The project uses for reference the algorithm thought of sbc ( subband coding ) to measure off the audio to the corresponding frequency width and encode it by the different sensitivity of human hearing , which results in the lower coding rate and bearable voice quality . the algorithm processing low bit - rate audio is designed to be self - adaptive by the situation of network . the component developped by that algorithm and project has already been used in the realtime interactive educational system 该方案借鉴sbc ( subbandcoding )子带编码算法思想，将音频按对人听觉敏感程度不同划分为相应的频带并进行相应的编码，从而得到较低的编码率和较好的语音质量，设计了可根据网络状况进行自适应的低带宽音频处理算法。
For details below : 1 ) video changed from mpeg2 ps to mpeg2 ts 2 ) audio of ntsc format that can not be decoded by stb could be changed from dolby acs coding standard to mpeg1 / 2 layerll standard , and packed into mpeg2 ts format 3 ) well synchronized with audio and video by a new arithmetic " successive time stamp " this thesis made a introduction of mpeg2 standard in detail ; discussed the system timing model ; indicated the key during the transforming of video and audio ; especially explain how to deal with the pcr 2 )针对目前机顶盒不能解码的ntsc制式dolbyac3编码算法音频信息，转换成mpeg1 2layer编码，并打成满足mpeg2ts语法的信息包。 3 )提出了能使音视频达到良好同步的继承性时间标签打入算法本文详细介绍了mpeg2标准的语法，讨论了mpeg2系统的时间模型从而指出视音频处理中的关键，对pcr的处理进行了详细的分析，提出了新的视、音频同步算法。
This dissertation is concentrated on the design of ess decode project , which make use of mpeg decode ic ess6425 as the core supported by other ic cs4340 ( audio ic ) , gl811 ( usb 2 . 0 to ata / atapi bridge controller ) , etc . on the basis of the decode project , a multi - media mp4 hd player is designed with special features of convenient installment , competitive price and perfect performance 本研究以美国ess公司的mpeg专用解码芯片es6425为核心整合其他辅助芯片如cs4340 (音频处理芯片) , gl81 ( 1usb2 . 0toata / atapibridgecontroller )等,设计出一款mpeg - 4多媒体播放器,该播放器具有安装简单、价格低廉,功能全面等特点。
All - purpose conference room av amplification systems must handle audio in the forms of voice , music , movie soundtracks , singing ( for live performances ) , etc . , therefore the proper locations to install speakers , the power of the speakers , the number of microphones and audio channels must all be given serious consideration 多功能厅的音频扩声系统由于需要同时满足人声（会议） 、音乐播放声（电影播放） 、歌唱声（文艺演出）等多种需求，所以在音箱的合理安装位置、功率大小、话筒的数量、音频处理方面需要着重考虑。
