[FFmpeg-user] Specifying Video Stream with V instead of v

Moritz Barsnick barsnick at gmx.net
Wed Nov 11 23:56:06 CET 2015

Hi Josh,

On Wed, Nov 11, 2015 at 13:15:37 -0700, Josh Marell wrote:
> the shortened video file which still displays the behavior (I dropped it
> all the down to 0.5s to make it super small but still display the error)

Perfect. I had to dig through the code with a lot of av_log()s added,
and figured out that these four streams (0:3 to 0:6) do match "-c:V"
although they shouldn't, because their "stream disposition" doesn't
have the property "attached_pic". (If they did, "-c:V" wouldn't match

To check for yourself, run "ffprobe -show_streams" and check for this
from each stream:


Apparently, the Matroska demuxer doesn't set this disposition. With
your source file, it doesn't handle the four picture streams as
"attachments", and therefore never gets to the code which sets this

I haven't gotten further than that. I don't know enough about Matroska
to say what the demuxer thinks is "attachments", and whether the
demuxer is doing something incorrectly, or whether the streams in your
file are marked incorrectly.

> I read on the mailing list page that uncompressed files are preferred, I
> wasn't sure about the shorter video file though, so I do hope it's ok I've
> included that too.

As small as all your files were: fine by me.


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