[FFmpeg-devel] [RFC] LPCM 24 bits support

[Lars Täuber]

On Fri, 18 Apr 2008 22:52:40 +0200 Michael Niedermayer <michaelni at gmx.at> wrote:
> On Fri, Apr 18, 2008 at 09:37:12PM +0200, Lars T?uber wrote:
> > On Fri, 18 Apr 2008 22:08:24 +0200 Michael Niedermayer <michaelni at gmx.at> wrote:
> > > On Fri, Apr 18, 2008 at 09:05:23PM +0200, Lars T?uber wrote:
> > > > On Fri, 18 Apr 2008 15:39:43 +0200 Michael Niedermayer <michaelni at gmx.at> wrote:
> > > > > On Thu, Apr 17, 2008 at 10:13:40PM +0200, Lars T?uber wrote:
[...]
> > @@ -492,6 +498,35 @@ static int pcm_decode_frame(AVCodecConte
> >              *samples++ = s->table[*src++];
> >          }
> >          break;
> > +    case CODEC_ID_PCM_DVD: {
> > +            int audio24[8*2], *ap;
> > +            const uint8_t *src_LSB;
> > +
> > +            if (avctx->channels <= 0 || avctx->channels > 8) {
> > +                av_log(avctx, AV_LOG_ERROR, "PCM_DVD channels out of bounds\n");
> > +                return -1;
> > +            }
> > +            n = buf_size / (avctx->channels * 2 * avctx->bits_per_sample / 8);
> > +            while (n--) {
> > +                ap = audio24;
> > +                src_LSB = src + avctx->channels * 2 * 2;
> > +
> > +                if (avctx->bits_per_sample == 20)
> > +                    for (c=0; c < avctx->channels; c++, src+=4, src_LSB++ ) {
> > +                        *ap++ = src[0]<<16 | src[1]<<8 | (*src_LSB & 0xf0);
> > +                        *ap++ = src[2]<<16 | src[3]<<8 | (*src_LSB & 0x0f)<<4;
> > +                    }
> > +                else {
> > +                    for (c=0; c < 2*avctx->channels; c++, src+=2, src_LSB++ )
> > +                        *ap++ = src[0]<<16 | src[1]<<8 | *src_LSB;
> > +                }
> > +                src = src_LSB;
> > +
> > +                for (c=0; c < avctx->channels*2; c++)
> > +                    *samples++ = audio24[c] >> 8;
> > +            }
> 
> and what if bits_per_sample is something else than 20 or 24 ?

Switch statement added.

I'm not sure about the wording of the error message.
Is it
- sample depth
- sample width or
- sample resolution
???

Good night.
Lars
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