FFmpeg command with -ss option fails on .flv files

Question

I am using FFmpeg to extract screenshot from a video with the following command

/usr/bin/ffmpeg -ss 15 -y -i test.flv -vcodec mjpeg -vframes 1 -an -f rawvideo test.png

But the command fails. Last 3 lines of the response are

frame=    0 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=   0.0kbits/s
video:0kB audio:0kB global headers:0kB muxing overhead -nan%
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)

Note that command runs successfully for other video types (3gp, mp4).

Also, when I replace "-ss 15" option with "itsoffset 15" it runs successfully with flv files as well.

Does anybody know why -ss option doesn't work for .flv files?

-ss option is working for me: `ffmpeg -ss 5s -i input.flv -t 5s output.flv`, skips 5 seconds and gives me 5 seconds output video. but my ffmpeg is actually avconv. — jcomeau_ictx, May 05 '13 at 02:18

score 10 · Answer 1 · answered Oct 01 '13 at 00:11

10

In newer versions of ffmpeg the -ss and -t options must go after -i [filename].

answered Oct 01 '13 at 00:11

Soheil

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But note that the position of -ss can be either before or after -i, they serve different purposes. Read here for more: https://trac.ffmpeg.org/wiki/Seeking – TripleAntigen Dec 14 '14 at 03:18
Worked in `ffmpeg version 4.2.7-0ubuntu0.1 Copyright (c) 2000-2022 the FFmpeg developers` – JRichardsz Aug 06 '22 at 21:53

score 1 · Answer 2 · answered Jan 08 '13 at 13:39

It might be a syntax issue. The following should work just fine:

/usr/bin/ffmpeg -ss 15 -y -i test.flv -frames:v 1 -an test.png

Notice i removed the codec and the format parameters. I don't think it's wise to force mjpeg on a png continuer & flv is not a rawvideo format

score 0 · Answer 3 · answered Sep 23 '14 at 13:31

U need to set video format options (EX: -preset ultrafast -s 1366x768 -r 10 -b:v 555k -crf 45 -vcodec libx264 -threads 0 -pix_fmt yuv420p)

I had the same issue when was cutting part from video, -c:v copy simply gives mentioned warning and nothing happens.

FFmpeg command with -ss option fails on .flv files

3 Answers3