[Libva] [PATCH] H.264 encoder: respect min QP setting
Mark Thompson
sw at jkqxz.net
Tue Jan 3 23:43:38 UTC 2017
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;
--
2.11.0
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