[FFmpeg-devel] [PATCH] Issue 636 : ALAC encoding sometimes fails

Jai Menon jmenon86
Wed Dec 10 06:19:10 CET 2008


Hi,

-------- Original-Nachricht --------
> Datum: Fri, 5 Dec 2008 13:16:59 +0100
> Von: Michael Niedermayer <michaelni at gmx.at<http://service.gmx.net/de/cgi/g.fcgi/mail/new?CUSTOMERNO=12720674&t=uk602561993.1228886151.33ee9c8f&to=michaelni%40gmx.at>
>
> An: FFmpeg development discussions and patches <ffmpeg-devel at mplayerhq.hu<http://service.gmx.net/de/cgi/g.fcgi/mail/new?CUSTOMERNO=12720674&t=uk602561993.1228886151.33ee9c8f&to=ffmpeg-devel%40mplayerhq.hu>
>
> Betreff: Re: [FFmpeg-devel] [PATCH] Issue 636 : ALAC encoding
sometimes    fails

> On Fri, Dec 05, 2008 at 10:09:16AM +0530, Jai Menon wrote:
> > Hi,
> >
> > Attached patch fixes issue 636 and a few other fringe cases where the
> > alac encoder produces
> > lossy output. I'm behind a NAT and svn doesn't work, so could someone
> > please apply. Thanks.
> >
> > Regards,
> >
> > Jai
>
> > Index: libavcodec/alacenc.c
> > ===================================================================
> > --- libavcodec/alacenc.c    (revision 15797)
> > +++ libavcodec/alacenc.c    (working copy)
> > @@<http://service.gmx.net/de/cgi/g.fcgi/mail/new?CUSTOMERNO=12720674&t=uk602561993.1228886151.33ee9c8f&to=>-253,7 +253,8
@@<http://service.gmx.net/de/cgi/g.fcgi/mail/new?CUSTOMERNO=12720674&t=uk602561993.1228886151.33ee9c8f&to=>
> >
> >              sum >>= lpc.lpc_quant;
> >              sum += samples[0];
> > -            residual[i] = samples[lpc.lpc_order+1] - sum;
> > +            residual[i] = (samples[lpc.lpc_order+1] - sum) << (32 -
> s->write_sample_size) >>
> > +                          (32 - s->write_sample_size);
> >              res_val = residual[i];
>
> you are missing a int32_t cast in there, without it this wont work on
> systems where int is not exactly 32bit
>

Oversight on my part. 16 bit systems are a nightmare from which I'm trying
to awake.
Is the attached patch ok?

> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Regards,

Jai
-------------- next part --------------
A non-text attachment was scrubbed...
Name: alacenc_issue636.patch
Type: application/octet-stream
Size: 563 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20081210/f78f222d/attachment.obj>



More information about the ffmpeg-devel mailing list