[FFmpeg-user] Extract all keyframes

Simon Thelen ffmpeg-user at c-14.de
Sat Jun 28 14:56:07 CEST 2014

On 27/06/14 at 18:54, Matthew Bondy wrote:
> Thanks Simon. Any suggested resource to learn more on this topic? Searching
> for encoding fps on google is not so helpful unfortunately with the
> ubiquity of those two terms.
I don't know of any documentation, but that value is just an indication
for how fast the encoding process is happening. ie if you wanted to
create a progress bar displaying current encoding progress and rate
you'd take the current number of frames as the position of the bar, the
total number of frames as the length of the bar and the encoding fps
would dictate how fast the bar moves.
> I have also noticed something about duplicate frames is displayed on the
> command line while the extraction of frames is in progress. The number of
> frames obtained is not consistent with the number of frames I expect from
> simple calculations. I tried increasing the precision of the specified
> frame rate (i.e. -r 17.1 instead of -r 17) but the result was worse in
> terms of the number of frames extracted/expected.
Can you attach your full command line and complete console output?
> When I bring the images into the other software I mentioned I observe a
> small shift in the data. Unfortunately, I am interested in some of the last
> frames so a progressive insertion of extra (or deletion) of frames stacks
> up against me.
I'd again need your command line to see exactly what you're trying to

Also, could you refrain from top-posting when you reply to this list?
It's considered rude.

Simon Thelen
I am looking for a honest man.
		-- Diogenes the Cynic

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