[FFmpeg-devel] [PATCH] lavf/img2dec: add ppm pipe demuxer

[Michael Niedermayer]

On Fri, Jun 10, 2016 at 03:34:28PM +0200, Clément Bœsch wrote:
> On Fri, Jun 10, 2016 at 04:28:55AM +0200, Michael Niedermayer wrote:
> > On Thu, Jun 09, 2016 at 04:35:02PM +0200, Clément Bœsch wrote:
> > > On Thu, Jun 09, 2016 at 03:59:30PM +0200, Clément Bœsch wrote:
> > > > On Thu, Jun 09, 2016 at 01:35:19PM +0000, Carl Eugen Hoyos wrote:
> > > > > Clément Bœsch <u <at> pkh.me> writes:
> > > > > 
> > > > > > +            if (b[3] == '#')
> > > > > > +                return AVPROBE_SCORE_EXTENSION + 1;
> > > > > > +            if (b[3] >= '0' && b[3] <= '9')
> > > > > > +                return AVPROBE_SCORE_MAX - 1;
> > > > > 
> > > > > Imo, this should be:
> > > > > if (b[3] == '#' || (b[3] >= '0' && b[3] <= '9'))
> > > > >   return AVPROBE_SCORE_EXTENSION + 2;
> > > > > or similar
> > > > > 
> > > > > I count 37 and 34 bits which is only a little more than 
> > > > > the usual 32 bit for EXTENSION + 1.
> > > > > 
> > > > 
> > > > Sure. Changed locally, will push soon, thanks.
> > > > 
> > > 
> > > For some reasons it makes seeking with pgm somehow working. The reference
> > > test doesn't look that great IIUC, but seeking in these file with ffplay
> > > is fine AFAICT.
> > 
> > it seems it messes with pgmyuv detection (which i think was filename extension based)
> > 
> > example:
> > ./ffmpeg -i matrixbench_mpeg2.mpg -pix_fmt yuv420p16be -vframes 1 test.pgmyuv
> > ./ffplay-ref test.pgmyuv
> > Input #0, image2, from 'test.pgmyuv':B vq=    0KB sq=    0B f=0/0
> >   Duration: 00:00:00.04, start: 0.000000, bitrate: 248835 kb/s
> >     Stream #0:0: Video: pgmyuv, yuv420p16le, 720x576, 25 tbr, 25 tbn
> > 
> > ./ffplay test.pgmyuv
> > Input #0, ppm_pipe, from 'test.pgmyuv':vq=    0KB sq=    0B f=0/0
> >   Duration: N/A, bitrate: N/A
> >     Stream #0:0: Video: ppm, gray16le, 720x864, 25 tbr, 25 tbn, 25 tbc
> > 
> 
> Yes, this is a good thing (same thing happens if you s/pgmyuv/png/).

iam not sure i understand
when storing yuv420p16be in test.pgmyuv prior to the patch the file
can be read after the patch its read incorrectly as gray16
this admitably is a annoying as probably the only way to detect the
difference is the file extension

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

During times of universal deceit, telling the truth becomes a
revolutionary act. -- George Orwell
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