[FFmpeg-user] Image extraction broken with ffmpeg, but not with mencoder. How can I fix this?

Tom Evans tevans.uk at googlemail.com
Fri Sep 6 13:47:06 CEST 2013

On Fri, Sep 6, 2013 at 12:13 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> Tom Evans <tevans.uk <at> googlemail.com> writes:
>> What the image2 muxer produces as frame 100 is the
>> 100th frame of the CFR output. What the select filter
>> filters on is the 100th frame of the VFR input.
> But we do all agree that this is only true because of the
> specific command line?
> Because the select filter doesn't know anything about VFR
> or the input file, but only sees the frames that are
> output by the prior filter (which may be the fps filter).

Yes I agree, the select filter is filtering on the frames that are
delivered to it, it can only work that way, and the frames that it
sees depend upon whether frames are getting created or dropped by the
choice of vsync on the command line, the input file and the preceding



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