CN102761526B - VC 1 encodes the method that video and audio is transmitted in the terminal unit supporting H.323 protocol suite - Google Patents

Abstract

The invention discloses a method for transmitting VC-1 coded video and audio in a terminal device supporting the H.323 protocol family, which includes the steps of: establishing a call flow between terminal device A and terminal device B based on the H.225 protocol; After the called terminal device B goes off-hook, a media negotiation about VC‑1 coded video and audio transmission is performed between the terminal device A and the terminal device B based on the H.245 protocol; according to the media negotiation result, the terminal device Perform VC‑1 coded video and audio transmission between A and the terminal device B. The method of the invention enables the terminal equipment to support VC-1 media transmission in the H.323 network, breaks the barrier that the original network media cannot transmit the VC-1 media, and makes it possible to integrate different network services.

Description

VC-1 coded video and audio are transmitted in terminal equipment supporting the H.323 protocol family method

technical field

The invention relates to a video and audio transmission method, in particular to a method for transmitting VC-1 coded video and audio in a terminal device supporting the H.323 protocol family.

Background technique

VC-1 (Video Codec 1, video coding 1 technology) is based on Microsoft Windows Media Video9 (WMV9) format, and proposed by Microsoft, a video coding standard released by the American Society of Motion Picture and Television Engineers SMPTE, the standard is MPEG2 After H.264, the latest recognized high-definition video coding format, this coding has the characteristics of small code stream, high versatility, low cost and less system resource occupation.

The H.323 standard protocol suite is a standard protocol stack of the International Telecommunication Union (ITU). According to the functional division, the H.323 protocol family can be divided into the following types of protocols: overall system framework (H.323), video codec (H.263, etc.), audio codec (H.723.1, etc.), system control ( H.245), data stream multiplexing (H.225), etc.

At present, the H.323 protocol family is widely used in the field of audio and video communication. However, the supported video protocols include H.261/H.263, which does not support Microsoft's VC-1 video coding method. Therefore, At present, it is impossible to transmit VC-1 encoded video and audio in terminal equipment supporting the H.323 protocol family, which brings great difficulties to the integration of different network services.

Contents of the invention

The purpose of the present invention is to provide a method for transmitting VC-1 encoded video and audio in terminal equipment supporting the H.323 protocol family. By this method, VC-1 can be freely transmitted between terminal equipment supporting the H.323 protocol family. Encode video and audio.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for transmitting VC-1 coded video and audio in a terminal device supporting the H.323 protocol family, characterized in that: it comprises steps:

Step 1: Establish a call flow between terminal equipment A and terminal equipment B based on the H.225 protocol;

Step 2: After the called terminal device B goes off-hook, media negotiation about VC-1 coded video and audio transmission is carried out between the terminal device A and the terminal device B based on the H.245 protocol;

Step 3: According to the media negotiation result, perform VC-1 encoded video and audio transmission between the terminal device A and the terminal device B;

in:

Both the terminal equipment A and the terminal equipment B support the H.323 protocol family;

In step 2, by specifying the corresponding parameters of VC-1 encoding in the TCS signaling and OLC signaling of the H.245 protocol, the capabilities of the terminal equipment A and terminal equipment B are expanded to define media negotiation The VC-1 capability set about the VC-1 capability in the process, so that the terminal equipment A and the terminal equipment B perform media negotiation on VC-1 transmission.

The advantages of the present invention are:

In the method of the present invention, by adding the corresponding parameters of VC-1 encoding in the TCS signaling and OLC signaling, the capabilities of the terminal equipment can be expanded to define the VC-1 capabilities in the media negotiation process. VC-1 capability set, so that the terminal equipment supporting the H.323 protocol family can support the media negotiation of VC-1 coded transmission, that is, a transmission VC-1 The mechanism of encoding video and audio enables terminal equipment supporting the H.323 protocol family to not only receive VC-1 encoded video and audio (for example, from an IP network), but also decode, restore and present video and audio media through the VC-1 decoder set by itself , Moreover, the VC-1 encoded video and audio can also be encoded by the VC-1 encoder set by itself, and the VC-1 encoded video and audio (for example, through an IP network) can be transmitted to other terminal devices supporting the H.323 protocol family for video and audio presentation.

The method of the invention enables the terminal equipment to support VC-1 media transmission in the H.323 network, breaks the barrier that the original network media cannot transmit the VC-1 media, and makes it possible to integrate different network services.

Description of drawings

Fig. 1 is the realization flowchart of the present invention;

Fig. 2 is a schematic diagram of an implementation process of an embodiment of the present invention.

detailed description

As shown in Figure 1, the method that VC-1 coded video and audio of the present invention transmits in the terminal equipment that supports H.323 protocol family comprises steps:

Step 1: Establish a call flow between terminal equipment A and terminal equipment B based on the H.225 protocol;

Step 2: After the called terminal device B goes off-hook, media negotiation about VC-1 coded video and audio transmission is carried out between the terminal device A and the terminal device B based on the H.245 protocol;

Step 3: According to the media negotiation result, perform VC-1 encoded video and audio transmission between the terminal device A and the terminal device B;

in:

Both the terminal equipment A and the terminal equipment B support the H.323 protocol suite, the H.323 protocol suite includes the H.225 protocol and the H.245 protocol, and the H.225 and H.245 protocols adopt abstract syntax notation (ASN. 1) to represent groupings of syntactic or structured data;

In step 2, by specifying the corresponding parameters of VC-1 encoding in the TCS signaling and OLC signaling of the H.245 protocol, the capabilities of the terminal equipment A and terminal equipment B are expanded to define media negotiation The VC-1 capability set of the VC-1 capability in the process, so that the terminal equipment A and the terminal equipment B can perform media negotiation on VC-1 transmission.

In step 2, the corresponding parameters of VC-1 encoding specified in TCS signaling and OLC signaling involve the identification (OID) of VC-1 encoding, the maximum bit rate when transmitting VC-1 encoding, and the maximum bit rate when transmitting VC-1 encoding. The bit stream syntax principle adopted and the codec algorithm adopted by VC-1 encoding; by specifying the corresponding parameters of VC-1 encoding in TCS signaling and OLC signaling, the VC-1 in terminal equipment A and terminal equipment B These parameters representing VC-1 capabilities are correspondingly added to the 1 capability set, and these parameters appear in the VC-1 capability set in the form of a list. Furthermore, TCS signaling specifies how to define VC-1 capabilities during media negotiation in the H.323 network, and a VC-1 capability set is a list containing one or more VC-1 capabilities.

For example, three transmission types can be set in the VC-1 capability set—simple, main, and advanced. These three transmission types correspond to different bitstream syntax principles and different codec algorithms, and are suitable for different application scenarios. Among them: simple is applied to low-bit-rate environment, has low-complexity algorithm, and the maximum bit rate is 384kbps; main is applied to high-bit-rate environment, such as streaming transmission and TVOverIP, this method trades higher complexity for improved high Compression efficiency; while advanced is designed for broadcast applications, such as digital TV, HD-DVD or HDTV, the maximum bit stream is 135Mbps, and the video is almost losslessly encoded. For each transport type, a series of levels can be defined, identifying properties of the syntax rationale, such as bit rate and buffer size, etc. For example, set simple to include 2 levels, main to include 3 levels, and advanced to include 5 levels.

In actual implementation, the identification of VC-1 encoding in TCS signaling and OLC signaling, the maximum bit rate when transmitting VC-1 encoding, the bit stream syntax principle used when transmitting VC-1 encoding, and the VC-1 encoding The setting of the codec algorithm used can be determined according to the actual transmission needs. By setting these parameters, a mechanism for transmitting VC-1 can be established between terminal equipment that transmits VC-1 coded video and audio, so that the terminal equipment VC-1 coded video and audio transmission is carried out according to the set transmission mechanism of VC-1.

In actual implementation, Step 1 specifically includes the following steps:

Step 1: Terminal device A establishes a TCP (TCP, Transmission Control Protocol, Transmission Control Protocol) connection to terminal device B;

Step 2: terminal device A sends a call signaling SETUP message to terminal device B, indicating that a call is initiated;

Step 3: After receiving the SETUP message sent by terminal device A, terminal device B sends a provisional response message CALLPROCEEDING to terminal device A;

Step 4: terminal device B sends the ringing message ALERTING to terminal device A;

Step 5: After terminal device B goes off-hook, it sends a CONNECT message to terminal device A.

In actual implementation, Step 2 specifically includes the following steps:

Step 6: Establish a logical channel TCP connection based on the H.245 protocol between the terminal device A and the terminal device B;

Step 7: Terminal device A and terminal device B send TCS/TCSACK signaling to each other (TCS, TerminalCapability Set, terminal capability set; TCSACK, Terminal Capability Set ACKnowledge, terminal capability set approval), where:

Terminal device A and terminal device B inform each other about the ability to receive and send VC-1 coded video and audio through TCS signaling; if both terminal devices A and B have the function of receiving and sending VC-1 coded video and audio, the terminal Devices A and B send TCSACK messages to each other and enter the next step; if one or both of terminal devices A and B do not have the function of receiving and sending VC-1 encoded video and audio, then terminal devices A and B send mutual TCSReject signaling and call release message, abandoning VC-1 encoded video and audio transmission operations;

Step 8: MSD/MSDACK signaling (MSD, Master Slave Determination, master-slave decision; MSDACK, Master Slave Determination ACKnowledge, master-slave decision approval) is sent between terminal device A and terminal device B to determine the media negotiation priority;

Step 9: Terminal device A and terminal device B send OLC/OLCACK signaling to each other (OLC, Open LogicChannel, open logical channel; OLCACK, Open Logic Channel ACKnowledge, open logical channel recognition), through the information transmitted in the OLC signaling VC-1 encoded parameters to determine the media negotiation result, the media negotiation result includes video and audio encoding mode, media logical address and port.

In actual implementation, step three specifically includes the following steps:

Step 10: Terminal devices A and B open the video and audio channels, and send the VC-1 encoded video and audio compressed and encoded by their respective encoders to the other party as RTP media streams according to the media logical address and port provided by the other party, and receive the other party The sent RTP media stream (that is, VC-1 encoded video and audio) is decoded and presented on the corresponding video and audio I/O device.

The H.323 protocol family stipulates that audio and video packets must be encapsulated in RTP (RTP, Real Time Protocol, real-time protocol), and carried by a UDP Socket pair at the sending end and the receiving end, while the real-time control protocol RTCP uses to evaluate session and connection quality, and to provide feedback between communicating parties. In the present invention, please refer to RFC 4425 for the RTP encapsulation of VC-1 encoding, which is a known technology and will not be described in detail here.

That is to say, for terminal devices A and B that do not need to register with the gatekeeper (GK, Gatekeeper) or gateway, after the above steps 1-10, the H.323 network connection between terminal devices A and B can be realized. VC-1 encoded video and audio transmission.

For terminal equipment A and terminal equipment B registered on the gatekeeper or gateway, it is necessary to add terminal authentication and routing confirmation steps in step 1. The specific implementation is shown in Figure 2:

Step 101: terminal device A initiates an ARQ request (ARQ, Admission Request, access request) to the gatekeeper/gateway based on the H.225 protocol (ie RAS, Registration, Admission and Status, registration, access, status management);

Step 102: the gatekeeper/gateway sends the call permission signaling ACF (ACF, AdmissionConfirmation, access confirmation) to the terminal equipment A;

Step 103: terminal device A establishes a TCP connection to terminal device B;

Step 104: terminal device A sends a call signaling SETUP message to terminal device B, indicating that a call is initiated;

Step 105: after terminal device B receives the SETUP message sent by terminal device A, it sends a provisional response message CALLPROCEEDING to terminal device A;

Step 106: terminal device B sends an ARQ request message to the gatekeeper/gateway;

Step 107: the gatekeeper/gateway authenticates the terminal equipment B, if the authentication is passed, then responds to the ACF to the terminal equipment B (if the authentication fails, then terminates the operation, and abandons the VC-1 encoded video and audio transmission operation);

Step 108: terminal device B sends a ringing message ALERTING to terminal device A;

Step 109: after terminal device B goes off-hook, send a CONNECT message to terminal device A;

Step 110: Establish a logical channel TCP connection based on the H.245 protocol between the terminal device A and the terminal device B;

Step 111: Terminal device A and terminal device B send TCS/TCSACK signaling to each other, wherein: terminal device A and terminal device B tell each other the ability to receive and send VC-1 encoded video and audio through TCS signaling; if the terminal Both devices A and B have the function of receiving and sending VC-1 encoded video and audio, then terminal devices A and B send TCSACK messages to each other and enter the next step (however, if one or both of terminal devices A and B do not have The function of receiving and sending VC-1 coded video and audio, then terminal equipment A and B send TCSReject signaling and call release messages to each other, and give up the VC-1 coded video and audio transmission operation);

Step 112: MSD/MSDACK signaling is sent between terminal equipment A and terminal equipment B to determine the media negotiation priority;

Step 113: Terminal device A and terminal device B send OLC/OLCACK signaling to each other, and determine the media negotiation result through the parameters about VC-1 encoding transmitted in the OLC signaling. The media negotiation result includes video and audio coding methods, Media logical address and port;

Step 114: Terminal devices A and B open the video and audio channels, and send the VC-1 encoded video and audio after compression and encoding by their respective encoders to the other party as RTP media streams according to the media logical address and port provided by the other party, and receive the video and audio from the other party The sent RTP media stream (that is, VC-1 encoded video and audio) is decoded and presented on the corresponding video and audio I/O device, thus completing the VC-1 encoded video and audio between terminal devices A and B transmission.

The advantages of the present invention are:

In the method of the present invention, by adding the corresponding parameters of VC-1 encoding in the TCS signaling and OLC signaling, the capabilities of the terminal equipment can be expanded to define the VC-1 capabilities in the media negotiation process. VC-1 capability set, so that the terminal equipment supporting the H.323 protocol family can support the media negotiation of VC-1 coded transmission, that is, a transmission VC-1 The mechanism of encoding video and audio enables terminal equipment supporting the H.323 protocol family to not only receive VC-1 encoded video and audio (for example, from an IP network), but also decode, restore and present video and audio media through the VC-1 decoder set by itself , Moreover, the VC-1 encoded video and audio can also be encoded by the VC-1 encoder set by itself, and the VC-1 encoded video and audio (for example, through an IP network) can be transmitted to other terminal devices supporting the H.323 protocol family for video and audio presentation.

The method of the invention enables the terminal equipment to support VC-1 media transmission in the H.323 network, breaks the barrier that the original network media cannot transmit the VC-1 media, and makes it possible to integrate different network services.

The above are preferred embodiments of the present invention and the technical principles used therefor. For those skilled in the art, without departing from the spirit and scope of the present invention, any equivalent based on the technical solution of the present invention Obvious changes such as conversion and simple replacement all fall within the protection scope of the present invention.

Claims (5)

1. the method that a VC-1 coding video and audio is transmitted in the terminal unit supporting H.323 protocol suite, it is characterised in that: it Including step:

Step one: set up call flow between terminal unit A and terminal unit B based on H.225 agreement；

Step 2: after called this terminal unit B off-hook, based on H.245 agreement at this terminal unit A and this terminal unit B Between carry out about VC-1 coding video and audio transmission media negotiation；

Step 3: according to media negotiation result, performs VC-1 coding video and audio and passes between this terminal unit A and this terminal unit B Defeated operation；

Wherein:

This terminal unit A, terminal unit B all support H.323 protocol suite；

In step 2, by the relevant parameter of VC-1 coding being advised in the TCS signaling of H.245 agreement and OLC signaling Fixed, make this terminal unit A, terminal unit B institute with capability set in expand and define in media consultation process about VC-1 ability VC-1 capability set so that between this terminal unit A and this terminal unit B to VC-1 transmission carry out media negotiation；

In step 2, in this TCS signaling and OLC signaling, the relevant parameter of the VC-1 coding of regulation relates to the mark of VC-1 coding Know, transmission VC-1 coding time Maximum Bit Rate, transmission VC-1 coding time the bitstream syntax principle that used and VC-1 compile The encoding and decoding algorithm that code uses；

By specifying the relevant parameter of VC-1 coding in this TCS signaling and OLC signaling, this terminal unit A, terminal set Adding, in VC-1 capability set in standby B, these parameters representing VC-1 ability accordingly, these parameters occur in tabular form In VC-1 capability set.

2. the method that VC-1 coding video and audio as claimed in claim 1 is transmitted in the terminal unit supporting H.323 protocol suite, It is characterized in that:

Described step one includes step:

Step 1: described terminal unit A sets up the TCP of described terminal unit B and connects；

Step 2: described terminal unit A sends call signaling SETUP message to described terminal unit B, represents and initiates calling；

Step 3: after described terminal unit B receives the SETUP message that described terminal unit A transmission comes, sends Temporary Response and disappears Breath CALLPROCEEDING to described terminal unit A；

Step 4: described terminal unit B sends ALERTING message ALERTING to described terminal unit A；

Step 5: after described terminal unit B off-hook, transmission CONNECT message to described terminal unit A.

3. the method that VC-1 coding video and audio as claimed in claim 1 is transmitted in the terminal unit supporting H.323 protocol suite, It is characterized in that:

Described step 2 includes step:

Step 6: set up logical channel TCP based on H.245 agreement between described terminal unit A with described terminal unit B and be connected；

Step 7: described terminal unit A and described terminal unit B mutually sends TCS/TCSACK signaling, wherein:

By TCS signaling, described terminal unit A, described terminal unit B tell that the other side's local terminal encodes about receiving and send VC-1 The ability of video and audio；If described terminal unit A and B is owned by receiving and sending the function of VC-1 coding video and audio, then described Terminal unit A and B sends mutually TCSACK message, and enters next step；If the side in described terminal unit A and B or Two sides do not have the function receiving and sending VC-1 coding video and audio, send mutually between the most described terminal unit A and B TCSReject signaling and call release message, abandon VC-1 coding video and audio transmission operation；

Step 8: send MSD/MSDACK signaling between described terminal unit A and described terminal unit B, to determine that media negotiation is excellent First weigh；

Step 9: send mutually OLC/OLCACK signaling between described terminal unit A and described terminal unit B, by OLC signaling The parameter about VC-1 coding of middle transmission determines media negotiation result, and this media negotiation result includes video encoding side Formula, media logic address and port.

4. the method that VC-1 coding video and audio as claimed in claim 1 is transmitted in the terminal unit supporting H.323 protocol suite, It is characterized in that:

Described step 3 includes step:

Step 10: described terminal unit A and B opens audio channel and video channel, the media logic address provided according to the other side and port, will VC-1 coding video and audio after each encoder is compressed and encodes to the other side with RTP media stream, and receives the other side and sends out The RTP Media Stream sent, and be decoded process after be presented on corresponding video and audio I/O equipment.

5. the method that VC-1 coding video and audio as claimed in claim 2 is transmitted in the terminal unit supporting H.323 protocol suite, It is characterized in that:

If described terminal unit A and described terminal unit B is registered on gatekeeper or gateway, then increase eventually in described step one End certification and route confirm step, particularly as follows:

Following steps are increased: described terminal unit A initiates ARQ based on H.225 agreement and asks gatekeeper/net before described step 1 Close；Gatekeeper/gateway sends call admission signaling ACF to described terminal unit A；

Following steps are increased: described terminal unit B sends ARQ request message to gatekeeper/net between described step 3 and step 4 Close；Described terminal unit B is authenticated by gatekeeper/gateway, if certification is passed through, then responds ACF to described terminal unit B, as Really certification is not passed through, then terminate operation, abandons VC-1 coding video and audio transmission operation.