[FFmpeg-devel] [PATCH v4 3/3] avcodec/adpcm: Fixes output from Westwood ADPCM.

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Sun Apr 25 02:40:09 EEST 2021


Aidan Richmond:
> Fixes bug #9198
> 
> Signed-off-by: Aidan Richmond <aidan.is at hotmail.co.uk>
> ---
>  libavcodec/adpcm.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
> index be14607eac..5ec9691001 100644
> --- a/libavcodec/adpcm.c
> +++ b/libavcodec/adpcm.c
> @@ -1400,16 +1400,16 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
>  
>                  for (n = nb_samples / 2; n > 0; n--) {
>                      int v = bytestream2_get_byteu(&gb);
> -                    *smp++ = adpcm_ima_expand_nibble(&c->status[channel], v >> 4  , 3);
>                      *smp++ = adpcm_ima_expand_nibble(&c->status[channel], v & 0x0F, 3);
> +                    *smp++ = adpcm_ima_expand_nibble(&c->status[channel], v >> 4  , 3);
>                  }
>              }
>          } else {
>              for (n = nb_samples / 2; n > 0; n--) {
>                  for (channel = 0; channel < avctx->channels; channel++) {
>                      int v = bytestream2_get_byteu(&gb);
> -                    *samples++  = adpcm_ima_expand_nibble(&c->status[channel], v >> 4  , 3);
> -                    samples[st] = adpcm_ima_expand_nibble(&c->status[channel], v & 0x0F, 3);
> +                    *samples++  = adpcm_ima_expand_nibble(&c->status[channel], v & 0x0F, 3);
> +                    samples[st] = adpcm_ima_expand_nibble(&c->status[channel], v >> 4  , 3);
>                  }
>                  samples += avctx->channels;
>              }
> 
This format is covered by FATE (namely the adpcm-ima-ws test) and so you
need to update the checksums in your patch; of course you should verify
that your change is correct. See https://ffmpeg.org/fate.html for more.

- Andreas


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