[Libva] [PATCH] H.264 encoder: respect min QP setting

Xiang, Haihao haihao.xiang at intel.com
Wed Jan 4 08:50:48 UTC 2017


Could you send your new revision in a separate email with a version number in the future? I thought this email was just a reply
to the previous email. 

BTW I failed to apply the 2nd patch in the patch series by git-am. Could you rebase the 2nd patch?

Thanks
Haihao


> Signed-off-by: Mark Thompson <sw at jkqxz.net>
> ---
> On 03/01/17 07:54, Xiang, Haihao wrote:
> > On Fri, 2016-12-30 at 16:15 +0000, Mark Thompson wrote:
> > > Signed-off-by: Mark Thompson <sw at jkqxz.net>
> > > ---
> > > This is helpful to avoid some extremes of the CBR rate control (the QP can easily get down to 1 on a static image, which
> > > then
> > > consumes the entire HRD buffer encoding the next non-static frame with far more detail that is wanted).
> > > 
> > > The ROI code is not affected by this, it can still go below the configured min QP - I think this behaviour is the right
> > > one,
> > > but if you don't think so I update that as well.
> > 
> > I agree ROI should also follow the min_qp setting.
> 
> Ok, I've added it in a new version of the patch.
> 
> > > 
> > > 
> > >  src/gen6_mfc_common.c | 18 +++++++++---------
> > >  src/i965_encoder.c    |  4 +++-
> > >  src/i965_encoder.h    |  1 +
> > >  3 files changed, 13 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/src/gen6_mfc_common.c b/src/gen6_mfc_common.c
> > > index 15c0637..e8596ff 100644
> > > --- a/src/gen6_mfc_common.c
> > > +++ b/src/gen6_mfc_common.c
> > > @@ -179,9 +179,9 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
> > >          mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P];
> > >          mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I];
> > >  
> > > -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], 1, 51);
> > > -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], 1, 51);
> > > -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], 1, 51);
> > > +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], (int)encoder_context->brc.min_qp, 51);
> > > +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], (int)encoder_context->brc.min_qp, 51);
> > > +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], (int)encoder_context->brc.min_qp, 51);
> > 
> > How about to set the clamp range to (MAX(1, encoder_context->brc.min_qp), 51) ? According to the API comment, setting min_qp
> > to
> > 0 means the driver can choose a minimal QP. Usually user doesn't set min_qp and we can keep the behavior unchanged for
> > min_qp =
> > 0.
> 
> Yes, sorry, that change was an error on my part - indeed it should continue to be bounded below at 1.  Fixed in the new patch
> using MAX.
> 
> Thanks,
> 
> - Mark
> 
> 
>  src/gen6_mfc_common.c | 28 ++++++++++++++++------------
>  src/i965_encoder.c    |  4 +++-
>  src/i965_encoder.h    |  1 +
>  3 files changed, 20 insertions(+), 13 deletions(-)
> 
> diff --git a/src/gen6_mfc_common.c b/src/gen6_mfc_common.c
> index 15c0637..90cee05 100644
> --- a/src/gen6_mfc_common.c
> +++ b/src/gen6_mfc_common.c
> @@ -98,6 +98,7 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
>      double frame_per_bits = 8 * 3 * encoder_context->frame_width_in_pixel * encoder_context->frame_height_in_pixel / 2;
>      double qp1_size = 0.1 * frame_per_bits;
>      double qp51_size = 0.001 * frame_per_bits;
> +    int min_qp = MAX(1, encoder_context->brc.min_qp);
>      double bpf, factor, hrd_factor;
>      int inum = encoder_context->brc.num_iframes_in_gop,
>          pnum = encoder_context->brc.num_pframes_in_gop,
> @@ -179,9 +180,9 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
>          mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P];
>          mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I];
>  
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], 1, 51);
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], 1, 51);
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], 1, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], min_qp, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], min_qp, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], min_qp, 51);
>      }
>  }
>  
> @@ -226,6 +227,7 @@ int intel_mfc_brc_postpack(struct encode_state *encode_state,
>      int qpn; // predicted quantizer for next frame of current type in integer format
>      double qpf; // predicted quantizer for next frame of current type in float format
>      double delta_qp; // QP correction
> +    int min_qp = MAX(1, encoder_context->brc.min_qp);
>      int target_frame_size, frame_size_next;
>      /* Notes:
>       *  x - how far we are from HRD buffer borders
> @@ -318,7 +320,7 @@ int intel_mfc_brc_postpack(struct encode_state *encode_state,
>      qpn = (int)(qpn + delta_qp + 0.5);
>  
>      /* making sure that with QP predictions we did do not leave QPs range */
> -    BRC_CLIP(qpn, 1, 51);
> +    BRC_CLIP(qpn, min_qp, 51);
>  
>      if (sts == BRC_NO_HRD_VIOLATION) { // no HRD violation
>          /* correcting QPs of slices of other types */
> @@ -338,9 +340,9 @@ int intel_mfc_brc_postpack(struct encode_state *encode_state,
>              if (abs(qpn - BRC_I_B_QP_DIFF - qpi) > 4)
>                  mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_I] += (qpn - BRC_I_B_QP_DIFF - qpi) >> 2;
>          }
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_I], 1, 51);
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_P], 1, 51);
> -        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_B], 1, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_I], min_qp, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_P], min_qp, 51);
> +        BRC_CLIP(mfc_context->brc.qp_prime_y[next_frame_layer_id][SLICE_TYPE_B], min_qp, 51);
>      } else if (sts == BRC_UNDERFLOW) { // underflow
>          if (qpn <= qp) qpn = qp + 1;
>          if (qpn > 51) {
> @@ -349,8 +351,8 @@ int intel_mfc_brc_postpack(struct encode_state *encode_state,
>          }
>      } else if (sts == BRC_OVERFLOW) {
>          if (qpn >= qp) qpn = qp - 1;
> -        if (qpn < 1) { // < 0 (?) overflow with minQP
> -            qpn = 1;
> +        if (qpn < min_qp) { // overflow with minQP
> +            qpn = min_qp;
>              sts = BRC_OVERFLOW_WITH_MIN_QP; // bit stuffing to be done
>          }
>      }
> @@ -1815,6 +1817,7 @@ intel_h264_enc_roi_cbr(VADriverContextP ctx,
>                         struct intel_encoder_context *encoder_context)
>  {
>      int nonroi_qp;
> +    int min_qp = MAX(1, encoder_context->brc.min_qp);
>      VAEncROI *region_roi;
>      bool quickfill = 0;
>  
> @@ -1889,7 +1892,7 @@ intel_h264_enc_roi_cbr(VADriverContextP ctx,
>          param_regions[i].height_mbs = roi_height_mbs;
>  
>          roi_qp = base_qp + region_roi->roi_value;
> -        BRC_CLIP(roi_qp, 1, 51);
> +        BRC_CLIP(roi_qp, min_qp, 51);
>  
>          param_regions[i].roi_qp = roi_qp;
>          qstep_roi = intel_h264_qp_qstep(roi_qp);
> @@ -1911,7 +1914,7 @@ intel_h264_enc_roi_cbr(VADriverContextP ctx,
>          nonroi_qp = intel_h264_qstep_qp(qstep_nonroi);
>      }
>  
> -    BRC_CLIP(nonroi_qp, 1, 51);
> +    BRC_CLIP(nonroi_qp, min_qp, 51);
>  
>  qp_fill:
>      memset(vme_context->qp_per_mb, nonroi_qp, mbs_in_picture);
> @@ -1992,6 +1995,7 @@ intel_h264_enc_roi_config(VADriverContextP ctx,
>          VAEncPictureParameterBufferH264 *pic_param = (VAEncPictureParameterBufferH264 *)encode_state->pic_param_ext->buffer;
>          VAEncSliceParameterBufferH264 *slice_param = (VAEncSliceParameterBufferH264 *)encode_state->slice_params_ext[0]-
> >buffer;
>          int qp;
> +        int min_qp = MAX(1, encoder_context->brc.min_qp);
>  
>          qp = pic_param->pic_init_qp + slice_param->slice_qp_delta;
>          memset(vme_context->qp_per_mb, qp, width_in_mbs * height_in_mbs);
> @@ -2015,7 +2019,7 @@ intel_h264_enc_roi_config(VADriverContextP ctx,
>              qp_delta = region_roi->roi_value;
>              qp_clip = qp + qp_delta;
>  
> -            BRC_CLIP(qp_clip, 1, 51);
> +            BRC_CLIP(qp_clip, min_qp, 51);
>  
>              for (i = row_start; i < row_end; i++) {
>                  qp_ptr = vme_context->qp_per_mb + (i * width_in_mbs) + col_start;
> diff --git a/src/i965_encoder.c b/src/i965_encoder.c
> index ae31f01..3056900 100644
> --- a/src/i965_encoder.c
> +++ b/src/i965_encoder.c
> @@ -575,8 +575,10 @@ intel_encoder_check_rate_control_parameter(VADriverContextP ctx,
>          encoder_context->brc.need_reset = 1;
>      }
>  
> -    if (encoder_context->brc.window_size != misc->window_size) {
> +    if (encoder_context->brc.window_size != misc->window_size ||
> +        encoder_context->brc.min_qp      != misc->min_qp) {
>          encoder_context->brc.window_size = misc->window_size;
> +        encoder_context->brc.min_qp      = misc->min_qp;
>          encoder_context->brc.need_reset = 1;
>      }
>  
> diff --git a/src/i965_encoder.h b/src/i965_encoder.h
> index be19ce6..16a6f3f 100644
> --- a/src/i965_encoder.h
> +++ b/src/i965_encoder.h
> @@ -92,6 +92,7 @@ struct intel_encoder_context
>          unsigned int hrd_buffer_size;
>          unsigned int hrd_initial_buffer_fullness;
>          unsigned int window_size;
> +        unsigned int min_qp;
>          unsigned int need_reset;
>  
>          unsigned int num_roi;


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