Decode and Playing Mpeg-2 Stream on PC Windows

After receiving the Mpeg-2 stream from the MOST network, the program should demultiplex the Mpeg-2 stream, which will separate the video and audio stream. The program feeds the audio stream to Mpeg-2 Audio Decoder and the video stream to Mpeg-2 Video Decoder, then output audio data to the DirectSound filter to play the sound and output video data to the Video Render filter to show the video on PC Windows. The block diagram is shown in Fig 4-24.

Fig 4-24 Decode and Play Mpeg-2 Streaming

The property of MOST Capture should be properly configured. As shown in Fig 4-25.

The channel number should be set to the value as the same as allocated channel number. The channel width should be set to 16 Bytes since the number of allocated channels is sixteen. Also the property of Mepg-2 Demultiplexer should be properly configured as shown in Fig 4-26. “stream_id” and “Content” of the output pins should follow Mpeg-2 standard [14] [15]. Fig 4-27 shows the picture of captured Mpeg-2 video.

Fig 4-25 MOST Capture Property Setting

Fig 4-26 Mpeg-2 Demultiplexer Property Setting

Fig 4-27 Picture of Mpeg-2 video

Chapter 5 Conclusion

The application of MOST technology in multimedia automobile network has been explored in this thesis. There are many benefits for adopting MOST technology instead of traditional vehicle bus system. Due to the high bandwidth requirement of the multimedia and integration of different protocols in car electronics, MOST defines a standard from the lowest hardware layer to the highest application layer to help car vendors to develop their own MOST devices. For speed consideration, MOST supports two physical transmission interfaces which are Plastic Optical Fiber (POF) and Unshielded Twisted Pair (UTP). The speed can reach 24.8Mbps with POF and 50Mbps with UTP. MOST also has flexibility in network topologies. It supports direct point-to-point, token ring, star, rings incorporating splitters connections. There can have up to sixty-four devices on each MOST network. This greatly reduces the connection overhead. In each MOST network, there is a timing master which generates a synchronous bit stream to provide the synchronization of the other timing slaves. To avoid the transmission overhead, MOST supplies resource share service.

Every node on the MOST network can simultaneously share resource from the single source. For example, a CD player can send the audio stream to two or more amplifiers to play the sound at the same time. MOST also supports Plug and Play, this provides the convenience of expansion and maintenance. MOST system supports a variety of data types such as control data, packet data and synchronous stream data to accommodate different transmission demands. The control data contains the control message which often indicates some operation of controlled device. The packet data contains the non-real-time information. The synchronous stream data is available for the real-time information like the audio or video stream. The asynchronous data and

synchronous data share the same bandwidth. The arrangement of bandwidth is controlled by the timing master. In the application level, MOST defines Function Blocks (FBlock) and Function (FktID)…etc. Function is used to control the device or access the property of the device. A function block contains a set of functions. A MOST device may contain several function blocks. Every device contains a mandatory function block called NetBlock which contains the functions that affects the entire device. For communication between devices, MOST defines MOST protocol. By MOST protocol, every device can exchange messages and data via the network services provided by the network layer. MOST defines several network services for management of the entire MOST network and data transmission. The MOST Supervisor Service (MSV) is used to manage the states of MOST device. The Control Message Service (CMS), Application Message Service (AMS), and Remote Control Service (RCS) are used to handle the control messages. The Synchronous Channel Allocation Service (SCS) and Transparent Channel Allocation Service (TCS) can manage the routing path of stream data. The Asynchronous Data Transmission Service (ADS) supports the transmission of packet data. The Transceiver Control Service provides the access the low level MOST Transceiver.

The application of MOST technology in this thesis uses only one part of MOST NetServices API. For other similar applications, we can extend our program by adding the PDA or the Bluetooth device like Wireless Mobile Hand Free Car Kit and applies it in the automobile environment.

REFERENCES

[1] Website of MOST Cooperation:

http://www.mostcooperation.com/technology/index.php

[2] 郭長祐, “車用電子之多媒體傳控網路：MOST 技術,” April 04, 2004 Website:

http://tech.digitimes.com.tw/ShowNews.aspx?zCatId=135&zNotesDocId=682

AC814E4CE9A048257156005C846C

[3] MOST Cooperation, “MOST Specification Framework Rev. 1.1,” 1999.

[4] MOST Cooperation, “MOST Specification Rev 2.2,” Nov. 2002.

[5] MOST Cooperation, “MOST NetServices: Application Socket, User Manual and Specification Rev1.10,” Jan. 23, 2004.

[6] MOST Cooperation, “MOST Function Catalog, V2.0,” Oct. 2000.

[7] MOST Cooperation, “OS 8104 MOST Network Transceiver, Final Product Data Sheet,” Sep. 2006

[8] Oasis SiliconSystems, “MOST NetServices Licensing Policy,” May 17, 2005.

http://www.smsc-ais.com/files/mostnetservices/PFL-MOSTNetServicesLicensing _V01_00_XX-1.pdf

[9] Oasis SiliconSystems, “MOST NetServices Layer 1 User Manual/Specification Rev. 1.10.x,” Jan 23, 2004.

[10] Oasis SiliconSytems, “DVDPlayer 4 MOST User Manual, V1.2.0,” Oct 13, 2003.

[11] Oasis SiliconSystems, “RadioTuner 4 MOST User Manual, V1.0.0,” August 22, 2003.

[12] Oasis SiliconSystems, “Amplifier Controller 4 MOST Advanced Product Data Sheet,“ Jun. 2003.

[13] Microsoft, “DirectX 9.0 Documentation for C++,“ 2002.

[14] ISO-13818, “Information Technology - generating coding of moving pictures and associated audio information - Systems, Second edition,” Dec. 1, 2000.

[15] Dr. Gorry’s web site:

http://erg.abdn.ac.uk/research/future-net/digital-video/mpeg2-trans.html.