Audio and Video Subsystem Design and Implementation on Video IP Phone Platform Based on Davinci
|Course||Applied Computer Technology|
|Keywords||Davinci Visual telephone Audio driver Video driver|
Has been considerable progress with the development of the video signal processor , audio and video processing technology . The rising demand for audio and video communication , social good opportunity for the development of proprietary applications in the field of demand for visual communication and video conferencing to bring visual communications . Videophone use of PSTN and Ethernet data transmission deficiencies due to the PSTN bandwidth , Ethernet has become the only choice of high - quality communication videophone . Currently embedded processor frequency is generally not high in terms of performance , it is difficult to meet the high-quality real-time video communications , audio and video algorithms run need . In terms of design , the videophone generally use separate design of multi-chip , chip brought bad compatibility between design difficulty and high cost , and can not meet the high bandwidth board-level audio and video data transmission problem , resulting in real - time video telephony is not good , the audio quality is not high , and the high cost . This article Davinci processor and the VDP research and analysis on the basis of a Davinci 's IP videophone terminal . First of all , the by EDMA way transmission of audio and video data , using RAM - based caching mechanism to solve the problem of data transfer rate ; Secondly , the use of the advantage of its chip VPSS video processing , video processing part driven rewritten to achieve video capture and playback stage processing of video data to improve the efficiency of video capture and processing stages to improve the real-time nature of the videophone ; once again , rewriting and tuning drive external audio interface chip AIC32 audio mode a processing function of the digital conversion stage , in the acquisition phase , fine-tuning, improved audio quality ; Finally, through the external video capture interface chip TVP5146 driver to complete the adjustment of the video quality of the video analog to digital conversion stage , improved video capture video stage quality. After the actual test results show that the improved real-time video , basically meet the real-time requirements . Video playback resolution of the pseudo- D1 level , improved video quality compared to existing videophone . The audio quality is good , reach of ordinary MP3 playback .