Am Sa., 21. Sept. 2019 um 04:06 Uhr schrieb Andriy Gelman
<andriy.gel...@gmail.com>:
>
> From: Andriy Gelman <andriy.gel...@gmail.com>
>
> Since reading 4 bits always returns a value in the range [0, 15], the
> check for vps_id >= HEVC_MAX_VPS_COUNT, where HEVC_MAX_VPS_COUNT = 16, is 
> redudant.
> ---
>  libavcodec/hevc_ps.c | 12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
>
> diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
> index abf08b919b..498467730b 100644
> --- a/libavcodec/hevc_ps.c
> +++ b/libavcodec/hevc_ps.c
> @@ -447,11 +447,7 @@ int ff_hevc_decode_nal_vps(GetBitContext *gb, 
> AVCodecContext *avctx,
>      }
>      memcpy(vps->data, gb->buffer, vps->data_size);
>
> -    vps_id = get_bits(gb, 4);
> -    if (vps_id >= HEVC_MAX_VPS_COUNT) {
> -        av_log(avctx, AV_LOG_ERROR, "VPS id out of range: %d\n", vps_id);
> -        goto err;
> -    }
> +    vps_id = get_bits(gb, 4); // vps_id in [0, HEVC_MAX_VPS_COUNT-1] so no 
> check needed
>
>      if (get_bits(gb, 2) != 3) { // vps_reserved_three_2bits
>          av_log(avctx, AV_LOG_ERROR, "vps_reserved_three_2bits is not 
> three\n");
> @@ -882,11 +878,7 @@ int ff_hevc_parse_sps(HEVCSPS *sps, GetBitContext *gb, 
> unsigned int *sps_id,
>
>      // Coded parameters
>
> -    sps->vps_id = get_bits(gb, 4);
> -    if (sps->vps_id >= HEVC_MAX_VPS_COUNT) {
> -        av_log(avctx, AV_LOG_ERROR, "VPS id out of range: %d\n", 
> sps->vps_id);
> -        return AVERROR_INVALIDDATA;
> -    }
> +    sps->vps_id = get_bits(gb, 4); // sps->vps_id in [0, 
> HEVC_MAX_VPS_COUNT-1] so no check needed

The comments look unneeded.

Carl Eugen
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".

Reply via email to