On Fri, May 16, 2025 at 7:05 PM Gabriel Hege <g+ffm...@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 @James Almer <jamr...@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-requ...@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-requ...@ffmpeg.org with subject "unsubscribe".
