[FFmpeg-devel] [PATCH 4/4] avcodec/ffv1enc: avoid slices larger than 360x288 if no value is specified

[James Almer]

On 4/3/2025 7:50 AM, Michael Niedermayer wrote:
> This improves speed by providing more independent things for more CPUs
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>   libavcodec/ffv1enc.c                             |  6 +++++-
>   .../ref/fate/matroska-mastering-display-metadata | 16 ++++++++--------
>   2 files changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c
> index ce3f8e023e5..221344794e2 100644
> --- a/libavcodec/ffv1enc.c
> +++ b/libavcodec/ffv1enc.c
> @@ -581,7 +581,11 @@ int ff_ffv1_encode_determine_slices(AVCodecContext *avctx)
>                   if (  ff_need_new_slices(avctx->width , s->num_h_slices, s->chroma_h_shift)
>                       ||ff_need_new_slices(avctx->height, s->num_v_slices, s->chroma_v_shift))
>                       continue;
> -            if (avctx->slices == s->num_h_slices * s->num_v_slices && avctx->slices <= MAX_SLICES || !avctx->slices)
> +            if (avctx->slices == s->num_h_slices * s->num_v_slices && avctx->slices <= MAX_SLICES)
> +                return 0;
> +            if (maxw*maxh > 360*288)
> +                continue;
> +            if (!avctx->slices)
>                   return 0;
>           }
>       }
> diff --git a/tests/ref/fate/matroska-mastering-display-metadata b/tests/ref/fate/matroska-mastering-display-metadata
> index 91ce6a05584..6a2ff15b1b2 100644
> --- a/tests/ref/fate/matroska-mastering-display-metadata
> +++ b/tests/ref/fate/matroska-mastering-display-metadata
> @@ -1,7 +1,7 @@
> -ad5e3c4e338599c81ef7d0f9ae25f871 *tests/data/fate/matroska-mastering-display-metadata.matroska
> -1669589 tests/data/fate/matroska-mastering-display-metadata.matroska
> +c1e5e2ecf433cf05af8556debc7d4d0b *tests/data/fate/matroska-mastering-display-metadata.matroska
> +1669773 tests/data/fate/matroska-mastering-display-metadata.matroska
>   #extradata 0:        4, 0x040901a3
> -#extradata 3:      200, 0x506463a8
> +#extradata 3:      202, 0xfce96279

Why did extradata change? Slice dimension value changes?

>   #tb 0: 1/1000
>   #media_type 0: video
>   #codec_id 0: prores
> @@ -24,23 +24,23 @@ ad5e3c4e338599c81ef7d0f9ae25f871 *tests/data/fate/matroska-mastering-display-met
>   #sar 3: 1/1
>   0,          0,          0,       16,    57008, 0x43416399
>   1,          0,          0,       16,     2403, 0xaa818522
> -3,          0,          0,       16,   274117, 0xc439610f
> +3,          0,          0,       16,   274884, 0x775840e5
>   0,         17,         17,       16,    57248, 0xa06cd7b5
>   1,         17,         17,       16,     2403, 0xe1a991e5
>   2,         17,         17,       16,     1602, 0x5d868171
> -3,         17,         17,       16,   273691, 0x5a3b88a5, F=0x0
> +3,         17,         17,       16,   273716, 0xa41fc5e3, F=0x0
>   0,         33,         33,       16,    57200, 0x5623da10
>   1,         33,         33,       16,     2400, 0x6650907f
>   2,         33,         33,       16,     1600, 0xa90f0044
> -3,         33,         33,       16,   272987, 0x48c443e7, F=0x0
> +3,         33,         33,       16,   272838, 0x3c308d03, F=0x0
>   0,         50,         50,       16,    57152, 0x52d89d3f
>   1,         50,         50,       16,     2403, 0x43398a08
>   2,         50,         50,       16,     1602, 0x3a350084
> -3,         50,         50,       16,   271465, 0x251b9cbe, F=0x0
> +3,         50,         50,       16,   271251, 0xe802cc77, F=0x0
>   0,         67,         67,       16,    56960, 0x431d5189
>   1,         67,         67,       16,     2403, 0x61cd96cb
>   2,         67,         67,       16,     1602, 0xd74800c6
> -3,         67,         67,       16,   270800, 0x8fb2e217, F=0x0
> +3,         67,         67,       16,   270553, 0x36d83705, F=0x0
>   [STREAM]
>   index=0
>   codec_name=prores

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