| /* |
| * 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 <optional> |
| |
| #include "api/array_view.h" |
| #include "api/field_trials_view.h" |
| #include "api/scoped_refptr.h" |
| #include "api/units/data_rate.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 { |
| |
| // TODO(sprang): Split this up and separate the codec specific parts. |
| VideoCodec VideoCodecInitializer::SetupCodec( |
| const FieldTrialsView& field_trials, |
| 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; |
| |
| std::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 active simulcast streams. |
| if (streams[i].active && |
| 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: { |
| // When the SvcRateAllocator is used, "active" is controlled by |
| // `SpatialLayer::active` instead. |
| if (video_codec.numberOfSimulcastStreams <= 1) { |
| 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 (video_codec.GetScalabilityMode().has_value()) { |
| // Layering is set via scalability mode. |
| spatial_layers = GetVp9SvcConfig(video_codec); |
| } 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; |
| // Only propagate if we're not doing simulcast. Simulcast is assumed not |
| // to have multiple spatial layers, if we wanted to support simulcast+SVC |
| // combos we would need to calculate unique spatial layers per simulcast |
| // layer, but VideoCodec is not capable of expressing per-simulcastStream |
| // spatialLayers. |
| if (video_codec.numberOfSimulcastStreams == 1) { |
| 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))) { |
| // If min bitrate is set via RtpEncodingParameters, use this value on |
| // lowest spatial layer. |
| if (!config.simulcast_layers.empty() && |
| config.simulcast_layers[0].min_bitrate_bps > 0) { |
| video_codec.spatialLayers[0].minBitrate = std::min( |
| config.simulcast_layers[0].min_bitrate_bps / 1000, |
| static_cast<int>(video_codec.spatialLayers[0].targetBitrate)); |
| } |
| 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; |
| } |
| case kVideoCodecH265: |
| // TODO(bugs.webrtc.org/13485) |
| 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 std::optional<DataRate> experimental_min_bitrate = |
| GetExperimentalMinVideoBitrate(field_trials, 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.codecType == kVideoCodecAV1) { |
| video_codec.spatialLayers[0].minBitrate = experimental_min_bitrate_kbps; |
| } |
| } |
| |
| return video_codec; |
| } |
| |
| } // namespace webrtc |
