|  | /* | 
|  | *  Copyright (c) 2016 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/include/video_codec_initializer.h" | 
|  |  | 
|  | #include <stdint.h> | 
|  | #include <string.h> | 
|  |  | 
|  | #include <algorithm> | 
|  |  | 
|  | #include "absl/types/optional.h" | 
|  | #include "api/scoped_refptr.h" | 
|  | #include "api/units/data_rate.h" | 
|  | #include "api/video/video_bitrate_allocation.h" | 
|  | #include "api/video_codecs/video_encoder.h" | 
|  | #include "modules/video_coding/codecs/av1/av1_svc_config.h" | 
|  | #include "modules/video_coding/codecs/vp8/vp8_scalability.h" | 
|  | #include "modules/video_coding/codecs/vp9/svc_config.h" | 
|  | #include "modules/video_coding/include/video_coding_defines.h" | 
|  | #include "modules/video_coding/svc/scalability_mode_util.h" | 
|  | #include "rtc_base/checks.h" | 
|  | #include "rtc_base/experiments/min_video_bitrate_experiment.h" | 
|  | #include "rtc_base/logging.h" | 
|  | #include "rtc_base/numerics/safe_conversions.h" | 
|  |  | 
|  | namespace webrtc { | 
|  |  | 
|  | bool VideoCodecInitializer::SetupCodec(const VideoEncoderConfig& config, | 
|  | const std::vector<VideoStream>& streams, | 
|  | VideoCodec* codec) { | 
|  | if (config.codec_type == kVideoCodecMultiplex) { | 
|  | VideoEncoderConfig associated_config = config.Copy(); | 
|  | associated_config.codec_type = kVideoCodecVP9; | 
|  | if (!SetupCodec(associated_config, streams, codec)) { | 
|  | RTC_LOG(LS_ERROR) << "Failed to create stereo encoder configuration."; | 
|  | return false; | 
|  | } | 
|  | codec->codecType = kVideoCodecMultiplex; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | *codec = VideoEncoderConfigToVideoCodec(config, streams); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | // TODO(sprang): Split this up and separate the codec specific parts. | 
|  | VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec( | 
|  | const VideoEncoderConfig& config, | 
|  | const std::vector<VideoStream>& streams) { | 
|  | static const int kEncoderMinBitrateKbps = 30; | 
|  | RTC_DCHECK(!streams.empty()); | 
|  | RTC_DCHECK_GE(config.min_transmit_bitrate_bps, 0); | 
|  |  | 
|  | VideoCodec video_codec; | 
|  | video_codec.codecType = config.codec_type; | 
|  |  | 
|  | switch (config.content_type) { | 
|  | case VideoEncoderConfig::ContentType::kRealtimeVideo: | 
|  | video_codec.mode = VideoCodecMode::kRealtimeVideo; | 
|  | break; | 
|  | case VideoEncoderConfig::ContentType::kScreen: | 
|  | video_codec.mode = VideoCodecMode::kScreensharing; | 
|  | break; | 
|  | } | 
|  |  | 
|  | video_codec.legacy_conference_mode = | 
|  | config.content_type == VideoEncoderConfig::ContentType::kScreen && | 
|  | config.legacy_conference_mode; | 
|  |  | 
|  | video_codec.SetFrameDropEnabled(config.frame_drop_enabled); | 
|  | video_codec.numberOfSimulcastStreams = | 
|  | static_cast<unsigned char>(streams.size()); | 
|  | video_codec.minBitrate = streams[0].min_bitrate_bps / 1000; | 
|  | bool codec_active = false; | 
|  | // Active configuration might not be fully copied to `streams` for SVC yet. | 
|  | // Therefore the `config` is checked here. | 
|  | for (const VideoStream& stream : config.simulcast_layers) { | 
|  | if (stream.active) { | 
|  | codec_active = true; | 
|  | break; | 
|  | } | 
|  | } | 
|  | // Set active for the entire video codec for the non simulcast case. | 
|  | video_codec.active = codec_active; | 
|  | if (video_codec.minBitrate < kEncoderMinBitrateKbps) | 
|  | video_codec.minBitrate = kEncoderMinBitrateKbps; | 
|  | video_codec.timing_frame_thresholds = {kDefaultTimingFramesDelayMs, | 
|  | kDefaultOutlierFrameSizePercent}; | 
|  | RTC_DCHECK_LE(streams.size(), kMaxSimulcastStreams); | 
|  |  | 
|  | int max_framerate = 0; | 
|  |  | 
|  | absl::optional<ScalabilityMode> scalability_mode = | 
|  | streams[0].scalability_mode; | 
|  | for (size_t i = 0; i < streams.size(); ++i) { | 
|  | SimulcastStream* sim_stream = &video_codec.simulcastStream[i]; | 
|  | RTC_DCHECK_GT(streams[i].width, 0); | 
|  | RTC_DCHECK_GT(streams[i].height, 0); | 
|  | RTC_DCHECK_GT(streams[i].max_framerate, 0); | 
|  | RTC_DCHECK_GE(streams[i].min_bitrate_bps, 0); | 
|  | RTC_DCHECK_GE(streams[i].target_bitrate_bps, streams[i].min_bitrate_bps); | 
|  | RTC_DCHECK_GE(streams[i].max_bitrate_bps, streams[i].target_bitrate_bps); | 
|  | RTC_DCHECK_GE(streams[i].max_qp, 0); | 
|  |  | 
|  | sim_stream->width = static_cast<uint16_t>(streams[i].width); | 
|  | sim_stream->height = static_cast<uint16_t>(streams[i].height); | 
|  | sim_stream->maxFramerate = streams[i].max_framerate; | 
|  | sim_stream->minBitrate = streams[i].min_bitrate_bps / 1000; | 
|  | sim_stream->targetBitrate = streams[i].target_bitrate_bps / 1000; | 
|  | sim_stream->maxBitrate = streams[i].max_bitrate_bps / 1000; | 
|  | sim_stream->qpMax = streams[i].max_qp; | 
|  |  | 
|  | int num_temporal_layers = | 
|  | streams[i].scalability_mode.has_value() | 
|  | ? ScalabilityModeToNumTemporalLayers(*streams[i].scalability_mode) | 
|  | : streams[i].num_temporal_layers.value_or(1); | 
|  |  | 
|  | sim_stream->numberOfTemporalLayers = | 
|  | static_cast<unsigned char>(num_temporal_layers); | 
|  | sim_stream->active = streams[i].active; | 
|  |  | 
|  | video_codec.width = | 
|  | std::max(video_codec.width, static_cast<uint16_t>(streams[i].width)); | 
|  | video_codec.height = | 
|  | std::max(video_codec.height, static_cast<uint16_t>(streams[i].height)); | 
|  | video_codec.minBitrate = | 
|  | std::min(static_cast<uint16_t>(video_codec.minBitrate), | 
|  | static_cast<uint16_t>(streams[i].min_bitrate_bps / 1000)); | 
|  | video_codec.maxBitrate += streams[i].max_bitrate_bps / 1000; | 
|  | video_codec.qpMax = std::max(video_codec.qpMax, | 
|  | static_cast<unsigned int>(streams[i].max_qp)); | 
|  | max_framerate = std::max(max_framerate, streams[i].max_framerate); | 
|  |  | 
|  | // TODO(bugs.webrtc.org/11607): Since scalability mode is a top-level | 
|  | // setting on VideoCodec, setting it makes sense only if it is the same for | 
|  | // all simulcast streams. | 
|  | if (streams[0].scalability_mode != streams[i].scalability_mode) { | 
|  | scalability_mode.reset(); | 
|  | // For VP8, top-level scalability mode doesn't matter, since configuration | 
|  | // is based on the per-simulcast stream configuration of temporal layers. | 
|  | if (video_codec.codecType != kVideoCodecVP8) { | 
|  | RTC_LOG(LS_WARNING) << "Inconsistent scalability modes configured."; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | if (scalability_mode.has_value()) { | 
|  | video_codec.SetScalabilityMode(*scalability_mode); | 
|  | } | 
|  |  | 
|  | if (video_codec.maxBitrate == 0) { | 
|  | // Unset max bitrate -> cap to one bit per pixel. | 
|  | video_codec.maxBitrate = | 
|  | (video_codec.width * video_codec.height * video_codec.maxFramerate) / | 
|  | 1000; | 
|  | } | 
|  | if (video_codec.maxBitrate < kEncoderMinBitrateKbps) | 
|  | video_codec.maxBitrate = kEncoderMinBitrateKbps; | 
|  |  | 
|  | video_codec.maxFramerate = max_framerate; | 
|  | video_codec.spatialLayers[0] = {0}; | 
|  | video_codec.spatialLayers[0].width = video_codec.width; | 
|  | video_codec.spatialLayers[0].height = video_codec.height; | 
|  | video_codec.spatialLayers[0].maxFramerate = max_framerate; | 
|  | video_codec.spatialLayers[0].numberOfTemporalLayers = | 
|  | streams[0].scalability_mode.has_value() | 
|  | ? ScalabilityModeToNumTemporalLayers(*streams[0].scalability_mode) | 
|  | : streams[0].num_temporal_layers.value_or(1); | 
|  |  | 
|  | // Set codec specific options | 
|  | if (config.encoder_specific_settings) | 
|  | config.encoder_specific_settings->FillEncoderSpecificSettings(&video_codec); | 
|  |  | 
|  | switch (video_codec.codecType) { | 
|  | case kVideoCodecVP8: { | 
|  | if (!config.encoder_specific_settings) { | 
|  | *video_codec.VP8() = VideoEncoder::GetDefaultVp8Settings(); | 
|  | } | 
|  |  | 
|  | // Validate specified scalability modes. If some layer has an unsupported | 
|  | // mode, store it as the top-level scalability mode, which will make | 
|  | // InitEncode fail with an appropriate error. | 
|  | for (const auto& stream : streams) { | 
|  | if (stream.scalability_mode.has_value() && | 
|  | !VP8SupportsScalabilityMode(*stream.scalability_mode)) { | 
|  | RTC_LOG(LS_WARNING) | 
|  | << "Invalid scalability mode for VP8: " | 
|  | << ScalabilityModeToString(*stream.scalability_mode); | 
|  | video_codec.SetScalabilityMode(*stream.scalability_mode); | 
|  | break; | 
|  | } | 
|  | } | 
|  | video_codec.VP8()->numberOfTemporalLayers = | 
|  | streams.back().scalability_mode.has_value() | 
|  | ? ScalabilityModeToNumTemporalLayers( | 
|  | *streams.back().scalability_mode) | 
|  | : streams.back().num_temporal_layers.value_or( | 
|  | video_codec.VP8()->numberOfTemporalLayers); | 
|  |  | 
|  | RTC_DCHECK_GE(video_codec.VP8()->numberOfTemporalLayers, 1); | 
|  | RTC_DCHECK_LE(video_codec.VP8()->numberOfTemporalLayers, | 
|  | kMaxTemporalStreams); | 
|  |  | 
|  | break; | 
|  | } | 
|  | case kVideoCodecVP9: { | 
|  | // Force the first stream to always be active. | 
|  | video_codec.simulcastStream[0].active = codec_active; | 
|  |  | 
|  | if (!config.encoder_specific_settings) { | 
|  | *video_codec.VP9() = VideoEncoder::GetDefaultVp9Settings(); | 
|  | } | 
|  |  | 
|  | video_codec.VP9()->numberOfTemporalLayers = static_cast<unsigned char>( | 
|  | streams.back().num_temporal_layers.value_or( | 
|  | video_codec.VP9()->numberOfTemporalLayers)); | 
|  | RTC_DCHECK_GE(video_codec.VP9()->numberOfTemporalLayers, 1); | 
|  | RTC_DCHECK_LE(video_codec.VP9()->numberOfTemporalLayers, | 
|  | kMaxTemporalStreams); | 
|  |  | 
|  | RTC_DCHECK(config.spatial_layers.empty() || | 
|  | config.spatial_layers.size() == | 
|  | video_codec.VP9()->numberOfSpatialLayers); | 
|  |  | 
|  | std::vector<SpatialLayer> spatial_layers; | 
|  | if (!config.spatial_layers.empty()) { | 
|  | // Layering is set explicitly. | 
|  | spatial_layers = config.spatial_layers; | 
|  | } else if (scalability_mode.has_value()) { | 
|  | // Layering is set via scalability mode. | 
|  | spatial_layers = GetVp9SvcConfig(video_codec); | 
|  | if (spatial_layers.empty()) | 
|  | break; | 
|  | } else { | 
|  | size_t first_active_layer = 0; | 
|  | for (size_t spatial_idx = 0; | 
|  | spatial_idx < config.simulcast_layers.size(); ++spatial_idx) { | 
|  | if (config.simulcast_layers[spatial_idx].active) { | 
|  | first_active_layer = spatial_idx; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | spatial_layers = GetSvcConfig( | 
|  | video_codec.width, video_codec.height, video_codec.maxFramerate, | 
|  | first_active_layer, video_codec.VP9()->numberOfSpatialLayers, | 
|  | video_codec.VP9()->numberOfTemporalLayers, | 
|  | video_codec.mode == VideoCodecMode::kScreensharing); | 
|  |  | 
|  | // If there was no request for spatial layering, don't limit bitrate | 
|  | // of single spatial layer. | 
|  | const bool no_spatial_layering = | 
|  | video_codec.VP9()->numberOfSpatialLayers <= 1; | 
|  | if (no_spatial_layering) { | 
|  | // Use codec's bitrate limits. | 
|  | spatial_layers.back().minBitrate = video_codec.minBitrate; | 
|  | spatial_layers.back().targetBitrate = video_codec.maxBitrate; | 
|  | spatial_layers.back().maxBitrate = video_codec.maxBitrate; | 
|  | } | 
|  |  | 
|  | for (size_t spatial_idx = first_active_layer; | 
|  | spatial_idx < config.simulcast_layers.size() && | 
|  | spatial_idx < spatial_layers.size() + first_active_layer; | 
|  | ++spatial_idx) { | 
|  | spatial_layers[spatial_idx - first_active_layer].active = | 
|  | config.simulcast_layers[spatial_idx].active; | 
|  | } | 
|  | } | 
|  |  | 
|  | RTC_DCHECK(!spatial_layers.empty()); | 
|  | for (size_t i = 0; i < spatial_layers.size(); ++i) { | 
|  | video_codec.spatialLayers[i] = spatial_layers[i]; | 
|  | } | 
|  |  | 
|  | // The top spatial layer dimensions may not be equal to the input | 
|  | // resolution because of the rounding or explicit configuration. | 
|  | // This difference must be propagated to the stream configuration. | 
|  | video_codec.width = spatial_layers.back().width; | 
|  | video_codec.height = spatial_layers.back().height; | 
|  | video_codec.simulcastStream[0].width = spatial_layers.back().width; | 
|  | video_codec.simulcastStream[0].height = spatial_layers.back().height; | 
|  |  | 
|  | // Update layering settings. | 
|  | video_codec.VP9()->numberOfSpatialLayers = | 
|  | static_cast<unsigned char>(spatial_layers.size()); | 
|  | RTC_DCHECK_GE(video_codec.VP9()->numberOfSpatialLayers, 1); | 
|  | RTC_DCHECK_LE(video_codec.VP9()->numberOfSpatialLayers, | 
|  | kMaxSpatialLayers); | 
|  |  | 
|  | video_codec.VP9()->numberOfTemporalLayers = static_cast<unsigned char>( | 
|  | spatial_layers.back().numberOfTemporalLayers); | 
|  | RTC_DCHECK_GE(video_codec.VP9()->numberOfTemporalLayers, 1); | 
|  | RTC_DCHECK_LE(video_codec.VP9()->numberOfTemporalLayers, | 
|  | kMaxTemporalStreams); | 
|  |  | 
|  | break; | 
|  | } | 
|  | case kVideoCodecAV1: | 
|  | if (SetAv1SvcConfig(video_codec, | 
|  | /*num_temporal_layers=*/ | 
|  | streams.back().num_temporal_layers.value_or(1), | 
|  | /*num_spatial_layers=*/ | 
|  | std::max<int>(config.spatial_layers.size(), 1))) { | 
|  | for (size_t i = 0; i < config.spatial_layers.size(); ++i) { | 
|  | video_codec.spatialLayers[i].active = config.spatial_layers[i].active; | 
|  | } | 
|  | } else { | 
|  | RTC_LOG(LS_WARNING) << "Failed to configure svc bitrates for av1."; | 
|  | } | 
|  | break; | 
|  | case kVideoCodecH264: { | 
|  | RTC_CHECK(!config.encoder_specific_settings); | 
|  |  | 
|  | *video_codec.H264() = VideoEncoder::GetDefaultH264Settings(); | 
|  | video_codec.H264()->numberOfTemporalLayers = static_cast<unsigned char>( | 
|  | streams.back().num_temporal_layers.value_or( | 
|  | video_codec.H264()->numberOfTemporalLayers)); | 
|  | RTC_DCHECK_GE(video_codec.H264()->numberOfTemporalLayers, 1); | 
|  | RTC_DCHECK_LE(video_codec.H264()->numberOfTemporalLayers, | 
|  | kMaxTemporalStreams); | 
|  | break; | 
|  | } | 
|  | default: | 
|  | // TODO(pbos): Support encoder_settings codec-agnostically. | 
|  | RTC_DCHECK(!config.encoder_specific_settings) | 
|  | << "Encoder-specific settings for codec type not wired up."; | 
|  | break; | 
|  | } | 
|  |  | 
|  | const absl::optional<DataRate> experimental_min_bitrate = | 
|  | GetExperimentalMinVideoBitrate(video_codec.codecType); | 
|  | if (experimental_min_bitrate) { | 
|  | const int experimental_min_bitrate_kbps = | 
|  | rtc::saturated_cast<int>(experimental_min_bitrate->kbps()); | 
|  | video_codec.minBitrate = experimental_min_bitrate_kbps; | 
|  | video_codec.simulcastStream[0].minBitrate = experimental_min_bitrate_kbps; | 
|  | if (video_codec.codecType == kVideoCodecVP9) { | 
|  | video_codec.spatialLayers[0].minBitrate = experimental_min_bitrate_kbps; | 
|  | } | 
|  | } | 
|  |  | 
|  | return video_codec; | 
|  | } | 
|  |  | 
|  | }  // namespace webrtc |