libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_svc_layercontext.c

Index: source/libvpx/vp9/encoder/vp9_svc_layercontext.c
===================================================================
--- source/libvpx/vp9/encoder/vp9_svc_layercontext.c	(revision 0)
+++ source/libvpx/vp9/encoder/vp9_svc_layercontext.c	(revision 0)
@@ -0,0 +1,224 @@
+/*
+ *  Copyright (c) 2014 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 "vp9/encoder/vp9_onyx_int.h"
+#include "vp9/encoder/vp9_svc_layercontext.h"
+
+void vp9_init_layer_context(VP9_COMP *const cpi) {
+  SVC *const svc = &cpi->svc;
+  const VP9_CONFIG *const oxcf = &cpi->oxcf;
+  int layer;
+  int layer_end;
+
+  svc->spatial_layer_id = 0;
+  svc->temporal_layer_id = 0;
+
+  if (svc->number_temporal_layers > 1) {
+    layer_end = svc->number_temporal_layers;
+  } else {
+    layer_end = svc->number_spatial_layers;
+  }
+
+  for (layer = 0; layer < layer_end; ++layer) {
+    LAYER_CONTEXT *const lc = &svc->layer_context[layer];
+    RATE_CONTROL *const lrc = &lc->rc;
+    lc->current_video_frame_in_layer = 0;
+    lrc->avg_frame_qindex[INTER_FRAME] = oxcf->worst_allowed_q;
+    lrc->ni_av_qi = oxcf->worst_allowed_q;
+    lrc->total_actual_bits = 0;
+    lrc->total_target_vs_actual = 0;
+    lrc->ni_tot_qi = 0;
+    lrc->tot_q = 0.0;
+    lrc->avg_q = 0.0;
+    lrc->ni_frames = 0;
+    lrc->decimation_count = 0;
+    lrc->decimation_factor = 0;
+    lrc->rate_correction_factor = 1.0;
+    lrc->key_frame_rate_correction_factor = 1.0;
+
+    if (svc->number_temporal_layers > 1) {
+      lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
+      lrc->last_q[INTER_FRAME] = oxcf->worst_allowed_q;
+    } else {
+      lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
+      lrc->last_q[0] = oxcf->best_allowed_q;
+      lrc->last_q[1] = oxcf->best_allowed_q;
+      lrc->last_q[2] = oxcf->best_allowed_q;
+    }
+
+    lrc->buffer_level = vp9_rescale((int)(oxcf->starting_buffer_level),
+                                    lc->target_bandwidth, 1000);
+    lrc->bits_off_target = lrc->buffer_level;
+  }
+}
+
+// Update the layer context from a change_config() call.
+void vp9_update_layer_context_change_config(VP9_COMP *const cpi,
+                                            const int target_bandwidth) {
+  SVC *const svc = &cpi->svc;
+  const VP9_CONFIG *const oxcf = &cpi->oxcf;
+  const RATE_CONTROL *const rc = &cpi->rc;
+  int layer;
+  int layer_end;
+  float bitrate_alloc = 1.0;
+
+  if (svc->number_temporal_layers > 1) {
+    layer_end = svc->number_temporal_layers;
+  } else {
+    layer_end = svc->number_spatial_layers;
+  }
+
+  for (layer = 0; layer < layer_end; ++layer) {
+    LAYER_CONTEXT *const lc = &svc->layer_context[layer];
+    RATE_CONTROL *const lrc = &lc->rc;
+
+    if (svc->number_temporal_layers > 1) {
+      lc->target_bandwidth = oxcf->ts_target_bitrate[layer] * 1000;
+    } else {
+      lc->target_bandwidth = oxcf->ss_target_bitrate[layer] * 1000;
+    }
+    bitrate_alloc = (float)lc->target_bandwidth / target_bandwidth;
+    // Update buffer-related quantities.
+    lc->starting_buffer_level =
+        (int64_t)(oxcf->starting_buffer_level * bitrate_alloc);
+    lc->optimal_buffer_level =
+        (int64_t)(oxcf->optimal_buffer_level * bitrate_alloc);
+    lc->maximum_buffer_size =
+        (int64_t)(oxcf->maximum_buffer_size * bitrate_alloc);
+    lrc->bits_off_target = MIN(lrc->bits_off_target, lc->maximum_buffer_size);
+    lrc->buffer_level = MIN(lrc->buffer_level, lc->maximum_buffer_size);
+    // Update framerate-related quantities.
+    if (svc->number_temporal_layers > 1) {
+      lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
+    } else {
+      lc->framerate = oxcf->framerate;
+    }
+    lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
+    lrc->max_frame_bandwidth = rc->max_frame_bandwidth;
+    // Update qp-related quantities.
+    lrc->worst_quality = rc->worst_quality;
+    lrc->best_quality = rc->best_quality;
+  }
+}
+
+static LAYER_CONTEXT *get_layer_context(SVC *svc) {
+  return svc->number_temporal_layers > 1 ?
+         &svc->layer_context[svc->temporal_layer_id] :
+         &svc->layer_context[svc->spatial_layer_id];
+}
+
+void vp9_update_temporal_layer_framerate(VP9_COMP *const cpi) {
+  SVC *const svc = &cpi->svc;
+  const VP9_CONFIG *const oxcf = &cpi->oxcf;
+  LAYER_CONTEXT *const lc = get_layer_context(svc);
+  RATE_CONTROL *const lrc = &lc->rc;
+  const int layer = svc->temporal_layer_id;
+
+  lc->framerate = oxcf->framerate / oxcf->ts_rate_decimator[layer];
+  lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
+  lrc->max_frame_bandwidth = cpi->rc.max_frame_bandwidth;
+  // Update the average layer frame size (non-cumulative per-frame-bw).
+  if (layer == 0) {
+    lc->avg_frame_size = lrc->av_per_frame_bandwidth;
+  } else {
+    const double prev_layer_framerate =
+        oxcf->framerate / oxcf->ts_rate_decimator[layer - 1];
+    const int prev_layer_target_bandwidth =
+        oxcf->ts_target_bitrate[layer - 1] * 1000;
+    lc->avg_frame_size =
+        (int)((lc->target_bandwidth - prev_layer_target_bandwidth) /
+              (lc->framerate - prev_layer_framerate));
+  }
+}
+
+void vp9_update_spatial_layer_framerate(VP9_COMP *const cpi, double framerate) {
+  const VP9_CONFIG *const oxcf = &cpi->oxcf;
+  LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
+  RATE_CONTROL *const lrc = &lc->rc;
+
+  lc->framerate = framerate;
+  lrc->av_per_frame_bandwidth = (int)(lc->target_bandwidth / lc->framerate);
+  lrc->min_frame_bandwidth = (int)(lrc->av_per_frame_bandwidth *
+                                   oxcf->two_pass_vbrmin_section / 100);
+  lrc->max_frame_bandwidth = (int)(((int64_t)lrc->av_per_frame_bandwidth *
+                                   oxcf->two_pass_vbrmax_section) / 100);
+  lrc->max_gf_interval = 16;
+
+  lrc->static_scene_max_gf_interval = cpi->key_frame_frequency >> 1;
+
+  if (oxcf->play_alternate && oxcf->lag_in_frames) {
+    if (lrc->max_gf_interval > oxcf->lag_in_frames - 1)
+      lrc->max_gf_interval = oxcf->lag_in_frames - 1;
+
+    if (lrc->static_scene_max_gf_interval > oxcf->lag_in_frames - 1)
+      lrc->static_scene_max_gf_interval = oxcf->lag_in_frames - 1;
+  }
+
+  if (lrc->max_gf_interval > lrc->static_scene_max_gf_interval)
+    lrc->max_gf_interval = lrc->static_scene_max_gf_interval;
+}
+
+void vp9_restore_layer_context(VP9_COMP *const cpi) {
+  LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
+  const int old_frame_since_key = cpi->rc.frames_since_key;
+  const int old_frame_to_key = cpi->rc.frames_to_key;
+
+  cpi->rc = lc->rc;
+  cpi->twopass = lc->twopass;
+  cpi->oxcf.target_bandwidth = lc->target_bandwidth;
+  cpi->oxcf.starting_buffer_level = lc->starting_buffer_level;
+  cpi->oxcf.optimal_buffer_level = lc->optimal_buffer_level;
+  cpi->oxcf.maximum_buffer_size = lc->maximum_buffer_size;
+  cpi->output_framerate = lc->framerate;
+  // Reset the frames_since_key and frames_to_key counters to their values
+  // before the layer restore. Keep these defined for the stream (not layer).
+  if (cpi->svc.number_temporal_layers > 1) {
+    cpi->rc.frames_since_key = old_frame_since_key;
+    cpi->rc.frames_to_key = old_frame_to_key;
+  }
+}
+
+void vp9_save_layer_context(VP9_COMP *const cpi) {
+  const VP9_CONFIG *const oxcf = &cpi->oxcf;
+  LAYER_CONTEXT *const lc = get_layer_context(&cpi->svc);
+
+  lc->rc = cpi->rc;
+  lc->twopass = cpi->twopass;
+  lc->target_bandwidth = (int)oxcf->target_bandwidth;
+  lc->starting_buffer_level = oxcf->starting_buffer_level;
+  lc->optimal_buffer_level = oxcf->optimal_buffer_level;
+  lc->maximum_buffer_size = oxcf->maximum_buffer_size;
+  lc->framerate = cpi->output_framerate;
+}
+
+void vp9_init_second_pass_spatial_svc(VP9_COMP *cpi) {
+  SVC *const svc = &cpi->svc;
+  int i;
+
+  for (i = 0; i < svc->number_spatial_layers; ++i) {
+    struct twopass_rc *const twopass = &svc->layer_context[i].twopass;
+
+    svc->spatial_layer_id = i;
+    vp9_init_second_pass(cpi);
+
+    twopass->total_stats.spatial_layer_id = i;
+    twopass->total_left_stats.spatial_layer_id = i;
+  }
+  svc->spatial_layer_id = 0;
+}
+
+void vp9_inc_frame_in_layer(SVC *svc) {
+  LAYER_CONTEXT *const lc = (svc->number_temporal_layers > 1)
+      ? &svc->layer_context[svc->temporal_layer_id]
+      : &svc->layer_context[svc->spatial_layer_id];
+  ++lc->current_video_frame_in_layer;
+}