[FFmpeg-devel] [PATCH v2 1/4] lavc/vaapi_encode: add EQUAL_MULTI_ROWS support for slice structure

[Linjie Fu]

On Tue, May 12, 2020 at 9:49 PM Linjie Fu <linjie.fu at intel.com> wrote:
>
> VA_ENC_SLICE_STRUCTURE_EQUAL_MULTI_ROWS is added to in the latest
> libva (1.8.0) which matches the hardware behaviour:
>
> /** \brief Driver supports any number of rows per slice but they must be the same
> *       for all slices except for the last one, which must be equal or smaller
> *       to the previous slices. */
>
> And VA_ENC_SLICE_STRUCTURE_EQUAL_ROWS is kind of deprecated for iHD
> since it's somehow introduced in [1] however misleading from what we
> actually handle, and one row per slice would not get a good quality.
>
> Caps query support in driver is WIP, and this would fix the multi slice
> encoding for VAEntrypointEncSliceLP.
>
> [1]<https://github.com/intel/libva/commit/0e6d5441f19bdc674b4da3169d614d10fd644778>
>
> Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> ---
>  libavcodec/vaapi_encode.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index cb05ebd..234618a 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -1888,6 +1888,9 @@ static av_cold int vaapi_encode_init_slice_structure(AVCodecContext *avctx)
>          req_slices = avctx->slices;
>      }
>      if (slice_structure & VA_ENC_SLICE_STRUCTURE_ARBITRARY_ROWS ||
> +#if VA_CHECK_VERSION(1, 8, 0)
> +        slice_structure & VA_ENC_SLICE_STRUCTURE_EQUAL_MULTI_ROWS ||
> +#endif
>          slice_structure & VA_ENC_SLICE_STRUCTURE_ARBITRARY_MACROBLOCKS) {
>          ctx->nb_slices  = req_slices;
>          ctx->slice_size = ctx->slice_block_rows / ctx->nb_slices;
> --
> 2.7.4

Full support is provided in libva[1] and media-driver[2], and we've
observed it works for multi slice encoding for AVC. (300+ cases)

Prefer to apply this soon with commit message refined.

- Linjie

[1] https://github.com/intel/libva/commit/0e6d5441f19bdc674b4da3169d614d10fd644778
[2] https://github.com/intel/media-driver/commit/c63d4b1dbed4ed186e4c4ea67a3e3601367d9a8e