[FFmpeg-devel] [PATCH v2] avcodec/h264_parse: decode sps before pps

[Jun Li]

On Mon, Oct 7, 2019 at 8:33 PM Jun Li <junli1026 at gmail.com> wrote:

> Fix ticket #6422
> The content put pps before sps, which is not a common case. The change
> put decoding sps before pps, just for compability.
>
> Signed-off-by: Jun Li <junli1026 at gmail.com>
> ---
>  libavcodec/h264_parse.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c
> index 352ffea948..eeda5a76e5 100644
> --- a/libavcodec/h264_parse.c
> +++ b/libavcodec/h264_parse.c
> @@ -373,35 +373,36 @@ static int decode_extradata_ps(const uint8_t *data,
> int size, H264ParamSets *ps,
>          goto fail;
>      }
>
> +    /* decode sps before pps, just in case some bitstream put pps before
> sps. */
>      for (i = 0; i < pkt.nb_nals; i++) {
>          H2645NAL *nal = &pkt.nals[i];
> -        switch (nal->type) {
> -        case H264_NAL_SPS: {
> +        if (nal->type == H264_NAL_SPS) {
>              GetBitContext tmp_gb = nal->gb;
>              ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps,
> 0);
>              if (ret >= 0)
> -                break;
> +                continue;
>              av_log(logctx, AV_LOG_DEBUG,
>                     "SPS decoding failure, trying again with the complete
> NAL\n");
>              init_get_bits8(&tmp_gb, nal->raw_data + 1, nal->raw_size - 1);
>              ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps,
> 0);
>              if (ret >= 0)
> -                break;
> +                continue;
>              ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps,
> 1);
>              if (ret < 0)
>                  goto fail;
> -            break;
>          }
> -        case H264_NAL_PPS:
> +    }
> +
> +    for (i = 0; i < pkt.nb_nals; i++) {
> +        H2645NAL *nal = &pkt.nals[i];
> +        if (nal->type == H264_NAL_PPS) {
>              ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx,
> ps,
>                                                         nal->size_bits);
>              if (ret < 0)
>                  goto fail;
> -            break;
> -        default:
> +        } else if (nal->type != H264_NAL_SPS) {
>              av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in
> extradata\n",
>                     nal->type);
> -            break;
>          }
>      }
>
> --
> 2.17.1
>
>
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