[FFmpeg-devel] [PATCH 06/16] vmdaudio: correct the silent chunk count in the first block.

Reimar Döffinger Reimar.Doeffinger
Tue Feb 22 20:28:05 CET 2011


On Tue, Feb 22, 2011 at 02:05:25PM -0500, Justin Ruggles wrote:
> diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c
> index 025d23a..ed3c5f8 100644
> --- a/libavcodec/vmdav.c
> +++ b/libavcodec/vmdav.c
> @@ -517,11 +517,7 @@ static int vmdaudio_decode_frame(AVCodecContext *avctx,
>          uint32_t flags = AV_RB32(p);
>          int raw_block_size = s->block_align *
>                               (av_get_bits_per_sample_fmt(avctx->sample_fmt) / 8);
> -        int silent_chunks;
> -        if(flags == 0xFFFFFFFF)
> -            silent_chunks = 32;
> -        else
> -            silent_chunks = av_log2(flags + 1);
> +        int silent_chunks = av_popcount(flags);

Hm, what exactly is the difference in meaning between
0x1, 0x2, 0x4 for example?

>          if(*data_size < (s->block_align*silent_chunks + buf_size - 20) * 2)

Unrelated, but isn't it possible this might overflow?



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