[FFmpeg-devel] [PATCH 1/3] libavcodec/vaapi_encode: Change the way to call async to increase performance

[Xiang, Haihao]

On Wed, 2021-10-27 at 16:57 +0800, Wenbin Chen wrote:
> Fix: #7706. After commit 5fdcf85bbffe7451c2, vaapi encoder's performance
> decrease. The reason is that vaRenderPicture() and vaSyncSurface() are
> called at the same time (vaRenderPicture() always followed by a
> vaSyncSurface()). When we encode stream with B frames, we need buffer to
> reorder frames, so we can send serveral frames to HW at once to increase
> performance. Now I changed them to be called in a
> asynchronous way, which will make better use of hardware.
> 1080p transcoding increases about 17% fps on my environment.

Could you provide your command ? I'd like to have a try. 

Thanks
Haihao

> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavcodec/vaapi_encode.c | 41 ++++++++++++++++++++++++++++-----------
>  libavcodec/vaapi_encode.h |  3 +++
>  2 files changed, 33 insertions(+), 11 deletions(-)
> 
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index ec054ae701..5927849233 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -951,8 +951,10 @@ static int vaapi_encode_pick_next(AVCodecContext *avctx,
>      if (!pic && ctx->end_of_stream) {
>          --b_counter;
>          pic = ctx->pic_end;
> -        if (pic->encode_issued)
> +        if (pic->encode_complete)
>              return AVERROR_EOF;
> +        else if (pic->encode_issued)
> +            return AVERROR(EAGAIN);
>      }
>  
>      if (!pic) {
> @@ -1177,20 +1179,31 @@ int ff_vaapi_encode_receive_packet(AVCodecContext
> *avctx, AVPacket *pkt)
>              return AVERROR(EAGAIN);
>      }
>  
> -    pic = NULL;
> -    err = vaapi_encode_pick_next(avctx, &pic);
> -    if (err < 0)
> -        return err;
> -    av_assert0(pic);
> +    while (av_fifo_size(ctx->encode_fifo) <= MAX_PICTURE_REFERENCES *
> sizeof(VAAPIEncodePicture *)) {
> +        pic = NULL;
> +        err = vaapi_encode_pick_next(avctx, &pic);
> +        if (err < 0)
> +            break;
> +        av_assert0(pic);
>  
> -    pic->encode_order = ctx->encode_order++;
> +        pic->encode_order = ctx->encode_order +
> +                            (av_fifo_size(ctx->encode_fifo) /
> sizeof(VAAPIEncodePicture *));
>  
> -    err = vaapi_encode_issue(avctx, pic);
> -    if (err < 0) {
> -        av_log(avctx, AV_LOG_ERROR, "Encode failed: %d.\n", err);
> -        return err;
> +        err = vaapi_encode_issue(avctx, pic);
> +        if (err < 0) {
> +            av_log(avctx, AV_LOG_ERROR, "Encode failed: %d.\n", err);
> +            return err;
> +        }
> +
> +        av_fifo_generic_write(ctx->encode_fifo, &pic, sizeof(pic), NULL);
>      }
>  
> +    if (!av_fifo_size(ctx->encode_fifo))
> +        return err;
> +
> +    av_fifo_generic_read(ctx->encode_fifo, &pic, sizeof(pic), NULL);
> +    ctx->encode_order = pic->encode_order + 1;
> +
>      err = vaapi_encode_output(avctx, pic, pkt);
>      if (err < 0) {
>          av_log(avctx, AV_LOG_ERROR, "Output failed: %d.\n", err);
> @@ -2520,6 +2533,11 @@ av_cold int ff_vaapi_encode_init(AVCodecContext *avctx)
>          }
>      }
>  
> +    ctx->encode_fifo = av_fifo_alloc((MAX_PICTURE_REFERENCES + 1) *
> +                                      sizeof(VAAPIEncodePicture *));
> +    if (!ctx->encode_fifo)
> +        return AVERROR(ENOMEM);
> +
>      return 0;
>  
>  fail:
> @@ -2552,6 +2570,7 @@ av_cold int ff_vaapi_encode_close(AVCodecContext *avctx)
>  
>      av_freep(&ctx->codec_sequence_params);
>      av_freep(&ctx->codec_picture_params);
> +    av_fifo_freep(&ctx->encode_fifo);
>  
>      av_buffer_unref(&ctx->recon_frames_ref);
>      av_buffer_unref(&ctx->input_frames_ref);
> diff --git a/libavcodec/vaapi_encode.h b/libavcodec/vaapi_encode.h
> index b41604a883..89fe8de466 100644
> --- a/libavcodec/vaapi_encode.h
> +++ b/libavcodec/vaapi_encode.h
> @@ -29,6 +29,7 @@
>  
>  #include "libavutil/hwcontext.h"
>  #include "libavutil/hwcontext_vaapi.h"
> +#include "libavutil/fifo.h"
>  
>  #include "avcodec.h"
>  #include "hwconfig.h"
> @@ -345,6 +346,8 @@ typedef struct VAAPIEncodeContext {
>      int             roi_warned;
>  
>      AVFrame         *frame;
> +
> +    AVFifoBuffer *encode_fifo;
>  } VAAPIEncodeContext;
>  
>  enum {