[FFmpeg-devel] [PATCH] lavc/vaapi_encode: Async the encoding and output procedure of encoder

[Fu, Linjie]

> -----Original Message-----
> From: Fu, Linjie <linjie.fu at intel.com>
> Sent: Friday, November 8, 2019 00:32
> To: ffmpeg-devel at ffmpeg.org
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: [PATCH] lavc/vaapi_encode: Async the encoding and output
> procedure of encoder
> 
> Currently, vaapi encodes a pic if all its references are ready,
> and then outputs it immediately by calling vaapi_encode_output.
> 
> However, while working on output procedure, hardware is be able to
> cope with encoding tasks in the meantime to have the better performance.
> 
> So a more efficient way is to send all the pics with available refs to
> hardware to allow encoding while output.
> 
> It's what vaapi originally did before the regression, and the performance
> could be improved for ~20%.
> 
> CMD:
> ffmpeg -hwaccel vaapi -vaapi_device /dev/dri/renderD128
> -hwaccel_output_format vaapi -i bbb_sunflower_1080p_30fps_normal.mp4
> -c:v h264_vaapi -f h264 -y /dev/null
> 
> Source:
> https://download.blender.org/demo/movies/BBB/
> 
> Before:
>     ~164 fps
> After:
>     ~198 fps
> 
> Fix #7706.
> 
> Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> ---
>  libavcodec/vaapi_encode.c | 27 +++++++++++++++++++--------
>  1 file changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index 3be9159d37..aceb268315 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -1109,17 +1109,28 @@ int
> ff_vaapi_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
>              return AVERROR(EAGAIN);
>      }
> 
> +pick_next:
>      pic = NULL;
>      err = vaapi_encode_pick_next(avctx, &pic);
> -    if (err < 0)
> -        return err;
> -    av_assert0(pic);
> +    if (!err) {
> +        av_assert0(pic);
> 
> -    pic->encode_order = ctx->encode_order++;
> +        pic->encode_order = ctx->encode_order++;
> 
> -    err = vaapi_encode_issue(avctx, pic);
> -    if (err < 0) {
> -        av_log(avctx, AV_LOG_ERROR, "Encode failed: %d.\n", err);
> +        err = vaapi_encode_issue(avctx, pic);
> +        if (err < 0) {
> +            av_log(avctx, AV_LOG_ERROR, "Encode failed: %d.\n", err);
> +            return err;
> +        }
> +        goto pick_next;
> +    } else if (err == AVERROR(EAGAIN)) {
> +        for (pic = ctx->pic_start; pic; pic = pic->next)
> +            if (pic->encode_issued && !pic->encode_complete &&
> +                pic->encode_order == ctx->output_order)
> +                break;
> +        if (!pic)
> +            return err;
> +    } else {
>          return err;
>      }
> 
> @@ -1143,7 +1154,7 @@ int
> ff_vaapi_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
>      av_log(avctx, AV_LOG_DEBUG, "Output packet: pts %"PRId64"
> dts %"PRId64".\n",
>             pkt->pts, pkt->dts);
> 
> -    ctx->output_order = pic->encode_order;
> +    ctx->output_order++;
>      vaapi_encode_clear_old(avctx);
> 
>      return 0;

Ping.

- linjie