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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 "modules/video_coding/utility/simulcast_utility.h"
#include <algorithm>
#include <cmath>
#include <cstdint>
#include "api/video/video_codec_type.h"
#include "api/video_codecs/video_codec.h"
#include "modules/video_coding/svc/scalability_mode_util.h"
#include "rtc_base/checks.h"
#include "video/config/video_encoder_config.h"
namespace webrtc {
uint32_t SimulcastUtility::SumStreamMaxBitrate(int streams,
const VideoCodec& codec) {
uint32_t bitrate_sum = 0;
for (int i = 0; i < streams; ++i) {
bitrate_sum += codec.simulcastStream[i].maxBitrate;
}
return bitrate_sum;
}
int SimulcastUtility::NumberOfSimulcastStreams(const VideoCodec& codec) {
int streams =
codec.numberOfSimulcastStreams < 1 ? 1 : codec.numberOfSimulcastStreams;
uint32_t simulcast_max_bitrate = SumStreamMaxBitrate(streams, codec);
if (simulcast_max_bitrate == 0) {
streams = 1;
}
return streams;
}
bool SimulcastUtility::ValidSimulcastParameters(const VideoCodec& codec,
int num_streams) {
// Check resolution.
if (codec.width != codec.simulcastStream[num_streams - 1].width ||
codec.height != codec.simulcastStream[num_streams - 1].height) {
return false;
}
for (int i = 0; i < num_streams; ++i) {
if (codec.width * codec.simulcastStream[i].height !=
codec.height * codec.simulcastStream[i].width) {
return false;
}
}
for (int i = 1; i < num_streams; ++i) {
if (codec.simulcastStream[i].width < codec.simulcastStream[i - 1].width) {
return false;
}
}
// Check frame-rate.
for (int i = 1; i < num_streams; ++i) {
if (fabs(codec.simulcastStream[i].maxFramerate -
codec.simulcastStream[i - 1].maxFramerate) > 1e-9) {
return false;
}
}
// Check temporal layers.
for (int i = 0; i < num_streams - 1; ++i) {
if (codec.simulcastStream[i].numberOfTemporalLayers !=
codec.simulcastStream[i + 1].numberOfTemporalLayers)
return false;
}
return true;
}
bool SimulcastUtility::IsConferenceModeScreenshare(const VideoCodec& codec) {
return codec.mode == VideoCodecMode::kScreensharing &&
codec.legacy_conference_mode &&
(codec.codecType == kVideoCodecVP8 ||
codec.codecType == kVideoCodecH264);
}
bool SimulcastUtility::IsConferenceModeScreenshare(
const VideoEncoderConfig& encoder_config) {
return encoder_config.content_type ==
VideoEncoderConfig::ContentType::kScreen &&
encoder_config.legacy_conference_mode &&
(encoder_config.codec_type == VideoCodecType::kVideoCodecVP8 ||
encoder_config.codec_type == VideoCodecType::kVideoCodecH264);
}
int SimulcastUtility::NumberOfTemporalLayers(const VideoCodec& codec,
int spatial_id) {
int num_temporal_layers = 0;
if (auto scalability_mode = codec.GetScalabilityMode(); scalability_mode) {
num_temporal_layers = ScalabilityModeToNumTemporalLayers(*scalability_mode);
} else {
switch (codec.codecType) {
case kVideoCodecVP8:
num_temporal_layers = codec.VP8().numberOfTemporalLayers;
break;
case kVideoCodecVP9:
num_temporal_layers = codec.VP9().numberOfTemporalLayers;
break;
case kVideoCodecH264:
num_temporal_layers = codec.H264().numberOfTemporalLayers;
break;
// For AV1 and H.265 we get temporal layer count from scalability mode,
// instead of from codec-specifics.
case kVideoCodecAV1:
case kVideoCodecH265:
case kVideoCodecGeneric:
break;
}
}
if (codec.numberOfSimulcastStreams > 0) {
RTC_DCHECK_LT(spatial_id, codec.numberOfSimulcastStreams);
num_temporal_layers =
std::max(num_temporal_layers,
static_cast<int>(
codec.simulcastStream[spatial_id].numberOfTemporalLayers));
}
return std::max(1, num_temporal_layers);
}
} // namespace webrtc
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