[FFmpeg-devel] [PATCH v4 8/9] lavc/qsvenc: enable QVBR mode

Mark Thompson sw at jkqxz.net
Sun Dec 9 21:09:48 EET 2018


On 29/11/2018 08:29, Zhong Li wrote:
> QVBR mode is to use the variable bitrate control algorithm
> with constant quality.
> mfxExtCodingOption3 should be supported to enable QVBR mode.
> 
> Example usage: ffmpeg -hwaccel qsv -c:v h264_qsv -i input.mp4 -c:v
> h264_qsv -global_quality 25 -maxrate 2M test_qvbr.mp4 -v verbose
> 
> Signed-off-by: Zhong Li <zhong.li at intel.com>
> ---
>  libavcodec/qsvenc.c | 39 +++++++++++++++++++++++++++++++++++++--
>  libavcodec/qsvenc.h |  7 +++++--
>  2 files changed, 42 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c
> index ba74821..2dd41d7 100644
> --- a/libavcodec/qsvenc.c
> +++ b/libavcodec/qsvenc.c
> @@ -136,6 +136,9 @@ static void dump_video_param(AVCodecContext *avctx, QSVEncContext *q,
>  #if QSV_HAVE_CO2
>      mfxExtCodingOption2 *co2 = (mfxExtCodingOption2*)coding_opts[1];
>  #endif
> +#if QSV_HAVE_CO3
> +    mfxExtCodingOption3 *co3 = (mfxExtCodingOption3*)coding_opts[2];
> +#endif

With a slightly older header, I got:

src/libavcodec/qsvenc.c: In function ‘dump_video_param’:
src/libavcodec/qsvenc.c:140:26: warning: unused variable ‘co3’ [-Wunused-variable]
     mfxExtCodingOption3 *co3 = (mfxExtCodingOption3*)coding_opts[2];
                          ^~~

av_unused or condition on QVBR rather than CO3 to avoid that?

>  
>      av_log(avctx, AV_LOG_VERBOSE, "profile: %s; level: %"PRIu16"\n",
>             print_profile(info->CodecProfile), info->CodecLevel);
> @@ -190,7 +193,12 @@ static void dump_video_param(AVCodecContext *avctx, QSVEncContext *q,
>                 info->ICQQuality, co2->LookAheadDepth);
>      }
>  #endif
> -
> +#if QSV_HAVE_QVBR
> +    else if (info->RateControlMethod == MFX_RATECONTROL_QVBR) {
> +        av_log(avctx, AV_LOG_VERBOSE, "QVBRQuality: %"PRIu16"\n",
> +               co3->QVBRQuality);
> +    }
> +#endif
>      av_log(avctx, AV_LOG_VERBOSE, "NumSlice: %"PRIu16"; NumRefFrame: %"PRIu16"\n",
>             info->NumSlice, info->NumRefFrame);
>      av_log(avctx, AV_LOG_VERBOSE, "RateDistortionOpt: %s\n",
> @@ -326,7 +334,7 @@ static int select_rc_mode(AVCodecContext *avctx, QSVEncContext *q)
>      }
>  #endif
>  #if QSV_HAVE_ICQ
> -    else if (avctx->global_quality > 0) {
> +    else if (avctx->global_quality > 0 && !avctx->rc_max_rate) {
>          rc_mode = MFX_RATECONTROL_ICQ;
>          rc_desc = "intelligent constant quality (ICQ)";
>      }
> @@ -341,6 +349,12 @@ static int select_rc_mode(AVCodecContext *avctx, QSVEncContext *q)
>          rc_desc = "average variable bitrate (AVBR)";
>      }
>  #endif
> +#if QSV_HAVE_QVBR
> +    else if (avctx->global_quality > 0) {
> +        rc_mode = MFX_RATECONTROL_QVBR;
> +        rc_desc = "constant quality with VBR algorithm (QVBR)";
> +    }
> +#endif
>      else {
>          rc_mode = MFX_RATECONTROL_VBR;
>          rc_desc = "variable bitrate (VBR)";
> @@ -551,10 +565,17 @@ static int init_video_param(AVCodecContext *avctx, QSVEncContext *q)
>  #if QSV_HAVE_VCM
>      case MFX_RATECONTROL_VCM:
>  #endif
> +#if QSV_HAVE_QVBR
> +    case MFX_RATECONTROL_QVBR:
> +#endif
>          q->param.mfx.BufferSizeInKB   = avctx->rc_buffer_size / 8000;
>          q->param.mfx.InitialDelayInKB = avctx->rc_initial_buffer_occupancy / 1000;
>          q->param.mfx.TargetKbps       = avctx->bit_rate / 1000;
>          q->param.mfx.MaxKbps          = avctx->rc_max_rate / 1000;
> +#if QSV_HAVE_QVBR
> +        if (q->param.mfx.RateControlMethod == MFX_RATECONTROL_QVBR)
> +            q->extco3.QVBRQuality = avctx->global_quality;

I think you don't want bit_rate / TargetKbps to be set in this case?  (Though if it's definitely just ignored then I guess it's fine to pass whatever value.)

> +#endif
>          break;
>      case MFX_RATECONTROL_CQP:
>          quant = avctx->global_quality / FF_QP2LAMBDA;
> @@ -699,6 +720,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
>              }
>  #endif
>          }
> +#if QSV_HAVE_CO3
> +        q->extco3.Header.BufferId      = MFX_EXTBUFF_CODING_OPTION3;
> +        q->extco3.Header.BufferSz      = sizeof(q->extco3);
> +        q->extparam_internal[q->nb_extparam_internal++] = (mfxExtBuffer *)&q->extco3;
> +#endif
>      }
>  
>      if (!check_enc_param(avctx,q)) {
> @@ -753,6 +779,12 @@ static int qsv_retrieve_enc_params(AVCodecContext *avctx, QSVEncContext *q)
>          .Header.BufferSz = sizeof(co2),
>      };
>  #endif
> +#if QSV_HAVE_CO3
> +    mfxExtCodingOption3 co3 = {
> +        .Header.BufferId = MFX_EXTBUFF_CODING_OPTION3,
> +        .Header.BufferSz = sizeof(co3),
> +    };
> +#endif
>  
>      mfxExtBuffer *ext_buffers[] = {
>          (mfxExtBuffer*)&extradata,
> @@ -760,6 +792,9 @@ static int qsv_retrieve_enc_params(AVCodecContext *avctx, QSVEncContext *q)
>  #if QSV_HAVE_CO2
>          (mfxExtBuffer*)&co2,
>  #endif
> +#if QSV_HAVE_CO3
> +        (mfxExtBuffer*)&co3,
> +#endif
>      };
>  
>      int need_pps = avctx->codec_id != AV_CODEC_ID_MPEG2VIDEO;
> diff --git a/libavcodec/qsvenc.h b/libavcodec/qsvenc.h
> index c2aa88e..075c86b 100644
> --- a/libavcodec/qsvenc.h
> +++ b/libavcodec/qsvenc.h
> @@ -55,7 +55,7 @@
>  #define QSV_HAVE_AVBR   0
>  #define QSV_HAVE_ICQ    QSV_VERSION_ATLEAST(1, 28)
>  #define QSV_HAVE_VCM    0
> -#define QSV_HAVE_QVBR   0
> +#define QSV_HAVE_QVBR   QSV_VERSION_ATLEAST(1, 28)
>  #define QSV_HAVE_MF     QSV_VERSION_ATLEAST(1, 25)
>  #endif
>  
> @@ -110,6 +110,9 @@ typedef struct QSVEncContext {
>  #if QSV_HAVE_CO2
>      mfxExtCodingOption2 extco2;
>  #endif
> +#if QSV_HAVE_CO3
> +    mfxExtCodingOption3 extco3;
> +#endif
>  #if QSV_HAVE_MF
>      mfxExtMultiFrameParam   extmfp;
>      mfxExtMultiFrameControl extmfc;
> @@ -118,7 +121,7 @@ typedef struct QSVEncContext {
>      mfxFrameSurface1       **opaque_surfaces;
>      AVBufferRef             *opaque_alloc_buf;
>  
> -    mfxExtBuffer  *extparam_internal[2 + QSV_HAVE_CO2 + (QSV_HAVE_MF * 2)];
> +    mfxExtBuffer  *extparam_internal[2 + QSV_HAVE_CO2 + QSV_HAVE_CO3 + (QSV_HAVE_MF * 2)];
>      int         nb_extparam_internal;
>  
>      mfxExtBuffer **extparam;
> 

There should probably be a check somewhere that the quality value is actually in the 1-51 supported range.

Thanks,

- Mark


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