VC1 support fixes

There are two tricks to make VC1 decoding work:
1) VC1 sequence and entry point headers must be present in context->extradata.
2) video width and height must be known when opening decoder.

Some container formats store required extra data, but mpeg-ts does not.

1) is fixed by scanning the stream for headers and discarding all data until
proper headers are found.

2) is fixed by re-opening decoder with width and height information from
first open.

0 files changed, 0 insertions, 0 deletions