[FFmpeg-user] problems with IPB Frames

[Carl Eugen Hoyos]

Guido Holz <guido <at> sportograf.com> writes:

> When I do this
> 
> ffmpeg.exe -i tmp.mp4 -ss 00:00:04.0 -t 00:00:12.0 -y out.mp4
>
> should I get normaly  a piece of footage beginning with an I-Frame, right?

(Unrelated: For larger values of -ss, you want to specify 
seeking before the input file, the way you do it, all 
content before the specifed time value has to be decoded.)

Of course, since you are encoding and not remuxing.
I assume you wanted to write:
ffmpeg -ss 4 -i tmp.mp4 -codec copy -t 12 out.mp4

This provides an output file that starts with an I-frame 
here, if that is not true for you, please provide:
a sample
and
complete, uncut console output.

Please do not top-post here, it is considered rude.

Carl Eugen