PyFFmpegDemuxer or built-in demuxer, and why?

[allenling]

any tips/advice for when to use either of these two demuxers?

i ran samples/SampleDecode.py in both STANDALONE and BUILTIN mode, and both of them worked well.

it seems that a demuxer extracts the info, like width, height, format, etc, from the input source, and both of those demuxers are

able to do this task. and why two demuxers? and which one should i use?