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

[Måns Rullgård]

Lars T?uber <lars.taeuber at gmx.net> writes:

> 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:
>> > On Thu, 17 Apr 2008 22:49:08 +0200 Michael Niedermayer <michaelni at gmx.at> wrote:
>> > > On Thu, Apr 17, 2008 at 09:10:07PM +0100, M?ns Rullg?rd wrote:
> [...]
>> > diff -pur ffmpeg/libavcodec/pcm.c ffmpeg.1/libavcodec/pcm.c
>> > --- ffmpeg/libavcodec/pcm.c	2008-03-21 13:17:05.000000000 +0100
>> > +++ ffmpeg.1/libavcodec/pcm.c	2008-04-17 21:46:27.000000000 +0200
>> > @@ -492,6 +498,31 @@ 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;
>> > +
>> 
>> > +            n = buf_size / (avctx->channels * 2 * avctx->bits_per_sample / 8);
>> 
>> Is there something that prevents that from overflowing? If not then
>> this is a little risky
>
> I'm not sure what you mean, but all values are calculated in
> libavformat/mpeg.c during parsing:

What if something else set the values?  Not all data comes from lavf,
and it could have been corrupted underway.  Never assume anything
about input data.

-- 
M?ns Rullg?rd
mans at mansr.com