[FFmpeg-devel] [PATCH] lavc/qsvenc: add support for external bitrate control for HEVC

[Zhong Li]

Linjie Fu <linjie.fu at intel.com> 于2020年2月13日周四 下午8:50写道：
>
> Enables option for hevc_qsv encoder:
>     -extbrc
>
> Improvements in BD-Rate could be observed with extbrc on.
>
> Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> ---
> Details for extbrc:
> https://github.com/Intel-Media-SDK/MediaSDK/blob/master/doc/mediasdk-man.md#external-bit-rate-control
>
> The improvement differs depending on the platform/clips/bitrate.
> Based on the verifying on ICL, ~20% improvement in BD-Rate could be observed.

Is there any HW platform requirement for this feature? And how much
quality improvement  for H264?

>  libavcodec/qsvenc.c | 18 ++++++++++++------
>  1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c
> index 9e41650..7f964ad 100644
> --- a/libavcodec/qsvenc.c
> +++ b/libavcodec/qsvenc.c
> @@ -681,11 +681,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
>
>          q->extparam_internal[q->nb_extparam_internal++] = (mfxExtBuffer *)&q->extco;
>
> -        if (avctx->codec_id == AV_CODEC_ID_H264) {
>  #if QSV_HAVE_CO2
> -            q->extco2.Header.BufferId     = MFX_EXTBUFF_CODING_OPTION2;
> -            q->extco2.Header.BufferSz     = sizeof(q->extco2);
> -
> +        if (avctx->codec_id == AV_CODEC_ID_H264) {
>              if (q->int_ref_type >= 0)
>                  q->extco2.IntRefType = q->int_ref_type;
>              if (q->int_ref_cycle_size >= 0)
> @@ -697,8 +694,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
>                  q->extco2.BitrateLimit = q->bitrate_limit ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
>              if (q->mbbrc >= 0)
>                  q->extco2.MBBRC = q->mbbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
> -            if (q->extbrc >= 0)
> -                q->extco2.ExtBRC = q->extbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
>
>              if (q->max_frame_size >= 0)
>                  q->extco2.MaxFrameSize = q->max_frame_size;
> @@ -746,9 +741,20 @@ FF_ENABLE_DEPRECATION_WARNINGS
>                  q->extco2.MaxQPP = q->extco2.MaxQPB = q->extco2.MaxQPI;
>              }
>  #endif
> +        }
> +
> +        if (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC) {
> +            if (q->extbrc >= 0)
> +                q->extco2.ExtBRC = q->extbrc ? MFX_CODINGOPTION_ON : MFX_CODINGOPTION_OFF;
> +
> +            q->extco2.Header.BufferId = MFX_EXTBUFF_CODING_OPTION2;
> +            q->extco2.Header.BufferSz = sizeof(q->extco2);
> +
>              q->extparam_internal[q->nb_extparam_internal++] = (mfxExtBuffer *)&q->extco2;
> +        }
>  #endif
>
> +        if (avctx->codec_id == AV_CODEC_ID_H264) {
>  #if QSV_HAVE_MF
>              if (QSV_RUNTIME_VERSION_ATLEAST(q->ver, 1, 25)) {
>                  q->extmfp.Header.BufferId     = MFX_EXTBUFF_MULTI_FRAME_PARAM;
> --
> 2.7.4

Patch LGTM