[FFmpeg-user] Intent of -copyinkf and non-key frames in video stream copy

[Carl Eugen Hoyos]

Doug Handy <doug <at> doughandy.com> writes:

> If there is no initial key frame generated, what is 
> the value of using this option to include non-keyframes? 
> I'm trying now to understand the potential uses for the 
> -copyinkf option.

If your input video does not start with a keyframe, 
the option allows you not to start stream copying 
with the first keyframe (this is the defaul 
behaviour), but with the first frame of the 
input stream (no matter if it is a keyframe or 
not).

If you really want to know "why", please be assured 
that for every option (of the huge number FFmpeg 
provides) a user has once requested it.
(In the specific case of -copyinkf, it is also 
useful if you want to copy subtitles that are for 
some reason not marked as keyframes, but this is 
more a work-around than a feature.)

Carl Eugen