[FFmpeg-devel] Extracting individual macroblocks H.264

[Marty Sullivan]

I am looking to write a program that will extract individual macroblocks
and motion vectors from an H.264 encoded video.

I've been able to extract the vectors but when it comes to matching them to
a specific macroblock and getting the data for that macroblock I am having
trouble. When I just pull blocks from an AVFrame, it doesn't seem to match
properly.

Some structs I've been looking at seem useful (H264Context and its
MotionEstContext) but I'm not quite sure how to use them. If I have an
AVCodec & AVCodecContext and *know* they are decoding an H.264 video
stream, how would I get these structures and how would I use them to
extract macroblocks?

Some advice or sample code would be phenomenal! Thanks!