[FFmpeg-user] Macroblock to pixel mapping

[Nathan Trevivian]

I would like to extract pixels associated with specific macroblocks in a
video frame.

I can extract macroblock types and identity if one is 8x16 rather than
16x16, for example, but how do I map from this information to the frame
pixels themselves?

When I extract the macroblock type information (using -debug mb_type), I'm
also confused as to why I don't see 8x16 macroblock types adjacent to one
another. I thought frames were first divided into 16x16 blocks, then
subdivided into, for example 8x16. Is this incorrect?

Thanks for any help offered!