flv: Index the audio stream

And leverage the video index if the video is just disabled as wm4
did in an initial patch.
avcodec/mpeg12dec: print the amount of overread

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mpeg12dec: fix support for interlaced mpeg2 with missing last slice

Fixes Ticket3809

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'fa14804c83a7108a50c63d1f2180e30c75909529'

* commit 'fa14804c83a7108a50c63d1f2180e30c75909529':
  flv: Index the audio stream

Conflicts:
	libavformat/flvdec.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/dvdsub_parser: never return 0 when the input isnt 0

Fixes a infinite loop
Fixes Ticket3804

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>