On Tue, Jun 18, 2024 at 12:00 AM Mark Filipak <markfilipak.i...@gmail.com> wrote:
> On 17/06/2024 17.18, Paul B Mahol wrote: > > On Mon, Jun 17, 2024 at 8:29 PM Mark Filipak <markfilipak.i...@gmail.com > > > > wrote: > > > >> On 17/06/2024 13.50, Paul B Mahol wrote: > >>> On Mon, Jun 17, 2024 at 5:35 PM Mark Filipak < > markfilipak.i...@gmail.com > >>> > >>> wrote: > >>> > >>>> On 17/06/2024 03.16, Paul B Mahol wrote: > >>>>> On Mon, Jun 17, 2024 at 3:16 AM Mark Filipak < > >> markfilipak.i...@gmail.com > >>>>> > >>>>> wrote: > >>>>> > >>>>>> To expand on my idea: > >>>>>> > >>>>>> The video is this: > >>>>>> I P B B P B B P B B I P B B.. > >>>>>> I want to change it to this: > >>>>>> I B B P B B P B B P I B B P.. > >>>>>> > >>>>> > >>>>> If this is what I think it is, your are wasting your time. > >>>> > >>>> It is possible. But can FFmpeg do it? You see, Paul, I read in several > >>>> places from seemingly > >>>> authoritative people that professional videos are PTS-ordered. I've > >> since > >>>> discovered that > >>>> professional videos are almost always DTS-ordered -- I now have a > packet > >>>> browser and have seen it to > >>>> be true. However, I have seen professional videos that are PTS-ordered > >> but > >>>> I didn't think too much > >>>> about it at the time. > >>> > >>> PTS order is order once frames are decoded and going to be presented to > >>> user, thats why it is called presentation timestamps. > >> > >> Yes of course. > >> > >>>> My idea is to take the 4-second video -- DTS-ordered -- that I sent to > >>>> trac, change it to > >>>> PTS-ordered, and see if '-vf showinfo' and '-f show_frames' respond > >>>> correctly. It's a long shot, but > >>>> it might show something useful -- what if PTS-order made showinfo > >>>> show_frames and framecrc all > >>>> agree? Wouldn't that be something interesting? > >>> > >>> If decoder follows specifications for decoding bitstreams correctly > than > >>> changing order of raw encoded frames as stored in bitstream will almost > >>> every-time cause broken decoding. > >>> > >>>>> Its nonsense to change order of encoded frames, no manipulation of > >> clock > >>>>> can fix that. > >>>> > >>>> No, no. Manipulation of PCR. Fix up the PCRs so that the result is > truly > >>>> PTS-ordered. > >>> > >>> If this is at format container layer, I dunno how would that work even > if > >>> its is possible to be useful. > >> > >> The container would contain a PES packet stream with PCRs like any other > >> PES packet stream. It would > >> work like any PTS-ordered stream does. You know, there _are_ PTS-ordered > >> streams. And you know, MPEG > >> is silent on the matter of what physical order frames are in the stream, > >> only that they must be > >> given to the decoder in DTS-order. > >> > >> Look, I agree that it would be nonsense. I want to turn the DTS-ordered > >> stream into a PTS-ordered > >> stream merely as a test: '-f show_frames' appears to be getting DTSes > and > >> PTSes mixed up, then > >> applying a fix that results in completely new DTSes. If it treats the > >> PTS-ordered stream > >> differently, that will say a lot. What is says depends on what it does. > >> Capiche? > >> > >> I thought I could do it by demuxing, then moving them like you can move > >> frames in a filter_complex, > >> and then remuxing, but I don't know how to do that to PES packets > (instead > >> of decoded pictures) and > >> I don't know how to rewrite PCRs. > >> > > > > But aren't you working with HEVC and not MPEG video? > > I'm working with AVC-M2TS, then transcoding-remuxing to HEVC-MP4. > > So you operate with bsf filters to create HEVC output? > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
