[FFmpeg-user] What is the fastest way to run cropdetect onspecificframes in the video?

Matt Kim matthkim at gmail.com
Sun Jul 31 21:40:56 CEST 2011

Thanks for the reply!  I am very new to the video encoding scene, and
so I hope it's okay that I have a lot of questions.

On Sun, Jul 31, 2011 at 12:04 AM, Etienne Buira
<etienne.buira.lists at free.fr> wrote:
> I guess your input is mpegts, with wrapping timestamps. To solve this
> issue, please try attached patch. It is workable, but sometimes breaks
> trying to read the whole file and just quit when EOF is reached.

Yes, my input is mpegts.  I'm not sure if the timestamps are wrapped.
How would I know if the timestamps in my source video are wrapped?  I
will try to run your patch and see how it works and reply by Monday.

Another thing I might add is--I've tried running -ss before -i on
H.264 encoded videos, and quick seeking doesn't seem to work on these
files either.

What is the main reason for way -ss fails to seek instantly to a
specific time or frame?
>From what I understand, there is supposed to be some sort of reference
to I-frames at the beginning of the file--and if for some reason these
don't exist then FFmpeg will be unable to jump to the passed in
seektime.  I am not too sure how correct this statement is--and so any
advice or suggestion to outside references would be super helpful.

Matt Kim

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