[FFmpeg-devel] [PATCH 1/3][GSoC 2024] libavcodec/vvc: convert (*sad) to (*sad[6]) to prepare for AVX2 funcs

[Andreas Rheinhardt]

Stone Chen:
> To prepare for adding AVX2 functions for different block widths, change VVCInterDSPContext to contain (*sad[6]) instead of (*sad). This also default initializes the pointer array with the scalar function and the calling sites to jump to the correct function based on block width. There's no change in functionality.
> ---
>  libavcodec/vvc/dsp.h            | 2 +-
>  libavcodec/vvc/inter.c          | 4 ++--
>  libavcodec/vvc/inter_template.c | 5 ++++-
>  3 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/vvc/dsp.h b/libavcodec/vvc/dsp.h
> index 9810ac314c..b06a3ef10e 100644
> --- a/libavcodec/vvc/dsp.h
> +++ b/libavcodec/vvc/dsp.h
> @@ -86,7 +86,7 @@ typedef struct VVCInterDSPContext {
>  
>      void (*apply_bdof)(uint8_t *dst, ptrdiff_t dst_stride, int16_t *src0, int16_t *src1, int block_w, int block_h);
>  
> -    int (*sad)(const int16_t *src0, const int16_t *src1, int dx, int dy, int block_w, int block_h);
> +    int (*sad[6])(const int16_t *src0, const int16_t *src1, int dx, int dy, int block_w, int block_h);
>      void (*dmvr[2][2])(int16_t *dst, const uint8_t *src, ptrdiff_t src_stride, int height,
>          intptr_t mx, intptr_t my, int width);
>  } VVCInterDSPContext;
> diff --git a/libavcodec/vvc/inter.c b/libavcodec/vvc/inter.c
> index 4a8d1d866a..a68f4f9452 100644
> --- a/libavcodec/vvc/inter.c
> +++ b/libavcodec/vvc/inter.c
> @@ -742,7 +742,7 @@ static void dmvr_mv_refine(VVCLocalContext *lc, MvField *mvf, MvField *orig_mv,
>          fc->vvcdsp.inter.dmvr[!!my][!!mx](tmp[i], src, src_stride, pred_h, mx, my, pred_w);
>      }
>  
> -    min_sad = fc->vvcdsp.inter.sad(tmp[L0], tmp[L1], dx, dy, block_w, block_h);
> +    min_sad = fc->vvcdsp.inter.sad[av_log2(block_w) - 2](tmp[L0], tmp[L1], dx, dy, block_w, block_h);
>      min_sad -= min_sad >> 2;
>      sad[dy][dx] = min_sad;
>  
> @@ -752,7 +752,7 @@ static void dmvr_mv_refine(VVCLocalContext *lc, MvField *mvf, MvField *orig_mv,
>          for (dy = 0; dy < SAD_ARRAY_SIZE; dy++) {
>              for (dx = 0; dx < SAD_ARRAY_SIZE; dx++) {
>                  if (dx != sr_range || dy != sr_range) {
> -                    sad[dy][dx] = fc->vvcdsp.inter.sad(lc->tmp, lc->tmp1, dx, dy, block_w, block_h);
> +                    sad[dy][dx] = fc->vvcdsp.inter.sad[av_log2(block_w) - 2](lc->tmp, lc->tmp1, dx, dy, block_w, block_h);
>                      if (sad[dy][dx] < min_sad) {
>                          min_sad = sad[dy][dx];
>                          min_dx = dx;
> diff --git a/libavcodec/vvc/inter_template.c b/libavcodec/vvc/inter_template.c
> index e2fbfd4fc0..545e8dd184 100644
> --- a/libavcodec/vvc/inter_template.c
> +++ b/libavcodec/vvc/inter_template.c
> @@ -458,7 +458,10 @@ static void FUNC(ff_vvc_inter_dsp_init)(VVCInterDSPContext *const inter)
>      inter->apply_prof_uni_w     = FUNC(apply_prof_uni_w);
>      inter->apply_bdof           = FUNC(apply_bdof);
>      inter->prof_grad_filter     = FUNC(prof_grad_filter);
> -    inter->sad                  = vvc_sad;
> +    
> +    for (int i = 0; i < FF_ARRAY_ELEMS(inter->sad); i++) {
> +        inter->sad[i]           = vvc_sad;
> +    }
>  }
>  
>  #undef FUNCS

Why is the jump depending upon block width not performed inside your
avx2 implementation?

- Andreas