Metadata Extractor for .avi, .mkv, .mp4 files

I working on metadata of various file formats,extraction of these metadata and changing these 开发者_如何学JAVAmetadata. I found some java libraries for these but I want to implement these metadata extractors in C.

Please somebody give me some advice for how to proceed for writing these extractors. I would be really happy if somebody can provide me good links regarding these also

I would suggest you take a look at libavformat, which is part of ffmpeg. It's a C library that parses essentially all important audio and video containers.

Here's the documentation: http://www.ffmpeg.org/documentation.html