[FFmpeg-devel] [PATCH] [v4] avcodec/vaapi_encode: add customized surface alignment

[Mark Thompson]

On 21/03/2024 17:02, Araz Iusubov wrote:
> This commit fixes issues with AMD HEVC encoding.
> By default AMD hevc encoder asks for the alignment 64x16, while FFMPEG VAAPI has 16x16.
> Adding support for customized surface size from VASurfaceAttribAlignmentSize in VAAPI version 1.21.0
> 
> Signed-off-by: Araz Iusubov <Primeadvice at gmail.com>
> ---
>   libavcodec/vaapi_encode.c   | 11 +++++++++++
>   libavutil/hwcontext.h       |  7 +++++++
>   libavutil/hwcontext_vaapi.c |  5 +++++
>   3 files changed, 23 insertions(+)
> 
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index 940f0678a5..2a74db23b1 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -2711,6 +2711,17 @@ static av_cold int vaapi_encode_create_recon_frames(AVCodecContext *avctx)
>       av_log(avctx, AV_LOG_DEBUG, "Using %s as format of "
>              "reconstructed frames.\n", av_get_pix_fmt_name(recon_format));
>   
> +    if (constraints->log2_alignment) {
> +        ctx->surface_width = FFALIGN(avctx->width,
> +                              1 << (constraints->log2_alignment & 0xf));
> +        ctx->surface_height = FFALIGN(avctx->height,
> +                              1 << ((constraints->log2_alignment & 0xf0) >> 4));
> +        av_log(avctx, AV_LOG_VERBOSE, "Using customized alignment size "
> +                "[%dx%d].\n",
> +                (1 << (constraints->log2_alignment & 0xf)),
> +                (1 << ((constraints->log2_alignment & 0xf0) >> 4)));
> +    }
> +
>       if (ctx->surface_width  < constraints->min_width  ||
>           ctx->surface_height < constraints->min_height ||
>           ctx->surface_width  > constraints->max_width ||
> diff --git a/libavutil/hwcontext.h b/libavutil/hwcontext.h
> index bac30debae..1eb56aff78 100644
> --- a/libavutil/hwcontext.h
> +++ b/libavutil/hwcontext.h
> @@ -465,6 +465,13 @@ typedef struct AVHWFramesConstraints {
>        */
>       int max_width;
>       int max_height;
> +
> +    /**
> +     * The frame width/height log2 alignment when available
> +     * the lower 4 bits, width; another 4 bits, height
> +     * (Zero is not applied, use the default value)
> +     */
> +    int log2_alignment;

What other users do you have in mind for this?  (Are you expecting hwupload to use it as well, say?)

If this is only used in VAAPI encode then I would suggest putting the query there rather than adding new library API for it.

Also agree with Anton that this form is unnecessarily confusing - just make it a normal field, don't pack it like this.  (And possibly drop the log2 as well?  That doesn't seem like it adds anything useful.)

>   } AVHWFramesConstraints;
>   
>   /**
> diff --git a/libavutil/hwcontext_vaapi.c b/libavutil/hwcontext_vaapi.c
> index 56d03aa4cd..6cda0fd811 100644
> --- a/libavutil/hwcontext_vaapi.c
> +++ b/libavutil/hwcontext_vaapi.c
> @@ -294,6 +294,11 @@ static int vaapi_frames_get_constraints(AVHWDeviceContext *hwdev,
>               case VASurfaceAttribMaxHeight:
>                   constraints->max_height = attr_list[i].value.value.i;
>                   break;
> +#if VA_CHECK_VERSION(1, 21, 0)
> +            case VASurfaceAttribAlignmentSize:
> +                constraints->log2_alignment = attr_list[i].value.value.i;
> +                break;
> +#endif
>               }
>           }
>           if (pix_fmt_count == 0) {

Thanks,

- Mark