Re: [FFmpeg-devel] [PATCH] avformat/movenc: fix VVC encoding with leading pictures

[Nuo Mi <nuomi2021@gmail.com>]

On Tue, May 27, 2025 at 10:52 PM Gabriel Hege <g+ffmpeg@hege.cc> wrote:

> On 25.05.25 04:08, Nuo Mi wrote:
> > On Thu, May 22, 2025 at 4:35 PM Gabriel Hege <g+ffmpeg@hege.cc> wrote:
> >
> >>
> >> On 17.05.25 04:26, Nuo Mi wrote:
> >>> On Fri, May 16, 2025 at 7:05 PM Gabriel Hege <g+ffmpeg@hege.cc> wrote:
> >>>
> >>>> This is a resubmission with a corrected commit message.
> >>>>
> >>>>
> >>>> The default behavior for VVenC (since v1.10.0) is to create an IDR
> with
> >>>> leading pictures for the first picture in decoding order (POC 32).
> This
> >>>> leads to FFmpeg generating an edit list with an empty entry, skipping
> >>>> the leading pictures.
> >>>>
> >>>> This patch fixes the calculation for the start_pts, while the DTS is
> >>>> negative (as produced by libvvenc).
> >>>>
> >>>>
> >>>> How to reproduce the issue (needs --enable-libvvenc and a recent
> >>>> libvvenc, e.g. v1.13):
> >>>>
> >>> Hi Gabriel,
> >>> Thank you for your patch. It addresses the MP4 issue, but it looks like
> >> MKV
> >>> has the same problem as well.
> >>
> >> Hi Nuo Mi,
> >>
> >> I'm sorry I don't really have an understanding of the MKV format. I had
> >> a quick look at the code, but the processing seems quite different and I
> >> didn't really find the corresponding code locations to fix the problem
> >> there.
> >>
> > Hi Gabriel,
> > Thank you for checking.
> > Could you help create a similar issue for MKV? Someone familiar with MKV
> > might pick it up.
>
> I filed a bug report: https://trac.ffmpeg.org/ticket/11611

Thank you. Gabriel
Applied.

>
>
>
> > Hi  James and all,
> > If no one objects, I’ll push this.
> >
> > Thank you.
> >
> >>
> >>
> >>> Hi @James Almer <jamrial@gmail.com> ,
> >>> Could you please take a look at the patch when you have a moment?
> You've
> >>> been the most active contributor to this file recently.
> >>>
> >>>>
> >>>> Encode VVC directly into MP4 container:
> >>>> ./ffmpeg -i /data/YUV/foreman_352x288_30Hz_i420_8.y4m -an -preset
> faster
> >>>> -vcodec vvc test.mp4
> >>>>
> >>>>      -> encodes 300 frames.
> >>>>
> >>>> Decode to YUV (or play back using ffplay):
> >>>> ./ffmpeg -i test.mp4 test.yuv
> >>>>
> >>>>      -> outputs 271 frames
> >>>>
> >>>> When dumping the mp4-structure using 'MP4Box -diso test.mp4', I see
> the
> >>>> following EditListBox, which skips the first couple of
> >>>> frames:<EditListBox Size="40" Type="elst" Version="0" Flags="0"
> >>>> Specification="p12" Container="edts" EntryCount="2">
> >>>> <EditListEntry Duration="1033" MediaTime="-1" MediaRate="1"/>
> >>>> <EditListEntry Duration="8967" MediaTime="18432" MediaRate="1"/>
> >>>> </EditListBox>
> >>>>
> >>>>
> >>>> With the fix applied 300 frames are decoded as expected and the
> >>>> EditListBox looks like this:
> >>>> <EditListBox Size="28" Type="elst" Version="0" Flags="0"
> >>>> Specification="p12" Container="edts" EntryCount="1">
> >>>> <EditListEntry Duration="10000" MediaTime="2560" MediaRate="1"/>
> >>>> </EditListBox>
> >>>> _______________________________________________
> >>>> ffmpeg-devel mailing list
> >>>> ffmpeg-devel@ffmpeg.org
> >>>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>>>
> >>>> To unsubscribe, visit link above, or email
> >>>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >>>>
> >>> _______________________________________________
> >>> ffmpeg-devel mailing list
> >>> ffmpeg-devel@ffmpeg.org
> >>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>>
> >>> To unsubscribe, visit link above, or email
> >>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >>
> >> _______________________________________________
> >> ffmpeg-devel mailing list
> >> ffmpeg-devel@ffmpeg.org
> >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>
> >> To unsubscribe, visit link above, or email
> >> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> >>
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".