JP2013055633A - Electronic apparatus and content transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus achieving a content transfer function requiring copyright protection at low cost.SOLUTION: The electronic apparatus includes first coding means, second coding means, multiplexing means, and content transfer means. The first coding means encodes a video data to be displayed on a display. An encryption means encrypts the coded video data. The second coding means encodes video data to be output to a speaker. The multiplexing means generates multiplexed data including the encrypted video data, the coded voice data, and notification information including information related to the existence or non-existence of copyright protection of the video data and information related to the existence or non-existence of copyright protection of the voice data. The content transfer means transmits the generated multiplexed data to an encrypted transmission path through radio communication.

Description

  Embodiments described herein relate generally to a content transfer technique for transferring content that requires copyright protection via a transmission path such as a LAN (Local Area Network).

  In recent years, electronic devices capable of handling digitized video and audio, such as personal computers and smartphones, have become widespread. This type of electronic device is generally equipped with a data communication function, and can transmit and receive so-called AV (Audio and visual) content with other electronic devices.

  On the other hand, there are many AV contents that require copyright protection, such as restrictions on copying. For this purpose, various mechanisms for transmitting and receiving AV content between a plurality of electronic devices while protecting the copyright have been proposed.

JP 2009-71786 A

  For example, HDCP (High-bandwidth digital content protection system) is known as a method for protecting the copyright of video. Further, as a method for protecting the copyright of audio, for example, SCMS (Serial copy management system) is known. HDCP is a method involving encryption of copyright protection target data, and SCMS is a method not involving encryption of copyright protection target data. Therefore, although the purpose of copyright protection is common between video and audio included in one AV content, one is required to be encrypted, while the other is not required until encryption, etc. There may be cases where the degree of measures required for copyright protection is different.

  By the way, so far, there is one copyright protection method applied when one AV content is sent to one transmission path, and a plurality of copyrights are used when one AV content is sent to one transmission path. The application of the right protection method is not considered at all. Therefore, for example, it is necessary to perform encryption required for video even for audio that is not required until encryption. However, this causes an unnecessary cost increase such as mounting a module for encrypting / decrypting audio (which is not normally necessary) in both electronic devices on the transmitting side and receiving side of AV content.

  An object of the present invention is to provide an electronic device and a content transfer method that can realize a content transfer function that requires copyright protection at a low cost.

  According to the embodiment, the electronic device includes a connection unit, a first encoding unit, a second encoding unit, a multiplexing unit, and a content transfer unit. The connection means connects to the communication partner device by a method in which the transmission path is encrypted. The first encoding means encodes video data displayed on the display. The encryption unit encrypts the video data encoded by the first encoding unit. The second encoding means encodes audio data output to the speaker. Multiplexing means includes the audio data in the video data encrypted by the encryption means, the audio data encoded by the second encoding means, and information relating to copyright protection of the video data. Multiplexed data including notification information including information on whether or not copyright protection is included is generated. The content transfer means sends the multiplexed data generated by the multiplexing means to the encrypted transmission path by wireless communication.

The figure which shows the system configuration | structure of the copyright protection content transfer system which concerns on 1st Embodiment. The flowchart which shows the operation | movement procedure by the side of the content transmitter of the copyright protection content transfer system of 1st Embodiment. The flowchart which shows the procedure of the encoding process of the video which the content transmitter of the copyright protection content transfer system of 1st Embodiment performs. The flowchart which shows the procedure of the audio encoding process which the content transmitter of the copyright protection content transfer system of 1st Embodiment performs. The flowchart which shows the operation | movement procedure by the side of the content receiver of the copyright protection content transfer system of 1st Embodiment. The flowchart which shows the procedure of the decoding process of the video which the content receiver of the copyright protection content transfer system of 1st Embodiment performs. The flowchart which shows the procedure of the audio | voice decoding process which the content receiver of the copyright protection content transfer system of 1st Embodiment performs. The figure which shows the functional block of the transfer function of the content with a copyright protection mounted in the content transmitter of the copyright protection content transfer system of 1st Embodiment. The figure which shows the system configuration | structure of the copyright protection content transfer system which concerns on 2nd Embodiment. The figure which shows the functional block of the transfer function of the content with a copyright protection mounted in the content transmitter of the copyright protection content transfer system of 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
First, the first embodiment will be described.

  FIG. 1 is a diagram showing a system configuration of a copyright-protected content transfer system according to this embodiment.

  As shown in FIG. 1, the copyright-protected content transfer system according to this embodiment includes a content transmitter 1, a content receiver 2, and an audio player 3. The content transmitter 1 and the content receiver 2 are connected by, for example, a wireless LAN (Wi-Fi) of the IEEE 802.11 standard, and the content receiver 2 and the audio player 3 are, for example, S / It is assumed that the connection is made by PDIF.

  The content transmitter 1 is, for example, a PC (Personal computer), encodes content (video output to a display or the like and sound output to a speaker or the like), and transmits the encoded content to the content receiver 2 via Wi-Fi.

  The content receiver 2 is, for example, a television receiver, which decodes (encoded) content received from the content transmitter 1 and displays a video on a screen. The audio is output from the audio player 3 via the speaker or S / PDIF built in the content receiver 2 after decoding.

  The data format of the content transferred between the content transmitter 1 and the content receiver 2 is, for example, the MPEG2-TS format, and the transfer protocol is, for example, RTP (Real-time transport protocol). The copyright-protected content transfer system according to the present embodiment uses, for example, HDCP (High-bandwidth digital content protection system) 2.0 as a copyright protection method (first copyright protection method) for protecting the video ES. Alternatively, for example, SCMS (Serial copy management system) is applied as a copyright protection method (second copyright protection method) for protecting the audio ES by applying the successor standard of HDCP 2.0. That is, the copyright-protected content transfer system of the present embodiment applies a plurality of copyright protection methods to one content when transferring one content through one transmission path.

  First, referring to FIG. 2, in the copyright-protected content transfer system of this embodiment, the procedure from when the content transmitter 1 transmits video and audio to when the content receiver 2 reproduces the video and audio is described. The operation on the content transmitter 1 side will be described.

When a content transfer application (program) is started by a user operation after the content transmitter 1 is turned on, the content transmitter 1 tries to connect to the content receiver 2 via Wi-Fi. When the connection with the content receiver 2 is established (block A1), the content transmitter 1 executes authentication and key exchange processing according to HDCP 2.0 with the content receiver 2 (block A2). ). As a result, the encryption key for the video ES and the part r _iv of the initial vector (IV) when transferring content with copyright protection (content that requires copyright protection) are determined.

  The content transmitter 1 starts encoding video output to a display or the like and audio output to a speaker or the like (block A3). Details of the video encoding process and the audio encoding process will be described later with reference to FIGS. For example, when a content with copyright protection written on a DVD is being played by a DVD player application or the like (YES in block A4), the content transmitter 1 turns on a CP (Copy protection) flag as a copyright protection presence / absence determination. (Block A5). Here, since it is assumed that the content to be transferred is played back by the content transmitter 1, and the played content is re-encoded and transferred to the content receiver 2, the DVD playback is simplified for the sake of simplicity. Whether the CP flag is ON / OFF is determined based on the presence or absence, but copyright protection information embedded in the DVD itself may be added to the determination standard.

  Immediately after starting the content transfer application, when the CP flag is switched from ON to OFF, or when the CP flag is switched from OFF to ON (YES in block A6), the content transmitter 1 receives the video ES, A PMT (Program map table) describing the PID of the audio ES is generated (block A7). When the CP flag is ON (YES in block A8), the registration_descriptor defined in HDCP2.0 is inserted into the PMT. (Block A9). The content transmitter 1 inserts the generated MPEG2-TS packet including the PMT into the content data to be transferred to the content receiver 2. The PMT may be generated at regular intervals such as every second and inserted into content data for confirmation of stream information on the content receiver 2 side. The PMT generated at this time is the same data unless the CP flag is switched.

  Subsequently, the content transmitter 1 generates content data in the MPEG2-TS format by MUX (multiplexing) processing using content data in the PES format generated by video encoding and audio encoding described later (block A10). Then, it transmits to the content receiver 2 by RTP (block A11). The content transmitter 1 sequentially repeats the above operations while the content transfer application is running.

  FIG. 3 is a flowchart showing the procedure of video encoding processing.

  The content transmitter 1 first converts the video output to a display or the like to H.264. Encode in PES format according to a codec such as H.264 (block B1).

If the CP flag is ON (YES in block B2), the content transmitter 1 determines inputCtr and streamCtr defined in HDCP2.0, which are part of the initial vector, and is also defined in HDCP2.0. PES_private_data is generated (block B3). Next, the content transmitter 1 sets the encryption key and the initial vector by combining the determined inputCtr and streamCtr with the encryption key generated by the key exchange process (block A2) and a part r _iv of the initial vector. (Block B4). The content transmitter 1 encrypts the PES payload by the AES-CTR method adopted in HDCP 2.0 (block B5), and inserts the generated PES_private_data into the PES header (block B6). Then, the content transmitter 1 outputs the generated video PES to the MUX (block B7). The content transmitter 1 sequentially repeats the above operations while the content transfer application is running.

  FIG. 4 is a flowchart showing the procedure of the audio encoding process.

  The content transmitter 1 first encodes audio output to a speaker or the like in the PES format according to a codec such as AAC (block C1). The content transmitter 1 outputs the generated audio PES to the MUX (block C2). The content transmitter 1 sequentially repeats the above operations while the content transfer application is running.

  In the above procedure, the audio PES is not encrypted, but when connected by the WPA method or the like during Wi-Fi connection, the transmission path is encrypted and the content data is transferred. That is, in this case, the entire content data in the MPEG2-TS format including the audio ES is encrypted.

  Next, referring to FIG. 5, in the copyright-protected content transfer system of this embodiment, the procedure from when the content transmitter 1 transmits video and audio to when the content receiver 2 reproduces the video and audio. The operation on the content receiver 2 side will be described.

When the content receiver 2 is turned on and then switched to the content transfer mode by a user operation, the content receiver 2 waits for connection from the content transmitter 1 via Wi-Fi. When a connection request is received from the content transmitter and a connection with the content transmitter 1 is established (block D1), the content receiver 2 makes an authentication and key in accordance with HDCP 2.0 with the content transmitter 1. The exchange process is executed (block D2). As a result, the decryption key for the video ES and the part r _{iv of the} initial vector when the content with copyright protection is transferred are determined.

  The content receiver 2 starts decoding video and audio (block D3). Details of the video decoding process and the audio decoding process will be described later with reference to FIGS.

  The content receiver 2 receives the content data transferred from the content transmitter 1 by RTP (block D4) and analyzes the PMT (block D5). If registration_descriptor is included in the PMT (YES in block D6), the content receiver 2 sets the CP flag to ON (block D7), whereas if not included (NO in block D6), the CP The flag is set to OFF (block D8). The content receiver 2 filters the MPEG2-TS packet using the stream information obtained by analyzing the PMT, and DEMUX (separates) the video ES and audio ES from the content data (block D9). The content receiver 2 sequentially repeats the above operations during content transfer from the content transmitter 1.

  FIG. 6 is a flowchart showing a procedure of video decoding processing.

When the video ES is input by the DEMUX (block E1), the content receiver 2 analyzes the PES header (block E2). When the CP flag is ON and PES_private_data is included (YES in block E3), the content receiver 2 acquires PES_private_data (block E4), and the video ES decryption key generated by the key exchange process The decryption key and the initial vector are set by combining the initial vector part r _iv (block E5). Then, the content receiver 2 decrypts the encrypted PES payload by the AES-CTR method (block E6).

  Subsequently, the content receiver 2 decodes the content data in the PES format (block E7), and outputs the video to a display or the like (block E8). The content receiver 2 sequentially repeats the above operations during content transfer from the content transmitter 1.

  FIG. 7 is a flowchart showing the procedure of the audio decoding process.

  When the audio ES is input by the DEMUX (block F1), the content receiver 2 sets “copy prohibited” as the SCMS copy control information when the CP flag is ON (YES in block F2) (block F3) On the other hand, if the CP flag is OFF (NO in block F2), “copy permitted” is set as the SCMS copy control information (block F4). That is, in the copyright-protected content transfer system of this embodiment, it is defined by HDCP 2.0, which is the first copyright protection method applied to copyright protection of video (in order to notify whether video copyright protection is present). The registration_descriptor is also used as information for notifying whether or not the copyright protection of the sound to which the second copyright protection method SCMS is applied is applied.

  Subsequently, the content receiver 2 decodes the content data in the PES format (block F5) and outputs it to the audio player 3 together with the set copy control information (block F6). The content receiver 2 sequentially repeats the above operations during content transfer from the content transmitter 1.

  The audio player 3 outputs the audio data received from the content receiver 2 to a speaker or the like, and performs audio copy control according to the copy control information received from the content receiver 2.

  As described above, the copyright-protected content transfer system of the present embodiment applies a plurality of copyright protection methods to one content. As exemplified in the above description, when HDCP 2.0 is applied to copyright protection of video and SCMS is applied to copyright protection of audio, the content transmitter 1 side is required to encrypt video. Below, as shown in FIG. 8, the module (12b) for encrypting / decrypting the voice can be made unnecessary. Similarly, on the content receiver 2 side, a module for encrypting and decrypting audio can be made unnecessary. That is, the copyright-protected content transfer system of the present embodiment realizes a copyright-protected content transfer function at a low cost.

  In the above description, an example in which the presence / absence of registration_descriptor defined in HDCP 2.0 (applied to video) is used as audio copy control (applying SCMS) is described. Immediately after the content transfer application is started, when the CP flag is switched from ON to OFF, or when the CP flag is switched from OFF to ON, copy control is performed by communication using RTSP (Real time streaming protocol) or the like. Information may be notified from the content transmitter 1 to the content receiver 2. The content receiver 2 switches the copy control information to be output to the audio player 3 according to the received copy control information.

  Also, here, the copy control information is only handled as either “copy prohibited” or “copy allowed”, but depending on the content to be played back on the content transmitter 1 side, there is a case where “only one generation can be copied”. Conceivable.

(Second Embodiment)
Next, a second embodiment will be described.

  FIG. 9 is a diagram showing a system configuration of the copyright-protected content transfer system according to the present embodiment.

  The difference from the first embodiment described above is that the transfer destination devices for video and audio from the content transmitter 1 are separated. As shown in FIG. 9, in the copyright-protected content transfer system of this embodiment, the content transmitter 1 transfers video to the first content receiver 2a and audio to the second content receiver 2b. As in the first embodiment, the first content receiver 2a is, for example, a television receiver, and the second content receiver 2b is, for example, an AV amplifier.

  The operation of the content transmitter 1 in the present embodiment is basically the same as the operation of the content transmitter 1 in the first embodiment, except for the following points.

(A) Establishing a connection with each of the first content receiver 2a and the second content receiver 2b (b) HDCP 2.0 with the second content receiver 2b Authentication / key exchange processing is not required (c) Content data to be transferred to the first content receiver 2a and content data to be transferred to the second content receiver 2b are respectively generated in the MPEG2-TS format. The content data transferred to the first content receiver 2a includes only the video ES as ES, and the content data transferred to the second content receiver 2b includes only the audio ES as ES. The operations of both the first content receiver 2a and the second content receiver 2b in FIG. 5 are the content receiver 2 in the first embodiment. Although the operation is basically the same as the first content receiver 2a is only the video, is that the second content receiver 2b outputs only the audio different.

  Also in the copyright-protected content transfer system of the present embodiment in which the transfer destination of the video and audio from the content transmitter 1 is separated into the first content receiver 2a and the second content receiver 2b, 1 By applying a plurality of copyright protection methods to one piece of content, as shown in FIG. 10, a module (12b) for encrypting / decrypting audio is not required on the content transmitter 1 side. it can. The content data including only the video ES as the ES and the content data including only the audio ES as the ES can be generated, for example, by providing a switch 14 that supplies one of the video and audio to the multiplexing module (MUX) 13. . The switch 14 may be configured to be controllable to supply both video and audio to the multiplexing module (MUX) 13.

  Further, the module for encrypting and decrypting audio can be made unnecessary on the first content receiver 2a side. Furthermore, the presence of the encryption / decryption module itself can be eliminated on the second content receiver 2b side. That is, the copyright-protected content transfer system of the present embodiment also realizes a copyright-protected content transfer function at a low cost.

  The notification of copy control information regarding audio from the content transmitter 1 to the second content receiver 2b is performed by including registration_descriptor in the PMT of the content data transferred from the content transmitter 1 to the second content receiver 2b. Alternatively, communication by RTSP or the like may be performed.

  When the registration_descriptor is included in the PMT, the second content receiver 2b turns on the CP flag when the registration_descriptor is included in the PMT, and turns off the CP flag when the registration_descriptor is not included in the PMT. When the audio ES is input by the DEMUX, the second content receiver 2b uses “copy prohibited” as SCMS copy control information when the CP flag is ON, and as SCMS copy control information when the CP flag is OFF. Set "Copyable".

  On the other hand, in the case of communication using RTSP or the like, the second content receiver 2b switches copy control according to the copy control information received from the content transmitter 1.

  Here, the content transmitter 1 transfers content data including only the video ES as ES to the first content receiver 2a, and as ES to the second content receiver 2b. Although the example which transfers the content data containing only audio | voice ES was shown, it is not limited to this, Video ES and audio | voice ES as ES with respect to both the 1st content receiver 2a and the 2nd content receiver 2b. The same content data including may be transferred by multicast. In other words, each of the first content receiver 2a and the second content receiver 2b may select ES. In any case, the content transmitter 1 sends the video ES and the audio ES to the outside from one communication module such as a Wi-Fi module.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Content transmitter, 2 ... Content receiver, 2a ... 1st content receiver, 2b ... 2nd content receiver, 3 ... Audio | voice player.

Claims (6)

A connection means for connecting to a communication partner device in a method in which the transmission path is encrypted;
First encoding means for encoding video data displayed on a display;
Encryption means for encrypting the video data encoded by the first encoding means;
Second encoding means for encoding audio data output to the speaker;
Copyright information of the audio data is added to the information about the copyright protection of the video data, the audio data encoded by the second encoding means, and the audio data encoded by the second encoding means. Multiplexing means for generating multiplexed data including notification information including information about,
Content transfer means for transmitting the multiplexed data generated by the multiplexing means to the encrypted transmission path by wireless communication;
An electronic device comprising: The video data displayed on the display and the audio data output to the speaker are included in one content,
A discriminator for discriminating whether the content is copyright-protected content;
The encryption means encrypts the video data when it is determined that the content is copyright-protected content,
The multiplexing means generates the multiplexed data when it is determined that the content is copyright-protected content;
The electronic device according to claim 1.   When it is determined that the content is not copyright-protected content, the multiplexing means encodes the video data encoded by the first encoding means and the second encoding means. 3. The electronic apparatus according to claim 2, wherein second multiplexed data including the audio data thus generated is generated. Encode the video data displayed on the display,
Encrypting the encoded video data;
Encode the audio data output to the speaker,
Multiplexed data including the encrypted video data, the encoded audio data, and notification information including information related to copyright protection of the audio data in information related to copyright protection of the video data Produces
Sending the generated multiplexed data to the encrypted transmission path by wireless communication,
Content transfer method for electronic devices. The video data displayed on the display and the audio data output to the speaker are included in one content,
Determining whether the content is copyright-protected content;
Encrypting the video data means encrypting the video data when it is determined that the content is copyright-protected content,
Generating the multiplexed data generates the multiplexed data when it is determined that the content is copyright-protected content.
The content transfer method according to claim 4.   If the content is determined not to be copyright-protected content, generating the multiplexed data includes the encoded video data and the encoded audio data. The content transfer method according to claim 5, wherein multiplexed data is generated.

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