an effective manner.

In order to perform the above task, provided the device and the method of processing an encrypted data stream, the apparatus and method of processing a data stream having a sequence of packets and timing information related to the packages, the program element and the computer-readable media in accordance with the independent claims.

In accordance with an illustrative alternative embodiment of the invention provides a device for processing an encrypted data stream that contains the decryption module to generate decrypted stream data from the stream of encrypted data, a detection module for detecting information on the position of the at least one intra-coded frame in the stream of decrypted data and module replacement for replacement on the basis of the detected positional information pieces of the encrypted data stream corresponding portions of the decrypted stream data.

In accordance with another illustrative alternative embodiment of the invention provides a method of printing handling the key stream of encrypted data, containing phases, which form the stream of decrypted data from the encrypted data stream, detect information on a position of at least one intra-coded frame in the stream of decrypted data and replace based on the detected information about the position, part of the stream of encrypted data relevant parts of the stream of decrypted data.

In accordance with another illustrative alternative embodiment of the invention provides a device for processing a data stream having a sequence of packets and timing information related to the packages containing the module distribution for uniform distribution of packets in the data flow and module replacement for replacement information synchronization data stream modified information synchronization, adjusted for uniform distribution packages.

In accordance with another illustrative alternative embodiment of the invention provides a method of processing a data stream having a sequence of packets and timing information related to the packages containing phases in which uniformly distribute the packets in the data flow and replace the timing information of the data stream with the modified information synchronization, adjusted for uniform distribution packages.

Furthermore in accordance with another illustrative alternative embodiment of the invention provides machine-readable medium, in which is stored a computer program, which when executed by the processor is configured to control to perform any of the above ways or to perform them.

In addition, in accordance with another illustrative alternative embodiment of the invention is provided a program element which, when performed by a processor configured to control to perform any of the above ways or to perform them.

Data processing in accordance with the invention can be implemented by a computer program, i.e. software, or through one or more special electronic optimization schemes, i.e. in hardware, or in hybrid form, i.e. by means of software components and hardware components.

Distinctive signs, in accordance with the invention, in particular, have the advantage that the processing of a data stream can be performed efficiently by selectively replacing only the data in the data stream that are required for further use of the data stream. In other words, the existing data flow changes only partially (and preferably is as small as possible modifications), so that the resulting data stream could and what to use as the basis for a specific target application, for example for the formation of the special playback mode. Thus, the overall aspect of the variants of embodiment of the invention is directed to selective replacement of individual parts of the data stream.

In accordance with one aspect of the invention is, in particular, is realized by the full decryption of the encrypted data stream, detecting the position of the I-frames in the fully decoded data stream and selectively replace only those parts of the stream of encrypted data, which correspond to the positions of I-frames. By taking these steps, you can ensure that there decrypted only those parts for which unencrypted transmission is absolutely necessary - in particular, to ensure that the processed data stream which is a mixture of encrypted and decrypted parts, could be used as the basis for the formation of the special playback mode. Thus, at the same time can be achieved efficient processing and high level security.

Therefore, in the case of encrypted original stream for normal playback (in particular, in the standard MPEG) stream for the special playback mode, encrypted using the algorithm DVB (digital video), can be formed even in scenarios in which not allowed the use of fur is ISM encryption DVB (for example, at home).

In accordance with an illustrative alternative embodiment of this aspect of the invention provides a method of forming a hybrid stream from the transport stream encrypted video consisting of data packets, and initially, a decrypted transport stream from the transport stream encrypted video. Then in a decrypted transport stream can be detected I-frames, and can be identified by the pointers to the beginning and end of I-frame (frame). In addition, the positions of the pointers at the beginning and at the end of I-frames corresponding to the decrypted packets decrypted transport stream can replace the encrypted packets in the transport stream.

Thus, it may be formed of a hybrid transport stream (i.e., mainly the encrypted transport stream with some unencrypted packets). In this context, can be formed or selected packets of the transport stream, which minimally must be unencrypted (to be able to form a suitable transport stream standard MPEG2 for special playback mode of this hybrid flow). In addition, can be performed in the discovery of several important fields required to create a transport stream of a specialized R is press play. Therefore, encrypted (using the algorithm DVB) stream for the special playback mode can be formed, even if the use of encryption (using the algorithm DVB) in the home is not permitted.

Illustrative applications of the system, in accordance with the invention, represent a digital video recording device (such as hard disk drives (HDD), rewritable digital versatile discs (DVD+RW), etc) and network devices using specialized playback mode.

In accordance with the described aspect of the invention may be assessed a minimum amount of data of any frame (I-frame, P-frame or B-frame), which must be unencrypted in order to give the opportunity to form an encrypted stream for the special playback mode. In addition, it is possible to decide which packets of the transport stream must be unencrypted and what can be encrypted. It is assumed that this decision and the corresponding transformation (in particular, decoding) must be made either on the transmission side, or in a storage device that receives the stream.

In addition, in accordance with the invention, it is possible to detect the boundaries of the frame in this partially (but often almost completely) Salif the consistent thread again on the receiver side, when this flow should be generated stream for the special playback mode. This allows you to create encrypted stream for the special playback mode. Therefore, it may be created encrypted transport stream, and to this end can be detected positions of frames.

In accordance with the described aspect of the invention it is possible to start with an encrypted stream, and can be decrypted only those packets that you want to change. Usually they are not re-encrypted, in particular, in scenarios in which can not be used in the encoder. To perform this action, the first stream can be decoded to find the headers. In fact described aspect may be used as input information unencrypted and encrypted stream. Based on the detection of headers can be made by selecting which input stream is passed to the output. All processing can be performed in a secure environment, for example, inside an integrated circuit (IC), so that the unencrypted stream could not be available. This means that the system can be encrypted input stream and for the most part, the encrypted output stream with some unencrypted packets. In some cases, not all the packets that contain header information, can be unencrypted, is as unencrypted must be only those parts, that will be changed, and not necessarily the full header. This is particularly clear in the case when, for example, the initial code image is divided into more than two packages. In this case, the initial part of the code image can still be encrypted. It is possible to provide an algorithm to select the packages that should be in the clear. This algorithm can lead to a partially-encrypted initial codes image, but can minimize the memory requirements. The full source code of the image in an unencrypted form would require a larger buffer.

In accordance with another aspect of the invention, the data stream having a sequence of packets and timing information related to these packets can be processed by smoothing or uniform distribution of packets of a data stream by replacing and updating information synchronization data flow through the formation and insertion of synchronization information related to the smoothed data stream. However, the replacement can be performed prior to distribution. Through this change, parts of the data flow for approval of the smoothed data stream with the relevant requirements of the synchronization information is generated modified data stream, which can serve as this is and the formation of the special playback mode.

In accordance with this aspect of the invention provides a method of forming stream for the special playback mode of the video stream, the video stream may be composed of a group of pictures (GOP), organized in packets, the packets are transmitted within a time interval of a group of pictures (GOP). In accordance with the described method packages with the reference times of the program (samples PCR) can be calculated based on the time interval between packets of the total number of packets of the group of pictures (GOP) and the time interval of the group of pictures (GOP). In addition, packets with PCR at the beginning of each group of pictures (GOP) for the special playback mode can form a timeline for the stream for the special playback mode.

Timestamp decoding (DTS) and/or a timestamp representation (PTS), if they exist, can be adapted in accordance with the scale of time.

In the illustrative case, the encrypted stream for the special playback mode in this stream for the special playback mode can present messages access control (ECM), to enable decryption by the receiver (e.g., cable box or set top box (STB). For example, the message is their ECM can be added to the end of the previous group of pictures (GOP) for the special playback stream for the special playback mode.

In accordance with the described aspect of the invention the stream for the special playback mode (encrypted or unencrypted or their mixture) at the level of the transport stream can be processed via the same output circuit, which is used for normal playback (in particular, without any re-multiplexing). In addition, to create a special playback mode at the level of the transport stream can be small enough processing resources. Additionally, the special playback mode in accordance with an illustrative alternative embodiment of the invention, can be used for traffic flows with time-stamp packets arrive or without them.

Thus, in accordance with an illustrative alternative embodiment of the present invention create a stream for the special playback mode at the level of the transport stream is made possible without re-multiplexing. To this end, the stream for the special playback mode can be formed from the transport stream and the packet smoothed by the group of pictures (GOP) of the stream for the special playback mode, the synchronization information may be replaced with the new information time scale (n is an example, labels PTS, DTS, PCR), and to encrypted stream for the special playback mode can be added messages ECM (for example, at the end of the group of pictures (GOP) for the special playback mode).

Hereinafter will be described in some additional aspects, in accordance with an illustrative alternative embodiment of the invention.

The packets of the transport stream can be smoothed by one group of pictures (GOP) for the special playback mode ("TP GOP"). In addition, the distance in time transfer between groups of images for the special playback mode (TP GOP) can be constant and exactly equal to the total time frame and group of pictures (GOP). Additional PCR-package can be provided at the beginning of each group of pictures (GOP). The size of the PES packet may be equal to one group of images for the special playback mode (TP GOP), which leads to a single label DTS/PTS for each group of images for the special playback mode (TP GOP). In addition, the label DTS can be equal to or greater than the basics PCR the next group of images for the special playback mode (TP GOP). For example, it may be equitable PCR the next group of images for the special playback mode (TP GOP). The basis of PCR SL is blowing a group of images for the special playback mode (TP GOP) may be equal to the basis of the PCR of the current group of images for the special playback mode (TP GOP) plus a constant increment value. In addition, you can define exactly what the message ECM and at what point in the stream must be inserted to improve or optimize performance. Depending on the switch SCB (bits control scrambling) this position may be located within the boundaries of a group of images for the special playback mode (TP GOP) and sometimes within an I-frame.

Select the length of time transfer between groups of images for the special playback mode (TP GOP), which is constant and equal to full-time display of frames in the group of pictures (GOP), and providing additional PCR packet at the beginning of each group of images for the special playback mode (TP GOP) can lead to a simple mechanism for the formation of PCR, because the extension PCR can be set equal to zero, which eliminates the need for a more complex calculation module 300. In addition, the difference between successive PCR may be a fixed value, which may additionally contribute to the simplification algorithm.

By ensuring that the size of the PES packet is equal to one group of images for the special playback mode (TP GOP), and by providing labels DTS equal to or greater than the basis of PCR the next group of images for specializirovannogo playback mode (TP GOP), received a simple algorithm to generate values labels DTS, because the same fixed increment can be used for PCR. In fact, the label DTS can be equal to PCR, which must be inserted in the following group of images for the special playback mode (TP GOP). Or, in other words, PCR may be equal to the label DTS previous group of images for the special playback mode (TP GOP). This means that the calculation should actually be executed only once instead of two.

Inserting the message ECM allows to optimize the structure of the modified data stream.

In addition, it may be advantageous to create an encrypted stream for the special playback of the encrypted stream for normal playback. This can be especially beneficial to fast-forward or rewind, but even more for slow-forward. In addition, it may be beneficial to the encryption method for the stream for the special playback mode was identical to the encryption method for the normal playback.

Next will be described an illustrative variants of embodiment of the invention with reference to the dependent claims.

Then will be described illustrative variants of embodiment of the device for processing the flow of zashifrovan the x data. These variants of the embodiment can also be applied to a method of processing encrypted data stream, the computer-readable medium and a program element.

The detection module may be configured to detect positional information of at least one frame with a direct prediction (P-frames) and/or at least one frame with bi-directional prediction (B-frames) in the stream of decrypted data. In other words, as a Supplement or alternative to the detection of the boundaries of the I-frame and replace the corresponding encrypted portions of the data stream is decoded parts can also be detected boundaries of the P-frames and/or B-frame and replaced with the appropriate decoded parts. For some applications, special playback mode may be advantageous to locate the borders of all frames.

The device may also be configured to record the hybrid flow. Hybrid stream containing the original encrypted part decrypted and modified parts can be stored in the device.

The detection module device can be performed with the opportunity to discover as information about the position of the start position and end position of the at least one intra-coded frame in the stream of decrypted data. Only the initial position is the end position of the I-frame should be inserted in the decoded form in the stream of encrypted data. By undertaking this, the number of decoded data in the data stream can be minimized, so that could be maximized security.

Module replacement can be performed with the opportunity to replace part of the stream of encrypted data relevant parts of the stream of decrypted data in the detected initial position and the final position of at least one intra-coded frame in the stream of decrypted data. In particular, the main part I-frames can be encrypted, which ensures a high degree of security.

In addition, it may be provided by adding executed with ability to add timing information to the data stream that was previously processed by module replacement. As the old information synchronization refers to the original data stream, the transition to specialized playback mode can have this effect, that the information synchronization can no longer be correct for the special playback mode. To this end, the synchronization information may be updated in accordance with the modified data stream.

In particular, the adding can be done with the ability to add timing information in an unencrypted form. Then unencrypted can be only the information synchronization and the beginning and ends of the I-frames, and the rest of the data stream may be encrypted. Module replacement may optionally be performed with the opportunity to replace such quantity of the data stream of encrypted data relevant parts of the stream of decrypted data, which is the minimum required to generate a data stream for special playback mode. By minimizing the number of decoded information in the encrypted data stream minimizes the risk of unauthorized access to data.

Module replacement can be performed so that the data between the start position and end position of the at least one key frame could be free from them replace the relevant parts of the stream of decrypted data. Decoding only at the beginning and at the end of the I-frame allows you to save a large portion of data block I-frame is encrypted, and only the necessary parts are decrypted and transmitted in an unencrypted form. Adding can be located in the module formation of a special playback mode, while the module replacement can be located on the recording side. The change module may be further configured to replace the indicator of the length of the PES packet, the timestamp representation (PTS) and/or timestamp decode the Finance (DTS) in the title block of the partially encrypted stream data.

The device in accordance with the invention, can be performed with the opportunity to handle the encrypted data stream comprising video data or audio data. However, such information media is not the only type of data that can be processed using the scheme in accordance with the invention. The formation of a special playback mode and similar applications are subject to review as video processing and for processing (clean) audio.

The device in accordance with the invention, can be performed with the opportunity to handle the flow of encrypted data consisting of digital data.

In addition, the device may contain a module forming a specialized playback mode, is configured to generate a data stream for reproduction in a special playback mode based on the output module replacement. The user can adjust this specialized playback mode, selecting the appropriate options in the user interface, for example, buttons on the device, keyboard, or remote control. The user selected a specialized playback mode, which may require information regarding the position of the I-frames may be particularly the one mode from a group, consisting of playback, fast forward, playback, fast rewind, playback, mode playback, stop-frame playback mode quick repeat and reverse playback. However, there may be other schemes special playback mode. For the special playback mode only a portion of subsequent data should be used for output (for example, for visual display and/or audio playback). As for the formation of the displayed signals are not all of the data (P-frames, B-frames) in the data stream can be used independently of other data (I-frames)may be desirable knowledge independently of the used data (I-frames).

The device in accordance with the invention, can be performed with the opportunity to handle the flow of encrypted data standard MPEG2. MPEG2 is the designation for a group of standards for audio and video coding, agreed by the expert group on movies (MPEG) and published as an international standard 13818 International organization for standardization (ISO) /International electrotechnical Commission (IEC). MPEG2 can be used to encode audio and video for broadcast signals, including digital satellite and cable TV the vision, but it is also used for digital versatile disks (DVD).

The device in accordance with the invention, may be implemented as at least one device from the group consisting of digital video recording devices, devices that support networking, conditional access system, a portable audio player, portable video player, mobile phone, player, digital versatile discs (DVDs), CD player (CD), a media player, based on a hard disk device, an Internet radio device, a public entertainment, and MP3 players. However, these applications are only illustrative.

Next will be described an illustrative variants of embodiment of the device for processing a data stream having a sequence of packets and timing information related to the packages. These variants of the embodiment can also be applied for a method of processing a data stream having a sequence of packets and timing information related to the packets, the computer-readable medium and software elements.

In this device, the distribution module may be configured to uniformly distribute the packets that belong to part of the data flow between two successive intra-coded frames. In mo the ule broadcast different packages, related to the I-frame can be represented with unequal intervals between them. The distribution module may redistribute the packages, so that the intervals between them are equal, that is, to smooth the distribution of packets in the time domain. This smoothing can be performed independently for each group of packets belonging to a single I-frame. Through this it is possible to support local consumption bits (bit rate) as low as possible, while the average consumption remains the same.

Module replacement can be performed with the opportunity to have a modified timing information in the initial position of the processed data stream. Then the synchronization information is preceded by a packet - thus, the best position to provide such information synchronization.

Module replacement can be performed with the option to generate a reference timing of the program, the time stamp decoding and/or the time stamp of the submission as changed information synchronization. Timestamp decoding/timestamp representation depends on the reference timing of the program.

In particular, the device can be configured with the ability to handle the flow of encrypted data and can contain a module paste the information for decryption performed in the possibility to insert information for decryption in the processed data stream to decrypt the encrypted data stream. For example, as information for decryption by a module paste the information for decryption can be inserted messages ECM. In particular, it may be useful to insert the information for decryption at the end of the processed data stream. More specifically, it is possible that the synchronization information has been added in front of the actual data, and that the ECM messages were provided at the end of the data so that the data has been placed between information and synchronization information for decryption.

As already mentioned above, the device can be configured with the ability to process a data stream comprising video data or audio data. In particular, pure visual data, clean sound data or a mixture or combination can be processed in accordance with the invention.

The device can be configured with the ability to process a stream of data consisting of digital data. As mentioned above, the formation of specialized playback mode. Various illustrative specialized playback modes mentioned above.

As further mentioned above, it is possible to process the encrypted data stream standard MPEG2. In addition, the above described device, with which the device of the invention can be successfully combined.

Certain to enter the aspects and further aspects of the invention clearly can be seen from examples variant embodiment, which will be described hereinafter and are explained with reference to these examples of variant embodiments.

LIST of DRAWINGS

Hereinafter the invention will be described in more detail with reference to examples of a variant of the embodiment, but the invention is not limited to them.

Figure 1 illustrates a transport stream packets with timestamp.

Figure 2 shows the structure of the group of images of standard MPEG2 intra-coded frames and frames direct prediction.

Figure 3 illustrates the structure of the group of images of standard MPEG2 intra-coded frames, frames direct prediction frames and bidirectional prediction.

Figure 4 illustrates the file structure information of the characteristic points and the stored information flow content.

Figure 5 illustrates the system for specialized playback unencrypted stream.

6 illustrates the compression of time when a special playback mode.

Fig.7 illustrates the specialized playback mode with fractional interval.

Fig illustrates a specialized playback mode at low speed.

Fig.9 illustrates the overall structure of the system with conditional access.

Figure 10 illustrates the encrypted packet of the transport stream of the broadcast digital video.

11 illustrates the header of the packet the transport stream encrypted packet of the transport stream of the broadcast digital video, shown in figure 10.

Fig illustrates a system that gives the ability to perform special playback mode in the fully encrypted stream.

Fig illustrates the full transport stream and the partial transport stream.

Fig illustrates a data transmission system between a broadcasting station and storage device for converting a stream.

Fig illustrates a specialized playback unencrypted account.

Fig illustrates a specialized playback on a fully encrypted record.

Fig illustrates a specialized playback on partially encrypted record.

Fig illustrates the buffering requirement for full unencrypted source code of the image.

Fig illustrates a practical unencrypted region at the beginning of the I-frame.

Figa and figv illustrate the practical unencrypted region.

Fig illustrates the initial codes images, distributed in two packages.

Fig illustrates an empty P-frame that is attached to a partially-encrypted initial code image.

Fig illustrates the area of non-encrypted data.

Fig illustrates the structure of the header in the standard MPEG2.

Fig illustrates the extension of the sequence code and the reasons of the wka sequence.

Fig illustrates the expansion of encoding image and the initial image code.

Fig illustrates the code sequence header, distributed in two packages.

Fig illustrates the smoothing of the package when a special playback mode.

Fig illustrates the label DTS and tag PTS on a scale of time PCR.

Fig illustrates the insertion of ECM messages between groups of pictures (GOP) for the special playback mode.

Fig illustrates the insertion of messages ECM within the I-frame.

Fig illustrates the signal path between the broadcasting station and the storage device and the location for conversion to hybrid stream.

Fig illustrates the formation of a protected special playback mode from fully encrypted record.

Figa illustrates a block diagram of the formation of the hybrid flow device for processing a stream of encrypted data in accordance with an illustrative alternative embodiment of the invention.

Figv illustrates a block diagram of the forming stream for the special playback mode, which can be used in conjunction with the block diagram of the formation of hybrid flow shown in figa, devices for processing the stream of encrypted data in accordance with the illustrative option in the underlining of the invention.

Fig illustrates data packets at various stages of the method of processing encrypted data stream in accordance with an illustrative alternative embodiment of the invention.

Fig illustrates a device for processing a data stream having a sequence of packets and timing information related to the packets in accordance with an illustrative alternative embodiment of the invention.

DESCRIPTION of VARIANTS of the INCARNATION

The illustration in the drawing is schematic. In different drawings, similar or identical elements have the same signs for links.

Next with reference to Fig. 1 through 13 will be described various aspects of the implementation of the specialized playback of transport streams in accordance with an illustrative variant embodiment of the invention.

In particular, we have described several opportunities to perform specialized playback mode on the stream, encoded in standard MPEG2, which may be partially or fully encrypted or not encrypted. The following description will be for the methods that are specific to the format of a transport stream in standard MPEG2. However, the invention is not limited to this format.

In fact, experiments have been made with the extension, the so-called transport stream with timestamps. Here the go packets of the transport streams, to all of which the front was added 4-byte header, which placed the time of arrival of the packet of the transport stream. This time can be obtained from the values of the scale-time PCR at the time when the first byte of the packet is accepted in the recording device. Keeping information synchronized with the flow is the appropriate way to specialized playback mode has become relatively easy process.

One problem during playback is to ensure that the buffer of the decoder MPEG2 will not have any overflow or antiperiplanar. If the input stream was compatible with the model of the decoder buffer, the recovery of the relative synchronization ensures that the output stream is also compatible. Some of these methods specialized playback mode does not depend on the time stamps and performed equally well on traffic flow with time stamp and without them.

Figure 1 illustrates the package 100 of the transport stream with timestamps, having full length 104 equal to 188 bytes, and contains the label 101 time, having a length of 105, is 4 bytes, the header 102 of the package and useful information 103, having a length of 184 bytes.

This subsequent paper will give a brief overview of what the thread is created for specialized mode vosproizvedeny is, compatible with the MPEG/DVB (digital video broadcasting), from the recorded transport stream and expects to cover the full range of recorded flows from completely unencrypted streams in which you can manipulate each bit, until fully encrypted streams (for example, in accordance with the scheme of digital video (DVB)), in which manipulation is available only headers and some tables. The invention is also directed to a decision between these two extremes, when unencrypted are only those data that need to be manipulated to form a stream for the special playback mode.

When you create a custom mode for a transport stream of MPEG/DVB problems can arise when information content is at least partially encrypted. May not be able to go to the level of the elementary stream, which is the usual approach, or even to make access to any of the headers elementary stream packets (PES) before decoding. It also means that we can not detect frames of images. Known mechanisms specialized playback mode should be able to get access to this information and process it.

In the frame of this description Ter is in "ECM" means the message access control. This message may, in particular, to contain sensitive private information of the supplier and, among other things, may contain an encrypted control word (CW)required to decrypt the stream of the MPEG standard. Typically, the control words lose power after 10-20 seconds. Messages ECM embedded in the packets in the transport stream.

In the frame in the present description the term "keys", in particular, refers to data that can be stored in the smart card (the card with an embedded microchip) and can be transmitted to the smart card using the EMM messages, so-called "message authorization", which can be embedded in the transport stream. These keys can be used for the smart card to decrypt the control words in the message ECM. Illustrative validity of such a key is one month.

In the frame of this description, the term "control words" (CW), in particular, identifies information to decrypt to decrypt the actual content. The control word can be decrypted by the smart card and then stored in kernel memory decryption.

Hereinafter will be described some aspects related to specialized playback unencrypted streams.

Even if the stream standard MPEG2 is not encrypted, specialized offer various spare parts is to cancel the playback mode is not trivial. A simple solution is just faster data output to the decoder to receive the fast forward, but as a stream of MPEG has timing information encoded in the headers, it is not easy to do with waiting to get the proper fast forward. In addition, it can be difficult to decide which frames should be dropped because this method of performing fast forward can give a frame rate higher than the frequency display.

In addition, this stream is a transport stream compliant MPEG2. This may be acceptable if the decoder is in the storage device, but can be problematic if the signal transferred through a standard digital interface. In addition, the bit rate can dramatically increase in a circuit. If the stream for normal playback is a transport stream with timestamps one program coming from a satellite broadcast, the bit rate at the decoder, normal playback may be about 40 Mbps, and the packet may be in irregular positions with gaps between them (partial transport stream). If the stream is compressed with a factor of special playback mode, the bit rate may be about 120 MB/s to play with the three-speed is Yu. Required supported bandwidth media on hard drives can also increase with a factor of special playback mode.

Thus, it would continue to send the correct number of frames, but this can be a problem when using this technique to encode the video as MPEG, which uses temporal redundancy of video to achieve high degrees of compression. Frames can no longer be decoded independently.

Figure 2 shows the structure of the set of groups of pictures (GOP).

In particular, figure 2 shows the flow 200 that contains several structures of groups of pictures (GOP) standard MPEG2 sequence of I-frames 201 and P-frames 202. The size of the group of pictures (GOP) number 203. Size : 203 group of pictures (GOP) is set to 12 frames, and is shown here only I-frames 201 and P-frames 202.

In the MPEG standard can be used the structure of group of pictures (GOP), in which only the first frame is encoded independently of other frames. This so-called intra-coded frame or I-frame 201. Frames with prediction or P-frames 202 are encoded with unidirectional prediction means that they depend only on the previous I-frame 201 or P-frame 202, as indicated by the arrows 204 in figure 2.

This structure of group of pictures (GOP)usually has a size of 12 or 16 frames 201, 202. It is assumed that the desired playback speed forward with a factor of 2x. Thus, for example, every second frame should be skipped. This is not possible in the compressed region, due to the previous reconstructed frame during decoding. Therefore, only a drop of some compressed frames and amendment information synchronization is not an option.

The alternative is to first decode the entire stream, then skip every second frame and, finally, the encoding of the remaining frames again. This may lead to unacceptable complexity schemes specialized playback mode or software. So, in the best case, some of the shots from a group of pictures (GOP) can be omitted, which does not depend on any other frames. For example, the playback speed 2 when the size of the group of pictures (GOP) in 12 frames may be skipped only the last 6 P-frames. In this case, the displayed image become "choppy" character, which turns a short period of time at normal speed, followed by a sudden jump in time. Especially at higher speeds specialized playback mode, it can be unpleasant and does not give the viewer feel special playback mode.

On IG shows another structure 300 multiple groups of pictures (GOP).

In particular, figure 3 shows the structure of group of pictures (GOP) standard MPEG2 sequence of I-frames 201, P-frames 202 and B-frames 301. The size of the group of pictures (GOP) is again marked with number 203.

It is possible to use the structure of group of pictures (GOP), also containing frames with bi-directional prediction or B-frames 301, as shown in figure 3. Size : 203 group of pictures (GOP) of 12 frames. B-frames 301 encoded with bi-directional prediction, this means that they depend on the previous and next I - or P-frame 201, 202, as indicated for some B-frames 301 crooked arrows 204. The order of transmission of the compressed frames may differ from the order in which they appear.

To decode a B-frame 301, you need both a keyframe before and after the B-frame 301 (in display order). In order to minimize the buffer in the decoder, the compressed frames can be reordered. So when sending keyframes can come first. Reordered stream as it is transmitted, also shown in figure 3 at the bottom. Reordering denoted by straight arrows 302. A stream containing B-frames 301, can give a good picture of the special playback mode, if you skipped all the B-frames 301. For this example, this leads to the playback speed with a factor of 3x in direct n the Board.

Whatever the structure may have the flow described so far, the solution can give an acceptable form of specialized mode playback mode fast forward. For reverse shots would reorder in time, but due to the fact that MPEG uses a temporal correlation between successive frames to achieve high compression ratio, set the order in which must be decoded frames. Therefore, the group of pictures (GOP) must first be decoded in the forward direction. The order of groups of pictures (GOP), sent to the decoder, can be completely changed, and group of pictures (GOP) can be skipped for higher speed playback in the reverse direction. The reduction of groups of pictures (GOP) through the skip P-frames or B-frames, as described above, it is also possible in this case. Anyway, this may cause the displayed sequence playback in the forward direction and jumps back. Therefore, personnel specialized playback mode must be selected from the decoded group of pictures (GOP), and their order is reversed, after which the frames are re-encoded. Then selected and processed by a previous group of pictures (GOP), and so on. Although, it is possible that the complexity of such a procedure can in order to be high.

The conclusion of the preceding considerations is that using only I-frames in the formation of a specialized mode of reproduction could be the proper solution, because these frames can be decoded independently. As a result, the formation of a special playback mode can be simpler, especially for the reverse direction. In addition, the use of only I-frames allows the playback speed with a factor of 3x or 4x. For really low speeds can be implemented more complex the above-mentioned methods.

Hereinafter will be described some aspects related to CPI-file (the file information of the characteristic points").

Detection of I-frames in the stream usually requires parsing thread to find the frame header. Locating positions in which the start of I-frames that can be done at a time when the recording of, or in offline mode after the recording is finished, or in prointernational mode, which is actually an offline mode, but with a small delay relative to the time of the recording. The end of the I-frame can be found by detecting the beginning of the next P-frame or B-frame. Metadata, thus obtained, can be saved in the part, but the attached file, which can be designated as the file information of the characteristic points or CPI-file. This file can contain pointers to the beginning and end of each I-frame in the file is a transport stream. Each individual entry can have its own CPI file.

The file structure 400 information on the characteristic points are visualized in figure 4.

In addition to the CPI-file 400 shown stored information 401. CPI file 400 may also contain some other data, which are not considered here.

Using data from the CPI-file 400 may move to the beginning of any I-frame 201 in the flow. If CPI-file 400 also contains the end of the I-frames 201, you know precisely the amount of data that must be read from a file transport stream for a complete I-frame 201. If for some reason the end of the I-frame is unknown, it must be read by the whole group of pictures (GOP) or, at least, most of the data group of pictures (GOP), to ensure that you have read the entire I-frame 201. The end of the group of pictures (GOP) is set to the beginning of the next I-frame 201. From the measurements it is known that the size of data I-frame can be 40% or more of all data of the group of pictures (GOP).

Using the extracted I-frames 201 to create a new stream for the special playback mode, which is compatible with the four the atom transport stream of the MPEG-2 standard. All that is required is that the frames for a stream for the special playback mode were re-muxed correctly, so that there were no problems with the buffer MPEG decoder. Although this solution seems simple, it is not a trivial decision, as will become clear in the future.

Hereinafter will be described some aspects related to how to create a stream for the special playback mode.

Using CPI-file describing which position the package begins an I-frame 201, and where an I-frame 201 ends, provides access to all I-frames 201 from the original thread. But only one serial connection appropriately selected I-frames 201 in one large flow only from one I-frame 201 does not lead to the correct stream in the MPEG standard, as will become clear in the future.

The first paragraph of the research is the bitrate of the stream for the special playback mode. For example, the initial stream has an average video bitrate of 4 Mbps, and $ 203 group of pictures (GOP), equal to 12 frames. The bitrate can be extracted from measurements on a live stream broadcast. It is assumed that the stream for the special playback mode consists of only I-frames 201, each of which is displayed for a lie is any frame, which leads to the refresh rate of the stream for the special playback mode, set to the normal playback. Recall that the size of data I-frame 201 can comprise 40% of the data group of pictures (GOP). This number is taken from the dimension in which the average value was approximately 25%. Therefore, on average, 25% of the data must be compressed in time by a factor of 1/12, which leads to increased 3 times the bitrate. Thus, the average bit rate special playback mode would be 12 Mbps with peak values up to 20 Mbit/s This simple example is intended to give an idea of the effect of bit rate and its origin.

In fact, the size of I-frames 201 are known or can be obtained from measurements. Therefore, the bitrate for the stream for the special playback mode, consisting of only I-frames 201, as a function of time can easily be calculated accurately. Bit rate special playback mode can be 2-3 times higher than the bit rate to normal playback, and sometimes it can be higher than the permitted standard MPEG2. Taking into account that this is an example of a stream with a moderate bitrate and that you will find threads with higher bitrates, it becomes clear that must be applied some sort of reduction bi the traditional Tyrolean Guesthouse. For example, bit rate special playback mode may be comparable to the normal playback bitrate. This is especially important if the streams are sent to the decoder via the digital interface. Avoid additional requirements on bandwidth to the interface because of the specialized playback mode. The first option is to reduce the size of I-frames 201. However, this may add complexity and limitations relating to specialised mode for encrypted streams.

Acceptable for certain applications option is to reduce the frequency of updating the image of the specialized playback mode by displaying each I-frame 201 several times. The bit rate will be reduced accordingly. This can be achieved by adding so-called empty P-frames 202 between I-frames 201. This empty P-frame 202 actually is not empty, but may contain data giving an instruction decoder to repeat the previous frame. This is due to the limited number of bits, which in many cases can be neglected in comparison with the I-frame 201. From experiments it is known that such patterns of a group of pictures (GOP) for the special playback mode, as IPP or IPPP, can be p yimlamai for the image quality of the specialized playback mode and even beneficial at high speed special playback mode. The resulting bit rate special playback mode is of the same order as the bit rate to normal playback. It should also be mentioned that these patterns can be supported to reduce the bandwidth required from the storage device.

Hereinafter will be described some aspects related to the issues of synchronization and thread creation.

Figure 5 schematically depicts a system 500 special playback mode.

The system 500 special playback mode contains the module 501 recording module 502 selecting I-frames, module 503 of the formation of the specialized playback mode and MPEG2 decoder 504. Module 503 of the formation of the specialized playback mode contains a module 505 analysis module 506 is added, the module 507 batching module 508 table memory and the multiplexer 509.

Module 501 recording issues module 502 selecting I-frames unencrypted data 510 in the standard MPEG2. The multiplexer 509 outputs MPEG2-decoder 504 transport stream 511 compliant MPEG2 DVB.

The module 502 selecting I-frames reads individual I-frames 201 of the storage device 501. What I-frames 201 are selected, depends on the speed special playback mode, as will be described below. The extracted I-frames 201 are used to create a thread joint is valid MPEG-2/DVB, for the special playback mode, which then sends the MPEG-2 decoder 504 for decoding and rendering.

The position of the packages I-frame in the stream for the special playback mode cannot be attached to synchronize the original transport stream. When special playback mode, the time axis may be rotated with a speed ratio and in addition inverted to reverse the specialized playback mode. Therefore, the timestamp of the original transport stream with timestamps may not be suitable for the formation of the special playback mode.

In addition, the original timeline PCR may interfere with the specialized playback mode. First of all, it is not guaranteed that reference countdown will be available within the selected I-frame 201. But even more importantly, the scale-time PCR will be changed. In accordance with standard specification MPEG2 this frequency must be within 30 packs per minute of 27 MHz. Initial scale-time PCR to fulfill this requirement, but if it is used for special playback mode, it will be multiplied by a factor of speed special playback mode. To reverse this even drive the t to the timeline going in the wrong direction. So the old timeline PCR should be removed and added to the stream for the special playback mode.

Finally, I-frames 201 typically contain two time stamps, which indicate to the decoder 504, when to start decoding the frame (the time stamp decoding, DTS) and when to start his view, for example, display (timestamp representation, PTS). Decoding and presentation can be started when respectively the label DTS or tag PTS equal PCR on the timeline, which is reconstructed in the decoder 504 by PCR in the stream. For example, the gap between the label values of the PTS of the two I-frames 201 corresponds to their nominal amount at the time of display. When special playback mode, this time is compressed with the speed ratio. As a special playback mode uses a new scale-time PCR, and because the period for labels DTS and PTS is no longer correct, the original labels DTS and PTS of the I-frame 201 must be replaced.

In order to solve the above problems, an I-frame 201 may first be converted into an elementary stream in a module 505 parsing. Then, at the level of elementary stream is added to the empty P-frames 202. The resulting group of pictures (GOP) for specialized the second playback mode is displayed in one PES packet is converted into packets of a transport stream. Then add the fixed table, such as table RATH, RMT, etc. At this stage inserts a new time scale PCR with labels DTS and PTS. The packets of the transport stream from the front adds a 4-byte timestamp, which is tied to the time scale PCR, so that the stream for the special playback mode can be processed by the same circuit output, which is used for normal playback.

Hereinafter will be described some aspects related to the speed special playback mode.

In this context, firstly, will be considered fixed rate special playback mode.

As mentioned before, can be used the structure of group of pictures (GOP) for the special playback mode, as IPP, in which two empty P-frame 202 follow I-frame 201. It is assumed that the initial group of pictures (GOP) size is 203, equal to 12 HR, and that all of the original I-frames 201 are used for special playback mode. This means that I-frames 201 in the stream for normal playback have a period of 12 frames, and the same I-frames 201 in the stream for the special playback mode have a period of 3 frames. This leads to a speed special reproduction mode is svedeniya, equal 12/3=4x. If the initial size of 203 group of pictures (GOP) in frames designated as G, the size of the group of pictures (GOP) for the special playback mode in frames denoted as T, and the speed ratio of the specialized playback mode is designated as Nbspeed special playback mode in General is defined as:

Nb=G/T (1),

Nbwill also be referred to as the base rate. Higher speed can be realized by crossing I-frames 201 from the original thread. If taken every second I-frame 201, speed special playback mode is doubled, if taken every third I-frame 201, speed special playback mode is tripled, and so on. In other words, the distance between the I-frames 201 from the original thread is 2, 3, and so on. This distance can always be an integer. Denoting the distance between I-frames 201 used for the formation of a special playback mode, as D (D=1 means that there is every I-frame 201), the ratio N rate special playback mode in General is defined as:

N=D*G/T (2)

This means that can be implemented all integer coefficients base speed, which leads to acceptable the th set of speeds. It should be noted that D is negative for specialized reverse playback mode, and that D=0 leads to a stationary image. Data can only be read in the forward direction. Therefore, when the reverse playback data is read in the forward direction and made the jump back to the preset value D to retrieve the previous I-frame 201. It should also be noted that the greater the size T of the group of pictures (GOP) for the special playback mode leads to a lower base speed. For example, the structure of IPPP leads to the set of velocities is more jagged than the structure of the IPP.

Next, with reference to 6 will be explained by compression of time when a special playback mode.

6 shows the situation for T=3 (IPP) and G=12. For D=2 the initial time display 24 frames is compressed during the display of the specialized playback mode 3 frames, which gives N=8. In this example, the base rate is an integer, but this is not necessarily so. For G=16 and T=3 base speed is 16/3=5 1/3 that does not set the integer speed special playback mode. Therefore, the structure of IPPP (T=4) is better suited to the size of the group of pictures (GOP), is equal to 16, which leads to the base speed 4x. If desired one structure specialization is checked playback mode, which corresponds to the most common size of the group of pictures (GOP) 12 and 16 may be selected structure IPPP.

Secondly, will be considered arbitrary speed special playback mode.

In some cases, the set speed special playback mode, resulting from the above-described method is satisfactory, in some cases - no. In the case of G=16 and T=3, may still be preferable would be an integer factor of speed special playback mode. Even in the case of G=12 and T=4 it would be preferable to have the speed, not available in the set, for example, 7x. Now the formula for speed special playback mode will be inverted and will be computed distance D, which is defined as:

D=N*T/G (3)

Using the above example with G=12, T=4 and N=7 leads to D=2 1/3. Instead of skipping a fixed number of I-frames 201, could be used in an adaptive algorithm to skip, which selects the next I-frame 201 on the basis of what an I-frame 201 is better suited for the desired speed. In order to choose the most suitable I-frame 201 can be calculated following the ideal point Ip on the distance D, and can be selected one of the I-frames 201, which is the closest to this ideal point in order to create proposalsare (GOP) for the special playback mode. In the next step can again be computed by the following ideal point by increasing the last ideal point on the value of D.

As shown in figure 7, illustrating a specialized playback mode with fractional distances, there is, in particular, three choices I-frame 201:

A. I-frame closest to the ideal point; I=round(Ip)

B. the Last I-frame before the ideal point; I=int(Ip)

C. the First I-frame after the ideal point; I=int(Ip)+1

As clearly seen, the actual distance varies between int(D) and int(D)+1, and the ratio between the occurrences of these two cases depends on the fractional part of D in such a way that the average distance is equal to D. This means that the average speed special playback mode is equal to N, but actually used the frame has a small fluctuation with respect to a perfect frame. Were carried out several experiments, and although the speed special playback mode can be changed locally, it is not visually annoying. Usually it is not even noticeable, especially at high speeds specialized playback mode. From Fig.7 it is also clear that there are no significant differences to choose method a, b or C.

Using this method, the speed N of the specialized playback may not be an integer but m which may be any number, large base speed Nb. Speeds below this minimum can also be selected, but then the image refresh rate can locally be reduced, since the effective size of the T groups of pictures (GOP) for the special playback mode is doubled or even lower speeds even tripled or more. This is due to the repetition of groups of pictures (GOP) for the special playback mode, because the algorithm will choose the same I-frame 201 more than once.

Fig shows an example for D=2/3, which is equivalent to N=2/3 Nb. Here to select I-frames 201 uses rounding, and as you can see, the frames 2 and 4 are selected twice.

Anyway, the described method provides for continuously variable speed special playback mode. For reverse playback is selected negative value N. For example in Fig.7. this simply means that the arrow 700 point in the other direction. The described method will also include sets of fixed speed special playback mode, referred to earlier, and they will have the same quality, especially if you will use the rounding function. It would therefore be appropriate that has always been implemented are described in this section flexible way, whatever belabor speeds.

We will look at some aspects related with the image refresh rate special playback mode.

The term "refresh rate", in particular, indicates the frequency with which displays the new image. Although it does not depend on the speed, it will be briefly reviewed here because it can affect the choice of T. If we denote the frequency of update of the original image as R (25 or 30 Hz), the image refresh rate special playback mode (Rt) is defined as:

Rt=R/T (4)

For the structure of group of pictures (GOP) for the special playback mode IPP (T=3) or IPPP (T=4) frequency Rtpack accordingly is 8 1/3 or 6 1/4 Hz for Europe and 10 or 7 1/2 Hz for USA. Although the opinion on the image quality of the specialized playback mode is pretty subjective question, experiment and there are clear indications that these refresh rate is acceptable for low speed and even profitable at higher speeds.

Hereinafter will be described some aspects related to situations with encrypted stream.

Below is some information about encrypted transport streams as the basis for the description of the specialized playback of encrypted flows. is to focus on the conditional access system, used for broadcast.

Figure 9 illustrates a system 900 conditional access, which will be described later.

In the system 900 conditional access content 901 may be issued to a module 902 encryption information of the content. After encryption, information content 901 module 902 encryption information of the content providing module 904 decrypt content encrypted content 903.

The control word 906 may be provided to module 902 encryption information of the content and module 907 formation of ECM messages. Module 907 formation of ECM messages generates an ECM message and sends it to the module 908 decoding messages ECM smart card 905. Module 908 decoding messages ECM forms of messages ECM control word, which is information for decryption is required and issued by module 904 decrypt the content to decrypt the encrypted content 903.

In addition, the key 910 authorization is issued to the module 907 formation of ECM messages and module 911 formation message key management (KMM), the latter forms the KMM message and sends it to the module 912 decoding messages KMM smart card 905. Module 912 decoding messages KMM issues an output signal to the module 908 decoding the message is s ECM.

In addition, the group key 914 may be issued to the module 911 formation of the KMM message and the module 915 formation message group key (GKM), which optionally may be issued a user key 918. Module 915 forming messages GKM generates a signal message GKM and sends it to the module 916 decoding messages GKM smart card 905, and the module 916 decoding messages GKM receives as an additional input a user key 917.

In addition, the right 919 access can be issued to the module 920 formation of EMM messages, which generates a signal of EMM messages and sends it to the module 921 decoding messages EMM. Module 921 decoding messages EMM, located in the smart card 905 is connected to the module 913 the access rights list, and returns the module 908 decoding messages ECM corresponding control information.

The ECM indicates messages access control, KMM denotes the message control keys, GKM identifies the message group key and EMM message indicates authorization.

In many cases, content providers and service providers want to control access to certain content elements through a system of conditional access (CA).

To achieve this, data transmitted over broadcast content 901 sushi revivals running system 900 conditional access (CA). In the receiver of the information content is decoded before decoding and rendering, if the system 900 conditional access (CA) allows access.

The system 900 conditional access (CA) uses a multi-level hierarchy (figure 9). The system 900 conditional access (CA) sends the key to decrypt the content (control word (CW) 906, 909) from the server to the client in encrypted messages, called message access control (ECM). Messages ECM encrypted using the key 910 authorization (AK). For security reasons, the server 900 conditional access can update the key 910 authorization by issuing messages KMM (message, key management). The KMM message is actually a special type of EMM messages (messages authorization), but for clarity is used interchangeably with KMM. The KMM message is also encrypted using the key, which, for example, may be a group key (GK) 914, which is updated by sending a message GKM (message group key), which again is a special type of message EMM. Message GKM encrypted using the user key (UK) 917, 918, which is fixed on a unique key embedded in the smart card 905 and known only to the system 900 conditional access (CA) provider. Authorization keys and robovie keys stored in the smart card 905 receiver.

Right 919 access (for example, viewing rights) sent to individual customers in the form of EMM messages (messages authorization) and save it locally in a secure device (smart card 905). Right 919 access is bound to a given program. A list of 913 rights of access gives access to a group of programs depending on the type of subscription. Messages ECM are converted to keys (control word) via a smart card 905, only if for a given program has the right 919 access. Messages EMM with access rights subject to identical layered structure, as messages KMM (not depicted in Fig.9).

In the system of standard MPEG2 encrypted content, messages ECM and EMM (including message types KMM and GKM) multiplexed into a single transport stream standard MPEG2.

The above description is a General representation of a system 900 conditional access (CA). In the broadcasting of digital video is only defined encryption algorithm, odd/even structure of the control words, the global structure of the messages ECM and EMM and their references. The detailed structure of the system 900 conditional access (CA) and the encoding and use useful information messages ECM and EMM are dependent on the supplier. A smart card is also dependent on the provider. However, from experience it is known that many suppliers with the public adhere to the structure with a generic representation, shown in Fig.9.

Next will cover the topic of encryption/decryption DVB.

The applied encryption algorithm and decryption as defined by the organization for the standardization of DVB. In principle, there are two encryption capabilities, namely the level encryption PES (elementary stream packets) and the level encryption TS (transport stream). In reality, however, is used mainly encryption TS. Encrypting and decrypting packets of the transport stream is done on a per packet basis. This means that the encryption algorithm and decryption is restarted each time a new packet of the transport stream. So the packets can be encrypted or decrypted individually. In the transport stream is encrypted and unencrypted packets are mixed, as some parts of the encrypted stream (e.g. audio/video)and others not (e.g., tables). Even within the same part of the stream (e.g. video) is encrypted and unencrypted packets can be mixed.

Next, with reference to figure 10 will be described encrypted using the algorithm DVB package 1000 of the transport stream.

Package 1000 thread has a length of 1001 equal to 188 bytes, and contains three parts. The header 1002 package has a size of 1003, is 4 bytes. After the header 1002 package in package 1000 thread can be arise the Leno field 1004 adaptation. After it can be sent encrypted using the algorithm DVB useful information 1005 package.

11 illustrates the detailed structure of the header 1002 packet of the transport stream shown in figure 10.

The header 1002 packet of the transport stream contains block 1010 synchronization (SYNC), the indicator 1011 transport error (TEI), which may indicate the transport error in the packet, the indicator 1012 beginning of the block of useful information (PLUSI), which can, in particular, to indicate the possible start of the PES packet in the subsequent useful information 1005, block 1017 transport priority (procedures defined in the TPI)indicating the priority of transport, ID 1013 package (PID)that is used to determine the destination for the package, box 1014 control scrambling (SCB), is used to select the control word, which is necessary for decrypt the packet of the transport stream, field 1015 adaptation (AFLD) and counter 1016 continuity (CC). Thus, figure 10 and 11 show package 1000 transport stream standard MPEG2, which was encrypted and contains the various parts:

header 1002 packet is unencrypted. This is in order to get important information such as a packet identifier (PID)field adaptation, control bits scrambling, etc.;

- field 1004 adaptation is also in the clear is om. It may contain important information synchronization, such as PCR;

- encrypted using the algorithm DVB useful information 1005 package contains the actual content of the program, which may be encrypted using the algorithm of DVB.

To select the correct control word, which is necessary to decrypt the transmitted program, it is necessary to analyze the packet header of the transport stream. A schematic overview of this title Dan on 11. An important field for decrypting the transferred program is field 1014 bits control scrambling (SCB). This field 1014 SCB indicates the control word decoder must be used to decrypt the transferred program. In addition, it specifies whether encrypted useful information package or she is in the clear. For each new packet of the transport stream must be analyzed this field 1014 SCB, as it changes over time and can vary from package to package.

Hereinafter will be described some aspects related with specialized video playback on a fully encrypted streams.

The first reason why this theme is interesting, is that the specialized playback unencrypted and fully encrypted streams are the two who are the two extremes of the range of possibilities. Another reason is that there are applications in which it may be necessary to record fully encrypted streams. Thus, it would be useful to have at hand a method to perform special playback mode in the fully encrypted stream. The basic principle is to read a fairly large block of data from the storage device, to decode it, to choose an I-frame in the block and to create the stream for the special playback mode.

This system 1200 is depicted in Fig.

Fig shows the basic principle of the specialized playback on a fully encrypted stream. With this purpose, the data stored on the hard disk 1201, issued as a transport stream decoder 1202 1203. In addition, the hard disk 1201 generates a smart card 1204 message ECM, and smart card 1204 generates the control words from the ECM messages and sends them to the decoder 1203.

Using the control word decoder 1203 decrypts the encrypted transport stream 1202 and sends the decrypted data to the sensor I-frames and filter 1205. From there, the data is issued to block 1206 insert empty P-frames, which transmits data to the set-top box 1207. From there, the data are given on TV 1208.

Hereinafter will be referred to several aspects the s on the matter, that contains the entry.

When recording one channel record must contain all the data required to play the recording channel at a later stage. Can be used simply to record only a transmitter, but it will be recorded much more than you need for playback program that is designed for recording. This means that bandwidth, and memory will be wasted. So, instead, should be recorded only really necessary packages. For each program, this means you have to record all of the required packages of standard MPEG2, such as PAT (link table), a table CAT (table conditional access) and, obviously, for each program video and audio packets, and the PMT table (table maps programme), which describes which packages belong to the program. In addition, table (CAT/PMT can describe the conditional access packets (messages ECM), is required to decrypt the stream. If after decoding the entry is not made in decrypted form, these packages ECM must also be recorded.

If the record does not consist of all packages from the full multiplexing, the entry becomes a so-called partial transport stream 1300 (Fig). In addition, Fig illustrates the full transport stream 1301. The DVB standard requires that h is ordinary when playing a partial transport stream 1300 all the usual mandatory tables DVB, such as the NIT table (table information network), BAT (table binding bouquet), etc. were removed. Instead of these tables partial stream must be inserted tables SIT (table information) and DIT (table information gap sequence).

Next with reference to Fig. from 14 to 36 will be described systems that can handle the data flow in accordance with an illustrative variant embodiment of the invention.

It should be emphasized that the described system can be implemented in the framework and in combination with any of the systems described with reference to Fig. 1 to 13.

Next will be described the aspects related to specialized playback mode on the hybrid threads.

Then will be considered non-encrypted I-frames.

Recording, in which I-frames 201 are unencrypted, and the rest is encrypted, is an alternative to completely unencrypted stream from the point of view of the special functionality of storage, such as fast forward/backward.

Next, with reference to Fig will be described, the system 1400 for data transfer between the broadcast station 1401 and storage devices 1406, 1408 and 1409 in accordance with an illustrative alternative embodiment of the invention.

Broadcast station 1401 transmits the data to the satellite antenna 1402, which through JV is tnik 1403 data is transmitted satellite antenna 1404. From the satellite antenna 1404, the data is transmitted to the Central station 1405 cable television, gateway 1407 and storage device 1409. From the Central station 1405 cable television data can be further transmitted to the storage device 1406. From a service gateway 1407 data can be further transmitted to the storage device 1408.

As shown in Fig possible, in particular, four different ways of how can be formed unencrypted stream of I-frames. As indicated by the digit "1", broadcasting station 1401 can generate an unencrypted stream of I-frames. As indicated by the digit "2", station 1405 cable television can generate an unencrypted stream of I-frames. As indicated by the digit "3", gateway 1407 can generate an unencrypted stream of I-frames. As indicated by the digit "4", the storage device 1409 can generate an unencrypted stream of I-frames.

As shown in Fig, there are several places in the supply chain, where such a thread can be created.

Options "1" and "2" can be favorable situations in which the equipment of the consumer do not need any action. In the case of "3" may be limited to only one home device, which is the subscriber gateway 1407. Option "4" may be the most realistic.

Directly the NGO input module storing the stream may contain, at least, not encrypted I-frames, and the remainder may be encrypted or can be unencrypted, depending on the type of transmission that is stored. This means that in all cases can be formed CPI data relating to the start and end points of the I-frames. Data retrieved using data from the CPI, during a special playback mode now contain only non-encrypted I-frames. This means that for a system of specialized playback mode may be no difference between a dedicated video playback on a fully unencrypted stream and specialized playback mode on the hybrid stream.

Next will be described the aspects related to the unencrypted packets.

One possibility is that the generated stream for the special playback mode is completely unencrypted, and whether the original stream unencrypted or (partially) encrypted. This is not a problem if the engine specialized playback mode and the decoder/renderer are in the same device. But if the stream for the special playback mode created on the server and then distributed over the network, it may be desirable or n is permitted by the content provider to have a stream for the special playback mode in an unencrypted form. The same may be true for normal playback.

Next, with reference to Fig will be described, the system 1500 pertaining to specialized playback unencrypted account.

Module 1501 records connected with the module 1503 selection of frames and provides the latest unencrypted data 1502 standard MPEG2. Module 1503 selection of frames connected to the module 1504 formation of a specialized playback mode that produces MPEG2-decoder transport stream 1506 compliant MPEG2 DVB.

If the original recorded stream is unencrypted, as shown in Fig, there should not be problems in that stream for special playback mode is also unencrypted. But even on the thread that was recorded, being fully encrypted, can be formed stream for the special playback mode, which is completely unencrypted, as shown in Fig.

In addition to the system 1500, the system 1600 further comprises a module 1602 selection of blocks, which are issued encrypted data 1601 standard MPEG2 from the recording device 1501. In addition, between the module 1602 selection blocks and module 1503 selection of personnel is ensured module 1603 decryption.

In this situation unencrypted stream for technicians who yserowanego playback mode may be undesirable. Under certain circumstances it may not be possible to simply bypass the decoder, because no stream for the special playback mode cannot be created from a fully encrypted stream. The solution may be to re-encrypt formed unencrypted stream for the special playback mode. It may be necessary to adjust what the list of keys (control words, messages ECM and so on) and the encryption algorithm should be used. For example, you may not be allowed to add DVB encoder to the consumer device, so in this case must be selected a different encryption format. It may be a different encryption system such as DES, 3DES, AES, etc. doing this would mean that the current set-top box (STB) will not be able to decrypt the streams for the special playback mode. In addition, normal playback is implemented by passing the original algorithm DVB stream to the set-top box (STB) without any modifications at the level of encryption. Thus, a fitted box not only would be able to decrypt another format, it also would be able to determine which format to use for which part of the received stream. It may not be trivial is, because no indication is not present directly in the thread. Inherently specialized playback would have to be handled differently in contrast to normal playback.

The desired solution is that normal reproduction, and a dedicated playback mode are in the format of DVB encryption, but you can't use DVB encoder.

Next will be described the main solution to the problem of encryption.

Will explain how you can create encrypted using the algorithm DVB stream for the special playback mode even in scenarios in which the use of encryption DVB is not allowed in the home. First of all, it should be noted that the encrypted stream for the special playback mode should be necessary only when the original stream for normal playback is also encrypted. With this in mind, the stream for the special playback mode can be created directly from the encrypted packet of the transport stream for normal playback. This implies that the formation of the stream for the special playback mode at the level of elementary stream may no longer be possible. It must be formed directly the public at the level of the transport stream.

For the formation of a specialized playback mode may be at least need to know where in the encrypted transport stream for normal playback are I-frames. This can be achieved by decoding the stream, detecting I-frames and the formation of pointers to the beginning and end of the I-frame in an encrypted stream. But for the formation of suitable stream for the special playback mode may be necessary to change some data in an encrypted useful information some packages. This can be done only if these packages are first decrypted and then adapted. However, customized packages cannot be re-encrypted. Therefore, some packets in the stream for the special playback mode will always be unencrypted. Preferably these packages are already recorded in an unencrypted form. Then the unencrypted packets also allow direct detection of the position of the I-frames, which is then stored in the CPI file.

On Fig illustrated specialized playback on partially encrypted record.

The system 1700 shown in Fig, compared with Fig, module 1503 select frame unit 1501 records are issued partly encrypted data 1701 standard MPEG2. The AOC is e, module 1504 formation of a specialized mode playback issues module 1703 MPEG2 decoder and the decoder compliant MPEG2 DVB transport stream 1702, which is partially encrypted.

The number of unencrypted data stream should be minimized so that it actually still is a well-protected encrypted stream. Hereinafter the term "hybrid stream can refer to this thread.

Next will be described in which parts of the data stream, the minimum must be in plain text.

As mentioned above, stands for not all, but only what is really needed. To find out what you need, was analyzed practical stream.

- In addition to a discontinuity in the continuity counter, which is located in an unencrypted packet header, the first thing you need to adapt - this margin marks PTS/DTS in the header of the PES. Thus, the packet of the transport stream that contains the fields needed in an unencrypted form. This also means that the package, which starts an I-frame is typically unencrypted.

- The next thing that can be wrong is the last service I-frame, which may also contain the beginning of the next P-frame or B-frame. So this package can be adjusted by removing all data not related to the I-frame, and the bag is filled. Thus, this package must also be in plain text.

- All packets between these two packages contain only video I-frame that can be used as it is, and therefore to be encrypted.

In order to add the correct empty frames, it may be necessary to know the resolution of the image, and to add a new time scale, it may be necessary to know the frame rate. All necessary data can be found in the fields of the header of the PES/ES.

It is not guaranteed that all the headers of the PES/ES are in the package field PLUSI. If all header data does not reside in the same package, the following package(s) also need unencrypted, to have access to the fields described below.

In the header of the PES, which is guaranteed starts in the package field PLUSI, it may be necessary to change three fields:

- PES_packet_length (the length of the PES packet)

- PTS (timestamp views)

- DTS (timestamp decoding)

Tags PTS and DTS are not mandatory. However, they must be changed, when present.

To create an empty P-frames of the correct type, add a new timeline and fix temporary reference I-frame, you may need some data from the ES headers.

First of all, from the sequence header may be required fields:

-Horizontal_size_value (value size horizontal)

- Vertical_size_value (the value of the vertical size)

- Frame_rate_code (the value of the frame rate)

In the expansion sequence has one flag that may be important:

- Progressive sequence flag progressive sequence)

In the image header one item you may need to change:

- Temporal reference (temporary link)

Finally, from the enlargement, the image encoding may need to access two fields:

- Picture_structure (structure image)

- Top_field_first (top field)

After extracting these data it is possible to choose the type of the empty frame, which must be added. It is possible to use previously created a lookup table that contains the empty frames created for all the above combinations, taking into account the limitations of standard MPEG2. Although the specification does not require that all of these fields were present for each group of pictures (GOP), it is assumed that there is no broadcast signal, which omits these fields. The reason may be that the decoder will need to have access to these headers to correctly decode the data as soon as possible after switching between stations.

Thus, all that may be necessary in an unencrypted form for each I-frame is a multiple packets, at least, DINV the beginning and one at the end. Also has the advantage that it is possible to easily determine the exact position of each I-frame. Threads only those packets unencrypted actually still are fully encrypted, the first packet of each I-frame usually does not contain almost any video, but exists solely for header data (P) ES. The last package I-frame may also contain some data of the next P-frame or B-frame, but they will in any case be deleted.

Next, you will learn how to choose the packages that should be in the clear.

When the hybrid thread is created, you must decide which packages should be in the clear. To allow the detection and selection of the necessary unencrypted data, the video stream may be first fully deciphered. Then may be determined by the location of these data in an unencrypted stream and the unencrypted packets in which they are located, can replace the encrypted packets in the original thread, to form a hybrid stream.

To select unencrypted data can be used the following three criteria:

1. Tags DTS/PTS in the PES header can be replaced if they are present. To this end, all data of the PES header may be placed in an unencrypted form. This means that the packets within packets bit set field PLUSI to package containing the last byte of the PES header, can be transferred in an unencrypted form.

2. May be need some information from the sequence header and the extension sequence. To this end, all data from the sequence header to the start of the code image can be transferred in an unencrypted form. The title sequence and the initial code image can be detected by checking four-byte code. These four bytes are not necessarily located in the same package. The title sequence and the initial image code is detected when found the last of the four bytes. To avoid excessive buffering for building hybrid flow, all the packages from the package that contains the fourth byte of the sequence header to the packet that contains the fourth byte of start code image can be transferred in an unencrypted form. This can lead to some special situations when searching for sequence header and the start of the code image in the resulting hybrid thread.

3. The initial image code may be required to detect the edges of the frame. So the package that contains the initial code images must be transferred in an unencrypted form. Two bytes after the initial code image also dollars which have to be unencrypted. These bytes contain a temporary link that may need to be changed, and the type of encoding image that identifies an I-frame, P-frame or B-frame. In addition, there may be need some information from expanding the image encoding. To this end, all data from the initial code image to the end of the extension, the image encoding can be transferred in an unencrypted form. The initial code image may be detected when found, the fourth byte. To avoid excessive buffering, all the packages from the package that contains the fourth byte of the start code of the image to the package containing the last byte of the extension, the image encoding can be transferred in an unencrypted form. This will lead to an unencrypted packets on all edges of the frame that is more than necessary to build considered still flows for the special playback mode. But it may be necessary for the build thread for slow-motion playback in the forward direction.

Next will be explained, which means excessive buffering and what's causing it. If built hybrid flow, the packets from the original encrypted stream and the decoded stream can be merged into one thread. If this is done in real time, it may be necessary some what I buffering. It can be assumed that the initial code of the image are distributed by more than two video packages. This four-byte start code image can be detected in the decoded stream when found the last byte. To have full initial image code unencrypted means that unencrypted must be not only a video package with this last byte, but also the previous packet of the video.

Between these two video packages can be and usually will be other data. In principle, this can be a large number of packages.

Next, with reference to Fig will be described, the system 1800, showing the buffering requirement for full unencrypted source code of the image.

On Fig shows the buffer 1800, beginning with I-frame 1801, with the end part of the initial code 1802 image. It then shows the block 1803 audio. The following shows the block 1804 audio. In addition, it is shown the block 1805 PSI and block 1806 data. At the moment 1807 detection of the start code image begin block containing part of the initial code 1808 image, and the subsequent P-frame 1809.

Fig shows an example of a situation in which the initial image code at the end of the I-frame is distributed over more than two video packages. In this case, should be placed in the buffer not only these two packages of video, but also all Pak is you with other information located between the two video packages. Although the example shows the initial image code, it will be clear that the same argument is valid for the code sequence header. Criteria reduce the necessary buffering to only one package. If one of the three specific criteria is met, the corresponding packet will be transferred in an unencrypted form. The combination of these three criteria will often only lead to one unencrypted packet at each frame boundary. However, in some practical cases, some threads it can also be multiple packages. Theoretically it could even be a large number of packages.

The first example is a thread, composed of only I-frames and P-frames with the size of the group of pictures (GOP), equal to 12 HR, and one PES packet per group of pictures (GOP). In the performed experiments the number of unencrypted packets at the beginning of the I-frame is always equal to one. The number of unencrypted packets at the end of the I-frame and in fact on all other edges of the frame is usually one, but sometimes can be equal to two. At the beginning of the I-frame data of the PES header to expand the image encoding in one package. Unencrypted packets on other edges of the frame contain all the data from machinegood image to the end of the extension, the image encoding. These data can be distributed over more than two packages.

The second example is a thread, composed of I-frames, P-frames and B-frames with IBP structure of variable size group of pictures (GOP) with even values in the range of 2 to 12 and one PES packet per frame. The number of unencrypted packets at the beginning of the I-frame for the most part equal to two, and at the end of the I-frame and at the other boundaries of the frame is always equal to one. These two packages at the beginning of the I-frame occurs, mainly due to the presence of quantization table in the sequence header. At the end of the I-frame and other frame breaks all the data from the PES header to expand the image encoding are in the same package.

It should be noted that due to the structure of the PES for the second example, rejects the view is not the last packet of the I frame, and in fact the first packet of the next frame. For the first example, it can also sometimes occur. This is not a problem, because the last package I-frame in this case contains only the data of the I-frame and should not be cleaned. It should also be noted that almost a combination of three selection criteria leads to one continuous unencrypted video on each frame boundary. Theoretically this should not happen. Combination of criteria 2 and 3 always leads to continuous on the region, but theoretically unencrypted region of the PES header may be separate.

Next will be explained how to find the necessary information in a hybrid stream.

As mentioned above, in practice there can be one continuous non-encrypted area on each frame boundary. At the beginning of the I-frame (group of pictures (GOP)) unencrypted data extend from the first byte of the PES header to at least the last byte of the extension, the image encoding. An example is given on Fig. All necessary data are located in this area and can be easily found by analyzing the portion of the stream that begins in the package marked field PLUSI.

Next, with reference to Fig will be explained practical unencrypted region at the beginning of the I-frame

The data flow shown in Fig, contains the first packet 1900 I-frame and a subsequent second package 1901 I-frame. The first batch 1900 I-frame contains a header 1902 PES header, 1903 sequence, the extension 1904 sequence header 1905 a group of pictures (GOP), the initial code 1906 image and caption 1907 image. In addition, a second set of 1901 I-frame also contains a header 1907 image, the subsequent expansion of 1908, the image encoding and block 1909 data I-frame.

Next will be described the data flows shown in figa and figv.

In the data flow on the Phi is .20A specify the end of 2000 I-frame. Field 2001 PLUSI precedes the header 1902 PES, and then provided the initial code 1906 image. After it sends the header 1907 image and then the expansion of 1908, the image encoding. This is followed by a block 2003 data P - or B-frame.

In the data flow on FIGU recent data 2004 I-frame is completed in late 2005 I-frame and then the initial code 1906 image, title, 1907 image extension 1908, the image encoding and block 2003 data P - or B-frame.

At the end of the I-frame in practice, there are two possible options.

1. In the case of one PES packet per frame unencrypted region at the end (after the end) I-frame 2000 also begins with the first byte of the header 1902 PES and extends at least up to the last byte expansion 1908, the image encoding. All necessary data can be easily found, and there is no clear last package I-frame is not necessary (figa).

2. In the case of one PES packet per group of pictures (GOP) after the end of the I-frame there is no PES header. Almost in this position there is no sequence header. In this case, the package that contains the fourth byte of start code 1906 image, up to the last byte expansion 1908, the image encoding are unencrypted (pigv). Four-byte start code 1906 image may be the soap is defined by more than two packages, for example, the first three bytes in the packet, and the last byte of the next packet. In this case, the first three bytes can still be encrypted. It seems that this entails that the initial code 1906 image can not be found in the hybrid thread. How this problem can be solved, will be described next.

In fact, there may exist a non-encrypted area on each frame boundary. Therefore, the detection of the end of the I-frame means find the first initial code image after this code for an I-frame. It should be clear that the search for this code should be conducted only in an unencrypted packets of the video, in order to avoid false positive matches in the encrypted data. Whether there is useful information packet is encrypted or not, indicated by the control bits of the scrambling in the packet header. The discovery gives a positive match only when found in a given sequence of four bytes (h h h h). This sequence corresponds to the initial code image regardless of the type of frame. Unfortunately, the initial code image should not be aligned with the boundaries of the packet of the transport stream. This means that if the initial code of the image has been divided by more than two packages, only the second of these packages will be in nasasira the nom. This situation is depicted in Fig.

On Fig the packet header is indicated by 2100, unencrypted useful information package identified by the number 2101 and encrypted useful information package identified by the number 2102.

The top line 2103 shows the initial image code, which is located completely in the second batch. For the bottom line 2104 it is fully in the first batch. The remaining line 2105 show three possible options for the distribution of the initial code image. It can be expected that it is impossible to detect partially encrypted initial code image. However, this predicament has access. Each unencrypted region contains the initial code image or at least its last byte. Therefore, if the initial image code is not found in the clear region, it is known that this area must begin with some of the last byte start code image. This is the number of bytes may be equal to one, two or three, as shown in Fig. It is possible to see exactly how much there is of bytes. In this regard it should be noted that three bits of the coding type of the image can never be all zero, because it is prohibited by the implemented standard. Therefore, the second byte after the initial code of the image indicated Hu on Fig, can never be equal h. Therefore, if an unencrypted region begins with h h h, it must be the last three bytes of the start code image. If it starts with h h, this is the last two bytes. If it starts with h, not h h h, there is only the last byte. So, you know where is the initial code image, and the data after it can be analyzed. The image type can be read with byte how, if necessary.

You can also say that it is impossible to clear the last package I-frame, removing all Netanya not related to the I-frame, if the initial image code distributed more than two packages. This is actually true, because the encrypted part of the initial code image is not deleted. But when you build the stream for the special playback mode by the end of the I-frame will be attached to the empty P-frame. This empty P-frame begins with a start code image. Thus, the encrypted bytes of the start code image can be reused, as it is known, how many of those bytes at the end of the last encrypted packet. This is the number of bytes removed from the initial code image of the first empty P-frame, which will be added after the I-frame.

Fig shows an example of such a situation and, in particular,shows the initial code 2200 images temporary link 2201, type 2202, the image encoding and data 2203 empty frame.

Data inserted empty P-frame must be unencrypted in the absence of DVB-encoder in the storage device. Situations that should be expected almost described above, but in theory can occur some additional situations. This is because the unencrypted region of the PES header and an unencrypted region, resulting from criteria 2 and 3, theoretically, should not be connected, but can be separated encrypted video packets. For clarity it should be mentioned that continuous unencrypted region means that the sequence of video packets is in the clear, but between them there may be other encrypted packets.

In accordance with the criteria have three important areas of data that should be accessed:

1. Information of the PES header.

2. The information in the sequence header and the extension of the sequence.

3. Information from the initial code image before enlargement, the image encoding.

These three areas of data depicted on Fig.

Fig shows unencrypted data area corresponding to the three areas mentioned above. Regarding the first paragraph shows the box 2300 PLUSI (indicator start of block useful info is rmacie) and heading 2301 PES.

In accordance with the second paragraph shows the extension 2302 sequence code 2303 expansion sequence, the header 2304 sequence and code 2305 of title sequences, as well as the initial code 2306 image.

Regarding the third item, shows the initial code 2308 image and caption 2307 image and code 2309 enlargement, the image encoding and extension 2310, the image encoding.

Three elements must be found in the stream to locate and correct analysis of these data:

1. Bit 2300 PLUSI in the packet header.

2. Code 2305 title sequence (h h h HV).

3. The initial code 2308 image (h h h h).

The detection element 1 is simple, because just look a bit 2300 PLUSI in the packet header, and if it is set to "1", the packet starts with a header 2301 PES, which can then be parsed.

The situation for elements 2 and 3 may be more complex, because the code 2305 title sequence and the initial code 2308 images can be distributed over more than two packets, which leads to partially encrypted codes. Therefore, direct detection of these codes would have resulted in some data loss. However, there is a solution for this problem. In standard MPEG2 availability of extension 2302 sequence is eljnosti and extension 2310, the image encoding is required as shown in Fig.

Fig shows the heading 2304 sequence, coupled with the extension 2302 sequence, which provided for the extension and user data 2400. In addition to the extension and user data 2400 attached header 2401 group of images, which are attached to user data 2402. User data 2402 is attached to the header 2307 image that is attached to the extension 2310, the image encoding. This extension 2310 encoding image attached user data 2403, and to user data 2403 attached data 2404 image. Then you get to the end 2405 sequence.

How the criteria for unencrypted packets, ensures that these extensions will be completely in the clear. They can be found by searching first the initial code expansion, which is equal h h h HV. The following four bits are the ID initial code extensions. These four bits are 0001 to extend the sequence and is equal to 1000 for expanding the image encoding. If there is an extension sequence, the code sequence header must also be present, and similarly, if there is an extension of the encoding of the images, the initial image code must also be present. This leads to the following:

- If the extension 2302 sequence found in an unencrypted area code and 2304 of title sequences are not detected in this same area, the code 2304 of title sequence must be distributed over more than two packets, and the last byte code 2304 of title sequences are the first bytes of this unencrypted region, not paying attention to possible PES header (Fig).

- If the extension 2310, the image encoding found in the clear area and the initial code 2308 image is not detected in this same area, the initial code 2308 image must be distributed over more than two packages, and last bytes of the start code 2308 images are the first bytes of this unencrypted region, not paying attention to possible PES header (Fig).

It should be noted that these two situations can never occur simultaneously in the same unencrypted area. If the extension 2302 sequence and the extension 2310, the image encoding are present in both, the initial code 2308 image, which is located between the two will inevitably be completely unencrypted. In this case, only the code 2305 of title sequences may be partially ENC the van. Of course, if the code 2305 title sequence or the initial code 2308 images are completely unencrypted and therefore found a direct way, the syntactic analysis of the relevant data can begin immediately. However, if there is one of the situations mentioned above, you first need to know how many bytes these codes are in the beginning of the unencrypted region or after the PES header before you can start the correct parse. The method of detection for this initial code 2308 image was described earlier. The same method can also be applied to code 2305 title sequence.

The situation for the code 2305 title sequence depicted in Fig.

Unencrypted view only guaranteed starting from the fourth byte. This byte is the last byte code 2305 title sequence, which equals 0x00 0x00 0x01 0xB3. So if the code 2305 title sequence is present, but not detected in this area, some of his last byte must be present at the beginning of this area or after the PES header. As for the initial code 2308 image, it is possible to see exactly how many bytes there. Discovery will begin in the first unencrypted bytes in the field, oblivious to the PES header. If the first bytes of RA who have h h HV, there are three bytes, if they are equal h HV, there is two bytes, and if the first byte is equal to HV, there is only this byte. Knowledge of the number of bytes and, thus, the location of the last byte code 2305 title sequence or the initial code 2308 image gives the ability to properly parse the data after the code.

Next will be explained the construction of the stream at the level of the transport stream.

In this context, first will be described the positioning of the package.

The position of the packages copied to the stream for the special playback mode, usually cannot be tied to the relative timing of the initial traffic flow due to compression and possible inversion (reverse playback) time axis when a special playback mode. Therefore, labels the arrival time of the package of the original transport stream with timestamp packet arrival is not normally suitable for use for the formation of the special playback mode. This is the reason why the described method specialized playback mode can also be used for traffic flows without added labels the arrival time of the packet. Since the initial relative synchronization is not and who is, should you have a different synchronization mechanism. As will become clear later, the proper way to do this is to smooth the speed packet in the group of pictures (GOP) for the special playback mode, as shown in Fig.

Fig schematically illustrates the smoothing packages for the special playback mode.

As you can see, the flow 2800 broadcast includes data 2801 I-frames, the data 2802 P-/B-frames and additional data 2803 I-frames. Data 2801 I-frames are provided not equidistant, but contain many packages distributed random image in the time domain, as can be seen in the top row 2800 on Fig.

The format of the data as they are stored on the hard disk, shown in the series 2810 on Fig. Here are the various individual data packets 2801 I-frames are provided one after the other without space between them, as well as data 2802 P-/B-frames and additional data 2803 I-frames.

On Fig also illustrated the output 2820 special playback mode, showing the package 2824 PCR (reference timing of the program), followed by packages 2825 PAT (mapping table) and PMT (table maps programme). Then smoothed ensures that the sequence of data packets 2801 I-frames as the smoothed data 2822 I-to the wood, followed by the smoothed data 2823 empty P-frames. However, the smoothed empty B-frames are also available as supplements or alternatives. Further provided an additional package 2824 PCR and two packages 2825 PAT, PMT, followed by the smoothed additional data 2826 I-frames. Smoothed data 2822 I-frames and data 2823 empty P-frames separated by a nominal time 2821 group of pictures (GOP), is equal to the ratio T/R

The number of packets for I-frames 2822 known as well as for the empty P-frames 2823 and some additional packages (e.g., PCR, ECM, SIT, DIT etc). The total number of packets transmitted for a nominal time 2821 group of pictures (GOP), which is equal to 1/Rtor T/R. the distance between the packets is calculated from the number of packets and time 2821 group of pictures (GOP). In fact, the calculated time of a packet can be translated into new labels the arrival time of packets, which are added in front of the packages special playback mode. These labels the arrival time of the packets can be obtained from the calculated values of the new time scale in PCR for the special playback mode at the beginning of the package. Thus, the generated flow 2820 for the special playback mode can be processed the same output circuit, which can use isolates for normal playback. New scale-time PCR for the special playback mode will be discussed later.

Next will be described the aspects related to the reference times of the program (PCR).

The original timeline PCR usually cannot be used for special playback mode. First of all, probably, but not guaranteed that PCR will be present within the selected I-frame. More importantly, the frequency scale time PCR is no longer correct. This frequency must be within 30 packs per minute of 27 MHz, but now it is multiplied by a factor of speed special playback mode and even leads to the timeline, going in the wrong direction, reverse playback.

Thus, the old timeline PCR should be removed and should be added. Old PCR removed by cleaning the fields of adaptation, in which they are located. The field of adaptation is not encrypted. New PCR are added by placing additional package 2824 PCR at the beginning of each group 2821 pictures (GOP) for the special playback mode, as shown in Fig. As these groups of pictures (GOP) is transmitted exactly at the nominal time 2821 group of pictures (GOP), the distance between the values in the PCR is a constant and can be obtained from e the CSOs nominal time 2821 group of pictures (GOP). In the add new time scale PCR with high precision synchronization is very simple.

PCR 2824 consists of two parts, namely the basics of PCR and extension PCR. The latter is part consisting of the younger (LSB) 9 bits, and can vary from 0 to 299. The basis of PCR is part composed of senior (MSB) 33 bits, and can vary within the full range. Frequency fundamentals PCR is 27 MHz/300=90 kHz. Almost all of the frame rate matches the value of 90 kHz. For these frequencies, the extension PCR is constant for points that are multiples of time of a particular frame. Because the nominal time 2821 group of pictures (GOP) is a multiple of, the extension of all PCR inserted PCR new timeline can be set to zero. Only unusual frequency of 23.976 and 59.94Hz not correspond to the value of 90 kHz. However, for 59.94Hz extension PCR is a constant for a distance equal to an even multiple of the number of time frame, and for the case of 23.976 Hz - to fourfold time frame. For the structure of IPPP (T=4) group of pictures (GOP) for the special playback mode for extension PCR can be used a fixed value of zero for all frequencies frames, which further simplifies the insertion of a new scale-time PCR.

The distance between successive PCR 2824 in the transmitted stream in the accordance with the standard MPEG2 should not exceed 100 MS. In the DVB standard, this value is even lower, namely 40 MS. Sending only one PCR 2824, each group 2821 pictures (GOP) for the special playback mode clearly violates these limits. In the worst case, with T=4 and R=25 Hz, the distance between PCR 2824 is 160 MS. In experiments not tested the problem with a violation of this distance. Additional PCR 2824 can be inserted in the stream, but it is more complex and does not seem necessary in all cases.

Next will be discussed the aspects related to the time stamp decoding (DTS) and the timestamp representation (PTS).

Frames may contain two time stamps, which can tell the decoder when to decode frame (label DTS) and when to start its representation (e.g., display) (tag PTS). They start when the label accordingly DTS or tag PTS equal PCR timeline, which is reconstructed at the decoder by using PCR in the stream. Since the new timeline PCR added to the stream for the special playback mode, and because the intervals for the labels DTS and PTS are no longer correct, labels, DTS and PTS of the I-frame can be replaced if they are present. Tags DTS and PTS are in the PES header.

There are at least two ways to build a group of pictures (GOP) for the special playback mode, namely with the ne-PES packet per frame or one per group of pictures (GOP). In the case of a partially encrypted initial code image one PES packet per frame actually cannot be used. Thus, it can be selected one PES packet per group of pictures (GOP), even if the original thread was one PES packet per frame. Therefore inserted an empty P-frames do not have labels DTS or PTS. The PES packet length is set to zero (unlimited) regardless of their initial values.

Should be considered when it can begin decoding the I-frame. Packages that group of pictures (GOP) for the special playback mode distributed-constant-time group of pictures (GOP). Almost the entire group of pictures (GOP) for the special playback mode refers to the data of the I-frame, thus the end of the I-frame is close to the beginning of the next group of pictures (GOP). Therefore, the decoded I-frame may start at the beginning of the next group of pictures (GOP). Thus, the label DTS I-frame is set to the value corresponding to the scale-time PCR at the beginning of the next group of pictures (GOP). Tags DTS and PTS usually contain only a reference to the scale-time PCR. Tag DTS, therefore, identical to the basis of PCR, which will be inserted at the beginning of the next group of pictures (GOP).

Also, consider when you should start the presentation I-ka is RA. Time equal to one frame, between labels DTS and PTS is not only appropriate for a thread with only I-frames and P-frames, but is prescribed in the standard MPEG2 for this thread, if the flag is not set low_delay_flag. Therefore, tag PTS I-frame is set equal to the value of the label DTS plus the value corresponding to the time of one frame. For frame rates of 23.976 and 59.94Hz it will be a value close to the time of one frame. Distance PCR between the beginning of successive groups of pictures (GOP) for the special playback mode has already been computed. This distance is accurate, equitable PCR, and therefore is equal to the label of the DTS and PTS. The offset value between the PTS and DTS can be calculated by dividing the distance PCR on the size T of the group of pictures (GOP) for the special playback mode. It is actually very simple if structure IPPP (T=4), where it is necessary to divide by 4. Bits distances PCR simply shifted by two bits to calculate the offset of the labels PTS/DTS. This is depicted in Fig.

Fig shows a diagram 2900, where the time t is deposited on the abscissa 2901, and the basis of PCR is deposited on the ordinate 2902. Fig refers to the size of the group of pictures (GOP) T=4 and the refresh rate is R=25.

We will look at some aspects related to the insertion of messages (ECM) (message access control).

In the case of the AE encrypted stream for the special playback mode messages ECM must be present in this stream, to enable decryption by the receiver (for example, a set-top box (STB)). In this context it is necessary to decide when and where should be inserted messages ECM. In the preferred case, when a recorded stream already contains the necessary unencrypted packets, the block of data read from the storage device, will contain only the data of the I-frame. However, the way to insert messages ECM should also consider the more General case with large block sizes.

The first I-frame data block is used to build a group of pictures (GOP) for the special playback mode. The majority of ECM messages should be sent somewhere between I-frames, in fact between the two groups of pictures (GOP) for the special playback mode. As described previously, each group of pictures (GOP) for the special playback mode can be of equal length in time, and packets of the group of pictures (GOP) can be distributed over time to smooth out the bit rate. Insert messages ECM between these groups of pictures (GOP) unnecessarily increases the local bit rate. It may be better to embed the message ECM in the group of pictures (GOP) for the special playback mode. Then you need to decide which group of pictures (GOP) to add a message ECM. In castnet is, you have the following two options:

1. Message ECM can be added to the end of the previous group of pictures (GOP) for the special playback mode.

2. Message ECM can be added to the beginning of the next group of pictures (GOP) for the special playback mode.

In the second embodiment, the ECM message actually is not the first packet of the next group of pictures (GOP), because they are inserted PCR, which must remain in this position for reasons of synchronization. Thus, the ECM message in this case is the second package. Although in practice the difference between these two options may be insignificant in many cases, the optimal position is set to option 1, because it maximizes the time available for decoding the ECM messages.

This situation is depicted in Fig.

Fig shows, in addition to the components already entered, the switch 3000 SCB package 3001 messages ECM and data 3002 I-frame. In addition, Fig illustrated an empty P-frames 3003.

When direct special playback mode, also sometimes it may happen that the switch 3000 SCB is not located between I-frames, but somewhere within the selected I-frame. Message 3001 ECM should be sent when the switch 3000 SCB included. This means that in this case, the communication 3001 ECM should be inserted in the correct location within the I-frame. This includes, in particular, two options:

1. Message 3001 ECM can be inserted before the package I-frame with the switch 3000 SCB.

2. Message 3001 ECM can be inserted after the package I-frame with the switch 3000 SCB.

The packet switch 3000 SCB is encrypted videopokemon with SCB value, different from previous encrypted videobachata. In some cases it does not matter whether option 1 or 2, but theoretically the best position is usually located before the packet switch 3000 SCB. This is because, on the one hand, the control word of the previous period is no longer necessary with this point and, on the other hand, the time to decode the message 3001 ECM is maximized.

Option 1 is depicted on Fig. In particular, Fig shows the package 3100 with switch SCB.

In all cases, the packet identifier (PID) and the table ID of the inserted messages ECM are preferably original, to enable smooth switching between normal playback and special playback mode in both directions. The continuity counter in the packet header of the message ECM can still be fixed.

We will look at some aspects concerning where to do or to form a hybrid stream.

Described here died idny thread can be created in several places. In this context, reference is made to Fig.

Possible locations are actually the same locations as for the thread from a non-I-frames (Fig and corresponding description):

1'. In station 1401 broadcast or uplink communication in the case of satellite broadcasting.

2'. In the Central station 1405 cable television in the case of a cable network.

3'. In the residential gateway 1407 in the case of a secure authenticated domain.

4'. On the recording side memory device 1409.

However, for a stream with only a few unencrypted packets must be added the fifth location:

5'. On the reproducing side of the storage device 1406, 1408, 1409.

Possible locations 1' to 5' visualized on Fig.

Location 1' and 2' can be difficult to achieve, because there's only a limited impact. For storage device, actually there is no difference, if implemented conversion to hybrid flow at locations 1', 2' or 3'. Thus, option 3' can be a very good choice. In all three cases, the storage device can accept the hybrid stream on your login account. This means that the storage device does not need a transcript and a smart card, at least not for normal playback and the formation of specialized the tunes playing. But decoding may still be necessary if the storage device has a function of extracting metadata that uses the detection of intra-coded frames, etc. Suitable location to build a hybrid flow may be the case 4', that is, on the recording side of the storage device. Although this requires partial decryption on the recording side, it still has the advantage that the transcript is not necessary for the formation of the special playback mode. Anyway it is preferable that the recorded flow was hybrid. In the case of 5'in which the recording was made with all the encrypted packets, it is still possible to create a secure specialized playback mode, as described here. On Fig was shown the basic approach to working with fully encrypted stream. But instead of the full decryption can only be decrypted necessary packages, but leave the rest still encrypted (Fig).

Fig shows the system 3310, which is different from the system 1600 that the decoder 1603 generates a partially-encrypted data 3300 standard MPEG2 and MPEG2 decoder 1506 replaced MPEG2 decoder and decoder 3302, which accepts a partially decrypted compliant MPEG2 transport stream 3301. You can still POPs is your predominant way encrypted stream for the special playback mode.

Next, with reference to figa and 34B will be described device 3400 to flow 3401 encrypted data in accordance with an illustrative alternative embodiment of the invention.

In particular, figa illustrates a block diagram of the formation of the hybrid flow device 3400. Figv illustrates a block diagram of the forming stream for the special playback mode, which can be used in conjunction with the block diagram of the formation of hybrid flow shown in figa, device 3400.

The device 3400 includes a module 3402 decryption, which forms the flow 3403 decrypted data from the stream 3401 encrypted data.

In addition, the device 3400 includes a module 3404 detection, which detects information about the position of I-frames in the stream 3403 decrypted data. In particular, the module 3404 detection detects as information about the position of the start position and end position of each of the I-frames included in the flow 3403 decoded data.

In addition, the device 3400 includes a module 3405 replacement that replaces, based on the positional information detected by the module 3404 detection, part of the flow 3401 encrypted data provided to the first input module 3405 replacement, the relevant parts of the flow 3403 decoded data is provided to a second input module 3405 replacement. Other SL is you module 3405 replacement replaces part of the flow 3401 encrypted data relevant parts of the flow 3403 decoded data based on the detected initial position and the final position of the I-frames. As a result, the output module 3405 replacement block diagram of formation of the hybrid flow, shown in figa formed hybrid flow 3407 data.

Hybrid flow 3407 data issued at the output of the system shown in figa, can be connected to the input of the system at figv. However, the hybrid storage data can be provided by optional.

Module forming specialized playback figv can optionally include (optional) module 3404 detection.

Hybrid flow 3407 data can be supplied to the module 3408 formation of a specialized mode for forming stream 3409 data for playback in a special playback mode and can be supplied at additional module 3404 detection. Besides, the module 3406 add, which is issued to the output of the additional module 3404 detection. Module 3406 add can add timing information to the data flow. Data added module 3406 add, are unencrypted. The output module can be added the issued for module 3408 formation of the special playback mode.

Module 3408 formation of a specialized playback mode shapes based on its input stream 3409 data for playback mode special playback mode.

This thread 3409 for the special playback mode is issued to the module 3410 playback.

Module 3406 add can also add tables, data messages ECM and/or blank frames.

Module 3408 formation may take measures for the re-multiplexing, synchronization issues, smoothing re-multiplexed packets and/or cleaning personnel packages.

Module(s) 3404 detection can detect the boundaries of frames within the decoded stream 3403 or hybrid flow 3407. Such borders frames can be the boundaries of I-frames, B-frames and/or P-frames.

The situation is shown in figa, figv additionally described with reference to Fig showing the different data streams.

On Fig shows the flow 3401 encrypted data. After the transfer module 3402 decrypt the stream is generated 3403 fully decrypted data. Fig further illustrates the initial position 3500 and the final position 3501 detected within the flow 3403 decrypted data via the module 3404 detection. After the transfer module 3405 replacement part, related to the initial positions 3500 and ultimate positions 3501 of the flow 3401 encrypted data, replaced with the decrypted parts 3502. Module 3406 add adds information 3503 synchronization at the beginning of the stream.

In addition, as shown in Fig, information messages ECM (message access control), indicated by the number 3504 may be added to the end of the data stream.

It should be noted that as a complement or alternative to the detection of the boundaries of the I-frame is also possible to detect the boundaries (which are the starting and/or ending positions) B-frames and/or P-frames.

Next, with reference to Fig will be described device 3600 for stream processing 3601 data having a sequence of packets and timing information related to the packets, in accordance with another illustrative alternative embodiment of the invention.

The device 3600 includes a module 3602 distribution for uniform or homogeneous distribution of the packet flow 3601 data. This module 3602 distribution, which can also be called a smoothing module, generates a fair way posted part I-frames, as shown in the third row on Fig.

Module 3603 replacement replaces the timing information of the stream data, which is no longer valid, the changed information synchronization, adjusted for uniform distribution packages.

In addition, a module is 3604 paste the information for decryption which inserts into the stream of data messages access control (ECM) as the information for decryption.

In addition, the module provides 3605 formation of a specialized playback mode that generates a data stream for reproduction in a special playback mode. Data 3607 special playback mode is issued to the module 3606 playback for playback.

It should be noted that the location of the components on Fig can be changed. For example, the position module 3603 replacement module 3602 distribution can be replaced.

Next will be described the path of the signal Fig.

Module 3605 formation of a special playback mode is a stream 3601 data. The output module 3605 formation of a special playback mode is connected to the input module 3604 paste the information for decryption. The output module 3604 paste the information for decryption is connected to the input module 3603 replacement. The output module 3603 replacement is connected to the input module 3602 distribution. The output module 3602 distribution (where the given data 3607 special playback mode) is connected to the input module 3606 playback.

It should be noted that the term "comprising" does not exclude other elements or steps, and the use of the singular nicklachey many. The elements described in connection with different embodiments can be combined.

It should also be noted that the signs for references in the claims should not be considered as limiting the scope of the claims.

1. Device (3400) for processing stream (3401) encrypted data containing:
module (3402) decoding for forming stream (3403) decoded data from the stream (3401) encrypted data;
module (3404) detection to detect positional information of at least one intracavernosa frame in the stream (3403) decoded data, and the module (3404) detection performed with the opportunity to discover as information about the position of the initial position (3500) and end position (3501) mentioned at least one intracavernosa frame in the stream (3403) decoded data;
module (3405) replacement for replacement on the basis of the detected positional information pieces of stream (3401) encrypted data relevant parts of the stream (3403) decoded data; and a module (3405) replacement is made with the ability to replace part of the stream (3401) encrypted data relevant parts of the stream (3403) decoded data based on the detected initial position (3500) and target position (3501) mentioned at least one intracavernosa frame.

2. Device is (3400) according to claim 1, in which the module (3404) detection performed with the opportunity to discover information about the position of at least one frame with a direct prediction and/or at least one frame with bidirectional prediction in the stream (3403) decoded data.

3. Device (3400) according to claim 1, implemented with the ability to record hybrid stream.

4. Device (3400) according to claim 1 that contains the module (3406) add made with the possibility to add timing information to the data stream that was previously processed by the module (3405) substitutions, and the synchronization information includes a reference to the position of at least one intracavernosa frame.

5. Device (3400) according to claim 4, in which the module (3406) adding executed with the ability to add timing information in an unencrypted form.

6. Device (3400) according to claim 1, in which the module (3405) replacement is made with the ability to replace such quantity of the data stream (3401) encrypted data relevant parts of the stream (3403) decoded data that is minimally necessary for the formation of flow (3409) data for playback in a special playback mode.

7. Device (3400) according to claim 1, in which the module (3405) replacement designed in such a way that the data between the start position (3500) and end position (3501) mentioned at IU is e one intracavernosa frame are free from them replace the relevant parts of the stream (3403) decoded data.

8. Device (3400) according to claim 1, in which the module (3405) replacement is made with the ability to change the length indicator packet elementary stream packets, the timestamp representation and/or time stamp decoding in the block header of the stream (3401) encrypted data.

9. Device (3400) according to claim 1, configured to process the stream (3401) encrypted data composed of video data or audio data.

10. Device (3400) according to claim 1, configured to process the stream (3401) encrypted data consisting of digital data.

11. Device (3400) according to claim 1 that contains the module (3408) formation of a special playback mode, made possible to form the stream (3409) data for playback in a special playback mode based on the output module (3405) replacement.

12. Device (3400) according to claim 11, in which specialized playback mode is a single mode from the group consisting of playback, fast forward, playback, fast rewind, playback, mode playback, stop-frame playback mode repeat mode reverse function.

13. Device (3400) according to claim 1 which has a capability to process the encrypted data stream standard MPEG2.

14. the manual processing stream (3401) encrypted data, containing phases, which form the stream (3403) decoded data from the stream (3401) encrypted data, determine the initial position (3500) and end position (3501) at least one intracavernosa frame in the stream (3403) decoded data, replace part of the stream (3401) encrypted data relevant parts of the stream (3403) decoded data based on the detected initial position (3500) and target position (3501) mentioned at least one intracavernosa frame.

15. Machine-readable medium in which is stored a computer program processing stream (3401) encrypted data, and this computer program when executed by the processor, configured to control to execute the following steps of the method or to perform the following steps of the method are:
form the stream (3403) decoded data from the stream (3401) encrypted data;
find the starting position (3300) and end position (3501) at least one intracavernosa frame in the stream (3403) decoded data;
replace part of the stream (3401) encrypted data relevant parts of the stream (3403) decoded data based on the detected initial position (3500) and target position (3501) mentioned at least one intracavernosa frame.

16. Device (3600) for processing the stream (3601) data having the sequence of packets and timing information related to these packages contain:
module (3602) distribution for uniform distribution of the packet stream (3601) data, and the module (3602) distribution is configured to uniformly distribute the packets that belong to the part of the stream (3601) data, between two successive intracoronary personnel;
module (3603) replacement for replacement information synchronization stream (3601) data modified information synchronization, adjusted for uniform distribution of packets, and the module (3603) replacement is made possible to place the modified timing information in the initial position of the processed data stream.

17. Device (3600) according to clause 16, in which the module (3603) replacement is made with the option to generate a reference timing of the program, the time stamp decoding and/or the time stamp of the submission as changed information synchronization.

18. Device (3600) in article 16, which has a capability to process the stream (3601) encrypted data, and the device (3600) contains the module (3604) paste the information to decrypt made with the possibility to insert information for decryption in the processed data stream.

19. Device (3600) p in which the module (3604) paste the information to decrypt you Anen with the ability to insert messages access control information for decryption.

20. Device (3600) p in which the module (3604) paste the information for decryption is performed with the possibility to insert information for decrypting at the end of the processed data stream.

21. Device (3600) in article 16, which has a capability to process the stream (3601) data composed of video data or audio data.

22. Device (3600) in article 16, which has a capability to process the stream (3601) data consisting of digital data.

23. Device (3600) article 16 that contains the module (3605) formation of a special playback mode, made possible to form the stream (3607) data for playback in a special playback mode.

24. Device (3600) item 23, made with the ability to form stream (3607) data for playback in a special playback mode such that different groups of images generated flow data are essentially constant length of time.

25. Device (3600) item 23, in which specialized playback mode is a single mode from the group consisting of playback, fast forward, playback, fast rewind, playback, mode playback, stop-frame playback mode repeat and reverse mode in the works.

26. Device (3600) in article 16, which has a capability to process the encrypted data stream standard MPEG2.

27. The method of processing stream (3601) data having a sequence of packets and timing information related to the packets containing phases in which:
uniformly distribute the packets that belong to the part of the stream (3601) data, between two successive intracoronary personnel;
replace the timing information of the stream (3601) data modified information synchronization placed in the initial position of the processed data stream.

28. Machine-readable medium in which is stored a computer program processing stream (3601) data having a sequence of packets and timing information related to these packages, and this computer program when executed by the processor, configured to control to execute the following steps of the method or to perform the following steps of the method are:
uniformly distribute the packets that belong to the part of the stream (3601) data, between two successive intracoronary personnel;
replace the timing information of the stream (3601) data modified information synchronization placed in the initial position of the processed data stream.



 

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18 cl, 8 dwg

FIELD: information technologies.

SUBSTANCE: invention can be used in system of the forced performance of requirements which provides access possibility to the enciphered digital content on a computing mechanism only according to parametres the certain rights of the license got by the user of digital contents. The first confidential builder on the first computing mechanism carries out cryptographic, an estimate and the forced performance of requirements and forcedly contacts it, the first certificate of the user device corresponding to the first computing mechanism, forcedly contacts the user. Accordingly, the second confidential builder on the second computing mechanism carries out cryptographic processing, an estimate and the forced performance of requirements and forcedly contacts it, the second certificate of the user device corresponding to the second computing mechanism, also forcefully contacts the user. The first competent builder gains contents for reproduction on the first computing mechanism by means of the first certificate of the user device and the license, and the second confidential builder gains contents for reproduction on the second computing mechanism by means of the second certificate of the user device and the same license.

EFFECT: prevention of non-authorised duplication of digital content by the user related to the digital license and having of some computing mechanisms.

16 cl, 6 dwg

FIELD: information technologies.

SUBSTANCE: invention refers to method of control of decoding of program traffic set received by receiving system. Method of control of decoding of program traffic set received by receiving system implying that sequence of messages is received in conventional access subsystem (9, 10) comprising the specified receiving system, and each message is associated with one of coded program traffic set and represents information return enabling decoding of associated coded traffic by at least one decoding module (12) within receiving system. It is detected whether messages received within certain interval are associated with various coded program traffic set, and at least one of requests presented by messages received within certain interval is rejected, if number of various coded program traffics with which these messages are associated, exceeds preset value.

EFFECT: creation of receiving system, portable protector which enables program traffic provider to control program traffic set to which user of receiving system simultaneously addresses.

16 cl, 2 dwg

FIELD: information technology.

SUBSTANCE: decoder and subscription television data control system proposed contain at least two decoders, each of those is connected to at least one removable protective module. The protection is realised using identification data, contained in the decoder and protective module indicated. Besides, each of the decoders contains a descrambler and subscription television data processing deactivation units. Each decoder also contains a counter, which influences the deactivation units mentioned. Besides, at least one of the removable protective modules is assigned as primary and therefore contains decoder counter reinitialisation units.

EFFECT: provision of capability to regulate decoder operation time and to adjust operation parameters at any time using protective module.

19 cl, 13 dwg

FIELD: information encryption.

SUBSTANCE: system contains an encrypted data broadcasting centre, at least one control centre, a terminal device, a decoder located between the encrypted data broadcasting centre and the terminal device, the decoder includes an encrypted data reception and decryption module and a data access authority control module; the data access authority control module contains a protection module.

EFFECT: provision of system allowing to simplify access authority control at broadcasting centre level and ensuring optimal data security.

12 cl, 2 dwg

FIELD: receivers/decoders of services, provided with certain conditions, in particular in a system for accessing an encrypted data stream, priced per time unit.

SUBSTANCE: system contains control center (2), which transmits a data stream through a broadcasting channel, encrypted by means of control words, which are included in composition of access control messages, and meant for receipt by at least one user device (1), connected to safety block (3), having unique address and containing credit, which is reduced with purchase of products or consumption of data stream, where safety block (3) is provided with means for reducing credit for value, dependent on product, or for value, dependent on duration of access to data stream, where aforementioned values and/or duration are determined in access control messages or in conditional access messages, and system contains means, made independent from user device (1), for transmitting identifier, representing a unique number, and price code which indicates size of credit subject to load, in control center (2), and control center (2) additionally contains devices for receipt and verification of price code and for transmission of an encrypted message through broadcasting channel, having a unique address, corresponding to identifier, and giving a command to the safety block (3) to load the credit in defined amount.

EFFECT: development of a new approach to provision of access to paid television for broad clientele, substantially reduced subscriber management related costs.

5 cl, 1 dwg

FIELD: receivers/decoders of services, provided in conditional access mode, in particular, receivers having storage block (memorization device), such as a hard drive.

SUBSTANCE: method is claimed for storing an event, encrypted with usage of at least one control word (CW) in receiver/decoder (STB), connected to safety block (SC), where at least one control word and access privileges for aforementioned event are contained in access control messages (ECM-messages), method includes following operations: recording of encrypted event, and also of at least one ECM-message in storage block; transmission of at least one ECM-message into safety block (SC), verification of the fact that safety block (SC) contains access privileges for aforementioned event, generation of receipt (Q), which contains data related to management of event in reproduction mode, where receipt (Q) contains signature (SGN), generated on basis of the whole ECM-message or its part with usage of secret key (K) contained in safety block (SC) and specific for every safety block, where during later consumption of event the authenticity of the receipt (Q) is verified in prioritized manner compared to conventional access privileges, stored in safety block (SC), storage of aforementioned receipt (Q) in storage block.

EFFECT: provision of method for storing an event.

6 cl, 3 dwg

FIELD: method and systems for injecting command into device being controlled.

SUBSTANCE: in accordance to method, watermark is formed, containing inbuilt control command, which should be executed by device being controlled, control command being related to representation of advertisement, signal is generated, containing watermark, inbuilt in information block represented by it and transferred into device being controlled, generated signal is transferred with watermark into device being controlled for showing advertisement to user by executing control command, related to showing advertisement, user is questioned to determine his preferences and on basis of questioning user profile is generated with consideration of sales data for devices being controlled, product identification is added to control command, while control command contains value of parameter, specific for advertisement, while device being controlled receives advertisement, wherein parameter values are used.

EFFECT: creation of method and system for injecting command into device being controlled, wherein direct transfer of command into device is provided.

3 cl, 4 dwg

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