consumer_avformat.c:

consumer_avformat.c:
- Convert to ffmpeg and AVOptions exclusively. This makes ALL AVOptions as seen from \'ffmpeg -h\' available to MLT. Instead of ffmpeg\'s \'-option value\' use inigo\'s property syntax \'option=value\"
- Add dual pass encoding.
- Use multi-threading even with non-threaded codecs by separating producer and consumer threads.
- Whitespace cleanup.

git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@1070 d19143bc-622f-0410-bfdd-b5b2a6649095