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/*
* 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 <cstddef>
#include <cstdint>
#include <optional>
#include <string>
#include <vector>
#include "api/video/video_codec_constants.h"
#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_;
std::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_ = 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<std::optional<VideoBitrateAllocation>>
VideoBitrateAllocation::GetSimulcastAllocations() const {
std::vector<std::optional<VideoBitrateAllocation>> bitrates;
for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
std::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];
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
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