On Wed, Apr 3, 2024 at 8:02 AM Mark Filipak <[email protected]> wrote:
> Is there more to this? If there is, it's not evident to me. > > If there are several B-frames in a row, then adjust your mind to 'see' > larger shifts across the > multiple B-frames and adjust PTSs & DTSs to match. > > > Cutting off a leading open GOP: > <————open GOP————> <—————closed GOP——————> > PTS order [_I_][_B_][_P_][_B_][_I_][_B_][_P_][_B_][_P_][_I_] > __/ ___¦___/ ___¦___/ ___¦___/ ___¦___/ __/ > / / ¦ / ¦ / ¦ / ¦ / > DTS order [_I_][_P_][_B_][_I_][_B_][_P_][_B_][_P_][_B_][_I_] > X X X X > > PTS order [_I_][_B_][_P_][_B_][_P_][_I_] > __/ ___¦___/ ___¦___/ __/ > / / ¦ / ¦ / > DTS order [_I_][_P_][_B_][_P_][_B_][_I_] > > Cut on PTS, then fix up the 1st DTS & packet SCRs. > > Or, I don't think it's going to hurt anything to leave this: > PTS order [_I_][_B_][_P_][_B_][_P_][_I_] > _______/ ___¦___/ ___¦___/ __/ > / / ¦ / ¦ / > DTS order [_I_] [_P_][_B_][_P_][_B_][_I_] > and just fix-up the packet SCRs. > > ===== > Cutting off a leading closed GOP: > <—————closed GOP——————> <————open GOP————> > PTS order [_I_][_B_][_P_][_B_][_P_][_I_][_B_][_P_][_B_][_I_] > __/ ___¦___/ ___¦___/ __/ ___¦___/ ___¦___/ > / / ¦ / ¦ / / ¦ / ¦ > DTS order [_I_][_P_][_B_][_P_][_B_][_I_][_P_][_B_][_I_][_B_] > X X X X X > > PTS order [_I_][_B_][_P_][_B_][_I_] > __/ ___¦___/ ___¦___/ > / / ¦ / ¦ > DTS order [_I_][_P_][_B_][_I_][_B_] > > Just cut it and fix-up the packet SCRs. > > ===== > Cutting off a trailing GOP from a closed GOP: > <—————closed GOP——————> > PTS order [_I_][_B_][_P_][_B_][_P_][_I_].. > __/ ___¦___/ ___¦___/ > / / ¦ / ¦ > DTS order [_I_][_P_][_B_][_P_][_B_] > > Just cut at the end of the closed GOP. > > ===== > Cutting off a trailing GOP from an open GOP: > <————open GOP————> > PTS order [_I_][_B_][_P_][_B_][_I_].. > __/ ___¦___/ ___¦___/ > / / ¦ / ¦ > DTS order [_I_][_P_][_B_][_I_][_B_] > > PTS order [_I_][_B_][_P_][_B_][_I_] > __/ ___¦___/ ___¦___/ > / / ¦ / ¦ > DTS order [_I_][_P_][_B_][_I_][_B_] > > Cut retaining an ending I-frame, only. > > > Honestly, I don't know why the MPEG folks don't supply illustrations > instead of their torturous text. > > This isn't magic, it's Legos. > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
