[FFmpeg-devel] [PATCH 2/3] avcodec/ffv1enc: Prevent generation of files with broken slices

[Lynne]

On 01/10/2024 22:31, Michael Niedermayer wrote:
> Fixes: Ticket5548
> 
> Sponsored-by: Sovereign Tech Fund
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>   libavcodec/ffv1.c    | 7 +++++++
>   libavcodec/ffv1.h    | 1 +
>   libavcodec/ffv1enc.c | 4 ++++
>   3 files changed, 12 insertions(+)
> 
> diff --git a/libavcodec/ffv1.c b/libavcodec/ffv1.c
> index 56a36e479fc..2b8564c2f56 100644
> --- a/libavcodec/ffv1.c
> +++ b/libavcodec/ffv1.c
> @@ -119,6 +119,13 @@ av_cold int ff_ffv1_init_slices_state(FFV1Context *f)
>       return 0;
>   }
>   
> +int ff_need_new_slices(int width, int num_h_slices, int chroma_shift) {

Wrong coding style.

> +    int mpw = 1<<chroma_shift;

Same, leave a space.

> +    int i = width * (int64_t)(num_h_slices - 1) / num_h_slices;
> +
> +    return width % mpw && (width - i) % mpw == 0;

Would a check (if height < (subsampling ? 3 : 1)) would have been 
enough? This isn't really readable nor understandable.

Furthermore, this function is called with both width and height, yet all 
variables are named with the assumption that only width is used.
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