Receive And Process The Data Stream Of China Mobile Multimedia Broadcasting Terminal

The appearance of television enriches people's life in a great degree, and plays a very important role in transmitting and developing human culture. With the changing of people's life style, we spend more and more time in journey, so developing communication technology to receive multimedia information anytime and anywhere becomes quite necessary. It realizes the dream of receiving multimedia information as you are moving. The state administration of radio film and television formulate the newly CMMB standard of mobile television, it can meet people's requirement well. CMMB is mainly applied in those which screen is smaller than 7 inches portable terminal such as mobile phone, digital camera, MP3, MP4, PDA and laptop. Thus users can receive TV program and relative service anytime and anywhere.Being an important part of CMMB system, portable digital TV terminal matters users'satisfaction, so developing it is the key skill of CMMB digital TV system. In the product development process, my mainly responsible is the CMMB terminal data stream receiving and process. The receiving of CMMB terminal platform data stream, that is, the driver system in terminal platform. This includes the development of I2C and SPI driver under embedded platform PXA270 (ARM_LINUX). Data output by baseband can be received by using interrupt mode of SPI. Using I2C driver program to control the chip of baseband, the function of changing channels and frequency sweeping can be achieved. Besides, aiming at PC platform, USB firmware has been developed, this achieves the function of uploading data stream and controlling of baseband. The control of PC to baseband is achieved through USB to I2C.Processing of data stream is parsing multiplexing frame output from baseband; this includes the analysis of controlling information form, video stream, audio stream and ESG. In the end, playable video stream of H.264 format and audio stream of AAC format is formed. Besides, configuration files of INI format are formed by GZIP decompressing and XML parsing of ESG, this can be showed in player. This parsing arithmetic can analyze multiplexing frame encapsulated by mode 1 and mode 2.