如何从mp4文件读取音频和视频数据包

Question

I am trying to write a code in c/c++ (objective c) to parse the audio and video data from mp4 file. I know that data in mp4 file contains under the mp4 atom but not sure how i can parse out the audio and video data separately.

Thanks in advance for any help.

Answer 1

Mp4 format is fairly complicated. I suggest you use a library. But if you can't use a library, or just wan to learn the format, Than you must parse about a dozen boxes or atoms under the root moov box. The information from there can be used to find frames within the mdat atom. The full specifications is numbered ISO/IEC 14496-12 You should be able to find a copy online.