[FFmpeg-devel] [PATCH] deprecate SAMPLE_FMT_S24

[Peter Ross]

On Tue, Aug 19, 2008 at 03:31:52PM +0200, Michael Niedermayer wrote:
> On Tue, Aug 19, 2008 at 10:29:32PM +1000, Peter Ross wrote:
> > On Sun, Aug 17, 2008 at 05:10:39PM +0200, Michael Niedermayer wrote:
> > > On Sun, Aug 17, 2008 at 04:37:49PM +0200, Aurelien Jacobs wrote:
> > > > Michael Niedermayer wrote:
> > > > 
> > > > > On Sun, Aug 17, 2008 at 03:32:30PM +0200, Aurelien Jacobs wrote:
> > > > > > Peter Ross wrote:
> > > > > > 
> > > > > > > This patch flags SAMPLE_FMT_S24 as deprecated.
> > > > > > 
> > 
> > > bits_per_sample can NOT be used as SAMPLE_FMT_* bit count.
> > > It has a different and docuented purpose, it describes the coded bitstream
> > > and not the decoded samples, they match in bits only for lossless codecs.
> > > 
> > > example:
> > > the a demuxer sets bits_per_sample to 4 and passes the data to a ADPCM
> > > decoder which has SAMPLE_FMT_S16 output with 13 significant bits the
> > > last 3 being always 0
> > 
> > Thanks for taking the time to explain this. Revised patch within.
> > 
> > The proposed field make sense only for SAMPLE_FMT_S32. I've kept the language
> > generic, as it will have future utility when FFmpeg can manipulate 12/16-bit
> > luma planes.
> 
> i think that maybe a
> bits_per_coded_sample   // the number of bits in which each sample is coded
> and
> bits_per_raw_sample     // the number of bits in each PCM sample

Yes. Non-ambiguity is a desirable property. Done.

> would be better names, they are IMHO more clear
> Iam not even sure that bits_per_sample is not sometimes used with the
> expecttation that it is bits_per_raw_sample ...

An audit of bits_per_samples usage is on my todo list.

> I wonder if anyone would complain if we just renamed bits_per_sample to
> bits_per_coded_sample ? It doesnt break ABI, just API of apps accessing it
> without AVOptions and apps really should be using AVOptions

IMHO it should be guarded with an ifdef until the next major version bump.
Patch enclosed.

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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