[FFmpeg-devel] [PATCH] avcodec/wma: handle run_level_decode error

[Andreas Rheinhardt]

Stéphane Cerveau:
> Consider data as invalid if ff_wma_run_level_decode
> gets out with an error.
> 
> It avoids an unpleasant sound distorsion.
> 
> See http://trac.ffmpeg.org/ticket/9358
> ---
>  libavcodec/wmadec.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
> index d627bbe50e..74ea8cea77 100644
> --- a/libavcodec/wmadec.c
> +++ b/libavcodec/wmadec.c
> @@ -606,10 +606,11 @@ static int wma_decode_block(WMACodecContext *s)
>               * there is potentially less energy there */
>              tindex = (ch == 1 && s->ms_stereo);
>              memset(ptr, 0, s->block_len * sizeof(WMACoef));
> -            ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
> +            if (ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
>                                      s->level_table[tindex], s->run_table[tindex],
>                                      0, ptr, 0, nb_coefs[ch],
> -                                    s->block_len, s->frame_len_bits, coef_nb_bits);
> +                                    s->block_len, s->frame_len_bits, coef_nb_bits))
> +              return AVERROR_INVALIDDATA;
>          }
>          if (s->version == 1 && s->avctx->channels >= 2)
>              align_get_bits(&s->gb);
> 
Generally, one should forward error codes and not make up some on the
fly; in this case, the callee does not return proper error codes, so
this should be fixed, too (but not in the same commit and not
necessarily by you). Even more importantly, the callee emits an error
message, stating that an error will be ignored, which will no longer
true with this patch.

- Andreas