[FFmpeg-user] frame by frame scrub h264/mov issues?

[Brice]

Thanks for the response guys.

Looks like the solution may have been a combo of both responses.

I upgraded to 2.8.3 and frame by frame scrubbing was better but still
slow.  At least QT didn't hang anymore.

Then I added the "expr:" prefix to the -force_key_frames option.  Looks
like Ryan was right and it defaults to the "Time" format rather than
expression.

The updated cmd looks like:

-force_key_frames expr: 1

This seems to work as intended and I can scrub frame by frame in pretty
much anything I play it in.  The only exception is the 64bit decoder in
Nuke.

I get the following error:  "FFmpeg Reader failed to find timing reference
frame, possible file corruption."

Works fine when I select the 32bit decoder though.





On Wed, Dec 9, 2015 at 6:50 AM, Moritz Barsnick <barsnick at gmx.net> wrote:

> Hi Brice,
>
> On Tue, Dec 08, 2015 at 16:02:50 -0800, Brice wrote:
>
> > ffmpeg -start_number 0000476 -f image2 -r 24 -i <PATH><SEQ>.%07d.jpg
> >  -vcodec libx264 -acodec libfaac -r 23.976 -qp 22 -pix_fmt yuv420p
> >  -movflags +faststart -force_key_frames 1 <PATH><QTNAME>.mov -y
>
> As Ryan pointed out, you are probably not using key frames correctly,
> and perhaps have only one keyframe in the whole output file. If you had
> attached the full uncut console output of your ffmpeg command, we
> perhaps could have identified that. Please always do so.
>
> OTOH, I tried for myself, and got more than one key frame, despite the
> command line argument.
>
> > ffmpeg version 2.3.2
>
> Please, first and foremost, try a new version of ffmpeg first. This one
> is 15 months old, and a lot of work goes into ffmpeg in the run of 15
> months. If your issue turns out to be a bug and not a usage issue, it
> would be annoying to have debugged such an outdated version of the
> tool.
>
> Moritz
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