[FFmpeg-devel] [PATCH v2 2/2] lavc/vaapi_av1: Avoid sending the same slice buffer multiple times

[Neal Gompa]

On Wed, May 8, 2024 at 3:13 AM David Rosca <nowrep at gmail.com> wrote:
>
> When there are multiple tiles in one slice buffer, use multiple slice
> params to avoid sending the same slice buffer multiple times and thus
> increasing the bitstream size the driver will need to upload to hw.
> ---
> v2: Avoid allocations every slice.
>
>  libavcodec/vaapi_av1.c | 47 +++++++++++++++++++++++++++++-------------
>  1 file changed, 33 insertions(+), 14 deletions(-)
>
> diff --git a/libavcodec/vaapi_av1.c b/libavcodec/vaapi_av1.c
> index 4a90db1e09..4ee33a3ae3 100644
> --- a/libavcodec/vaapi_av1.c
> +++ b/libavcodec/vaapi_av1.c
> @@ -19,6 +19,7 @@
>   */
>
>  #include "libavutil/frame.h"
> +#include "libavutil/mem.h"
>  #include "hwaccel_internal.h"
>  #include "vaapi_decode.h"
>  #include "internal.h"
> @@ -42,6 +43,9 @@ typedef struct VAAPIAV1DecContext {
>      */
>      VAAPIAV1FrameRef ref_tab[AV1_NUM_REF_FRAMES];
>      AVFrame *tmp_frame;
> +
> +    int nb_slice_params;
> +    VASliceParameterBufferAV1 *slice_params;
>  } VAAPIAV1DecContext;
>
>  static VASurfaceID vaapi_av1_surface_id(AV1Frame *vf)
> @@ -97,6 +101,8 @@ static int vaapi_av1_decode_uninit(AVCodecContext *avctx)
>      for (int i = 0; i < FF_ARRAY_ELEMS(ctx->ref_tab); i++)
>          av_frame_free(&ctx->ref_tab[i].frame);
>
> +    av_freep(&ctx->slice_params);
> +
>      return ff_vaapi_decode_uninit(avctx);
>  }
>
> @@ -393,13 +399,24 @@ static int vaapi_av1_decode_slice(AVCodecContext *avctx,
>  {
>      const AV1DecContext *s = avctx->priv_data;
>      VAAPIDecodePicture *pic = s->cur_frame.hwaccel_picture_private;
> -    VASliceParameterBufferAV1 slice_param;
> -    int err = 0;
> +    VAAPIAV1DecContext *ctx = avctx->internal->hwaccel_priv_data;
> +    int err, nb_params;
> +
> +    nb_params = s->tg_end - s->tg_start + 1;
> +    if (ctx->nb_slice_params < nb_params) {
> +        ctx->slice_params = av_realloc_array(ctx->slice_params,
> +                                             nb_params,
> +                                             sizeof(*ctx->slice_params));
> +        if (!ctx->slice_params) {
> +            ctx->nb_slice_params = 0;
> +            err = AVERROR(ENOMEM);
> +            goto fail;
> +        }
> +        ctx->nb_slice_params = nb_params;
> +    }
>
>      for (int i = s->tg_start; i <= s->tg_end; i++) {
> -        memset(&slice_param, 0, sizeof(VASliceParameterBufferAV1));
> -
> -        slice_param = (VASliceParameterBufferAV1) {
> +        ctx->slice_params[i - s->tg_start] = (VASliceParameterBufferAV1) {
>              .slice_data_size   = s->tile_group_info[i].tile_size,
>              .slice_data_offset = s->tile_group_info[i].tile_offset,
>              .slice_data_flag   = VA_SLICE_DATA_FLAG_ALL,
> @@ -408,18 +425,20 @@ static int vaapi_av1_decode_slice(AVCodecContext *avctx,
>              .tg_start          = s->tg_start,
>              .tg_end            = s->tg_end,
>          };
> -
> -        err = ff_vaapi_decode_make_slice_buffer(avctx, pic, &slice_param, 1,
> -                                                sizeof(VASliceParameterBufferAV1),
> -                                                buffer,
> -                                                size);
> -        if (err) {
> -            ff_vaapi_decode_cancel(avctx, pic);
> -            return err;
> -        }
>      }
>
> +    err = ff_vaapi_decode_make_slice_buffer(avctx, pic, ctx->slice_params, nb_params,
> +                                            sizeof(VASliceParameterBufferAV1),
> +                                            buffer,
> +                                            size);
> +    if (err)
> +        goto fail;
> +
>      return 0;
> +
> +fail:
> +    ff_vaapi_decode_cancel(avctx, pic);
> +    return err;
>  }
>
>  const FFHWAccel ff_av1_vaapi_hwaccel = {
> --
> 2.45.0
>

LGTM and works fine with my AMD GPU.

Reviewed-by: Neal Gompa <ngompa13 at gmail.com>



-- 
真実はいつも一つ！/ Always, there's only one truth!