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| 1 /* |
| 2 * Copyright 2017 The WebRTC Project Authors. All rights reserved. |
| 3 * |
| 4 * Use of this source code is governed by a BSD-style license |
| 5 * that can be found in the LICENSE file in the root of the source |
| 6 * tree. An additional intellectual property rights grant can be found |
| 7 * in the file PATENTS. All contributing project authors may |
| 8 * be found in the AUTHORS file in the root of the source tree. |
| 9 */ |
| 10 |
| 11 #include "webrtc/rtc_base/bitrateallocationstrategy.h" |
| 12 #include <algorithm> |
| 13 #include <utility> |
| 14 |
| 15 namespace rtc { |
| 16 |
| 17 std::vector<uint32_t> BitrateAllocationStrategy::SetAllBitratesToMinimum( |
| 18 const ArrayView<const TrackConfig*> track_configs) { |
| 19 std::vector<uint32_t> track_allocations; |
| 20 for (const auto* track_config : track_configs) { |
| 21 track_allocations.push_back(track_config->min_bitrate_bps); |
| 22 } |
| 23 return track_allocations; |
| 24 } |
| 25 |
| 26 std::vector<uint32_t> BitrateAllocationStrategy::DistributeBitratesEvenly( |
| 27 const ArrayView<const TrackConfig*> track_configs, |
| 28 uint32_t available_bitrate) { |
| 29 std::vector<uint32_t> track_allocations = |
| 30 SetAllBitratesToMinimum(track_configs); |
| 31 uint32_t sum_min_bitrates = 0; |
| 32 uint32_t sum_max_bitrates = 0; |
| 33 for (const auto* track_config : track_configs) { |
| 34 sum_min_bitrates += track_config->min_bitrate_bps; |
| 35 sum_max_bitrates += track_config->max_bitrate_bps; |
| 36 } |
| 37 if (sum_min_bitrates >= available_bitrate) { |
| 38 return track_allocations; |
| 39 } else if (available_bitrate >= sum_max_bitrates) { |
| 40 auto track_allocations_it = track_allocations.begin(); |
| 41 for (const auto* track_config : track_configs) { |
| 42 *track_allocations_it++ = track_config->max_bitrate_bps; |
| 43 } |
| 44 return track_allocations; |
| 45 } else { |
| 46 // If sum_min_bitrates < available_bitrate < sum_max_bitrates allocate |
| 47 // bitrates evenly up to max_bitrate_bps starting from the track with the |
| 48 // lowest max_bitrate_bps. Reminder of available bitrate split evenly among |
| 49 // remaining tracks. |
| 50 std::multimap<uint32_t, size_t> max_bitrate_sorted_configs; |
| 51 for (const TrackConfig** track_configs_it = track_configs.begin(); |
| 52 track_configs_it != track_configs.end(); track_configs_it++) { |
| 53 max_bitrate_sorted_configs.insert(std::pair<uint32_t, size_t>( |
| 54 (*track_configs_it)->max_bitrate_bps, |
| 55 track_configs_it - track_configs.begin())); |
| 56 } |
| 57 uint32_t total_available_increase = (available_bitrate - sum_min_bitrates); |
| 58 int processed_configs = 0; |
| 59 for (const auto& track_config_pair : max_bitrate_sorted_configs) { |
| 60 uint32_t available_increase = |
| 61 total_available_increase / |
| 62 (static_cast<uint32_t>(track_configs.size() - processed_configs)); |
| 63 uint32_t consumed_increase = |
| 64 std::min(track_configs[track_config_pair.second]->max_bitrate_bps - |
| 65 track_configs[track_config_pair.second]->min_bitrate_bps, |
| 66 available_increase); |
| 67 track_allocations[track_config_pair.second] += consumed_increase; |
| 68 total_available_increase -= consumed_increase; |
| 69 ++processed_configs; |
| 70 } |
| 71 return track_allocations; |
| 72 } |
| 73 } |
| 74 |
| 75 AudioPriorityBitrateAllocationStrategy::AudioPriorityBitrateAllocationStrategy( |
| 76 std::string audio_track_id, |
| 77 uint32_t sufficient_audio_bitrate) |
| 78 : audio_track_id_(audio_track_id), |
| 79 sufficient_audio_bitrate_(sufficient_audio_bitrate) {} |
| 80 |
| 81 std::vector<uint32_t> AudioPriorityBitrateAllocationStrategy::AllocateBitrates( |
| 82 uint32_t available_bitrate, |
| 83 const ArrayView<const TrackConfig*> track_configs) { |
| 84 const TrackConfig* audio_track_config = NULL; |
| 85 size_t audio_config_index = -1; |
| 86 uint32_t sum_min_bitrates = 0; |
| 87 |
| 88 for (auto*& track_config : track_configs) { |
| 89 sum_min_bitrates += track_config->min_bitrate_bps; |
| 90 if (track_config->track_id == audio_track_id_) { |
| 91 audio_track_config = track_config; |
| 92 audio_config_index = &track_config - &track_configs[0]; |
| 93 } |
| 94 } |
| 95 if (audio_track_config == NULL) { |
| 96 return DistributeBitratesEvenly(track_configs, available_bitrate); |
| 97 } |
| 98 auto safe_sufficient_audio_bitrate = std::min( |
| 99 std::max(audio_track_config->min_bitrate_bps, sufficient_audio_bitrate_), |
| 100 audio_track_config->max_bitrate_bps); |
| 101 if (available_bitrate <= sum_min_bitrates) { |
| 102 return SetAllBitratesToMinimum(track_configs); |
| 103 } else { |
| 104 if (available_bitrate <= sum_min_bitrates + safe_sufficient_audio_bitrate - |
| 105 audio_track_config->min_bitrate_bps) { |
| 106 std::vector<uint32_t> track_allocations = |
| 107 SetAllBitratesToMinimum(track_configs); |
| 108 track_allocations[audio_config_index] += |
| 109 available_bitrate - sum_min_bitrates; |
| 110 return track_allocations; |
| 111 } else { |
| 112 const TrackConfig* saved_track_config = track_configs[audio_config_index]; |
| 113 TrackConfig sufficient_track_config(*track_configs[audio_config_index]); |
| 114 sufficient_track_config.min_bitrate_bps = safe_sufficient_audio_bitrate; |
| 115 track_configs[audio_config_index] = &sufficient_track_config; |
| 116 std::vector<uint32_t> track_allocations = |
| 117 DistributeBitratesEvenly(track_configs, available_bitrate); |
| 118 track_configs[audio_config_index] = saved_track_config; |
| 119 return track_allocations; |
| 120 } |
| 121 } |
| 122 } |
| 123 |
| 124 } // namespace rtc |
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