[FFmpeg-user] Crop, Scale, Pad without distortion
Carl Eugen Hoyos
ceffmpeg at gmail.com
Tue Jan 28 00:04:52 EET 2020
Am Mo., 27. Jan. 2020 um 23:03 Uhr schrieb William Caulfield via
ffmpeg-user <ffmpeg-user at ffmpeg.org>:
> On Sun, Jan 26, 2020 at 7:28 PM Hans Carlson <forbyta at gmx.com> wrote:
> > On Mon, 27 Jan 2020, Carl Eugen Hoyos wrote:
> > > Am Mo., 27. Jan. 2020 um 03:27 Uhr schrieb Hans Carlson <forbyta at gmx.com
> > >:
> > >
> > >> Is 16/9 the correct value for setdar since that's what I want it to end
> > >> up to be?
> > >
> > > Apparently not but it is what you told us you'd like. (I did not
> > > calculate myself)
> > OK... perhaps I don't know WHAT dar I want. I plan to concat this video
> > to some others (using concat protocol or demuxer) and the other videos
> > have a DAR of 16:9, eg:
> > Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, top first),
> > 720x480 [SAR 32:27 DAR 16:9], Closed Captions, 29.97 fps, 29.97 tbr, 90k
> > tbn, 59.94 tbc
> > So, based on that, I assumed it would be a good idea to match the aspect
> > ration (720x480) and the DAR.
> > If the DAR value doesn't matter when concat'ing multiple files, then I
> > just
> > want the video to LOOK correct.
> > How do I calculate the correct dar (and/or sar) values to use?
> > _______________________________________________
> Your larger issues are all coming from the anamorphic aspects of PAL and
> NTSC. They are not "right" to begin with, but will play back at the correct
> resolution using DAR. You need to take the original PAL 720x576 4:3, trim
> it to 704x416, then resize it to 720x480 with 16/9 DAR. Then you can
> combine the two with the 16/9 DAR and they will play back correctly. (This
> is highly over-simplified without doing the math).
Hans wants to crop black bars so above will not (completely) work for him...
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