[Ffmpeg-devel] bug - movenc.c: Issues with multi-slice H.264 video

[Tyler Loch]

If ffmpeg is run with multiple threads (-threads n), it will create H.264 video
with multiple slices - one per thread. This is good.

When muxed into a .mov or .mp4 wrapper, the multi-slice video will crash
QuickTime Player (this is bad). The first frame will be displayed with the first
half (if two slices were used) intact, and the second half as "nothing" grey.

If x264.c is forced to use one thread (hard-coded variable or no "-threads"
flag), the video plays without incident. Also, if another program such as
mp4creator is used to mux a raw, multi-slice .h264 file to .mp4, that resulting
file will also play without incident.

Here are two samples. One multi-slice, one not:
http://www.isquint.org/onethread.mp4
http://www.isquint.org/twothreads.mp4

Thanks.

-Tyler Loch