[FFmpeg-user] Selecting/dropping frames without re-encoding

[Carl Eugen Hoyos]

2016-10-07 14:06 GMT+02:00 Moritz Barsnick <barsnick at gmx.net>:
> On Fri, Oct 07, 2016 at 13:07:53 +0200, Carl Eugen Hoyos wrote:
>> 2016-10-06 17:34 GMT+02:00 Moritz Barsnick <barsnick at gmx.net>:
>> > $ ffmpeg -r 25 -f concat -i concatscript.txt -c:v copy output.mxf
>>
>> This scales very badly, no?
>
> It's just a proof of concept. :) It scales nicely (linearly? or is

I don't think so or at least I accept it to be magnitudes slower
than using the symlinks.

> seeking more expensive the deeper you seek?), and works
> assuming you have CFR input and output, and you know
> those rates, and ... , and ...
> ;-)
>
> It "scales" better then writing every frame to disk and selecting
> every second one by symlinking. That's 180000 intermediate
> files plus 90000 symlinks for one hour of video.

> Then I'd rather have ffmpeg seek into the input file 90000 times.

But it actually opens the file 90000 times;-(

Carl Eugen