JP2002374298A - Transcoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transcoder that can properly convert a code quantity of stream data or the like, so as to be compatible with a band required for communication between a client and a server. SOLUTION: The transcoder is provided with a request processing means (1) that receives a streaming request from the client via a network, converts the streaming request and transmits the converted request to the server on behalf of the client, a reply processing means (2) that receives a reply with respect to the streaming request from the server, converts the reply and transmits the converted reply to the client, and a transcode processing means (3), that converts stream data from the server and transmits the converted data to the client in accordance with the information of the client and the server acquired by the streaming request and the reply, with respect to the request.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transcoder provided on a network.

[0002]

2. Description of the Related Art In the Internet, IETF (Internet Eng.), Which is promoting the development of technologies related to the Internet, is required for communication requiring strict time continuity.
ineering Task Force), Resource Reservati
A communication protocol called on (resource reservation)
RSVP).

In RSVP, a terminal (PC) or the like that wants to receive data requests a desired signal transmission band from a network (reservation) before starting a target communication. At this time, a relay node (router or the like) within the network determines a transmission band that can be provided, and relays the reserved band to the next relay node. This procedure is repeatedly executed, and finally this reserved band is transmitted to the target server.

[0004] As described above, when the bandwidth is secured between all the relay nodes, the server returns the secured bandwidth information to the terminal that has issued the reception request. The available signal transmission band is set. After this setting procedure, the terminal and the server can transmit and receive signals using the reserved transmission band.

Meanwhile, there is a technique called transcodec for converting the code amount of an image signal in order to transmit the image signal to transmission paths having different transmission signal bands.

[0006] The technology related to transcodec is
It is described in JP-A-7-59091 and JP-A-8-84339. In these transcodecs, data (bit strings) of input image signals
Is decoded into the original signal by the reverse method of encoding (for example, discrete cosine transform and inverse discrete cosine transform, etc.), and the coefficient of the decoded signal is truncated, or the quantization width is changed, so that the code amount is Has been converted.

[0007]

SUMMARY OF THE INVENTION However, RSV
In order to secure the bandwidth using P, all the relay nodes (routers, etc.) between the receiving terminal and the server that distributes images must be R
There is a problem that it is necessary to support SVP.

[0008] In addition, when the amount of remaining bandwidth in response to a future bandwidth securing request differs between relay nodes (routers, etc.), there are many opportunities where the bandwidth cannot be secured between the receiving terminal and the server that performs image distribution. There was a problem that.

Therefore, there is a need for a transcoder device that can appropriately convert the code amount of stream data and the like so as to correspond to the required bandwidth during communication between a client (terminal) and a server.

[0010]

In order to solve the above-mentioned problems, a transcoder device of the present invention (1) receives a streaming request of a client from a network,
Request processing means for converting the streaming request and transmitting the request to the server on behalf of the client;
(2) reply processing means for receiving a reply to the streaming request from the server side, converting the reply, and transmitting the reply to the client; and (3) the streaming request and the client obtained by replying to the streaming request. And transcoding processing means for converting stream data from the server according to the information and the content information of the server and transmitting the converted data to the client.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) First Embodiment A first embodiment of a transcoder according to the present invention will be described below with reference to the drawings.

(A-1) Configuration of First Embodiment FIG. 1 is a block diagram showing a functional configuration of a transcoder device of a first embodiment.

The transcoder device 101 includes an IP packet filtering unit 110, a request conversion unit 120, a request reception unit 121, a request transmission unit 122, a reply conversion unit 130,
Reply receiving section 131, reply transmitting section 132, transcodec section 140, data receiving section 141, data transmitting section 1
42 and a control unit 150.

The transcoder device 101 is connected to at least two or more networks (in FIG. 1, two networks N1 and N2 are shown).

The IP packet filtering unit 110 includes:
Receiving IP packets from the networks N1 and N2,
It filters P packets and sends IP packets from the request transmitting unit 122, the reply transmitting unit 132, the data transmitting unit 142, etc. to the corresponding networks N1 and N2.

The request receiving unit 121 uses the function of the IP packet filtering unit 110 to convert a client C (terminal; see FIG. 2) arriving via one network from a server existing on the other network (see FIG. 2).
This is to receive an IP packet determined to be a stream request to the server. The request conversion unit 120 includes a request reception unit 121
Is converted into a stream request from the transcoder apparatus 101 to the server. The request transmission unit 122 transmits the stream request converted by the request conversion unit 120.

The reply receiving unit 131 receives an IP packet determined by the IP packet filtering unit 110 to be a reply of a stream request from the server to the transcoder device 101. Reply converter 13
0 is for converting a stream request reply received by the reply receiving unit 131 into a stream request reply from the server to the client. The reply transmission unit 132 transmits a reply of the stream request converted by the reply conversion unit 130.

The data receiving section 141 receives an IP packet determined as stream data from the server to the transcoder 101 by the IP packet filtering section 110. The transcode unit 140 transcodes the stream data received by the data receiving unit 141. The data transmission unit 142 transmits the stream data transcoded by the transcodec unit 140.

The control section 150 controls each section such as the request conversion section 120, the reply conversion section 130, and the transcodec section 140. The control unit 150 also determines whether or not the transcoding unit 140 needs to convert (transcode) the stream data according to the information of the client and the server.

(A-2) Operation of First Embodiment FIG. 2 is a block diagram showing a configuration example of a network in which transcoder devices 101 (T1, T2) having the configuration shown in FIG. 1 are installed. .

The network shown in FIG. 2 includes video-on-demand (VOD) servers S1 to S3 and a provider N1.
1, N12, N21, N22, routers N1, N2, first
And the client C accesses the transcoder devices T1 and T2 of the third embodiment as appropriate.

Hereinafter, a procedure in which the client C, which is dial-up connected (64 kbps) to the provider N11, reproduces the stream with the code amount of 512K provided by the server S2 via the transcoder device 101 (T1). This will be described with reference to the sequence diagram of FIG.

<Process P100> First, in order for the client C to make a server information acquisition request to the server S2, the information of the client C (type of player, receivable code amount, etc.) is transmitted to the server S2. I do. For example, the following information of the client C is transmitted.

Player: MPEG PLAYER Ver. 7 Code amount: 65536 In the transcoder apparatus 101, the client C
The IP packet filtering unit 110 determines that the server information acquisition request transmitted from is a stream request,
The request is passed to the request receiving unit 121.

The request receiving section 121 uses the request converting section 120 to send a request from the transcoder apparatus 101 to the server S.
2 is converted to a request. The converted server information acquisition request is transmitted to the server S2 via the request transmission unit 122 and the IP packet filtering unit 110.

The control unit 150 determines that it is a request to acquire server information based on the content of the request received by the request receiving unit 121, and acquires the information of the client C that made the request.

<Processing P101> The server S2 receives the server information acquisition request from the transcoder device 101, and sends the content information of the server S2 to the transcoder device 101 in order to reply to the server information acquisition request. (Content control method and transmission means, audio control method and communication means, video control method, code amount,
Codec information). For example, the following content information is transmitted.

Content control: rtsp: // foo / twister Audio control: rtsp: // foo / twister / audio Audio communication: RTP Video control: rtsp: // foo / twister / video Video communication: RTP Code amount: 512 Codec: H999 In the transcoder device 101, the IP packet filtering unit 110 determines that a reply to the server information acquisition request transmitted from the server S2 to the transcoder device 101 is a reply of a stream request. Then, the information is passed to the reply receiving unit 131.

The reply receiving section 131 converts the reply from the server S2 to the client C by using the reply converting section 130, and the converted reply information is transmitted via the reply transmitting section 132 and the IP packet filtering section 110. , Sent to the client C. The client information necessary for transmission to the client C is transmitted to the control unit 1 in the process P100.
50 is acquired.

The control unit 150 determines that a server information acquisition request has been returned, and acquires the content information of the server S2.

As described above, when the control unit 150 acquires the information of the client C and the content information of the server S2, the control unit 150 transmits stream data from the server S2 to the client C based on the information.
Determine if transcoding is required. Hereinafter, a description will be given assuming that transcoding is determined to be necessary.

<Process P102> The client C receives the server information acquisition request reply, and in order for the client C to make an audio setup request to the server S2, an audio communication protocol and a port number of the client C are set. Is transmitted to the server S2.

In the transcoder device 101, the IP packet filtering unit 110 determines that the audio setup request transmitted from the client C is a stream request, and passes it to the request receiving unit 121.

The request receiving section 121 uses the request converting section 120 to transmit the request from the transcoder apparatus 101 to the server S.
2, and the converted audio setup request is transmitted to the server S2 via the request transmission unit 122 and the IP packet filtering unit 110.

The control unit 150 determines that the request is an audio setup request and waits for a reply to the request.

<Process P103> The server S2 receives the audio setup request from the transcoder device 101, and sends the request to the transcoder device 101.
To respond to an audio setup request,
The audio communication protocol and the port number of the server S2 are transmitted.

In the transcoder device 101, the IP packet filtering unit 110 determines that the reply to the setup request of the audio stream transmitted from the server S2 to the transcoder device 101 is a reply of the stream request, and the reply receiving unit. Hand over to 131.

The reply receiving section 131 converts the reply from the server S2 to the client C by using the reply converting section 130, and the converted reply is transmitted via the return transmitting section 132 and the IP packet filtering section 110. Sent to client C.

The control unit 150 determines that the audio setup request is returned, and determines the audio communication protocol,
The port numbers of the client C and the server S2 are obtained.

<Process P104> The client C receives the reply of the audio setup request, and sends the video communication protocol and the port number of the client C to the server S2 in order for the client C to make a video setup request to the server S2. Send to S2.

In the transcoder apparatus 101, the IP packet filtering unit 110 determines that the video setup request transmitted from the client C is a stream request, and passes it to the request receiving unit 121.

The request receiving section 121 uses the request converting section 120 to send the request from the transcoder 101 to the server S.
2 is converted into a request to the request transmitting unit 1.
22 and transmitted to the server S2 via the IP packet filtering unit 110.

The control unit 150 determines that the request is a video setup request, and waits for a reply to the request.

<Process P105> The server S2 receives the video setup request from the transcoder device 101, and sends a video communication protocol and the video communication protocol to the transcoder device 101 in order to return the video setup request. The port number of the server S2 is transmitted.

In the transcoder device 101, a reply to the video setup request transmitted from the server S2 to the transcoder device 101 is transmitted by the IP.
The packet filtering unit 110 determines that the stream request has been returned, and passes it to the reply receiving unit 131.

The reply receiving unit 131 converts the reply from the server S2 to the client C by using the reply converting unit 130, and the converted reply is transmitted via the reply transmitting unit 132 and the IP packet filtering unit 110. Sent to client C.

The control unit 150 determines that a video setup request has been returned, and acquires the video communication protocol and the port numbers of the client C and the server S2.

<Process P106> The client C receives the reply to the video setup request, and transmits a transmission start request for the client C to make a transmission start request for the stream to the server S2.

In the transcoder device 101, the IP packet filtering unit 110 determines that the transmission start request of the stream transmitted from the client C is a stream request, and passes it to the request receiving unit 121.

The request receiving section 121 uses the request converting section 120 to transmit the request from the transcoder apparatus 101 to the server S.
2, and the converted request is sent to the request transmitting unit 12
2 and the IP packet filtering unit 110,
Sent to server S2.

The control section 150 determines that the request is a stream transmission start request and waits for a reply to the request.

<Process P107> The server S2 receives the stream transmission start request from the transcoder device 101, and transmits a transmission start request reply to the transcoder device 101 in order to return the stream transmission start request. I do.

In the transcoder device 101, the IP packet filtering unit 110 determines the reply of the stream request transmitted from the server S2 to the transcoder device 101, and passes it to the reply receiving unit 131.

The reply receiving section 131 converts the reply from the server S2 to the client C by using the reply converting section 130, and the converted reply is transmitted via the reply transmitting section 132 and the IP packet filtering section 110, Sent to client C.

The control unit 150 determines that the transmission start request of the stream is returned, and the IP packet filtering unit 11
0, instructs to receive stream data with the acquired audio / video communication protocol and port number.

<Process P108> The IP packet filtering section 110 of the transcoder apparatus 101 determines that the stream data transmitted from the server S2 to the transcoder apparatus 101 is the stream data, and passes the stream data to the data receiving section 141.

The data receiving section 141 uses the transcodec section 140 and sends an instruction to the server
Based on the code amount and the codec information of the stream data of No. 2, the data is converted into stream data that can be reproduced by (the player of) the client C, and transmitted to the client C via the data transmission unit 142 and the IP packet filtering unit 110.

When the control unit 150 determines that transcoding is unnecessary, the stream data received by the data receiving unit 141 is transmitted from the data transmitting unit 142 as it is. The same applies to the second and third embodiments described later.

<Process P109> The client C transmits a transmission end request for making a request to end transmission of a stream to the server S2.

In the transcoder device 101, the IP packet filtering unit 110 determines that the transmission end request of the stream transmitted from the client C is a stream request, and passes it to the request receiving unit 121. The request receiving unit 121 converts the request from the transcoder device 101 into a request to the server S2 using the request converting unit 120, and the converted request is transmitted via the request transmitting unit 122 and the IP packet filtering unit 110, Sent to server S2.

The control unit 150 determines that the transmission of the stream is a request to end transmission, and enters a state of waiting for a reply.

<Process P110> The server S2 receives the stream transmission end request from the transcoder device 101, and the server S2 returns a transmission end request to the client C in order to respond to the stream transmission end request. To stop sending the stream.

In the transcoder device 101, a reply to the transmission end request of the stream transmitted from the server S2 to the transcoder device 101 is transmitted by the IP.
The packet filtering unit 110 determines that the request is a reply to the request for terminating the transmission of the stream, and passes the request to the reply receiving unit 131.

The reply receiving unit 131 converts the reply from the server S2 to the client C by using the reply conversion unit 130, and the converted reply is transmitted via the reply transmitting unit 132 and the IP packet filtering unit 110. Sent to client C.

The control unit 150 determines that the transmission of the stream has been completed, and releases the acquired information.

(A-3) Effect of First Embodiment As described above, according to the first embodiment, the transcoder device 101 (T1) is arranged on the route of the network between the client C and the server S2. Accordingly, even when the code amount of the stream from the server S2 and the code amount or the type of media received by the client C are different, the stream of the server S2 can be reproduced on the client C side by the conversion by the transcoder device 101. it can.

That is, the client C and the server S2
It is possible to easily secure a band between the two.

(B) Second Embodiment Next, a second embodiment of the transcoder device according to the present invention will be described with reference to the drawings.

(B-1) Configuration of the Second Embodiment FIG. 4 is a block diagram showing a functional configuration of the transcoder device of the second embodiment, which is different from FIG. 1 of the first embodiment. Identical and corresponding parts are denoted by corresponding reference numerals.

The transcoder 201 includes an IP packet filtering unit 210, a request conversion unit 220, a request reception unit 221, a request transmission unit 222, a reply conversion unit 230,
Reply receiving section 231, reply transmitting section 232, transcodec section 240, data receiving section 241, data transmitting section 2
42, code amount comparison unit 250, cooperation management unit 260, cooperation request reception unit 261, cooperation request transmission unit 262, and control unit 27
Has zero.

Here, the request converter 220 and the request receiver 2
21, request transmission unit 222, reply conversion unit 230, reply reception unit 231, reply transmission unit 232, transcodec unit 240, data reception unit 241, and data transmission unit 242
Perform the same function as the corresponding part of the first embodiment, and the description of the function is omitted.

The IP packet filtering section 210
This is almost the same as the first embodiment, but differs from the first embodiment in that the cooperation request is subjected to filtering.

The code amount comparison unit 250 compares the code amount of the stream from the server with the code amount received by the client C.

The cooperation request receiving section 261 receives a request for cooperation with another transcoder device 201.
The cooperation management unit 260 manages the cooperation request received by the cooperation request receiving unit 261. Cooperation request transmission unit 262
Transmits a reply to the cooperation request processed by the cooperation management unit 260.

As will be described later, the coordination is for cooperatively determining which transcoder device performs transcoding when a plurality of the transcoder devices exist on a route between a client and a server. This is the process.

The control section 270 controls each section. In the case of the second embodiment, the code amount comparison section 250,
The cooperation management unit 260, the cooperation request reception unit 261, the cooperation request transmission unit 262, and the like are also controlled, and the control unit 270
Also cooperates with these elements to determine which transcoder device performs the transcoding.

(B-2) Operation of the Second Embodiment Next, the operation of the transcoder device 201 of the second embodiment will be described by taking the following case as an example.

That is, in FIG. 2 described above, the client C that is dial-up connected (64 kbps) to the provider N11 is connected to the transcoder device T1 (201) and the transcoder device T of the second embodiment.
The operation of the transcoder device 201 according to the second embodiment will be described by taking as an example a case where a stream with a code amount of 512 K provided by the server S3 is reproduced via the second (201).

In the following description, the transcoder 201 of the second embodiment close to the client C will be described.
Is represented by T1, and the transcoder device 201 of the second embodiment that is close to the server S3 is represented by T2.

<Process P200> First, in order for the client C to make a server information acquisition request to the server S3, the information of the client C (type of player, amount of receivable code, etc.) is directed to the server S3. Send. For example, the following information of the client C is transmitted.

Player: MPEG PLAYER Ver. 7 Code amount: 65536 In the transcoder device T1 close to the client C, the IP packet filtering unit 210 judges that the server information acquisition request transmitted from the client C is a stream request, and passes it to the request receiving unit 221.

The request receiving unit 221 converts the request from the transcoder device T1 to the request to the server S3 using the request converting unit 220, and the converted request passes through the request transmitting unit 222 and the IP packet filtering unit 210. Is transmitted to the server S3.

The control unit 270 determines that the request is for obtaining server information, and obtains the information of the client C.

The transcoder device T close to the server S3
2, the IP packet filtering unit 210 determines that the server information acquisition request transmitted from the transcoder device T1 is a stream request from the transcoder device T1, and passes the request to the cooperation request receiving unit 261.

The cooperation request receiving section 261 is
0 is used to inquire with the coordination information, and coordination is not performed.
The server information acquisition request is passed through via.

<Process P201> The server S3 receives the server information acquisition request from the transcoder device T1, and sends a response to the server information acquisition request to the transcoder device T1. Transmits content information (content control method and transmission means, audio control method and communication means, video control method, code amount, codec information, etc.). For example, the following content information is transmitted.

Content control: rtsp: // foo / twister Audio control: rtsp: // foo / twister / audio Audio communication: RTP Video control: rtsp: // foo / twister / video Video communication: RTP Code amount: 512 Codec: H999 In the transcoder device T2, the IP packet filtering unit 210 transmits a reply to the server information acquisition request transmitted from the server S3 to the transcoder device T1, and the stream request to the transcoder device T1. And sends it to the cooperation request receiving unit 261.

The cooperation request receiving section 261 is
0 is used to inquire with the cooperation information, and since there is no cooperation information, the information that has passed through the transcoder device T2 is added.
It is transmitted to the transcoder device T1 via the P packet filtering unit 210.

In the transcoder device T1, the IP packet filtering unit 210 determines that a reply to the server information acquisition request transmitted from the server S3 to the transcoder device T1 is a reply of a stream request, and receives a reply. To the unit 231.

The reply receiving section 231 converts the reply from the server S3 to the client C by using the reply conversion section 230, and the converted reply is sent to the client via the reply transmitting section 232 and the IP packet filtering section 210. Sent to C.

Control unit 270 determines that a server information acquisition request is returned, and acquires the content information of server S3 and the information of other transcoder device T2.

As described above, when the control unit 260 obtains the information of the client C and the content information of the server S2, the control unit 260 transmits the stream data from the server S3 to the client C based on the information.
Determine if transcoding is required. Hereinafter, a description will be given assuming that transcoding is determined to be necessary. Note that the following comparison of the code amounts is also a cause of the determination.

<Process P202> Transcoder T
The code amount comparison unit 250 compares the code amount of the stream from the server S3 with the code amount receivable by the client C. Then, when the code amount receivable by the client C is small, an inquiry is made to the cooperation management unit 260. The cooperative management unit 260 determines that another transcoder device T2 exists on the path to the server S3, and thus transmits the other transcoder device T2 via the cooperative request transmission unit 262 and the IP packet filtering unit 201. Send a cooperation request to.

<Processing P203> Transcoder T
In 2, the IP packet filtering unit 210 determines that the cooperation request transmitted from the other transcoder device T1 to the transcoder device T2 is a cooperation request, and passes the cooperation request to the cooperation request receiving unit 261.

The cooperation request receiving section 261 is
0 accepts the cooperation request from the other transcoder device T1, and a reply of the cooperation request is transmitted to the other transcoder device T1 via the cooperation request transmitting unit 262 and the IP packet filtering unit 210.

In the transcoder device T1, the reply of the cooperation request transmitted from the other transcoder device T2 to the transcoder device T1 is transmitted by the IP.
The packet filtering unit 210 determines that the cooperation request is returned, and passes it to the cooperation request receiving unit 261.

The cooperation request receiving section 261 is
0 manages that the cooperation request has been accepted from another transcoder device T3.

This means that, of the two transcoder devices T1 and T3, both transcoder devices T1 and T3 have accepted that the transcoder device T3 close to the server S3 executes transcoding.

<Process P204> The client C receives the reply of the server information acquisition request, and sends the audio communication protocol and the port number of the client C to the server S3 in order to make an audio setup request to the server S3. Send to

In the transcoder device T 1, the IP packet filtering unit 210 determines that the audio setup request transmitted from the client C is a stream request, and passes it to the request receiving unit 221.

The request receiving unit 221 uses the request converting unit 220 to transmit the request from the transcoder device T1 to the server S3.
The request after the conversion is converted to the request
Is transmitted to the server S3 via the IP packet filtering unit 210.

Control unit 270 determines that the request is an audio setup request, and waits for a reply.

In the transcoder device T2, the IP packet filtering unit 210 determines that the audio setup request transmitted from the other transcoder device T1 is a stream request, and the request receiving unit 221
Pass to.

The request receiving section 221 uses the request converting section 220 to transmit the request from the transcoder apparatus T2 to the server S3.
To the request, and the converted request is sent to the request receiving unit 222.
Is transmitted to the server S3 via the IP packet filtering unit 210.

Control unit 270 determines that the request is for audio setup, and waits for a reply.

<Process P205> The server S3 receives the audio setup request from the transcoder device T2, and sends an audio communication protocol and server to the transcoder device T2 in order to return the audio setup request. The port number of S3 is transmitted.

In the transcoder device T2, a reply to the audio setup request transmitted from the server S3 to the transcoder device T2 is transmitted by the I
The P-packet filtering unit 210 determines that the stream request has been returned, and passes it to the reply receiving unit 231.

The reply receiving unit 231 converts the reply from the server S3 to the transcoder device T1 using the reply conversion unit 230, and the converted reply is transmitted to the reply transmitting unit 232 and the I
The packet is transmitted to the client C via the P packet filtering unit 210.

Control unit 270 determines that the audio setup request is returned, and determines the audio communication protocol,
The port numbers of the client C and the server S3 are obtained.

In the transcoder device T1, the IP packet filtering unit 210 sends a reply to the audio setup request transmitted from the transcoder device T2 to the transcoder device T1.
It is determined that the stream request has been returned, and is passed to the reply receiving unit 231.

The reply receiving section 231 converts the reply from the server S3 to the client C using the reply converting section 230, and the converted reply is transmitted via the reply transmitting section 232 and the IP packet filtering section 210. Sent to client C.

Control unit 270 determines that the audio setup request has been returned, and determines the audio communication protocol,
The port numbers of the client C and the server S3 are obtained.

<Process P206> The client C receives the reply of the audio setup request, and
The server transmits the video communication protocol and the port number of the client C to the server S3 to make a video setup request to the server S3.

In the transcoder device T1, the IP packet filtering unit 210 determines that the video setup request transmitted from the client C is a stream request, and passes it to the request receiving unit 221.

The request receiving section 221 uses the request converting section 220 to transmit the request from the transcoder device T1 to the server S3.
The request after the conversion is converted to the request
Is transmitted to the server S3 via the IP packet filtering unit 210.

Control unit 270 determines that a video setup request has been returned and waits for a response.

In the transcoder device T2, the video setup request transmitted from the other transcoder device T1 is transmitted to the IP packet filtering unit 21.
0 is determined to be a stream request and is passed to the request receiving unit 221.

The request receiving section 221 uses the request converting section 220 to transmit the request from the transcoder apparatus T2 to the server S3.
The request after the conversion is converted to the request
Is transmitted to the server S3 via the IP packet filtering unit 210.

Control unit 270 determines that a video setup request has been returned and waits for a response.

<Processing P207> The server S3 receives the video setup request from the transcoder device T2, and sends a video communication protocol and server to the transcoder device T2 in order to reply to the video setup request. The port number of S3 is transmitted.

In the transcoder device T2, the IP packet filtering unit 110 determines that the reply to the video setup request transmitted from the server S3 to the transcoder device T2 is a reply of the stream request, and the reply is received. To the unit 231.

The reply receiving section 231 uses the reply converting section 230 to convert the reply from the transcoder apparatus T2 to a reply to another transcoder apparatus T1. The data is transmitted to the client C (transcoder device T1) via the unit 110.

The control unit 270 determines that a video setup request has been returned, and obtains the video communication protocol and the port numbers of the client C and the server S3.

In the transcoder device T1, the IP packet filtering unit 210 determines that a reply to the video setup request transmitted from the transcoder device T2 to the transcoder device T1 is a stream request reply, It is passed to the reply receiving unit 231.

The reply receiving section 231 converts the reply from the server S3 to the reply to the client C by using the reply converting section 230, and the converted reply is transmitted via the reply transmitting section 232 and the IP packet filtering section 210. Sent to client C.

The control unit 270 determines that a video setup request is returned, and obtains the video communication protocol and the port numbers of the client C and the server S3.

<Process P208> The client C receives the reply to the video setup request, and transmits a transmission start request for making a stream transmission start request to the server S3.

In the transcoder device T 1, the IP packet filtering unit 210 determines that the transmission start request of the stream transmitted from the client C is a stream request, and passes it to the request receiving unit 221.

The request receiving section 221 uses the request converting section 220 to convert the request from the transcoder device T1 to the request to the server S3.
The packet is transmitted to the server S3 via the P packet filtering unit 210.

The control unit 270 determines that the request is a stream transmission start request, and waits for a reply.

In the transcoder device T2, the transmission start request of the stream transmitted from the other transcoder device T1 is transmitted to the IP packet filtering unit 21.
0 is determined to be a stream request and is passed to the request receiving unit 221.

The request receiving section 221 uses the request converting section 220 to transmit the request from the transcoder apparatus T2 to the server S3.
To the request, and the converted request is sent to the request receiving unit 222.
Is transmitted to the server S3 via the IP packet filtering unit 210.

The control unit 270 determines that the request is a stream transmission start request and waits for a reply.

<Process P209> The server S3 receives the stream transmission start request from the transcoder device T2, and transmits a reply to the stream transmission start request to the transcoder device T2.

In the transcoder device T2, the IP packet filtering unit 210 determines that a reply to the transmission start request of the stream transmitted from the server S3 to the transcoder device T2 is a reply of the stream request, and the reply is received. To the unit 231.

The reply receiving section 231 converts the reply from the transcoder apparatus T2 to a reply to another transcoder apparatus T1 using the reply converting section 230, and the converted reply is transmitted to the reply transmitting section 232 and the IP packet filtering. The data is transmitted to the client C via the unit 210.

The control unit 270 determines that the transmission start request of the stream is returned, and the IP packet filtering unit 21
0 is instructed to receive stream data using the audio / video communication protocol and port number.

In the transcoder device T1, the IP packet filtering unit 210 determines that a response to the transmission start request of the stream transmitted from the transcoder device T2 to the transcoder device T1 is a reply of the stream request. Then, the information is passed to the reply receiving unit 231.

The reply receiving section 231 converts the reply from the server S3 to the reply to the client C by using the reply converting section 230, and the converted reply is transmitted via the reply transmitting section 232 and the IP packet filtering section 210. Sent to client C.

The control unit 270 determines that the audio setup request is returned, and determines the audio communication protocol,
The port numbers of the client C and the server S3 are obtained.

The control unit 270 determines that a request for starting transmission of a stream is returned.

<Processing P210> Transcoder T
In 2, the IP packet filtering unit 210 determines that the stream data transmitted from the server S3 to the transcoder device T2 is stream data, and passes the stream data to the data receiving unit 241.

The data receiving section 241 uses the transcodec section 240 to convert the stream data reproducible by the player of the client C based on the code amount and the codec information of the stream data of the server S3 according to an instruction of the control section 270. The client C is converted via the data transmitting unit 242 and the IP packet filtering unit 210.
Send to

The transcoder device T1 performs a through process on the stream data directed to the client C.

<Process P211> The client C transmits a transmission end request for making a stream transmission end request to the server S3.

In the transcoder device T 1, the IP packet filtering unit 210 determines that the transmission end request of the stream transmitted from the client C is a stream request, and passes it to the request receiving unit 221. The request receiving unit 221 converts the request from the transcoder device T1 to the server S3 using the request converting unit 220, and the converted request is transmitted to the server S3 via the request transmitting unit 222 and the IP packet filtering unit 210. Sent to

The control unit 270 determines that the request is a stream transmission end request.

In the transcoder device T2, the transmission end request of the stream transmitted from the transcoder device T1 is sent to the IP packet filtering unit 210.
Determines that the request is a stream request, and passes the request to the request receiving unit 221.

The request receiving section 221 uses the request converting section 220 to transmit the request from the transcoder apparatus T2 to the server S3.
The request after the conversion is converted to the request
Is transmitted to the server S3 via the IP packet filtering unit 210.

Control unit 270 determines that the request is a transmission end request.

<Process P212> The server S3 receives the stream transmission end request from the transcoder device T2, and sends a transmission end request reply to the client C in order to respond to the stream transmission end request. , Stop sending the stream.

In the transcoder device T2, the IP packet filtering unit 210 determines that the reply to the transmission end request of the stream transmitted from the server S3 to the transcoder device T2 is a reply of the stream request, and It is passed to the receiving unit 231.

The reply receiving unit 231 converts the reply from the transcoder device T2 to the reply to the transcoder device T1 by using the reply conversion unit 230, and the converted reply is sent to the reply transmitting unit 232 and the IP packet filtering unit 210.
, And is transmitted to the client C.

The control unit 270 determines that the transmission of the stream transmission end request is returned.

In the transcoder device T1, the IP packet filtering unit 210 determines that a reply to the transmission end request of the stream transmitted from the transcoder device T2 to the transcoder device T1 is a reply of the stream request. To the reply receiving unit 231.

The reply receiving unit 231 converts the reply from the server S3 to the client C by using the reply converting unit 230, and the converted reply is transmitted via the reply transmitting unit 232 and the IP packet filtering unit 210. Sent to client C.

The control unit 270 judges that the transmission of the stream transmission request has been returned (B-3). Effect of the Second Embodiment As described above, according to the second embodiment, the network between the client and the server By arranging a plurality of transcoder devices on the route, the code amount of the stream from the server and the code amount received by the client are compared. If the client side is smaller, the transcoder device closer to the server transcodes. Thus, the bandwidth load of the network can be reduced.

(C) Third Embodiment Next, a third embodiment of the transcoder device according to the present invention will be described with reference to the drawings.

(C-1) Configuration of the Third Embodiment FIG. 6 is a block diagram showing the functional configuration of the transcoder device of the third embodiment. The same or corresponding parts as those in FIG. 4 according to the second embodiment are denoted by corresponding reference numerals.

The transcoder apparatus 301 includes an IP packet filtering section 310, a request conversion section 320, a request reception section 321, a request transmission section 322, a reply conversion section 330,
Reply receiving section 331, reply transmitting section 332, transcodec section 340, data receiving section 341, data transmitting section 3
42, code amount comparison unit 350, cooperation inquiry unit 360, cooperation management unit 370, cooperation request reception unit 371, cooperation request transmission unit 3
72 and a control unit 380.

Here, the IP packet filtering unit 3
10, request conversion section 320, request reception section 321, request transmission section 322, reply conversion section 330, reply reception section 331, reply transmission section 332, transcodec section 340, data reception section 341, data transmission section 342, code amount comparison Part 35
0, the cooperation management unit 370, the cooperation request reception unit 371, the cooperation request transmission unit 372, and the like perform the same functions as the corresponding parts of the first and second embodiments, and the description of the functions will be omitted.

The cooperative inquiry unit 360 inquires a management server (see FIG. 7) managing transcoder device information arranged on the network about another transcoder device 301 close to the server. is there.

The control section 380 controls each section including the cooperation inquiry section 360.

(C-2) Operation of Third Embodiment FIG. 7 is a block diagram showing a configuration example of a network in which transcoder devices 301 (T1 to T3) having the configuration shown in FIG. 6 are installed. . The network shown in FIG. 7 is also provided with a management server AS that manages position information and the like of transcoder devices arranged on the network.

Hereinafter, the client C dial-up connected (64 kbps) to the provider N11 transmits the code amount 512K provided by the server S2 via the transcoder device 301 (T1) and the transcoder device 301 (T3). The operation of reproducing the stream is described.

In the following, the transcoder device 301 near the client C is represented by T1, and the server S2
Is expressed by T3.

The operation is different from the second embodiment in the following two points.

(1) Transcoder device T3 to cooperate
Is not on the path to the server S2, the management server AS managing the transcoder device on the network is instructed to provide the cooperation inquiry unit 360 of the transcoder device T1.
Makes an inquiry and obtains the existence of the transcoder device T3 which cooperates.

(2) Transcoder device T3 to cooperate
Exists as one node (not a router) of the network, and thus operates as a PROXY device (connection proxy device).

Such a difference appears in the operation sequence up to the process P303 in FIG. Note that the processes after the process P304 are almost the same as those in the second embodiment, and thus the description thereof is omitted.

<Process P300> First, in order for the client C to make a server information acquisition request to the server S2, the information of the client C (type of player, receivable code amount, etc.) is transmitted to the server S2. .

In the transcoder device T1, the server information acquisition request transmitted from the client C is
The IP packet filtering unit 310 determines that the request is a stream request, and passes the request to the request receiving unit 321.

The request receiving section 321 uses the request converting section 320 to send the request from the transcoder device T1 to the server S2.
To the request, and the converted request is sent to the request transmitting unit 322.
Is transmitted to the server S2 via the IP packet filtering unit 310.

The control unit 380 determines that the request is to acquire server information, and acquires the information of the client C.

<Process P301> The server S2 receives the server information acquisition request from the transcoder device T1, and sends back the server information acquisition request to the transcoder device T1 in order to reply to the server information acquisition request. Transmits information (content control method and transmission means, audio control method and communication means, video control method, code amount, codec information, etc.).

In the transcoder device T1, the IP packet filtering unit 310 determines that a reply to the server information acquisition request transmitted from the server S2 to the transcoder device T1 is a reply of a stream request, and receives a reply. To the unit 331.

The reply receiving section 331 converts the reply from the server S2 to the client C by using the reply converting section 330, and the converted reply information is transmitted via the reply transmitting section 332 and the IP packet filtering section 310. , Sent to the client C.

Control unit 380 determines that a server information acquisition request has been returned, and acquires the content information of server S2. As described above, when the control unit 380 obtains the information of the client C and the content information of the server S2, when providing the client C with the stream data from the server S2 based on the information, the transcoding is performed. Determine if it is necessary. Hereinafter, a description will be given assuming that transcoding is determined to be necessary.

<Processing P302> Transcoder T
The code amount comparison unit 350 of No. 1 compares the code amount of the stream from the server S2 with the code amount receivable by the client C, and uses the cooperation inquiry unit 360 if the code amount receivable by the client C is small. Then, the management server AS, which manages the management information of the transcoder devices existing on the network, is inquired about the presence or absence of a transcoder device existing near the route to the server S2, and the transcoder device T3 Get the existence of In FIG. 8, the sequence at this time is omitted.

Since it is determined that the transcoder device T3 exists near the route to the server S2, the cooperation management unit 370 sends the transcoder device 372 and the IP packet filtering unit 301 to the transcoder device T3. A cooperation request is transmitted to T3.

<Processing P303> Transcoder T
In 3, the cooperation request transmitted from the transcoder device T1 to the transcoder device T3 is transmitted.
The IP packet filtering unit 310 determines that the request is a cooperation request, and passes it to the cooperation request receiving unit 371.

The cooperation request receiving section 371 is
0, the cooperation request from the transcoder device T1 is given and accepted, whereby a reply of the cooperation request is transmitted to the transcoder device T1 via the cooperation request transmission unit 372 and the IP packet filtering unit 310. .

In the transcoder device T1, the IP packet filtering unit 310 determines that the reply of the cooperation request transmitted from the transcoder device T3 to the transcoder device T1 is a reply of the cooperation request, and receives the cooperation request. Pass it to the unit 371.

The cooperation request receiving section 371 is
0 manages that the cooperation with the transcoder device T3 has been accepted.

This means that both transcoders T1 and T3 have accepted that the transcoder T3 close to the server S2 transcodes the stream data from the server S2. Note that when there is no relationship between the codes described above, transcoding is unnecessary (the same applies to the second embodiment).

The processes after the process P304 are almost the same as those in the second embodiment, and therefore detailed description is omitted, but the following points are different.

[0187] In the second embodiment, the cooperating transcoder device T2 exists on the path to the server S3.
In the third embodiment, the cooperating transcoder device T
3 does not exist on the route to the server S2 but exists near the server S2.

Therefore, in the case of the third embodiment, the transcoder device T1 needs to intentionally transmit a request to the server S2 to the cooperating translator device T3. On the other hand, in the case of the second embodiment, since the cooperating translator device T2 intercepts the request from the translator device T1 to the server S3, the transcoder device T1 may transmit the request to the server S3. That is, the operation of the destination IP address for the converted request is slightly different. The same applies to the reply.

(C-3) Effect of Third Embodiment As described above, according to the third embodiment, a plurality of transcoder devices are arranged on a network, and the locations of the transcoder devices are managed. By providing the management server, the code amount of the stream from the server is compared with the code amount received by the client. If the client side is small, the transcoder device closer to the server transcodes to reduce the network bandwidth load. be able to.

(D) Other Embodiments In the first embodiment, the transcoder device comprises:
Although described as a router existing on a path between a client and a server, the client has a function of designating a transcoder device as a PROXY device (connection proxy device), so that it can be applied to a transcoder device as a PROXY device. is there.

In the second and third embodiments, the case where the code amount of the stream from the server is smaller than the code amount receivable by the client in the code amount comparison unit has been described. Applicable to If the code amount of the stream from the server is larger than the code amount that the client can receive,
The transcoder device close to the client may execute the transcoding.

In the third embodiment, the case where the number of management servers is one has been described. However, it is also possible to reduce the load of inquiries to the management server by operating a plurality of master servers and operating as master / slave. .

[0193]

As described above, according to the transcoder apparatus of the present invention, (1) a client receives a streaming request from a network, converts the streaming request, and sends the request to a server on behalf of the client. Request processing means for transmitting; (2) reply processing means for receiving a reply to the streaming request from the server side, converting the reply, and transmitting the reply to the client; and (3) the streaming request or the streaming. Transcoding processing means for converting stream data from the server according to the client information and the server content information obtained by replying to the request and transmitting the stream data to the client, which is necessary for communication between the client and the server. Stream to accommodate bandwidth It can be converted code amount data and the like as appropriate.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a detailed configuration of a transcoder device according to a first embodiment.

FIG. 2 is an explanatory diagram of a position of a transcoder device according to the first and second embodiments in a network.

FIG. 3 is a sequence diagram illustrating a flow of a process according to the first embodiment.

FIG. 4 is a block diagram illustrating a detailed configuration of a transcoder device according to a second embodiment.

FIG. 5 is a sequence diagram illustrating a flow of a process according to a second embodiment.

FIG. 6 is a block diagram illustrating a detailed configuration of a transcoder device according to a third embodiment.

FIG. 7 is an explanatory diagram of a position in a network of a transcoder device according to a third embodiment.

FIG. 8 is a sequence diagram illustrating a flow of a process according to the third embodiment.

[Explanation of symbols]

101, 201, 301: transcoder device, 110, 210, 310: IP packet filtering unit, 120, 220, 320: request conversion unit, 121, 221, 321: request reception unit, 122, 222, 322: request transmission unit , 130, 230, 330 ... reply conversion unit, 131, 231, 331 ... reply reception unit, 132, 232, 332 ... reply transmission unit, 140, 240, 340 ... transcodec unit, 141, 241, 341 ... data reception unit , 142, 242, 342 ... data transmission unit, 150, 270, 380 ... control unit, 250, 350 ... code amount comparison unit, 260, 370 ... cooperation management unit, 261, 371 ... cooperation request reception unit, 262, 372 ... Link request transmission unit, 360 ... Link inquiry unit.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriyuki Sato 1-7-112 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Kiyoshi Fukui 1-7-112 Toranomon, Minato-ku, Tokyo F-term (reference) in Electric Industries Co., Ltd. 5C064 BA01 BA07 BB05 BC10 BC18 BC23 BD02 BD08 BD09 5K030 GA08 HA08 HB18 HB21 HC01 HD03 JA11 JL07 KA05 KA19 LB15 LE11

Claims (8)

[Claims] 1. A request processing means for receiving a streaming request from a client from a network, converting the streaming request, and transmitting the converted request to a server on behalf of the client, and receiving a reply to the streaming request from the server. And a reply processing means for converting the reply and transmitting the reply to the client; and converting the stream data from the server according to the streaming request and the client information and the server content information obtained by replying to the streaming request. And a transcoder for transmitting the data to the client. 2. The transcoder according to claim 1, further comprising control means for determining whether or not the transcode processing means should execute the conversion of the stream data. 3. A data filtering means for filtering the streaming request, the reply to the streaming request, and the reception data and the transmission data such as the stream data, and can be connected to two or more networks. 3. The transcoder device according to 1 or 2. 4. Between the client and the server,
Determine whether there is another transcoder device,
If present, manages where the other transcoder device is on the path, and manages the streaming request or reply to the streaming request with the other transcoder device in cooperation with the other transcoder device. The transcoder device according to any one of claims 1 to 3, further comprising a cooperation management unit for exchanging between the servers. 5. The system according to claim 4, further comprising a cooperative inquiry means for inquiring of said transcoder device capable of cooperating with a management server managing said transcoder device existing on the network. The transcoder device as described. 6. The transcoder according to claim 4, further comprising code amount comparing means for comparing a code amount of stream data from the server with a code amount receivable by the client. 7. The code amount comparing means when the code amount comparing means determines that the code amount of the stream data from the server is larger than the code amount receivable by the client, and wherein the other code managed by the cooperation managing means is provided. 7. The method according to claim 6, wherein the control unit causes the transcoder processing unit to perform stream data conversion when the transcoder device is closer to the server according to the position information of the transcoder device. Transcoder device. 8. The method according to claim 1, wherein the code amount comparing means determines that the code amount of the stream data from the server is smaller than the code amount receivable by the client, and wherein the other code managed by the cooperative management means. According to the position information of the transcoder device, when the transcoder device is close to the client, the control means:
7. The transcoder according to claim 6, wherein said transcoder performs conversion of stream data.