[FFmpeg-devel] [PATCH] QCELP decoder

[Kenan Gillet]

Hi,

On Oct 3, 2008, at 4:43 PM, Baptiste Coudurier wrote:

> Hi,
>
> Kenan Gillet wrote:
>> [...]
>>
>> +*/
>> +static int qcelp_decode_init(AVCodecContext *avctx) {
>> +    QCELPContext *q = avctx->priv_data;
>> +    int          i;
>> +
>> +    if (avctx->sample_rate != 8000) {
>> +        if (avctx->sample_rate == 22050 ||
>> +            avctx->sample_rate == 11025) {
>> +            av_log(avctx, AV_LOG_WARNING,
>> +                   "Unofficial samplerate %d, but supported by  
>> Quicktime.", avctx->sample_rate);
>> +        } else {
>> +            av_log(avctx, AV_LOG_WARNING,
>> +                   "Unsupported samplerate %d, resampling.", avctx- 
>> >sample_rate);
>> +            avctx->sample_rate= 8000;
>> +        }
>> +    }
>
> It seems the qualcomm quicktime decoder supports more sampling rate  
> than
> these:
> http://sketchup.google.com/gsu6vtvideos.html
>
> Some are 24 khz, and it seems decoder kinda works with these files.
>
> [...]

It seems that setting the sample_rate in AVCodecContext
from the qcelp_decode_init function has no effect on how
FFmpeg 'sees' the sample_rate.
That explains why the 24khz sample kinda works ;)

Is it the expected behavior ?

If it is, it seems the only place to change the sample_rate in
AVCodecContext is to do it in libavcodec/mov.c.

Until now, all the files I came across had a valid sample_rate,
so maybe we can just drop this check and warning.

What would be the usual policy?


Kenan