Data parsing in Demuxer of container file(contains H.264 encoded bitstream)

[vikaskgp]

Hi,
I am searching for strategy which could be used to implement the demuxer,
I haven't found any document which could explain what should be the output of a demuxer especially for video stream.
I have found in my initial investigation that different-different container gives different data output after demuxing, my main focus is H.264. in some container i am getting sideband data separately from payload data but in other i don't.
Does Gstreamer spec  say anything about what should be data presentation after demuxing in case of container format.

Thanks.