WO2009117924A1

WO2009117924A1 - Method and device for processing transcoding of streaming media

Info

Publication number: WO2009117924A1
Application number: PCT/CN2009/070774
Authority: WO
Inventors: 沈烁; 陈旭
Original assignee: 华为技术有限公司
Priority date: 2008-03-25
Filing date: 2009-03-13
Publication date: 2009-10-01
Also published as: CN101547345A

Abstract

The embodiment of the present invention relates to the field of communications, discloses a method for processing transcoding of streaming media, and solves the problem that encrypted streaming media can not be transcoded in prior art. The method creates the transcoding metadata of the streaming media according to the requirement for code rate of the streaming media; transcodes the encrypted streaming media according to the transcoding metadata, and obtains the encrypted streaming media with said code rate. Not only the end-to-end security of streaming media content is guaranteed, but also the bandwidth resources are saved. The present invention also discloses a device for processing transcoding of streaming media.

Description

Method and device for processing streaming media transcoding This application claims to be filed on March 25, 2008, the Chinese Patent Office, the application number is 200810066187.X, the Chinese patent application entitled "Processing and System for Streaming Media Transcoding" Priority is hereby incorporated by reference in its entirety. Technical field

Embodiments of the present invention relate to the field of communications, and in particular, to a method and apparatus for processing streaming media transcoding. Background technique

The rapid development and popularity of the Internet has provided a strong market power for the development of streaming media services. Streaming media services have become increasingly popular and widely used in IPTV (Internet Protocol TV, online TV), online advertising, online advertising, e-commerce, video on demand. , Internet education, telemedicine, real-time video conferencing and other aspects of Internet information services.

Streaming media has different bit rates. For example, in iPTV, streaming media has HD (High Definition) with image horizontal resolution greater than 800 lines, SD (Standard Definition) with image horizontal resolution greater than 500 lines, and images. Several bit rates, such as LD (Low Definition), whose horizontal resolution is greater than 250 lines.

Different terminal devices require streaming media content of different code rates, such as mobile phones, personal computers, and set-top boxes, which require streaming media content of different code rates. Even customers of the same terminal device may select streaming media content of different bitrates according to actual conditions. For example, depending on factors such as bandwidth or price, different customers may also choose streaming content at different bitrates. In order to meet the different needs of customers, it is necessary to convert streaming media into different code rates, namely: transcoding the streaming media. For example, converting streaming media from HD to LD.

In carrying out the process of the present invention, the inventors have found that the prior art has at least the following problems:

In the prior art, streaming media requires end-to-end encrypted transmission for content protection purposes. Usually the transcoding can only be performed on the stream before encryption, and the encrypted stream (also Called ciphertext streaming) Due to the randomization of content and format, transcoding is not possible. Currently, if transcoding is required, the ciphertext streaming media must be decrypted, transcoded, and re-encrypted to obtain ciphertext streaming media of different code rates. Such a processing method has high requirements on the node device for transcoding. The transcoding node device needs to simultaneously handle encryption, decryption, and transcoding operations, which easily becomes a transmission bottleneck and affects the real-time performance of the service. Moreover, the transcoding node has the encryption key and the integrity protection key of the streaming media, and the content of the streaming media can be inserted, which cannot guarantee end-to-end security.

In the prior art, the streaming media of different code rates can be separately encrypted and transmitted, and the streaming media content of different code rates can be delivered according to the requirements of the customer's requirements or bandwidth. Although this type of processing can guarantee end-to-end security, it needs to transmit at least two different code rate streaming media, resulting in a huge waste of bandwidth. Summary of the invention

In view of this, the embodiments of the present invention provide a method and a device for processing streaming media transcoding, which solves the problem that ciphertext streaming media cannot be transcoded.

A method for processing streaming media transcoding, comprising:

Generating the transcoded metadata of the streaming media according to the requirement of the streaming media rate; transcoding the encrypted streaming media according to the transcoded metadata to obtain the ciphertext streaming media of the code rate.

A processing device for streaming media transcoding, comprising: a transcoding metadata unit and a transcoding unit: a transcoding metadata unit, configured to provide transcoding metadata to the transcoding unit according to a requirement of a streaming media code rate;

And a transcoding unit, configured to perform transcoding on the encrypted streaming media according to the transcoded metadata provided by the transcoded metadata unit to obtain a ciphertext streaming medium of the code rate.

Compared with the prior art, the embodiment of the invention has the following advantages:

The technical solution provided by the embodiment of the present invention directly transcodes the ciphertext streaming media to ensure the end-to-end security of the streaming media content and saves bandwidth resources. DRAWINGS

1 is a flowchart of a method for processing streaming media transcoding in an embodiment of the present invention; FIG. 2 is a schematic diagram showing a correspondence relationship between transcoded metadata and streaming media content according to an embodiment of the present invention;

3 is a schematic structural diagram of a processing device for streaming media transcoding according to an embodiment of the present invention; FIG. 4 is a schematic structural diagram of a transcoding metadata unit 300 according to an embodiment of the present invention; FIG. 5 is a schematic structural diagram of a transcoding unit 310 according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a device for processing a streaming media transcoding according to an embodiment of the present invention. detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , FIG. 1 is a flow chart of a method for processing streaming media transcoding according to an embodiment of the present invention, including:

100. Convert streaming media into multi-level, independent frames.

In this embodiment, the streaming media can be converted into a basic frame and an enhanced frame. Of course, streaming media can also be converted to more hierarchical, independent frames.

110. According to the requirement of the streaming media code rate, the analysis confirms that the part that needs to be reserved and the part that can be discarded in the content of the streaming media at the time of transcoding generates the transcoding metadata.

In this embodiment, according to the requirement of at least one code rate of the streaming media, the part of the content of the streaming media that needs to be retained and the part that can be discarded are analyzed and confirmed.

In this embodiment, the content in the basic frame must be reserved for different code rate streaming media, and is not discardable. The content in the enhanced frame can be analyzed and confirmed according to the data volume requirement of the different code rate streaming media. The content of the enhanced frame can also be completely retained or discarded. For example, if the content of the streaming media needs to be transcoded from the HD code rate to obtain the LD code rate, all the contents of the enhanced frame can be discarded.

After confirming the part of the content of the streaming media that needs to be retained and the part that can be discarded, The reserved portion and the discardable portion are respectively identified by different tags, and the transcoded metadata of the streaming media is generated. It can be understood that if the streaming media of the HD code rate needs to be separately coded,

The SD and LD code rate streaming media can generate transcoded metadata of the SD code rate streaming media and transcoded metadata of the LD code rate streaming media according to the requirements of the two code rates.

In this embodiment, "1" is used for discarding, and "0" is used for reservation. The generated transcoded data corresponds to the contents of the streaming media in sequence. As shown in FIG. 2, FIG. 2 is a schematic diagram of correspondence between transcoded metadata and streaming media content according to an embodiment of the present invention. Where "Kx" indicates the portion of the content of the streaming media that needs to be retained during transcoding, and "Dx" indicates the portion of the content of the streaming media that can be discarded during transcoding.

In this embodiment, the process of generating the transcoded metadata may be performed in units of a minimum encryption module, such as 128 bits.

It can be understood that if the streaming media is converted into more hierarchical and independent frames in 100, for example, the streaming media is converted into 8 hierarchical independent frames, then "000", "001" can be used. ", "010", "011", "100", "101", "110", "111" identify 8 levels in turn. Here, the first level of the "000" logo is the lowest-definition streaming media, which must be preserved for all bitrate streams; then the sharpness gradually increases.

The eighth level of the "111" logo is the highest definition streaming. At the time of transcoding, the retained portion and the discarded portion are analyzed and determined according to the requirements of different code rates.

120. Encrypt and transmit the foregoing streaming media.

Among them, the stream cipher can be used to encrypt the streaming media, and the more common stream cipher algorithms such as the RC4 algorithm ( Rivest Cipher 4 ), etc.; the block cipher stream mode can also be used to encrypt the streaming media. Of course, those skilled in the art can understand that other encryption algorithms can also be used to encrypt the streaming media, which is not enumerated here.

In this embodiment, the streaming media can be encrypted in the same unit as the smallest encryption module to obtain the ciphertext streaming media.

130. Transcode the ciphertext streaming media according to the transcoded metadata.

Specifically, when the ciphertext streaming media needs to be transcoded in the transmission process, the content corresponding to the transcoded metadata in the ciphertext streaming media is reserved or discarded according to the transcoded metadata. Still taking FIG. 2 as an example for description. As shown in Figure 2, the first bit of the transcoded metadata is "0", then the secret is retained. The content corresponding to the first bit of the transcoded metadata in the stream media; the third bit of the transcoded metadata is "1", and the third bit of the ciphertext stream and the transcoded metadata are discarded. Corresponding content.

After the above transcoding process, ciphertext streams of different code rates are obtained.

Similarly, if the streaming media is converted into more hierarchical, independent frames and then transcoded, the ciphertext streaming media may be transcoded according to the transcoded metadata.

For the fields in the ciphertext streaming media that are discarded during transcoding, you can still keep these fields in the transcoded ciphertext streaming media, or you can delete these fields.

140. Perform decryption processing on the transcoded ciphertext streaming media.

In this embodiment, the ciphertext streaming media of different code rates obtained by transcoding are transmitted. When the ciphertext streaming media needs to be decrypted, if the field in which the discarded content is located is retained during transcoding, then The transcoded metadata decrypts the ciphertext stream. For example, in FIG. 2, D1, D2, and D3 are contents that need to be discarded when transcoding in ciphertext streaming media. If the ciphertext streaming media after transcoding still retains the fields in which the content is located, the K1 and K2 are decrypted. It can be known from the transcoded metadata that Dl, D2 and D3 have been discarded, and it is not necessary to decrypt the contents of these fields to directly decrypt K3.

If the field in which the discarded content is deleted is deleted during transcoding, all contents of the transcoded ciphertext media need to be decrypted.

After decryption processing, streaming media of different code rates can be obtained.

In this embodiment, the transcoded metadata is generated, and the ciphertext streaming media is transcoded according to the transcoded metadata, thereby ensuring end-to-end security of the streaming media content and saving bandwidth resources.

The embodiment of the present invention further provides a processing device for streaming media transcoding. As shown in FIG. 3, FIG. 3 is a schematic structural diagram of a processing device for streaming media transcoding according to an embodiment of the present invention, including a transcoding metadata unit 300 and transcoding. Unit 310:

Transcoding metadata unit 300, for transcoding unit according to the requirement of streaming media code rate

310 provides transcoded metadata;

The transcoding unit 310 is configured to transcode the encrypted streaming media according to the transcoded metadata provided by the transcoded metadata unit 300 to obtain the ciphertext streaming media of the code rate.

As shown in FIG. 4, the transcoded metadata unit 300 includes: The content analysis sub-unit 302 is configured to analyze, according to the requirement of the streaming media code rate, the part that needs to be reserved in the content of the streaming media and the part that can be discarded;

The generating subunit 303 is configured to generate transcoded metadata according to the analysis result of the content analysis subunit 302.

Further, the transcoding metadata unit 300 further includes:

The first receiving subunit 301 is configured to receive the streaming media, and send the received streaming media to the content analyzing subunit 302;

The first sending subunit 304 is configured to send the transcoded data generated by the generating subunit 303.

As shown in FIG. 5, the transcoding unit 310 includes:

The processing sub-unit 312 is configured to reserve, according to the transcoded metadata data provided by the transcoded metadata unit 300, a portion that needs to be reserved in the content of the encrypted streaming media, and discard the portion that can be discarded in the content of the encrypted streaming media. Obtaining a ciphertext stream of the code rate.

Further, the transcoding unit 310 further includes:

a second receiving subunit 311, configured to receive the transcoded metadata data provided by the transcoded metadata unit 300, and send the received transcoded metadata to the processing subunit 312; and further configured to receive the ciphertext stream Media

The second sending subunit 313 is configured to send the ciphertext stream of the code rate obtained by the processing subunit 312.

As shown in FIG. 6, the streaming media transcoding processing apparatus provided by the embodiment of the present invention further includes an encryption unit 330 and a decryption unit 340:

The encryption unit 330 is configured to encrypt the streaming media, obtain the ciphertext streaming media, and send the ciphertext streaming media to the transcoding unit 310;

The decryption unit 340 is configured to receive the ciphertext stream of the code rate sent by the transcoding unit 310, and decrypt the ciphertext stream; or, to receive the transcoded metadata sent by the transcoded metadata unit 300, and Receiving the ciphertext stream of the code rate sent by the transcoding unit 310, and decrypting the ciphertext stream of the code rate according to the transcoded metadata.

Further, as shown in FIG. 6, the streaming media transcoding processing apparatus provided by the embodiment of the present invention further includes: The streaming media processing unit 320 is configured to convert the streaming media into multi-level, independent frames, and send the streaming media to the transcoded metadata unit 300 and the encryption unit 330.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform, and can also be implemented by hardware. Based on the understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions for making a computer. A device, or server, or other network device performs the methods described in various embodiments of the present invention or in some portions of the embodiments. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Rights request

A method for processing a streaming media transcoding, comprising:

The method according to claim 1, wherein the generating the transcoded data of the streaming media according to the requirement of the streaming media code rate comprises:

According to the requirement of at least one code rate of the streaming media, the analysis confirms the reserved portion and the discardable portion required in the content of the streaming media.

The method according to claim 2, wherein the generating the transcoded metadata of the streaming media according to the requirement of the streaming media code rate further includes:

Different portions of the content of the streaming media and portions that can be discarded are respectively identified by using different tags, and at least one transcoded metadata of the streaming media is generated.

The method according to any one of claims 1 to 3, wherein before the transcoding the encrypted streaming media according to the transcoded metadata, the method comprises: The media performs encryption, obtains ciphertext streaming media, and transmits the ciphertext streaming media.

The method according to claim 1, wherein the transcoding the encrypted streaming media according to the transcoded data to obtain the ciphertext media of the code rate comprises:

And retaining, in the content of the ciphertext stream, the part that needs to be reserved, and discarding the part that can be discarded in the content of the ciphertext stream, to obtain the ciphertext stream of the code rate. .

The method according to claim 5, wherein after the encrypted streaming media is transcoded according to the transcoding metadata, the ciphertext media of the code rate is obtained,

Transmitting the ciphertext streaming media and decrypting the ciphertext streaming media.

7. A processing device for streaming media transcoding, characterized in that the device comprises a transfer Symbol data unit and transcoding unit:

The transcoded metadata unit is configured to provide transcoded metadata to the transcoding unit according to a requirement of a streaming media code rate;

The transcoding unit is configured to transcode the encrypted streaming media according to the transcoded metadata provided by the transcoded metadata unit to obtain a ciphertext streaming medium of the code rate.

8. The apparatus according to claim 7, wherein the transcoding metadata unit comprises:

a content analysis subunit, configured to analyze and confirm a portion of the content of the streaming media that needs to be retained and a portion that can be discarded according to the requirement of the streaming media code rate;

And generating a subunit, configured to generate transcoded metadata according to the analysis result of the content analysis subunit.

The device according to claim 8, wherein the transcoding metadata unit further comprises:

a first receiving subunit, configured to receive the streaming media, and send the received streaming media to the content analysis subunit;

a first sending subunit, configured to send the transcoded data generated by the generating subunit.

The apparatus according to claim 7, wherein the transcoding unit comprises: a processing subunit, configured to retain the encrypted location according to the transcoded metadata data provided by the transcoded metadata unit The part of the content of the streaming media that needs to be reserved is discarded, and the part that can be discarded in the encrypted content of the streaming media is discarded, and the ciphertext streaming medium of the code rate is obtained.

The device of claim 10, wherein the transcoding unit further comprises:

a second receiving subunit, configured to receive transcoded metadata data provided by the transcoded metadata unit, and send the received transcoded metadata to the processing subunit; Streaming media

a second sending subunit, configured to send the ciphertext stream of the code rate obtained by the processing subunit.

12. Apparatus according to any one of claims 7 to 11 wherein the apparatus further comprises:

An encryption unit, configured to encrypt the streaming media, obtain a ciphertext streaming media, and send the ciphertext streaming media to the transcoding unit;

a decryption unit, configured to receive the ciphertext stream of the code rate sent by the transcoding unit, to decrypt the ciphertext stream; or, to receive the transfer sent by the transcoded metadata unit The symbol data, and the ciphertext stream that receives the code rate sent by the transcoding unit, decrypts the ciphertext stream of the code rate according to the transcoded metadata.

The device according to claim 12, wherein the device further comprises: a streaming media processing unit, configured to convert the streaming media into multi-level, independent frames, and send the streaming media to The transcoded metadata unit and the encryption unit.