[FFmpeg-user] ffprobe -show_frames values

Anatol anatol2002 at gmail.com
Wed May 13 07:07:06 CEST 2015


Werner, can you please shortly explain the no-scenecut issue.
Without scenecut detection, if such event occurs in the middle of the GOP,
as it usually does, the video quality till the end of the GOP will be
rather compromised. It appears as a 'breathing effect'.
It is mostly stands out when a high quality video played on a large screen.
Is there a way to avoid such effects without scene cut detection?

Thanks,
Anatol

On Tue, May 12, 2015 at 4:45 PM, Christian Ebert <blacktrash at gmx.net> wrote:

> * Werner Robitza on Tuesday, May 12, 2015 at 15:10:07 +0200
> > On Tue, May 12, 2015 at 2:45 PM, Christian Ebert <blacktrash at gmx.net>
> wrote:
> >> * Nicolas George on Tuesday, May 05, 2015 at 17:28:33 +0200
> >>> As an additional note, the second solution if by far preferable,
> because
> >>> forcing the frame type too frequently ruins x264's bit allocation
> >>> algorithms.
> >>
> >> As per this thread elsewhere there are different opinions on
> >> that. Others say that no-scenecut is not adviseable because it
> >> obviously removes scene detection.
> >>
> >> Which one is it then:
> >>
> >> -force_key_frames
> >> or
> >> -x264opts keyint=xxx:no-scenecut
> >>
> >> ?
> >>
> >> Personally I got ok looking results both ways with various
> >> material.
> >
> > I'm currently involved in ITU-T standardization of a quality model for
> > adaptive streaming, and in our video sequences that we use for
> > (subjective user) tests, we've disabled scene cut detection
> > throughout, with good-looking results. Nothing unexpected.
>
> Thanks for confirming. IIRC I had trouble with (some) older x264
> versions and no-scenecut and had therefore worked with
> -force_key_frames for a while. But I cannot reproduce the problem
> with current x264, so I switched to x264opts with no-scenecut.
>
> --
> theatre - books - texts - movies
> Black Trash Productions at home: http://www.blacktrash.org
> Black Trash Productions on Facebook:
> http://www.facebook.com/blacktrashproductions
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>


More information about the ffmpeg-user mailing list