[FFmpeg-devel] [PATCH 3/3] libavcodec/vaapi_encode: Add async_depth to vaapi_encoder to increase performance

[Chen, Wenbin]

> Add async_depth to increase encoder's performance. Reuse encode_fifo as
> async buffer. Encoder puts all reordered frame to HW and then check
> fifo size. If fifo < async_depth and the top frame is not ready, it will
> return AVERROR(EAGAIN) to require more frames.
> 
> 1080p transcoding (no B frames) with -async_depth=4 can increase 20%
> performance on my environment.
> The async increases performance but also introduces frame delay.
> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavcodec/vaapi_encode.c | 20 +++++++++++++++-----
>  libavcodec/vaapi_encode.h | 12 ++++++++++--
>  2 files changed, 25 insertions(+), 7 deletions(-)
> 
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index db0ae136a1..616fb7c089 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -1158,7 +1158,8 @@ static int
> vaapi_encode_send_frame(AVCodecContext *avctx, AVFrame *frame)
>          if (ctx->input_order == ctx->decode_delay)
>              ctx->dts_pts_diff = pic->pts - ctx->first_pts;
>          if (ctx->output_delay > 0)
> -            ctx->ts_ring[ctx->input_order % (3 * ctx->output_delay)] = pic->pts;
> +            ctx->ts_ring[ctx->input_order %
> +                        (3 * ctx->output_delay + ctx->async_depth)] = pic->pts;
> 
>          pic->display_order = ctx->input_order;
>          ++ctx->input_order;
> @@ -1212,7 +1213,8 @@ int
> ff_vaapi_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
>              return AVERROR(EAGAIN);
>      }
> 
> -    while (av_fifo_size(ctx->encode_fifo) <= MAX_PICTURE_REFERENCES *
> sizeof(VAAPIEncodePicture *)) {
> +    while (av_fifo_size(ctx->encode_fifo) <
> +            MAX_ASYNC_DEPTH * sizeof(VAAPIEncodePicture *)) {
>          pic = NULL;
>          err = vaapi_encode_pick_next(avctx, &pic);
>          if (err < 0)
> @@ -1234,6 +1236,14 @@ int
> ff_vaapi_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
>      if (!av_fifo_size(ctx->encode_fifo))
>          return err;
> 
> +    if (av_fifo_size(ctx->encode_fifo) < ctx->async_depth *
> sizeof(VAAPIEncodePicture *) &&
> +        !ctx->end_of_stream) {
> +        av_fifo_generic_peek(ctx->encode_fifo, &pic, sizeof(pic), NULL);
> +        err = vaapi_encode_wait(avctx, pic, 0);
> +        if (err < 0)
> +            return err;
> +    }
> +
>      av_fifo_generic_read(ctx->encode_fifo, &pic, sizeof(pic), NULL);
>      ctx->encode_order = pic->encode_order + 1;
> 
> @@ -1252,7 +1262,7 @@ int
> ff_vaapi_encode_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
>              pkt->dts = ctx->ts_ring[pic->encode_order] - ctx->dts_pts_diff;
>      } else {
>          pkt->dts = ctx->ts_ring[(pic->encode_order - ctx->decode_delay) %
> -                                (3 * ctx->output_delay)];
> +                                (3 * ctx->output_delay + ctx->async_depth)];
>      }
>      av_log(avctx, AV_LOG_DEBUG, "Output packet: pts %"PRId64"
> dts %"PRId64".\n",
>             pkt->pts, pkt->dts);
> @@ -2566,8 +2576,8 @@ av_cold int ff_vaapi_encode_init(AVCodecContext
> *avctx)
>          }
>      }
> 
> -    ctx->encode_fifo = av_fifo_alloc((MAX_PICTURE_REFERENCES + 1) *
> -                                      sizeof(VAAPIEncodePicture *));
> +    ctx->encode_fifo = av_fifo_alloc(MAX_ASYNC_DEPTH *
> +                                     sizeof(VAAPIEncodePicture *));
>      if (!ctx->encode_fifo)
>          return AVERROR(ENOMEM);
> 
> diff --git a/libavcodec/vaapi_encode.h b/libavcodec/vaapi_encode.h
> index 89fe8de466..1bf5d7c337 100644
> --- a/libavcodec/vaapi_encode.h
> +++ b/libavcodec/vaapi_encode.h
> @@ -48,6 +48,7 @@ enum {
>      MAX_TILE_ROWS          = 22,
>      // A.4.1: table A.6 allows at most 20 tile columns for any level.
>      MAX_TILE_COLS          = 20,
> +    MAX_ASYNC_DEPTH        = 64,
>  };
> 
>  extern const AVCodecHWConfigInternal *const
> ff_vaapi_encode_hw_configs[];
> @@ -298,7 +299,8 @@ typedef struct VAAPIEncodeContext {
>      // Timestamp handling.
>      int64_t         first_pts;
>      int64_t         dts_pts_diff;
> -    int64_t         ts_ring[MAX_REORDER_DELAY * 3];
> +    int64_t         ts_ring[MAX_REORDER_DELAY * 3 +
> +                            MAX_ASYNC_DEPTH];
> 
>      // Slice structure.
>      int slice_block_rows;
> @@ -348,6 +350,8 @@ typedef struct VAAPIEncodeContext {
>      AVFrame         *frame;
> 
>      AVFifoBuffer *encode_fifo;
> +
> +    int async_depth;
>  } VAAPIEncodeContext;
> 
>  enum {
> @@ -458,7 +462,11 @@ int ff_vaapi_encode_close(AVCodecContext *avctx);
>      { "b_depth", \
>        "Maximum B-frame reference depth", \
>        OFFSET(common.desired_b_depth), AV_OPT_TYPE_INT, \
> -      { .i64 = 1 }, 1, INT_MAX, FLAGS }
> +      { .i64 = 1 }, 1, INT_MAX, FLAGS }, \
> +    { "async_depth", "Maximum processing parallelism. " \
> +      "Increase this to improve single channel performance", \
> +      OFFSET(common.async_depth), AV_OPT_TYPE_INT, \
> +      { .i64 = 4 }, 0, MAX_ASYNC_DEPTH, FLAGS }
> 
>  #define VAAPI_ENCODE_RC_MODE(name, desc) \
>      { #name, desc, 0, AV_OPT_TYPE_CONST, { .i64 = RC_MODE_ ## name }, \
> --
> 2.25.1

ping