[FFmpeg-user] FFMPEG | Error converting video to a thumbnail

[Cley Faye]

2016-05-28 18:34 GMT+02:00 C0nw0nk <c0nw0nks at googlemail.com>:

> ffmpeg.exe -y -analyzeduration 2147483647 -probesize 2147483647 -itsoffset
> -768 -i file.mp4 -vcodec mjpeg -vframes 1 -an -f rawvideo -s 178x100
> fileimage.jpg
>

​I'm still learning how to use ffmpeg efficiently, but I think you provide
way too much stuff in that command line if your intent is to only create a
single-frame jpeg from a video input.​
As far as I can tell, your input command works with "ffmpeg version
N-78990-g689211d".
Also, from your log, it seems that ffmpeg is struggling with your input
file:

> [h264 @ 000000000554b9e0] no frame!
> [mov,mp4,m4a,3gp,3g2,mj2 @ 0000000004e3d300] stream 0, offset 0x1e79f03:
> partial file
> file.mp4: Invalid data found when processing input


My guess here is that the file is incomplete/corrupt.

I have some question about your command line though, to help me understand
ffmpeg a bit more:
- the analyzeduration and probesize seems superfluous (for the video stream
in an mp4 file anyway). Are they really needed?
- itsoffset might not be as good as -ss performance wise. At least in the
version I use, -ss immediately seek the asked time, while itsoffset crawls
the file until it reach the timestamp requested (ignore this question if
the input doesn't start at 0...)
- "-f rawvideo" and "-vcodec mjpeg" seems also superfluous, as ffmpeg will
happily output to jpeg if given a jpeg filename