Updates for 1-pass CBR rate control.

Adjustments based on buffer level, frame dropper.

Change-Id: Iaa85b570493526a60c4b9fb7ded4c0226b1b3a33
This commit is contained in:
Marco Paniconi 2013-12-17 15:45:30 -08:00
parent d2f4940783
commit 1b8b8b0d0d
7 changed files with 280 additions and 37 deletions

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@ -193,7 +193,10 @@ class DatarateTestVP9 : public ::libvpx_test::EncoderTest,
virtual void ResetModel() {
last_pts_ = 0;
bits_in_buffer_model_ = cfg_.rc_target_bitrate * cfg_.rc_buf_initial_sz;
frame_number_ = 0;
first_drop_ = 0;
num_drops_ = 0;
bits_total_ = 0;
duration_ = 0.0;
}
@ -209,8 +212,29 @@ class DatarateTestVP9 : public ::libvpx_test::EncoderTest,
}
virtual void FramePktHook(const vpx_codec_cx_pkt_t *pkt) {
// Time since last timestamp = duration.
vpx_codec_pts_t duration = pkt->data.frame.pts - last_pts_;
// Add to the buffer the bits we'd expect from a constant bitrate server.
bits_in_buffer_model_ += duration * timebase_ * cfg_.rc_target_bitrate
* 1000;
// Buffer should not go negative.
ASSERT_GE(bits_in_buffer_model_, 0) << "Buffer Underrun at frame "
<< pkt->data.frame.pts;
const int frame_size_in_bits = pkt->data.frame.sz * 8;
bits_total_ += frame_size_in_bits;
// If first drop not set and we have a drop set it to this time.
if (!first_drop_ && duration > 1)
first_drop_ = last_pts_ + 1;
// Update the number of frame drops.
if (duration > 1) {
num_drops_+= (duration - 1);
}
// Update the most recent pts.
last_pts_ = pkt->data.frame.pts;
++frame_number_;
@ -231,13 +255,17 @@ class DatarateTestVP9 : public ::libvpx_test::EncoderTest,
double duration_;
double effective_datarate_;
int set_cpu_used_;
int bits_in_buffer_model_;
int first_drop_;
int num_drops_;
};
// There is no buffer model/frame dropper in VP9 currently, so for now we
// have separate test for VP9 rate targeting for 1-pass CBR. We only check
// that effective datarate is within some range of target bitrate.
// No frame dropper, so we can't go to low bitrates.
// Check basic rate targeting,
TEST_P(DatarateTestVP9, BasicRateTargeting) {
cfg_.rc_buf_initial_sz = 500;
cfg_.rc_buf_optimal_sz = 500;
cfg_.rc_buf_sz = 1000;
cfg_.rc_dropframe_thresh = 1;
cfg_.rc_min_quantizer = 0;
cfg_.rc_max_quantizer = 63;
cfg_.rc_end_usage = VPX_CBR;
@ -257,6 +285,49 @@ TEST_P(DatarateTestVP9, BasicRateTargeting) {
}
}
// Check that (1) the first dropped frame gets earlier and earlier
// as the drop frame threshold is increased, and (2) that the total number of
// frame drops does not decrease as we increase frame drop threshold.
// Use a lower qp-max to force some frame drops.
TEST_P(DatarateTestVP9, ChangingDropFrameThresh) {
cfg_.rc_buf_initial_sz = 500;
cfg_.rc_buf_optimal_sz = 500;
cfg_.rc_buf_sz = 1000;
cfg_.rc_undershoot_pct = 20;
cfg_.rc_undershoot_pct = 20;
cfg_.rc_dropframe_thresh = 10;
cfg_.rc_min_quantizer = 0;
cfg_.rc_max_quantizer = 50;
cfg_.rc_end_usage = VPX_CBR;
cfg_.rc_target_bitrate = 200;
::libvpx_test::I420VideoSource video("hantro_collage_w352h288.yuv", 352, 288,
30, 1, 0, 140);
const int kDropFrameThreshTestStep = 30;
int last_drop = 140;
int last_num_drops = 0;
for (int i = 10; i < 100; i += kDropFrameThreshTestStep) {
cfg_.rc_dropframe_thresh = i;
ResetModel();
ASSERT_NO_FATAL_FAILURE(RunLoop(&video));
ASSERT_GE(effective_datarate_, cfg_.rc_target_bitrate * 0.85)
<< " The datarate for the file is lower than target by too much!";
ASSERT_LE(effective_datarate_, cfg_.rc_target_bitrate * 1.15)
<< " The datarate for the file is greater than target by too much!";
ASSERT_LE(first_drop_, last_drop)
<< " The first dropped frame for drop_thresh " << i
<< " > first dropped frame for drop_thresh "
<< i - kDropFrameThreshTestStep;
ASSERT_GE(num_drops_, last_num_drops)
<< " The number of dropped frames for drop_thresh " << i
<< " < number of dropped frames for drop_thresh "
<< i - kDropFrameThreshTestStep;
last_drop = first_drop_;
last_num_drops = num_drops_;
}
}
VP8_INSTANTIATE_TEST_CASE(DatarateTest, ALL_TEST_MODES);
VP9_INSTANTIATE_TEST_CASE(DatarateTestVP9,
::testing::Values(::libvpx_test::kOnePassGood),

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@ -129,6 +129,9 @@ extern "C"
int64_t optimal_buffer_level;
int64_t maximum_buffer_size;
// Frame drop threshold.
int drop_frames_water_mark;
// controlling quality
int fixed_q;
int worst_allowed_q;

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@ -2987,6 +2987,20 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
configure_static_seg_features(cpi);
}
// For 1 pass CBR, check if we are dropping this frame.
// Never drop on key frame.
if (cpi->pass == 0 &&
cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER &&
cm->frame_type != KEY_FRAME) {
if (vp9_drop_frame(cpi)) {
// Update buffer level with zero size, update frame counters, and return.
vp9_update_buffer_level(cpi, 0);
cm->current_video_frame++;
cpi->rc.frames_since_key++;
return;
}
}
vp9_clear_system_state();
vp9_zero(cpi->rd_tx_select_threshes);
@ -3587,6 +3601,11 @@ int vp9_get_compressed_data(VP9_PTR ptr, unsigned int *frame_flags,
if (cm->refresh_frame_context)
cm->frame_contexts[cm->frame_context_idx] = cm->fc;
// Frame was dropped, release scaled references.
if (*size == 0) {
release_scaled_references(cpi);
}
if (*size > 0) {
// if its a dropped frame honor the requests on subsequent frames
cpi->droppable = !frame_is_reference(cpi);

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@ -331,6 +331,9 @@ typedef struct {
int buffer_level;
int bits_off_target;
int decimation_factor;
int decimation_count;
int rolling_target_bits;
int rolling_actual_bits;
@ -480,9 +483,6 @@ typedef struct VP9_COMP {
int static_mb_pct; // % forced skip mbs by segmentation
int seg0_progress, seg0_idx, seg0_cnt;
int decimation_factor;
int decimation_count;
// for real time encoding
int speed;
int compressor_speed;

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@ -222,6 +222,31 @@ static void calc_iframe_target_size(VP9_COMP *cpi) {
// New Two pass RC
target = cpi->rc.per_frame_bandwidth;
// For 1-pass.
if (cpi->pass == 0) {
if (cpi->common.current_video_frame == 0) {
target = cpi->oxcf.starting_buffer_level / 2;
} else {
// TODO(marpan): Add in adjustment based on Q.
// If this keyframe was forced, use a more recent Q estimate.
// int Q = (cpi->common.frame_flags & FRAMEFLAGS_KEY) ?
// cpi->rc.avg_frame_qindex : cpi->rc.ni_av_qi;
int initial_boost = 32;
// Boost depends somewhat on frame rate.
int kf_boost = MAX(initial_boost, (int)(2 * cpi->output_framerate - 16));
// Adjustment up based on q: need to fix.
// kf_boost = kf_boost * kfboost_qadjust(Q) / 100;
// Frame separation adjustment (down).
if (cpi->rc.frames_since_key < cpi->output_framerate / 2) {
kf_boost = (int)(kf_boost * cpi->rc.frames_since_key /
(cpi->output_framerate / 2));
}
kf_boost = (kf_boost < 16) ? 16 : kf_boost;
target = ((16 + kf_boost) * cpi->rc.per_frame_bandwidth) >> 4;
}
cpi->rc.active_worst_quality = cpi->rc.worst_quality;
}
if (cpi->oxcf.rc_max_intra_bitrate_pct) {
int max_rate = cpi->rc.per_frame_bandwidth
* cpi->oxcf.rc_max_intra_bitrate_pct / 100;
@ -242,18 +267,154 @@ static void calc_gf_params(VP9_COMP *cpi) {
cpi->rc.frames_till_gf_update_due = cpi->rc.baseline_gf_interval;
}
// Update the buffer level: leaky bucket model.
void vp9_update_buffer_level(VP9_COMP *const cpi, int encoded_frame_size) {
VP9_COMMON *const cm = &cpi->common;
// Non-viewable frames are a special case and are treated as pure overhead.
if (!cm->show_frame) {
cpi->rc.bits_off_target -= encoded_frame_size;
} else {
cpi->rc.bits_off_target += cpi->rc.av_per_frame_bandwidth -
encoded_frame_size;
}
// Clip the buffer level to the maximum specified buffer size.
if (cpi->rc.bits_off_target > cpi->oxcf.maximum_buffer_size) {
cpi->rc.bits_off_target = cpi->oxcf.maximum_buffer_size;
}
cpi->rc.buffer_level = cpi->rc.bits_off_target;
}
static void calc_pframe_target_size(VP9_COMP *cpi) {
const int min_frame_target = MAX(cpi->rc.min_frame_bandwidth,
cpi->rc.av_per_frame_bandwidth >> 5);
int vp9_drop_frame(VP9_COMP *const cpi) {
if (!cpi->oxcf.drop_frames_water_mark) {
return 0;
} else {
if (cpi->rc.buffer_level < 0) {
// Always drop if buffer is below 0.
return 1;
} else {
// If buffer is below drop_mark, for now just drop every other frame
// (starting with the next frame) until it increases back over drop_mark.
int drop_mark = (int)(cpi->oxcf.drop_frames_water_mark *
cpi->oxcf.optimal_buffer_level / 100);
if ((cpi->rc.buffer_level > drop_mark) &&
(cpi->rc.decimation_factor > 0)) {
--cpi->rc.decimation_factor;
} else if (cpi->rc.buffer_level <= drop_mark &&
cpi->rc.decimation_factor == 0) {
cpi->rc.decimation_factor = 1;
}
if (cpi->rc.decimation_factor > 0) {
if (cpi->rc.decimation_count > 0) {
--cpi->rc.decimation_count;
return 1;
} else {
cpi->rc.decimation_count = cpi->rc.decimation_factor;
return 0;
}
} else {
cpi->rc.decimation_count = 0;
return 0;
}
}
}
}
// Adjust active_worst_quality level based on buffer level.
static int adjust_active_worst_quality_from_buffer_level(const VP9_COMP *cpi) {
// Adjust active_worst_quality: If buffer is above the optimal/target level,
// bring active_worst_quality down depending on fullness over buffer.
// If buffer is below the optimal level, let the active_worst_quality go from
// ambient Q (at buffer = optimal level) to worst_quality level
// (at buffer = critical level).
int active_worst_quality = cpi->rc.active_worst_quality;
// Maximum limit for down adjustment, ~20%.
int max_adjustment_down = active_worst_quality / 5;
// Buffer level below which we push active_worst to worst_quality.
int critical_level = cpi->oxcf.optimal_buffer_level >> 2;
int adjustment = 0;
int buff_lvl_step = 0;
if (cpi->rc.buffer_level > cpi->oxcf.optimal_buffer_level) {
// Adjust down.
if (max_adjustment_down) {
buff_lvl_step = (int)((cpi->oxcf.maximum_buffer_size -
cpi->oxcf.optimal_buffer_level) / max_adjustment_down);
if (buff_lvl_step) {
adjustment = (int)((cpi->rc.buffer_level -
cpi->oxcf.optimal_buffer_level) / buff_lvl_step);
}
active_worst_quality -= adjustment;
}
} else if (cpi->rc.buffer_level > critical_level) {
// Adjust up from ambient Q.
if (critical_level) {
buff_lvl_step = (cpi->oxcf.optimal_buffer_level - critical_level);
if (buff_lvl_step) {
adjustment =
(cpi->rc.worst_quality - cpi->rc.avg_frame_qindex[INTER_FRAME]) *
(cpi->oxcf.optimal_buffer_level - cpi->rc.buffer_level) /
buff_lvl_step;
}
active_worst_quality = cpi->rc.avg_frame_qindex[INTER_FRAME] + adjustment;
}
} else {
// Set to worst_quality if buffer is below critical level.
active_worst_quality = cpi->rc.worst_quality;
}
return active_worst_quality;
}
// Adjust target frame size with respect to the buffering constraints:
static int target_size_from_buffer_level(const VP9_COMP *cpi) {
int this_frame_target = cpi->rc.this_frame_target;
int percent_low = 0;
int percent_high = 0;
int one_percent_bits = (int)(1 + cpi->oxcf.optimal_buffer_level / 100);
if (cpi->rc.buffer_level < cpi->oxcf.optimal_buffer_level) {
percent_low = (int)((cpi->oxcf.optimal_buffer_level - cpi->rc.buffer_level)
/ one_percent_bits);
if (percent_low > cpi->oxcf.under_shoot_pct) {
percent_low = cpi->oxcf.under_shoot_pct;
} else if (percent_low < 0) {
percent_low = 0;
}
// Lower the target bandwidth for this frame.
this_frame_target -= (this_frame_target * percent_low) / 200;
} else if (cpi->rc.buffer_level > cpi->oxcf.optimal_buffer_level) {
percent_high = (int)((cpi->rc.buffer_level - cpi->oxcf.optimal_buffer_level)
/ one_percent_bits);
if (percent_high > cpi->oxcf.over_shoot_pct) {
percent_high = cpi->oxcf.over_shoot_pct;
} else if (percent_high < 0) {
percent_high = 0;
}
// Increase the target bandwidth for this frame.
this_frame_target += (this_frame_target * percent_high) / 200;
}
return this_frame_target;
}
static void calc_pframe_target_size(VP9_COMP *const cpi) {
int min_frame_target = MAX(cpi->rc.min_frame_bandwidth,
cpi->rc.av_per_frame_bandwidth >> 5);
if (cpi->refresh_alt_ref_frame) {
// Special alt reference frame case
// Per frame bit target for the alt ref frame
cpi->rc.per_frame_bandwidth = cpi->twopass.gf_bits;
cpi->rc.this_frame_target = cpi->rc.per_frame_bandwidth;
} else {
// Normal frames (gf,and inter)
// Normal frames (gf and inter).
cpi->rc.this_frame_target = cpi->rc.per_frame_bandwidth;
// Set target frame size based on buffer level, for 1 pass CBR.
if (cpi->pass == 0 && cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) {
// Need to decide how low min_frame_target should be for 1-pass CBR.
// For now, use: cpi->rc.av_per_frame_bandwidth / 16:
min_frame_target = MAX(cpi->rc.av_per_frame_bandwidth >> 4,
FRAME_OVERHEAD_BITS);
cpi->rc.this_frame_target = target_size_from_buffer_level(cpi);
// Adjust qp-max based on buffer level.
cpi->rc.active_worst_quality =
adjust_active_worst_quality_from_buffer_level(cpi);
}
}
// Check that the total sum of adjustments is not above the maximum allowed.
@ -262,11 +423,13 @@ static void calc_pframe_target_size(VP9_COMP *cpi) {
// not capable of recovering all the extra bits we have spent in the KF or GF,
// then the remainder will have to be recovered over a longer time span via
// other buffer / rate control mechanisms.
if (cpi->rc.this_frame_target < min_frame_target)
if (cpi->rc.this_frame_target < min_frame_target) {
cpi->rc.this_frame_target = min_frame_target;
}
// Adjust target frame size for Golden Frames:
if (cpi->rc.frames_till_gf_update_due == 0) {
if (cpi->rc.frames_till_gf_update_due == 0 &&
!(cpi->pass == 0 && cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)) {
cpi->refresh_golden_frame = 1;
calc_gf_params(cpi);
// If we are using alternate ref instead of gf then do not apply the boost
@ -608,17 +771,8 @@ int vp9_rc_pick_q_and_adjust_q_bounds(const VP9_COMP *cpi,
} else if ((cm->frame_type == KEY_FRAME) && cpi->rc.this_key_frame_forced) {
q = cpi->rc.last_boosted_qindex;
} else {
// Determine initial Q to try.
if (cpi->pass == 0) {
// 1-pass: for now, use per-frame-bw for target size of frame, scaled
// by |x| for key frame.
int scale = (cm->frame_type == KEY_FRAME) ? 5 : 1;
q = vp9_rc_regulate_q(cpi, scale * cpi->rc.av_per_frame_bandwidth,
active_best_quality, active_worst_quality);
} else {
q = vp9_rc_regulate_q(cpi, cpi->rc.this_frame_target,
active_best_quality, active_worst_quality);
}
q = vp9_rc_regulate_q(cpi, cpi->rc.this_frame_target,
active_best_quality, active_worst_quality);
if (q > *top_index)
q = *top_index;
}
@ -741,17 +895,7 @@ void vp9_rc_postencode_update(VP9_COMP *cpi, uint64_t bytes_used) {
cpi->rc.last_boosted_qindex = cm->base_qindex;
}
// Update the buffer level variable.
// Non-viewable frames are a special case and are treated as pure overhead.
if (!cm->show_frame)
cpi->rc.bits_off_target -= cpi->rc.projected_frame_size;
else
cpi->rc.bits_off_target += cpi->rc.av_per_frame_bandwidth -
cpi->rc.projected_frame_size;
// Clip the buffer level at the maximum buffer size
if (cpi->rc.bits_off_target > cpi->oxcf.maximum_buffer_size)
cpi->rc.bits_off_target = cpi->oxcf.maximum_buffer_size;
vp9_update_buffer_level(cpi, cpi->rc.projected_frame_size);
// Rolling monitors of whether we are over or underspending used to help
// regulate min and Max Q in two pass.
@ -777,8 +921,6 @@ void vp9_rc_postencode_update(VP9_COMP *cpi, uint64_t bytes_used) {
cpi->rc.total_target_vs_actual += (cpi->rc.this_frame_target -
cpi->rc.projected_frame_size);
cpi->rc.buffer_level = cpi->rc.bits_off_target;
#ifndef DISABLE_RC_LONG_TERM_MEM
// Update bits left to the kf and gf groups to account for overshoot or
// undershoot on these frames

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@ -61,4 +61,10 @@ int vp9_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
void vp9_twopass_postencode_update(VP9_COMP *cpi,
uint64_t bytes_used);
// Decide if we should drop this frame: For 1-pass CBR.
int vp9_drop_frame(VP9_COMP *cpi);
// Update the buffer level.
void vp9_update_buffer_level(VP9_COMP *cpi, int encoded_frame_size);
#endif // VP9_ENCODER_VP9_RATECTRL_H_

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@ -307,6 +307,8 @@ static vpx_codec_err_t set_vp9e_config(VP9_CONFIG *oxcf,
oxcf->starting_buffer_level = cfg.rc_buf_initial_sz;
oxcf->optimal_buffer_level = cfg.rc_buf_optimal_sz;
oxcf->drop_frames_water_mark = cfg.rc_dropframe_thresh;
oxcf->two_pass_vbrbias = cfg.rc_2pass_vbr_bias_pct;
oxcf->two_pass_vbrmin_section = cfg.rc_2pass_vbr_minsection_pct;
oxcf->two_pass_vbrmax_section = cfg.rc_2pass_vbr_maxsection_pct;