KR20080028673A - Apparatus and method of packaging/unpackaging h.264 movie file streamed or downloaded - Google Patents

Abstract

A packing/unpacking apparatus for the protection of an H.264 video file and a method thereof are provided to generate a video encrypted in a file format with the same structure as an original video file by using encryption video data, non-encryption video data, and metadata descriptor information under a service environment that the H.264 video file is provided in a VOD(Video On Demand) method, thereby protecting the H.264 video file using an existing streaming system. A metadata generator(120) receives video contents information and encryption information to generate a metadata descriptor to be inserted to a video. A stream analysis unit(110) analyzes an HY.264 video received by using the encryption information transmitted from the metadata generator to search for an encryption area. An encryption unit(130) encrypts the encryption area of the video transmitted from the stream analysis unit by using the encryption information transmitted from the metadata generator. A file generator(140) constitutes the same structure of file as an original file by using the meta descriptor transmitted from the metadata generator, non-encryption video data transmitted from the stream analysis unit, and encryption video data transmitted from the encryption unit to generate an encrypted video file.

Description

PACKAGING / UNPACKING APPARATUS AND PROTECTION FOR THE PROTECTION OF H.264 MOVIE VIDEO FILES {APPARATUS AND METHOD OF PACKAGING / UNPACKAGING H.264 MOVIE FILE STREAMED OR DOWNLOADED}

1 is a view showing the structure of a video stream in H.264 format,

2 is a diagram showing the structure of a slice NAL to be encrypted according to the present invention;

3 is a diagram illustrating a stream hierarchy when a video stream in H.264 format is transmitted in an MPEG-2 system TS form;

4 is a diagram illustrating a structure of an audio stream of video content;

5 is a diagram illustrating encryption identification using a scrambling control bit of a TS packet;

6 is a diagram illustrating a structure in which metadata is inserted into a TS packet;

7 is a diagram illustrating a structure of a packaging / unpackaging device for protecting a H.264 format video file according to the present invention;

8 is a view showing a stream analysis process of the stream analysis unit of the packaging apparatus according to the present invention;

9 is a diagram illustrating an encryption process of an encryption unit of a packaging apparatus according to the present invention;

10 is a diagram illustrating a streaming video decoding process of an unpackaging apparatus according to the present invention.

The present invention relates to the protection of H.264 format video file serviced through the Internet. More particularly, the streaming of the encrypted H.264 format video without modifying the existing streaming server using a pre-encryption method The present invention relates to a packaging / unpackaging apparatus and method for protecting an H.264 format video file in consideration of characteristics of the H.264 format video structure.

H.264 is a new video compression standard that has been achieved by the standardization process between ITU-T and ISO / IEC. Therefore, H.264 is a new standard that can be applied to all areas of video applications and has a significant performance improvement. Compared with H.263v2 (H.263 +) or MPEG-4 Simple Profile, H.264 improves video compression efficiency by more than 50% in most Bit-Rates under the same conditions.

As digital information is easy to produce and distribute, digitalized video production is increasing. However, since digital contents are easily copied, transformed, and distributed, and distributed through the insecure Internet, security and copyright issues are emerging as important issues. In particular, this problem has occurred mainly in the video stored and played on the user's PC. Therefore, in order to protect the video file stored in the user's PC, the encrypted video file can be decrypted only for a legitimate user after encrypting the entire video file. Informational methods were used.

On the other hand, streaming is a technology that enables playback by transmitting data in real time without storing contents in a local system. In the case of large-capacity video content, it takes a lot of time to download, so it is common to provide services through streaming in the same way as video on demand.

Since the video played through the streaming service is not stored in the user's PC compared to the video played in the user's PC, it was possible to solve problems such as illegal copying.

However, with the recent emergence of programs that can store videos serviced through streaming, the need for protection measures for videos served through streaming is emerging.

Conventionally, the encryption method includes a real time encryption method for encrypting each streaming session in real time on a network whenever a user requests a streaming, and a pre-encryption method for encrypting and streaming a video in advance.

Since the real-time encryption method encrypts streaming data for every user in real time, there is a problem that the streaming quality of service (QoS) is affected by encryption performance when processing a large user. In addition, the pre-encryption method requires a modification of an existing streaming server in order to stream an encrypted file encrypted without considering a video compression format and a file format.

Accordingly, the present invention has been made to solve the problems of the prior art, the present invention is to analyze the video of H.264 format while using the pre-encryption method encrypted video data and non-encrypted video data and the encrypted region and Protects video files in H.264 format by generating encrypted video files with metadata descriptor information in the same file structure as the original so that encrypted H.264 video can be streamed without modifying the existing streaming server. An object of the present invention is to provide a packaging device.

Meanwhile, another object of the present invention is to provide an unpackaging apparatus for protecting a video file of H.264 format that can minimize the load and delay caused by decryption by using an encryption identification mark in the decryption process. .

A packaging apparatus for protecting a video file of the H.264 format of the present invention for achieving the above object comprises a metadata generation unit for receiving a video content information and encryption information to generate a metadata descriptor to be inserted into the video; A stream analysis unit searching for an encryption region by analyzing the received H.264 video using the encryption information transmitted from the metadata generator; An encryption unit for encrypting an encryption area of the video transmitted from the stream analyzer using the encryption information transmitted from the metadata generator; Encrypted video by using the metadata descriptor transmitted from the metadata generator, the unencrypted video data transmitted from the stream analysis unit, and the encrypted video data transmitted from the encryption unit to form a file having the same structure as the original. And a file generation unit for generating a file.

In addition, the unpackaging device for protecting the H.264 format video file of the present invention is a metadata analysis unit for analyzing the input encrypted video to extract the content information and encryption information from the metadata descriptor inserted in the video ; And a decryption unit configured to decrypt the encrypted region of the encrypted video using encryption information of the metadata analysis unit.

Meanwhile, a packaging method for protecting a H.264 video file of the present invention

Receiving a video content information and encryption information and generating a metadata descriptor to be inserted into the video; Step 2 of searching for an unencrypted area and an encrypted area by analyzing a video in H.264 format using the encrypted information received in step 1; Encrypting the encrypted region of the video searched in the second step using the encryption information; Using the metadata descriptor generated in the first step, the unencrypted video data found in the second step and the encrypted encrypted video data in the third step, the encrypted video file is generated by forming a file having the same structure as the original. Characterized in that it comprises four steps.

Hereinafter, a packaging / unpackaging apparatus and method for protecting a H.264 video file of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a structure of a video stream in an H.264 format.

It is assumed that the H.264 format video broadcast stream protected by the present invention is multiplexed into a transport stream (TS) of the MPEG-2 system and streamed in a multicast manner.

The H.264 video stream is in the form of a network adaptation layer (NAL) sequence. As shown in FIG. 1A, the H.264 video stream includes several types of NALs, such as a sequence parameter set (SPS) NAL, a picture parameter set (PPS) NAL, a supplementary enhanced information (SEI) NAL, an access unit delimiter NAL, and a slice NAL. It is made to include. Each NAL consists of a NAL header, data, and bit adjustments. The NAL header includes a nal_unit_type field, and the value of the NAL header indicates the type of NAL. Video encryption is performed to protect video streams in H.264 format through the Slice NAL's encryption, which contains the actual video data. SPS, PPS, SEL NAL, etc. are information required by the streaming server, so if these NALs are encrypted, they may result in the failure of normal operation on the streaming server.

2 is a diagram showing the structure of a slice NAL to be encrypted according to the present invention.

The structure of the slice NAL to be encrypted is composed of a NAL header, Slice header, Slice data, and adjustment bits. The Slice header consists of the First_mb_in_slice field and the Slice_type field. There are I type, B type, or P type of encoding method of Slice. You can know the encoding method through Slice_type field of Slice header. Depending on the encryption option, the Slice_type information in the Slice header is used when encrypting all slices or only I slices. The Slice header is also excluded from encryption and only the Slice data area is encrypted.

3 is a diagram illustrating a stream hierarchy when an H.264 format video stream is transmitted in the form of an MPEG-2 system TS.

When the H.264 video stream composed of consecutive NALs is in the TS format, it goes through the PES format in the middle. Consecutive NAL sequences are contained in PES packets and PES packets are again loaded in TS packets. In TS, encryption targets TS packets containing slice data. The diagonal lines in the figure below indicate the encrypted areas.

4 is a diagram illustrating a structure of an audio stream of video content.

Most audio in video content is in MP3, AAC, or AC3 format. The audio stream consists of consecutive audio frames, and the audio frame consists of an audio frame header and audio data. The audio frame header includes a Syncword indicating the start of the audio frame, so that the start of the audio frame can be known. Audio is also encrypted, except for audio frame headers, only TS packets containing audio data.

5 is a diagram illustrating an encryption identification mark using a scrambling control bit of a TS packet.

The method of distinguishing the encrypted TS packet and the unencrypted TS packet of the encrypted and transmitted video uses an encryption identification mark of the scrambling control bit of the TS packet header. As shown in FIG. 5, the unencrypted TS packet sets the scrambling control bit value to '00', and the encrypted TS packet sets the scrambling control bit value to '11'. The unpackaging apparatus for decrypting the encrypted video content may determine whether to decrypt the TS packet by looking at the scrambling control bit value. As a result, the decoding time can be reduced.

6 is a diagram illustrating a structure in which metadata is inserted into a TS packet.

Metadata can be inserted into the video so that the packaged video content can be used in a download service. However, if the packaged content is used only for the streaming service, there is no need for metadata. The metadata may be inserted into the video content in the form as shown in FIG. 6. The metadata adds a DRM_descriptor to the Program Map Table (PMT) in the video stream, and creates and inserts a new Content_info packet containing content information after the PMT packet.

The DRM_descriptor inserted in the Program Map Table includes the following information.

● Content_ID: Content_ID of the packaged content

● Key_acquisition_address: address for key acquisition to obtain key information necessary for playing the packaged content.

● Content_info_PID: PID (Program ID) of the packet containing the content information

 The Content_info packet containing the content information contains the following information.

● Content_Title: content title

● Conten_Produciton_Year: Content Creation Year

● Content_Genre: Content Genre

● Content_Synopsis: Content summary information

The method of inserting the DRM_descriptor into the PMT is a method of adding the DRM_descriptor to the descriptor area of the PMT.

Program _ info _ length for (i = 0; i <N; i ++) {VOD_DRM_descriptor ()} and CRC _ 32 are shown in blue in the table below. In other words, the part that is changed in the PMT is displayed in blue. Since the PMT information has changed, the CRC value also changes. The following table shows the structure of the PMT added with the DRM_descriptor.

Syntax  TS_program_map_section () {table_id section_syntax_indicator ‘0’ reserved section_length program_number reserved version_number current_next_indicator section_number last_section_number reserved PCR_PID reserved program _ info _ length   for (i = 0; i <N; i ++) {   VOD _ DRM _ descriptor ()   }  for (i = 0; i <N1; i ++) {stream_type reserved elementary_PID reserved ES_info_length for (i = 0; i <N; i ++) {descriptor ()}} CRC _32  }

The following table shows the structure of DRM_descriptor inserted in PMT.

Syntax description  VOD_DRM_descriptor () {descriptor_tag descriptor_length content_ID Key_acquisition_address_length Key_acquisition_address Content_info_PID}     0x80 The number of bytes from the next byte to the end of the descriptor. The identifier of the packaged content. The length of the key acquisition address. The relevant address to obtain the key. PID of the Content_info packet.

The following table shows the structure of a Content_info packet containing content information. When the length of content information is not included in one packet, it indicates that the next packet and content are connected by using private_indicator and adds another packet. If private_indicator is 0, it indicates that the contents of the current packet are not end. It indicates that the packet and the contents that follow are connected. If private_indicator is 1, this indicates that the contents of the current private section are over.

Syntax description  VOD_ContentInfo_private_section () {table_id section_syntax_indicator private_indicator reserved private_section_length content_title_length content_title content_genre_length content_gene content_production_year content_synopsis_length content_synopsis}   0x80 Use as '0' marker bit Number of bytes from '0' to the end title length title content Genre length content Genre Year Plot Length Plot

When inserting the DRM_descriptor into the PMT, the new content_info packet is inserted immediately after the changed PMT packet.

7 is a diagram illustrating a structure of a packaging / unpackaging apparatus for protecting a H.264 format video file according to the present invention.

The packaging apparatus 100 for protecting the H.264 format video file receives and encrypts the H.264 format video, and inserts metadata to generate an encrypted video having the same file type as the original video.

The trimming server 200 receives a video encrypted by the packaging apparatus 100 and provides a streaming service to a user terminal having a request.

The user terminal 300 decrypts the encrypted video streamed by the streaming server 200 to generate a decrypted video. The user terminal 300 includes an unpackaging apparatus 310 to decrypt the encrypted video.

The unpackaging apparatus 310 decrypts the encrypted video streamed from the streaming server or the encrypted video downloaded to the local system.

The packaging apparatus 100 includes a metadata generator 120, a stream analyzer 110, an encryption unit 130, and a file generator 140.

The metadata generator 120 receives metadata and encryption information. The metadata includes video content information and encryption information. Therefore, the metadata generator 120 receives encryption information such as video content information, encryption key information, encryption size, region selection information to be encrypted, and generates metadata description information to be inserted into the video.

The stream analyzer 110 receives the H.264 video file multiplexed in the TS format and analyzes the encrypted area and the non-encrypted area. The stream analyzer 110 analyzes the encryption region using the encryption information transferred from the metadata generator 120 to the H.264 format video multiplexed in the TS format. When analyzing the encryption area, the area selection information to be encrypted of the encryption information is used.

The encryption unit 130 encrypts the video data by using the encryption position information and the encryption size data among the video data of the H.264 format and the encryption information transmitted from the metadata generator 120 by the analysis of the stream analyzing unit 110. do. The encryption unit 130 encrypts the video data by the size of the transmitted encryption and then displays an encryption identification mark. The encryption identification mark uses the scrambling control bit of the TS packet header.

The file generator 140 generates an encrypted video file composed of a file having the same structure as the original. The file generator 140 receives metadata descriptor information, which is metadata description information generated by the metadata generator 120, and receives unencrypted video data by video analysis of the stream analyzer 110. Receive encrypted encrypted video data from the encryption unit 130. The file generator 140 adds a DRM_descriptor to the PMT table using metadata information, creates a new CRC, modifies an existing PMT packet, generates a Content_Info packet including content information, inserts a Content_Info packet after the PMT packet, and encrypts the video. Packets and unencrypted video packets are also written to files in the input order to form the same file format as the original to create an encrypted video file.

The streaming server 200 streams the video encrypted by the packaging apparatus 100 to the user terminal 300 by using a server for streaming the original H.264 video.

The unpackaging apparatus 310 includes a metadata analyzer 312 and a decoder 311. The metadata analyzer 312 analyzes the encrypted video input from the streaming server 200 and extracts content information and encryption information from a metadata descriptor inserted in the video.

The decryption unit 311 decrypts the encrypted region of the encrypted video by using the encryption information of the metadata analyzer 312 and reproduces the decrypted image by using the user terminal 300.

The unpackaging device 310 not only decrypts the encrypted video streamed by the streaming server 200, but also encrypts the encrypted video using the downloaded video file 320 that is previously encrypted and downloaded to the user terminal 300. Can be decrypted

8 is a diagram illustrating a stream analysis process of the stream analysis unit of the packaging apparatus according to the present invention.

The stream analyzing unit selects and reads a video packet using a PID (Program ID) of the header in the video. S810. The start code of the NAL (Network Adaptation Layer) is detected from the payload of the selected video packet. If there is no start code of the NAL, the enc_flag value is compared and immediately encrypted. If there is a start code of the NAL, the enc_flag value is set to '0' and the NAL type information is detected from the header of the NAL (S830). If the detected NAL has a type other than a slice, the next video packet is read. If the NAL has a slice type, it finds another NAL within the payload of the current video packet, and if there is more than one NAL in the current video packet. After setting the enc_flag value to '0', the next video packet is read. (S840) If there is no NAL, check whether the enc_flag value is '0'. (S850) If the enc_flag value is '0', enc_ Set the flag value to '1' and read the next video packet, and if the enc_flag value is not '0', compare the skip_cnt value with the incremented value of enc_cnt by 1 to specify the area to encrypt according to the skip_cnt value, which is the encryption region selection information. (S860) If the enc_cnt value is smaller, the next video packet is read. If the enc_cnt value is larger, the slice NAL in the payload of the current video packet is processed by the encryption unit (S870). It consists of the steps to set.

9 is a diagram illustrating an encryption process of an encryption unit of a packaging apparatus according to the present invention;

The enc_size value, which is encryption region selection information, is compared with the payload size of the current video packet (payload_size). (S910) enc_size value DL If the payload size of the current video packet is larger than the payload_size, the process ends. If it is smaller than the payload size (payload_size), an area corresponding to the size of enc_size is encrypted from the back of the payload (S920). In this way, it is detected whether there is a start code of NAL in the encrypted area. If there is no start code of the NAL in the encrypted region, the process terminates. If a start code of the NAL is detected in the encrypted region, the encrypted region is restored to its original state before being encrypted again (S940).

10 is a diagram illustrating a streaming video decoding process of an unpackaging apparatus according to the present invention.

The enc_size value, which is the encryption region selection information, is compared with the payload size (payload_size) of the current video packet. (S960) Check the encryption identification mark (enc_id) of the video packet header. (S970) If the encryption mark is not displayed, the next video packet is read, and the payload of the video packet marked with encryption is equal to the size of enc_size. (S980) The encryption identification mark of the decrypted video packet header is removed. (S990) At this time, the key and encryption region selection information used for decryption can be provided from a service provider through a separate channel before receiving a video streaming service. have.

Although the present invention has been described in more detail with reference to some embodiments, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, the packaging device for the protection of the H.264 format video file according to the present invention is encrypted video data, non-encrypted video data and metadata descriptors in an environment that serves a video on demand H.264 format It is possible to use the existing streaming system by generating the encrypted video information in the form of the file of the same structure as the original.

In addition, the unpackaging apparatus for protecting the H.264 format video file according to the present invention can easily find the region to be decrypted using the encryption identification mark of the encrypted region of the video file, such as a low-performance device such as a mobile device or a set-top box There is an effect that the decoding operation can be performed using the client terminal of. In addition, H.264 format video can be selected from a very small area to the area that occupies most of the video, thereby protecting the video without affecting the performance of the entire system.

Claims (19)

A metadata generator which receives the video content information and the encryption information to generate a metadata descriptor to be inserted into the video; A stream analysis unit searching for an encryption region by analyzing the received H.264 video using the encryption information transmitted from the metadata generator; An encryption unit for encrypting an encryption area of the video transmitted from the stream analyzer using the encryption information transmitted from the metadata generator; A video file encrypted by using the metadata descriptor transmitted from the metadata generator, the non-encrypted video data transmitted from the stream analyzer, and the encrypted video data transmitted from the encryption unit, in the form of a file having the same structure as the original. Packaging apparatus for protecting a video file of the H.264 format, characterized in that comprises a file generation unit for generating a. The method of claim 1, And the encryption information includes encryption key information, encryption size, and region selection information to be encrypted. The method of claim 1, And the stream analyzer finds an encrypted region by using the region selection information to be encrypted transmitted from the metadata generator. The method of claim 1, The encryption unit is a packaging device for protecting a video file of the H.264 format, characterized in that for encrypting the video, and the encryption identification display. The method of claim 1, And the file generator adds DRM_descriptor to the video program map table (PMT). The method of claim 5, And the file generation unit inserts a Content_info packet after the PMT packet. The method of claim 5, The DRM_descriptor is a packaging device for protecting a video file of the H.264 format, characterized in that added to the descriptor region of the PMT. A metadata analysis unit which analyzes the input encrypted video and extracts content information and encryption information from the metadata descriptor inserted in the video; And a decryption unit for decrypting the encrypted region of the encrypted video by using the encryption information of the metadata analysis unit. The method of claim 8, The unpackaging device for protecting the H.264 format video file, characterized in that the encrypted video is input by streaming. The method of claim 8, The unpackaged device for protecting the H.264 format video file, characterized in that the encrypted video is a downloaded video file. The method according to claim 9 or 10, And the decryption unit searches for an encrypted region by using an encryption identification mark of the encrypted video. 12. The unpackaging apparatus of claim 11, wherein the decryption unit decrypts the encrypted video and removes the encrypted identification mark. Receiving a video content information and encryption information and generating a metadata descriptor to be inserted into the video; Step 2 of searching for an unencrypted area and an encrypted area by analyzing a video in H.264 format using the encrypted information received in step 1; Encrypting the encrypted region of the video searched in the second step using the encryption information; Using the metadata descriptor generated in the first step, the unencrypted video data found in the second step and the encrypted encrypted video data in the third step, the encrypted video file is generated by forming a file having the same structure as the original. A packaging method for protecting a video file in H.264 format, characterized in that it comprises four steps. The method of claim 13, The encryption information is a packaging method for protecting a video file of the H.264 format, characterized in that it includes encryption key information, encryption size, region selection information to be encrypted. The method of claim 13, wherein the second step A packaging method for protecting a video file in H.264 format, characterized by searching for an encryption region using region selection information to be encrypted of the encryption information. The method of claim 13, wherein the third step Packaging method for protecting a video file of the H.264 format characterized in that it further comprises the step of displaying an encryption identification mark in the encryption area. The method of claim 13, wherein the fourth step The metadata descriptor is a packaging method for protecting a video file of the H.264 format, characterized in that for generating an encrypted video file by adding the DRM_descriptor to the Program Map Table (PMT). 18. The method of claim 17, wherein the fourth step is A packaging method for protecting a video file of H.264 format, characterized by inserting a Content_info packet after the PMT packet. The method of claim 17, The DRM_descriptor is a packaging method for protecting a H.264 format video file, characterized in that added to the descriptor region of the PMT.

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