ref: 1b8b8b0d0df9ac6f0a50db73d20231ecb7529666
parent: d2f49407830de9dbc466f03fcdc90d379a3c0269
author: Marco Paniconi <marpan@google.com>
date: Tue Dec 17 10:45:30 EST 2013
Updates for 1-pass CBR rate control. Adjustments based on buffer level, frame dropper. Change-Id: Iaa85b570493526a60c4b9fb7ded4c0226b1b3a33
--- a/test/datarate_test.cc
+++ b/test/datarate_test.cc
@@ -193,7 +193,10 @@
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 @@
}
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 @@
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;
@@ -254,6 +282,49 @@
ASSERT_LE(static_cast<double>(cfg_.rc_target_bitrate),
effective_datarate_ * 1.15)
<< " The datarate for the file missed the target!";
+ }
+}
+
+// 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_;
}
}
--- a/vp9/common/vp9_onyx.h
+++ b/vp9/common/vp9_onyx.h
@@ -129,6 +129,9 @@
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;
--- a/vp9/encoder/vp9_onyx_if.c
+++ b/vp9/encoder/vp9_onyx_if.c
@@ -2987,6 +2987,20 @@
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);
@@ -3586,6 +3600,11 @@
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
--- a/vp9/encoder/vp9_onyx_int.h
+++ b/vp9/encoder/vp9_onyx_int.h
@@ -331,6 +331,9 @@
int buffer_level;
int bits_off_target;
+ int decimation_factor;
+ int decimation_count;
+
int rolling_target_bits;
int rolling_actual_bits;
@@ -479,9 +482,6 @@
int mbgraph_n_frames; // number of frames filled in the above
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;
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -222,6 +222,31 @@
// 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;
@@ -242,10 +267,135 @@
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
@@ -252,8 +402,19 @@
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 @@
// 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 @@
} 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;
}
@@ -741,18 +895,8 @@
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;
+ vp9_update_buffer_level(cpi, 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;
-
// Rolling monitors of whether we are over or underspending used to help
// regulate min and Max Q in two pass.
if (cm->frame_type != KEY_FRAME) {@@ -776,8 +920,6 @@
// Debug stats
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
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -61,4 +61,10 @@
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_
--- a/vp9/vp9_cx_iface.c
+++ b/vp9/vp9_cx_iface.c
@@ -307,6 +307,8 @@
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;