[FFmpeg-devel] [PATCH 6/6] avcodec/h264dec: Support skipping frames that used gray gap frames

[James Almer]

On 11/14/2023 2:20 PM, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>   libavcodec/h264dec.c | 7 +++++++
>   libavcodec/h264dec.h | 1 +
>   2 files changed, 8 insertions(+)
> 
> diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
> index b48821db244..aa0022a3aba 100644
> --- a/libavcodec/h264dec.c
> +++ b/libavcodec/h264dec.c
> @@ -939,6 +939,12 @@ static int finalize_frame(H264Context *h, AVFrame *dst, H264Picture *out, int *g
>            (h->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL) ||
>            out->recovered)) {
>   
> +        if (h->skip_gray > 0 &&
> +            h->non_gray && out->gray &&
> +            !(h->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL)
> +        )
> +            return 0;
> +
>           if (!h->avctx->hwaccel &&
>               (out->field_poc[0] == INT_MAX ||
>                out->field_poc[1] == INT_MAX)
> @@ -1091,6 +1097,7 @@ static const AVOption h264_options[] = {
>       { "nal_length_size", "nal_length_size", OFFSET(nal_length_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 4, VDX },
>       { "enable_er", "Enable error resilience on damaged frames (unsafe)", OFFSET(enable_er), AV_OPT_TYPE_BOOL, { .i64 = -1 }, -1, 1, VD },
>       { "x264_build", "Assume this x264 version if no x264 version found in any SEI", OFFSET(x264_build), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, VD },
> +    { "skip_gray", "Do not return gray gap frames", OFFSET(skip_gray), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, VD },

Same here.

>       { "noref_gray", "Avoid using gray gap frames as references", OFFSET(noref_gray), AV_OPT_TYPE_INT, {.i64 = 1}, -1, 1, VD },
>       { NULL },
>   };
> diff --git a/libavcodec/h264dec.h b/libavcodec/h264dec.h
> index 591769ab258..447c2499d97 100644
> --- a/libavcodec/h264dec.h
> +++ b/libavcodec/h264dec.h
> @@ -572,6 +572,7 @@ typedef struct H264Context {
>   
>       int non_gray;                       ///< Did we encounter a intra frame after a gray gap frame
>       int noref_gray;
> +    int skip_gray;
>   } H264Context;
>   
>   extern const uint16_t ff_h264_mb_sizes[4];