[FFmpeg-user] issue with concat and seek

[Moritz Barsnick]

On Wed, Oct 19, 2016 at 17:17:20 +0200, Carles Vila wrote:
> Normal concat without seeking works just fine:
> ffmpeg -f concat -i list.txt -c copy output.mp4

You should probably be showing us list.txt. Actually, you should be
showing us the complete, uncut console output of your ffmpeg commands
as well.

> obviously updating the list.txt file,

Are you sure? You could extract input_2_nologos.mp4 image by image,
just to be absolutely sure, but ffmpeg should do the right thing.

> The logos are back! What am I doing wrong? Are the logos preserved, only
> hidden when seeking?

No, ffmpeg should actually cut with "-ss".

> Can I do the concat and seeking in one step?

Sure. The concat file takes per-file options such as "inpoint" and
"duration":
https://www.ffmpeg.org/ffmpeg-formats.html#Syntax
("inpoint" is a timestamp, and not an offset from the beginning, it
seems. I haven't tested the effects.)

Moritz