[Libav-user] reading video with multiple video streams

[Michael Bradshaw]

On Sun, Oct 21, 2012 at 2:24 AM, Svetlana Olonetsky
<svetlana.olonetsky at gmail.com> wrote:
> Hi,
>
> I am reading video files using ffmpeg in C++.
> I have some videos from users with multiple video streams.
>
> For example, running ffmpeg directly gives stream info:
> Stream #0:0: Video: mjpeg, yuvj420p, 640x480, 90k tbr, 90k tbn, 90k tbc
>     Metadata:
>       comment         : Movie/video screen capture
>     Stream #0:1(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 48000 Hz, stereo,
> s16, 192 kb/s
>     Stream #0:2(eng): Video: wmv3 (Main) (WMV3 / 0x33564D57), yuv420p,
> 640x480, 5500 kb/s, 29.97 tbr, 1k tbn, 1k tbc
>
> How can I figure out which video stream is Main ?

I'm not sure what the most appropriate method is, but I would probably
pick the stream with the longest duration. Stream 0:0 is probably just
a thumbnail/single frame, whereas stream 0:2 is probably an actual
video. Check AVStream.duration (if it's set).