1 files changed, 347 insertions, 0 deletions

diff --git a/libvpx/vp8/vp8_ratectrl_rtc.cc b/libvpx/vp8/vp8_ratectrl_rtc.cc
new file mode 100644
index 000000000..2f23c5b1d
--- /dev/null
+++ b/libvpx/vp8/vp8_ratectrl_rtc.cc
@@ -0,0 +1,347 @@
+/*
+ *  Copyright (c) 2021 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <math.h>
+#include <new>
+#include "vp8/vp8_ratectrl_rtc.h"
+#include "vp8/encoder/ratectrl.h"
+#include "vpx_ports/system_state.h"
+
+namespace libvpx {
+/* Quant MOD */
+static const int kQTrans[] = {
+  0,  1,  2,  3,  4,  5,  7,   8,   9,   10,  12,  13,  15,  17,  18,  19,
+  20, 21, 23, 24, 25, 26, 27,  28,  29,  30,  31,  33,  35,  37,  39,  41,
+  43, 45, 47, 49, 51, 53, 55,  57,  59,  61,  64,  67,  70,  73,  76,  79,
+  82, 85, 88, 91, 94, 97, 100, 103, 106, 109, 112, 115, 118, 121, 124, 127,
+};
+
+static const unsigned char kf_high_motion_minq[QINDEX_RANGE] = {
+  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,  1,  1,
+  1,  1,  2,  2,  2,  2,  3,  3,  3,  3,  3,  3,  3,  3,  4,  4,  4,  4,  5,
+  5,  5,  5,  5,  5,  6,  6,  6,  6,  7,  7,  8,  8,  8,  8,  9,  9,  10, 10,
+  10, 10, 11, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 15, 15, 15, 15, 16,
+  16, 16, 16, 17, 17, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
+  22, 22, 23, 23, 24, 25, 25, 26, 26, 27, 28, 28, 29, 30
+};
+
+static const unsigned char inter_minq[QINDEX_RANGE] = {
+  0,  0,  1,  1,  2,  3,  3,  4,  4,  5,  6,  6,  7,  8,  8,  9,  9,  10, 11,
+  11, 12, 13, 13, 14, 15, 15, 16, 17, 17, 18, 19, 20, 20, 21, 22, 22, 23, 24,
+  24, 25, 26, 27, 27, 28, 29, 30, 30, 31, 32, 33, 33, 34, 35, 36, 36, 37, 38,
+  39, 39, 40, 41, 42, 42, 43, 44, 45, 46, 46, 47, 48, 49, 50, 50, 51, 52, 53,
+  54, 55, 55, 56, 57, 58, 59, 60, 60, 61, 62, 63, 64, 65, 66, 67, 67, 68, 69,
+  70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 86,
+  87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
+};
+
+static int rescale(int val, int num, int denom) {
+  int64_t llnum = num;
+  int64_t llden = denom;
+  int64_t llval = val;
+
+  return (int)(llval * llnum / llden);
+}
+
+std::unique_ptr<VP8RateControlRTC> VP8RateControlRTC::Create(
+    const VP8RateControlRtcConfig &cfg) {
+  std::unique_ptr<VP8RateControlRTC> rc_api(new (std::nothrow)
+                                                VP8RateControlRTC());
+  if (!rc_api) return nullptr;
+  rc_api->cpi_ = static_cast<VP8_COMP *>(vpx_memalign(32, sizeof(*cpi_)));
+  if (!rc_api->cpi_) return nullptr;
+  vp8_zero(*rc_api->cpi_);
+
+  rc_api->InitRateControl(cfg);
+
+  return rc_api;
+}
+
+void VP8RateControlRTC::InitRateControl(const VP8RateControlRtcConfig &rc_cfg) {
+  VP8_COMMON *cm = &cpi_->common;
+  VP8_CONFIG *oxcf = &cpi_->oxcf;
+  oxcf->end_usage = USAGE_STREAM_FROM_SERVER;
+  cpi_->pass = 0;
+  cm->show_frame = 1;
+  oxcf->drop_frames_water_mark = 0;
+  cm->current_video_frame = 0;
+  cpi_->auto_gold = 1;
+  cpi_->key_frame_count = 1;
+  cpi_->rate_correction_factor = 1.0;
+  cpi_->key_frame_rate_correction_factor = 1.0;
+  cpi_->cyclic_refresh_mode_enabled = 0;
+  cpi_->auto_worst_q = 1;
+  cpi_->kf_overspend_bits = 0;
+  cpi_->kf_bitrate_adjustment = 0;
+  cpi_->gf_overspend_bits = 0;
+  cpi_->non_gf_bitrate_adjustment = 0;
+  UpdateRateControl(rc_cfg);
+  cpi_->buffer_level = oxcf->starting_buffer_level;
+  cpi_->bits_off_target = oxcf->starting_buffer_level;
+}
+
+void VP8RateControlRTC::UpdateRateControl(
+    const VP8RateControlRtcConfig &rc_cfg) {
+  VP8_COMMON *cm = &cpi_->common;
+  VP8_CONFIG *oxcf = &cpi_->oxcf;
+  vpx_clear_system_state();
+  cm->Width = rc_cfg.width;
+  cm->Height = rc_cfg.height;
+  oxcf->Width = rc_cfg.width;
+  oxcf->Height = rc_cfg.height;
+  oxcf->worst_allowed_q = kQTrans[rc_cfg.max_quantizer];
+  oxcf->best_allowed_q = kQTrans[rc_cfg.min_quantizer];
+  cpi_->worst_quality = oxcf->worst_allowed_q;
+  cpi_->best_quality = oxcf->best_allowed_q;
+  cpi_->output_framerate = rc_cfg.framerate;
+  oxcf->target_bandwidth =
+      static_cast<unsigned int>(1000 * rc_cfg.target_bandwidth);
+  cpi_->ref_framerate = cpi_->output_framerate;
+  oxcf->fixed_q = -1;
+  oxcf->error_resilient_mode = 1;
+  oxcf->starting_buffer_level_in_ms = rc_cfg.buf_initial_sz;
+  oxcf->optimal_buffer_level_in_ms = rc_cfg.buf_optimal_sz;
+  oxcf->maximum_buffer_size_in_ms = rc_cfg.buf_sz;
+  oxcf->starting_buffer_level = rc_cfg.buf_initial_sz;
+  oxcf->optimal_buffer_level = rc_cfg.buf_optimal_sz;
+  oxcf->maximum_buffer_size = rc_cfg.buf_sz;
+  oxcf->number_of_layers = rc_cfg.ts_number_layers;
+  cpi_->buffered_mode = oxcf->optimal_buffer_level > 0;
+  oxcf->under_shoot_pct = rc_cfg.undershoot_pct;
+  oxcf->over_shoot_pct = rc_cfg.overshoot_pct;
+  cpi_->oxcf.rc_max_intra_bitrate_pct = rc_cfg.max_intra_bitrate_pct;
+  cpi_->framerate = rc_cfg.framerate;
+  for (int i = 0; i < KEY_FRAME_CONTEXT; ++i) {
+    cpi_->prior_key_frame_distance[i] =
+        static_cast<int>(cpi_->output_framerate);
+  }
+
+  if (oxcf->number_of_layers > 1) {
+    memcpy(oxcf->target_bitrate, rc_cfg.layer_target_bitrate,
+           sizeof(rc_cfg.layer_target_bitrate));
+    memcpy(oxcf->rate_decimator, rc_cfg.ts_rate_decimator,
+           sizeof(rc_cfg.ts_rate_decimator));
+    oxcf->periodicity = 2;
+
+    double prev_layer_framerate = 0;
+    for (unsigned int i = 0; i < oxcf->number_of_layers; ++i) {
+      vp8_init_temporal_layer_context(cpi_, oxcf, i, prev_layer_framerate);
+      prev_layer_framerate = cpi_->output_framerate / oxcf->rate_decimator[i];
+    }
+  }
+
+  cpi_->total_actual_bits = 0;
+  cpi_->total_target_vs_actual = 0;
+
+  cm->mb_rows = cm->Height >> 4;
+  cm->mb_cols = cm->Width >> 4;
+  cm->MBs = cm->mb_rows * cm->mb_cols;
+  cm->mode_info_stride = cm->mb_cols + 1;
+
+  oxcf->starting_buffer_level =
+      rescale((int)oxcf->starting_buffer_level, oxcf->target_bandwidth, 1000);
+  /* Set or reset optimal and maximum buffer levels. */
+  if (oxcf->optimal_buffer_level == 0) {
+    oxcf->optimal_buffer_level = oxcf->target_bandwidth / 8;
+  } else {
+    oxcf->optimal_buffer_level =
+        rescale((int)oxcf->optimal_buffer_level, oxcf->target_bandwidth, 1000);
+  }
+  if (oxcf->maximum_buffer_size == 0) {
+    oxcf->maximum_buffer_size = oxcf->target_bandwidth / 8;
+  } else {
+    oxcf->maximum_buffer_size =
+        rescale((int)oxcf->maximum_buffer_size, oxcf->target_bandwidth, 1000);
+  }
+
+  if (cpi_->bits_off_target > oxcf->maximum_buffer_size) {
+    cpi_->bits_off_target = oxcf->maximum_buffer_size;
+    cpi_->buffer_level = cpi_->bits_off_target;
+  }
+
+  vp8_new_framerate(cpi_, cpi_->framerate);
+  vpx_clear_system_state();
+}
+
+void VP8RateControlRTC::ComputeQP(const VP8FrameParamsQpRTC &frame_params) {
+  VP8_COMMON *const cm = &cpi_->common;
+  vpx_clear_system_state();
+  if (cpi_->oxcf.number_of_layers > 1) {
+    cpi_->temporal_layer_id = frame_params.temporal_layer_id;
+    const int layer = frame_params.temporal_layer_id;
+    vp8_update_layer_contexts(cpi_);
+    /* Restore layer specific context & set frame rate */
+    vp8_restore_layer_context(cpi_, layer);
+    vp8_new_framerate(cpi_, cpi_->layer_context[layer].framerate);
+  }
+  cm->frame_type = frame_params.frame_type;
+  cm->refresh_golden_frame = (cm->frame_type == KEY_FRAME) ? 1 : 0;
+  cm->refresh_alt_ref_frame = (cm->frame_type == KEY_FRAME) ? 1 : 0;
+  if (cm->frame_type == KEY_FRAME && cpi_->common.current_video_frame > 0) {
+    cpi_->common.frame_flags |= FRAMEFLAGS_KEY;
+  }
+
+  vp8_pick_frame_size(cpi_);
+
+  if (cpi_->buffer_level >= cpi_->oxcf.optimal_buffer_level &&
+      cpi_->buffered_mode) {
+    /* Max adjustment is 1/4 */
+    int Adjustment = cpi_->active_worst_quality / 4;
+    if (Adjustment) {
+      int buff_lvl_step;
+      if (cpi_->buffer_level < cpi_->oxcf.maximum_buffer_size) {
+        buff_lvl_step = (int)((cpi_->oxcf.maximum_buffer_size -
+                               cpi_->oxcf.optimal_buffer_level) /
+                              Adjustment);
+        if (buff_lvl_step) {
+          Adjustment =
+              (int)((cpi_->buffer_level - cpi_->oxcf.optimal_buffer_level) /
+                    buff_lvl_step);
+        } else {
+          Adjustment = 0;
+        }
+      }
+      cpi_->active_worst_quality -= Adjustment;
+      if (cpi_->active_worst_quality < cpi_->active_best_quality) {
+        cpi_->active_worst_quality = cpi_->active_best_quality;
+      }
+    }
+  }
+
+  if (cpi_->ni_frames > 150) {
+    int q = cpi_->active_worst_quality;
+    if (cm->frame_type == KEY_FRAME) {
+      cpi_->active_best_quality = kf_high_motion_minq[q];
+    } else {
+      cpi_->active_best_quality = inter_minq[q];
+    }
+
+    if (cpi_->buffer_level >= cpi_->oxcf.maximum_buffer_size) {
+      cpi_->active_best_quality = cpi_->best_quality;
+
+    } else if (cpi_->buffer_level > cpi_->oxcf.optimal_buffer_level) {
+      int Fraction =
+          (int)(((cpi_->buffer_level - cpi_->oxcf.optimal_buffer_level) * 128) /
+                (cpi_->oxcf.maximum_buffer_size -
+                 cpi_->oxcf.optimal_buffer_level));
+      int min_qadjustment =
+          ((cpi_->active_best_quality - cpi_->best_quality) * Fraction) / 128;
+
+      cpi_->active_best_quality -= min_qadjustment;
+    }
+  }
+
+  /* Clip the active best and worst quality values to limits */
+  if (cpi_->active_worst_quality > cpi_->worst_quality) {
+    cpi_->active_worst_quality = cpi_->worst_quality;
+  }
+  if (cpi_->active_best_quality < cpi_->best_quality) {
+    cpi_->active_best_quality = cpi_->best_quality;
+  }
+  if (cpi_->active_worst_quality < cpi_->active_best_quality) {
+    cpi_->active_worst_quality = cpi_->active_best_quality;
+  }
+
+  q_ = vp8_regulate_q(cpi_, cpi_->this_frame_target);
+  vp8_set_quantizer(cpi_, q_);
+  vpx_clear_system_state();
+}
+
+int VP8RateControlRTC::GetQP() const { return q_; }
+
+void VP8RateControlRTC::PostEncodeUpdate(uint64_t encoded_frame_size) {
+  VP8_COMMON *const cm = &cpi_->common;
+  vpx_clear_system_state();
+  cpi_->total_byte_count += encoded_frame_size;
+  cpi_->projected_frame_size = static_cast<int>(encoded_frame_size << 3);
+  if (cpi_->oxcf.number_of_layers > 1) {
+    for (unsigned int i = cpi_->current_layer + 1;
+         i < cpi_->oxcf.number_of_layers; ++i) {
+      cpi_->layer_context[i].total_byte_count += encoded_frame_size;
+    }
+  }
+
+  vp8_update_rate_correction_factors(cpi_, 2);
+
+  cpi_->last_q[cm->frame_type] = cm->base_qindex;
+
+  if (cm->frame_type == KEY_FRAME) {
+    vp8_adjust_key_frame_context(cpi_);
+  }
+
+  /* Keep a record of ambient average Q. */
+  if (cm->frame_type != KEY_FRAME) {
+    cpi_->avg_frame_qindex =
+        (2 + 3 * cpi_->avg_frame_qindex + cm->base_qindex) >> 2;
+  }
+  /* Keep a record from which we can calculate the average Q excluding
+   * key frames.
+   */
+  if (cm->frame_type != KEY_FRAME) {
+    cpi_->ni_frames++;
+    /* Damp value for first few frames */
+    if (cpi_->ni_frames > 150) {
+      cpi_->ni_tot_qi += q_;
+      cpi_->ni_av_qi = (cpi_->ni_tot_qi / cpi_->ni_frames);
+    } else {
+      cpi_->ni_tot_qi += q_;
+      cpi_->ni_av_qi =
+          ((cpi_->ni_tot_qi / cpi_->ni_frames) + cpi_->worst_quality + 1) / 2;
+    }
+
+    /* If the average Q is higher than what was used in the last
+     * frame (after going through the recode loop to keep the frame
+     * size within range) then use the last frame value - 1. The -1
+     * is designed to stop Q and hence the data rate, from
+     * progressively falling away during difficult sections, but at
+     * the same time reduce the number of itterations around the
+     * recode loop.
+     */
+    if (q_ > cpi_->ni_av_qi) cpi_->ni_av_qi = q_ - 1;
+  }
+
+  cpi_->bits_off_target +=
+      cpi_->av_per_frame_bandwidth - cpi_->projected_frame_size;
+  if (cpi_->bits_off_target > cpi_->oxcf.maximum_buffer_size) {
+    cpi_->bits_off_target = cpi_->oxcf.maximum_buffer_size;
+  }
+
+  cpi_->total_actual_bits += cpi_->projected_frame_size;
+  cpi_->buffer_level = cpi_->bits_off_target;
+
+  /* Propagate values to higher temporal layers */
+  if (cpi_->oxcf.number_of_layers > 1) {
+    for (unsigned int i = cpi_->current_layer + 1;
+         i < cpi_->oxcf.number_of_layers; ++i) {
+      LAYER_CONTEXT *lc = &cpi_->layer_context[i];
+      int bits_off_for_this_layer = (int)round(
+          lc->target_bandwidth / lc->framerate - cpi_->projected_frame_size);
+
+      lc->bits_off_target += bits_off_for_this_layer;
+
+      /* Clip buffer level to maximum buffer size for the layer */
+      if (lc->bits_off_target > lc->maximum_buffer_size) {
+        lc->bits_off_target = lc->maximum_buffer_size;
+      }
+
+      lc->total_actual_bits += cpi_->projected_frame_size;
+      lc->total_target_vs_actual += bits_off_for_this_layer;
+      lc->buffer_level = lc->bits_off_target;
+    }
+  }
+
+  cpi_->common.current_video_frame++;
+  cpi_->frames_since_key++;
+
+  if (cpi_->oxcf.number_of_layers > 1) vp8_save_layer_context(cpi_);
+  vpx_clear_system_state();
+}
+}  // namespace libvpx