summaryrefslogtreecommitdiffstats
path: root/third_party/libwebrtc/api/video/video_bitrate_allocation.cc
blob: e189db1c1997515c0dd76103574459a17566c11e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*
 *  Copyright (c) 2018 The WebRTC 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 "api/video/video_bitrate_allocation.h"

#include <cstdint>

#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/strings/string_builder.h"

namespace webrtc {

VideoBitrateAllocation::VideoBitrateAllocation()
    : sum_(0), is_bw_limited_(false) {}

bool VideoBitrateAllocation::SetBitrate(size_t spatial_index,
                                        size_t temporal_index,
                                        uint32_t bitrate_bps) {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  RTC_CHECK_LT(temporal_index, kMaxTemporalStreams);
  int64_t new_bitrate_sum_bps = sum_;
  absl::optional<uint32_t>& layer_bitrate =
      bitrates_[spatial_index][temporal_index];
  if (layer_bitrate) {
    RTC_DCHECK_LE(*layer_bitrate, sum_);
    new_bitrate_sum_bps -= *layer_bitrate;
  }
  new_bitrate_sum_bps += bitrate_bps;
  if (new_bitrate_sum_bps > kMaxBitrateBps)
    return false;

  layer_bitrate = bitrate_bps;
  sum_ = rtc::dchecked_cast<uint32_t>(new_bitrate_sum_bps);
  return true;
}

bool VideoBitrateAllocation::HasBitrate(size_t spatial_index,
                                        size_t temporal_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  RTC_CHECK_LT(temporal_index, kMaxTemporalStreams);
  return bitrates_[spatial_index][temporal_index].has_value();
}

uint32_t VideoBitrateAllocation::GetBitrate(size_t spatial_index,
                                            size_t temporal_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  RTC_CHECK_LT(temporal_index, kMaxTemporalStreams);
  return bitrates_[spatial_index][temporal_index].value_or(0);
}

// Whether the specific spatial layers has the bitrate set in any of its
// temporal layers.
bool VideoBitrateAllocation::IsSpatialLayerUsed(size_t spatial_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  for (size_t i = 0; i < kMaxTemporalStreams; ++i) {
    if (bitrates_[spatial_index][i].has_value())
      return true;
  }
  return false;
}

// Get the sum of all the temporal layer for a specific spatial layer.
uint32_t VideoBitrateAllocation::GetSpatialLayerSum(
    size_t spatial_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  return GetTemporalLayerSum(spatial_index, kMaxTemporalStreams - 1);
}

uint32_t VideoBitrateAllocation::GetTemporalLayerSum(
    size_t spatial_index,
    size_t temporal_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  RTC_CHECK_LT(temporal_index, kMaxTemporalStreams);
  uint32_t sum = 0;
  for (size_t i = 0; i <= temporal_index; ++i) {
    sum += bitrates_[spatial_index][i].value_or(0);
  }
  return sum;
}

std::vector<uint32_t> VideoBitrateAllocation::GetTemporalLayerAllocation(
    size_t spatial_index) const {
  RTC_CHECK_LT(spatial_index, kMaxSpatialLayers);
  std::vector<uint32_t> temporal_rates;

  // Find the highest temporal layer with a defined bitrate in order to
  // determine the size of the temporal layer allocation.
  for (size_t i = kMaxTemporalStreams; i > 0; --i) {
    if (bitrates_[spatial_index][i - 1].has_value()) {
      temporal_rates.resize(i);
      break;
    }
  }

  for (size_t i = 0; i < temporal_rates.size(); ++i) {
    temporal_rates[i] = bitrates_[spatial_index][i].value_or(0);
  }

  return temporal_rates;
}

std::vector<absl::optional<VideoBitrateAllocation>>
VideoBitrateAllocation::GetSimulcastAllocations() const {
  std::vector<absl::optional<VideoBitrateAllocation>> bitrates;
  for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
    absl::optional<VideoBitrateAllocation> layer_bitrate;
    if (IsSpatialLayerUsed(si)) {
      layer_bitrate = VideoBitrateAllocation();
      for (int tl = 0; tl < kMaxTemporalStreams; ++tl) {
        if (HasBitrate(si, tl))
          layer_bitrate->SetBitrate(0, tl, GetBitrate(si, tl));
      }
    }
    bitrates.push_back(layer_bitrate);
  }
  return bitrates;
}

bool VideoBitrateAllocation::operator==(
    const VideoBitrateAllocation& other) const {
  for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
    for (size_t ti = 0; ti < kMaxTemporalStreams; ++ti) {
      if (bitrates_[si][ti] != other.bitrates_[si][ti])
        return false;
    }
  }
  return true;
}

std::string VideoBitrateAllocation::ToString() const {
  if (sum_ == 0)
    return "VideoBitrateAllocation [ [] ]";

  // Max string length in practice is 260, but let's have some overhead and
  // round up to nearest power of two.
  char string_buf[512];
  rtc::SimpleStringBuilder ssb(string_buf);

  ssb << "VideoBitrateAllocation [";
  uint32_t spatial_cumulator = 0;
  for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
    RTC_DCHECK_LE(spatial_cumulator, sum_);
    if (spatial_cumulator == sum_)
      break;

    const uint32_t layer_sum = GetSpatialLayerSum(si);
    if (layer_sum == sum_ && si == 0) {
      ssb << " [";
    } else {
      if (si > 0)
        ssb << ",";
      ssb << '\n' << "  [";
    }
    spatial_cumulator += layer_sum;

    uint32_t temporal_cumulator = 0;
    for (size_t ti = 0; ti < kMaxTemporalStreams; ++ti) {
      RTC_DCHECK_LE(temporal_cumulator, layer_sum);
      if (temporal_cumulator == layer_sum)
        break;

      if (ti > 0)
        ssb << ", ";

      uint32_t bitrate = bitrates_[si][ti].value_or(0);
      ssb << bitrate;
      temporal_cumulator += bitrate;
    }
    ssb << "]";
  }

  RTC_DCHECK_EQ(spatial_cumulator, sum_);
  ssb << " ]";
  return ssb.str();
}

}  // namespace webrtc