[FFmpeg-devel] [PATCH V2 1/3] libavcodec/vaapi_decode: fix the problem that init_pool_size < nb_surface

[Anton Khirnov]

Quoting Wenbin Chen (2021-11-30 09:44:04)
> For vaapi if the init_pool_size is not zero, the pool size is fixed.
> This means max surfaces is init_pool_size, but when mapping vaapi
> frame to qsv frame, the init_pool_size < nb_surface. The cause is that
> vaapi_decode_make_config() config the init_pool_size and it is called
> twice. The first time is to init frame_context and the second time is to
> init codec. On the second time the init_pool_size is changed to original
> value so the init_pool_size is lower than the reall size because
> pool_size used to initialize frame_context need to plus thread_count and
> 3 (guarantee 4 base work surfaces). Now add code to make sure
> init_pool_size is only set once. Now the following commandline works:
> 
> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 \
> -hwaccel_output_format vaapi -i input.264 \
> -vf "hwmap=derive_device=qsv,format=qsv" \
> -c:v h264_qsv output.264
> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavcodec/vaapi_decode.c | 34 ++++++++++++++++++----------------
>  1 file changed, 18 insertions(+), 16 deletions(-)
> 
> diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
> index 665af370ed..aab8162989 100644
> --- a/libavcodec/vaapi_decode.c
> +++ b/libavcodec/vaapi_decode.c
> @@ -572,22 +572,24 @@ static int vaapi_decode_make_config(AVCodecContext *avctx,
>          if (err < 0)
>              goto fail;
>  
> -        frames->initial_pool_size = 1;
> -        // Add per-codec number of surfaces used for storing reference frames.
> -        switch (avctx->codec_id) {
> -        case AV_CODEC_ID_H264:
> -        case AV_CODEC_ID_HEVC:
> -        case AV_CODEC_ID_AV1:
> -            frames->initial_pool_size += 16;
> -            break;
> -        case AV_CODEC_ID_VP9:
> -            frames->initial_pool_size += 8;
> -            break;
> -        case AV_CODEC_ID_VP8:
> -            frames->initial_pool_size += 3;
> -            break;
> -        default:
> -            frames->initial_pool_size += 2;
> +        if (!frames->initial_pool_size) {
> +            frames->initial_pool_size = 1;
> +            // Add per-codec number of surfaces used for storing reference frames.
> +            switch (avctx->codec_id) {
> +            case AV_CODEC_ID_H264:
> +            case AV_CODEC_ID_HEVC:
> +            case AV_CODEC_ID_AV1:
> +                frames->initial_pool_size += 16;
> +                break;
> +            case AV_CODEC_ID_VP9:
> +                frames->initial_pool_size += 8;
> +                break;
> +            case AV_CODEC_ID_VP8:
> +                frames->initial_pool_size += 3;
> +                break;
> +            default:
> +                frames->initial_pool_size += 2;
> +            }

Seems to me that ff_vaapi_decode_init() should not pass hw_frames_ctx to
vaapi_decode_make_config() at all, because it is already initialized and
must not be modified.

-- 
Anton Khirnov