[FFmpeg-cvslog] r14692 - in trunk: libavcodec/pcm.c tests/regression.sh

[Michael Niedermayer]

On Fri, Aug 29, 2008 at 04:59:16PM -0700, Baptiste Coudurier wrote:
> Daniel Serpell wrote:
> > Hi!
> > 
> > On Wed, Aug 13, 2008 at 3:43 AM,  <pross at xvid.org> wrote:
> >> On Tue, Aug 12, 2008 at 08:45:23PM -0400, Daniel Serpell wrote:
> >>> On Tue, Aug 12, 2008 at 8:40 PM, Daniel Serpell
> >>> <daniel.serpell at gmail.com> wrote:
> >>>> Hi!
> >>>>
> >>>> On Mon, Aug 11, 2008 at 5:52 AM, pross <subversion at mplayerhq.hu> wrote:
> >>>>> Author: pross
> >>>>> Date: Mon Aug 11 11:52:17 2008
> >>>>> New Revision: 14692
> >>>>>
> >>>>> Log:
> >>>>> Apply PCM ENCODE/DECODE() macros to the S/U,8/24/32,LE/BE PCM codecs.
> >>>>>
> >>>>>
> >>>>> Modified:
> >>>>>   trunk/libavcodec/pcm.c
> >>>>>   trunk/tests/regression.sh
> >>>>>
> >>>> This commit also broke transcoding from PCM from 8 bit to 16 bit, I
> >>>> uploaded a sample to
> >>>>   ftp://upload.mplayerhq.hu:/MPlayer/incoming/pcm-audio-11024
> >>>>
> >>>> The bug can be heard in output.avi from the command line:
> >>> Sorry, the correct command line is:
> >>>
> >>> ffmpeg -y -i pcm-audio-bug-r14692.avi -acodec pcm_s16le -ar 48000
> >>> -vcodec copy output.avi
> >>>
> >>> The bug is not present with only 8-16 bit conversion, you need to resample audio
> >>> also.
> >> The resampler only supports SAMPLE_FMT_S16, and is performed by conversion
> >> to the target format. Hence why transcoding U8->S16 fails.
> >>
> >> I guess the next step is to make resample.c handle different foramts.
> >>
> > 
> > I think is better to resample *after* conversion to S16.
> > 
> > This set of patches fixes my issue, first one exits ffmpeg if the resample is
> > called on any sample format different of S16.
> > 
> > The second patch resamples after sample format conversion, allowing to resample
> > from U8 to S16.
> > 
> > Please, consider applying.
> > 
> >    Daniel.
> > 
> > 
> > ------------------------------------------------------------------------
> > 
> > Index: ffmpeg.c
> > ===================================================================
> > --- ffmpeg.c	(revision 14745)
> > +++ ffmpeg.c	(working copy)
> > @@ -534,6 +534,11 @@
> >          ost->audio_resample = 1;
> >  
> >      if (ost->audio_resample && !ost->resample) {
> > +        if (dec->sample_fmt != SAMPLE_FMT_S16)
> > +        {
> > +            fprintf(stderr, "Resampler only works with 16 bits per sample\n");
> > +            av_exit(1);
> > +        }
> >          ost->resample = audio_resample_init(enc->channels,    dec->channels,
> >                                              enc->sample_rate, dec->sample_rate);
> >          if (!ost->resample) {
> > 
> > 
> > ------------------------------------------------------------------------
> > 
> > --- ffmpeg.ab.c	2008-08-13 21:36:23.000000000 -0400
> > +++ ffmpeg.c	2008-08-13 21:36:47.000000000 -0400
> > @@ -534,7 +534,7 @@
> >          ost->audio_resample = 1;
> >  
> >      if (ost->audio_resample && !ost->resample) {
> > -        if (dec->sample_fmt != SAMPLE_FMT_S16)
> > +        if (enc->sample_fmt != SAMPLE_FMT_S16)
> >          {
> >              fprintf(stderr, "Resampler only works with 16 bits per sample\n");
> >              av_exit(1);
> > @@ -616,23 +616,12 @@
> >          ost->sync_opts= lrintf(get_sync_ipts(ost) * enc->sample_rate)
> >                          - av_fifo_size(&ost->fifo)/(ost->st->codec->channels * 2); //FIXME wrong
> >  
> > -    if (ost->audio_resample) {
> > -        buftmp = audio_buf;
> > -        size_out = audio_resample(ost->resample,
> > -                                  (short *)buftmp, (short *)buf,
> > -                                  size / (ist->st->codec->channels * 2));
> > -        size_out = size_out * enc->channels * 2;
> > -    } else {
> > -        buftmp = buf;
> > -        size_out = size;
> > -    }
> > -
> >      if (dec->sample_fmt!=enc->sample_fmt) {
> > -        const void *ibuf[6]= {buftmp};
> > +        const void *ibuf[6]= {buf};
> >          void *obuf[6]= {audio_out2};
> >          int istride[6]= {av_get_bits_per_sample_format(dec->sample_fmt)/8};
> >          int ostride[6]= {av_get_bits_per_sample_format(enc->sample_fmt)/8};
> > -        int len= size_out/istride[0];
> > +        int len= size/istride[0];
> >          if (av_audio_convert(ost->reformat_ctx, obuf, ostride, ibuf, istride, len)<0) {
> >              printf("av_audio_convert() failed\n");
> >              return;
> > @@ -641,6 +630,17 @@
> >          /* FIXME: existing code assume that size_out equals framesize*channels*2
> >                    remove this legacy cruft */
> >          size_out = len*2;
> > +    } else {
> > +        buftmp = buf;
> > +        size_out = size;
> > +    }
> > +
> > +    if (ost->audio_resample) {
> > +        size_out = audio_resample(ost->resample,
> > +                                  (short *)audio_buf, (short *)buftmp,
> > +                                  size / (ist->st->codec->channels * 2));
> > +        size_out = size_out * enc->channels * 2;
> > +        buftmp = audio_buf;
> >      }
> >  
> >      /* now encode as many frames as possible */
> > 
> 
> Ping ? This is related to roundup issue #582.

Isnt this just moving the problem around?
I mean non 16bit decoder output vs. non 16bit encoder input being a
problem
I really think the resampler should be fixed to support all the sample
formats similar to swscale that also can scale from anything to anything.

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No great genius has ever existed without some touch of madness. -- Aristotle
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