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/*
* Copyright (c) 2015 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.
*
*/
// Everything declared/defined in this header is only required when WebRTC is
// build with H264 support, please do not move anything out of the
// #ifdef unless needed and tested.
#ifdef WEBRTC_USE_H264
#include "modules/video_coding/codecs/h264/h264_encoder_impl.h"
#include <algorithm>
#include <limits>
#include <string>
#include "absl/strings/match.h"
#include "absl/types/optional.h"
#include "api/video/video_codec_constants.h"
#include "api/video_codecs/scalability_mode.h"
#include "common_video/libyuv/include/webrtc_libyuv.h"
#include "modules/video_coding/include/video_codec_interface.h"
#include "modules/video_coding/include/video_error_codes.h"
#include "modules/video_coding/svc/create_scalability_structure.h"
#include "modules/video_coding/utility/simulcast_rate_allocator.h"
#include "modules/video_coding/utility/simulcast_utility.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/time_utils.h"
#include "system_wrappers/include/metrics.h"
#include "third_party/libyuv/include/libyuv/convert.h"
#include "third_party/libyuv/include/libyuv/scale.h"
#include "third_party/openh264/src/codec/api/wels/codec_api.h"
#include "third_party/openh264/src/codec/api/wels/codec_app_def.h"
#include "third_party/openh264/src/codec/api/wels/codec_def.h"
#include "third_party/openh264/src/codec/api/wels/codec_ver.h"
namespace webrtc {
namespace {
const bool kOpenH264EncoderDetailedLogging = false;
// QP scaling thresholds.
static const int kLowH264QpThreshold = 24;
static const int kHighH264QpThreshold = 37;
// Used by histograms. Values of entries should not be changed.
enum H264EncoderImplEvent {
kH264EncoderEventInit = 0,
kH264EncoderEventError = 1,
kH264EncoderEventMax = 16,
};
int NumberOfThreads(absl::optional<int> encoder_thread_limit,
int width,
int height,
int number_of_cores) {
// TODO(hbos): In Chromium, multiple threads do not work with sandbox on Mac,
// see crbug.com/583348. Until further investigated, only use one thread.
// While this limitation is gone, this changes the bitstream format (see
// bugs.webrtc.org/14368) so still guarded by field trial to allow for
// experimentation using th experimental
// WebRTC-VideoEncoderSettings/encoder_thread_limit trial.
if (encoder_thread_limit.has_value()) {
int limit = encoder_thread_limit.value();
RTC_DCHECK_GE(limit, 1);
if (width * height >= 1920 * 1080 && number_of_cores > 8) {
return std::min(limit, 8); // 8 threads for 1080p on high perf machines.
} else if (width * height > 1280 * 960 && number_of_cores >= 6) {
return std::min(limit, 3); // 3 threads for 1080p.
} else if (width * height > 640 * 480 && number_of_cores >= 3) {
return std::min(limit, 2); // 2 threads for qHD/HD.
} else {
return 1; // 1 thread for VGA or less.
}
}
// TODO(sprang): Also check sSliceArgument.uiSliceNum on GetEncoderParams(),
// before enabling multithreading here.
return 1;
}
VideoFrameType ConvertToVideoFrameType(EVideoFrameType type) {
switch (type) {
case videoFrameTypeIDR:
return VideoFrameType::kVideoFrameKey;
case videoFrameTypeSkip:
case videoFrameTypeI:
case videoFrameTypeP:
case videoFrameTypeIPMixed:
return VideoFrameType::kVideoFrameDelta;
case videoFrameTypeInvalid:
break;
}
RTC_DCHECK_NOTREACHED() << "Unexpected/invalid frame type: " << type;
return VideoFrameType::kEmptyFrame;
}
absl::optional<ScalabilityMode> ScalabilityModeFromTemporalLayers(
int num_temporal_layers) {
switch (num_temporal_layers) {
case 0:
break;
case 1:
return ScalabilityMode::kL1T1;
case 2:
return ScalabilityMode::kL1T2;
case 3:
return ScalabilityMode::kL1T3;
default:
RTC_DCHECK_NOTREACHED();
}
return absl::nullopt;
}
} // namespace
// Helper method used by H264EncoderImpl::Encode.
// Copies the encoded bytes from `info` to `encoded_image`. The
// `encoded_image->_buffer` may be deleted and reallocated if a bigger buffer is
// required.
//
// After OpenH264 encoding, the encoded bytes are stored in `info` spread out
// over a number of layers and "NAL units". Each NAL unit is a fragment starting
// with the four-byte start code {0,0,0,1}. All of this data (including the
// start codes) is copied to the `encoded_image->_buffer`.
static void RtpFragmentize(EncodedImage* encoded_image, SFrameBSInfo* info) {
// Calculate minimum buffer size required to hold encoded data.
size_t required_capacity = 0;
size_t fragments_count = 0;
for (int layer = 0; layer < info->iLayerNum; ++layer) {
const SLayerBSInfo& layerInfo = info->sLayerInfo[layer];
for (int nal = 0; nal < layerInfo.iNalCount; ++nal, ++fragments_count) {
RTC_CHECK_GE(layerInfo.pNalLengthInByte[nal], 0);
// Ensure `required_capacity` will not overflow.
RTC_CHECK_LE(layerInfo.pNalLengthInByte[nal],
std::numeric_limits<size_t>::max() - required_capacity);
required_capacity += layerInfo.pNalLengthInByte[nal];
}
}
auto buffer = EncodedImageBuffer::Create(required_capacity);
encoded_image->SetEncodedData(buffer);
// Iterate layers and NAL units, note each NAL unit as a fragment and copy
// the data to `encoded_image->_buffer`.
const uint8_t start_code[4] = {0, 0, 0, 1};
size_t frag = 0;
encoded_image->set_size(0);
for (int layer = 0; layer < info->iLayerNum; ++layer) {
const SLayerBSInfo& layerInfo = info->sLayerInfo[layer];
// Iterate NAL units making up this layer, noting fragments.
size_t layer_len = 0;
for (int nal = 0; nal < layerInfo.iNalCount; ++nal, ++frag) {
// Because the sum of all layer lengths, `required_capacity`, fits in a
// `size_t`, we know that any indices in-between will not overflow.
RTC_DCHECK_GE(layerInfo.pNalLengthInByte[nal], 4);
RTC_DCHECK_EQ(layerInfo.pBsBuf[layer_len + 0], start_code[0]);
RTC_DCHECK_EQ(layerInfo.pBsBuf[layer_len + 1], start_code[1]);
RTC_DCHECK_EQ(layerInfo.pBsBuf[layer_len + 2], start_code[2]);
RTC_DCHECK_EQ(layerInfo.pBsBuf[layer_len + 3], start_code[3]);
layer_len += layerInfo.pNalLengthInByte[nal];
}
// Copy the entire layer's data (including start codes).
memcpy(buffer->data() + encoded_image->size(), layerInfo.pBsBuf, layer_len);
encoded_image->set_size(encoded_image->size() + layer_len);
}
}
H264EncoderImpl::H264EncoderImpl(const Environment& env,
H264EncoderSettings settings)
: env_(env),
packetization_mode_(settings.packetization_mode),
max_payload_size_(0),
number_of_cores_(0),
encoded_image_callback_(nullptr),
has_reported_init_(false),
has_reported_error_(false) {
downscaled_buffers_.reserve(kMaxSimulcastStreams - 1);
encoded_images_.reserve(kMaxSimulcastStreams);
encoders_.reserve(kMaxSimulcastStreams);
configurations_.reserve(kMaxSimulcastStreams);
tl0sync_limit_.reserve(kMaxSimulcastStreams);
svc_controllers_.reserve(kMaxSimulcastStreams);
}
H264EncoderImpl::~H264EncoderImpl() {
Release();
}
int32_t H264EncoderImpl::InitEncode(const VideoCodec* inst,
const VideoEncoder::Settings& settings) {
ReportInit();
if (!inst || inst->codecType != kVideoCodecH264) {
ReportError();
return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
}
if (inst->maxFramerate == 0) {
ReportError();
return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
}
if (inst->width < 1 || inst->height < 1) {
ReportError();
return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
}
int32_t release_ret = Release();
if (release_ret != WEBRTC_VIDEO_CODEC_OK) {
ReportError();
return release_ret;
}
int number_of_streams = SimulcastUtility::NumberOfSimulcastStreams(*inst);
bool doing_simulcast = (number_of_streams > 1);
if (doing_simulcast &&
!SimulcastUtility::ValidSimulcastParameters(*inst, number_of_streams)) {
return WEBRTC_VIDEO_CODEC_ERR_SIMULCAST_PARAMETERS_NOT_SUPPORTED;
}
downscaled_buffers_.resize(number_of_streams - 1);
encoded_images_.resize(number_of_streams);
encoders_.resize(number_of_streams);
pictures_.resize(number_of_streams);
svc_controllers_.resize(number_of_streams);
scalability_modes_.resize(number_of_streams);
configurations_.resize(number_of_streams);
tl0sync_limit_.resize(number_of_streams);
max_payload_size_ = settings.max_payload_size;
number_of_cores_ = settings.number_of_cores;
encoder_thread_limit_ = settings.encoder_thread_limit;
codec_ = *inst;
// Code expects simulcastStream resolutions to be correct, make sure they are
// filled even when there are no simulcast layers.
if (codec_.numberOfSimulcastStreams == 0) {
codec_.simulcastStream[0].width = codec_.width;
codec_.simulcastStream[0].height = codec_.height;
}
for (int i = 0, idx = number_of_streams - 1; i < number_of_streams;
++i, --idx) {
ISVCEncoder* openh264_encoder;
// Create encoder.
if (WelsCreateSVCEncoder(&openh264_encoder) != 0) {
// Failed to create encoder.
RTC_LOG(LS_ERROR) << "Failed to create OpenH264 encoder";
RTC_DCHECK(!openh264_encoder);
Release();
ReportError();
return WEBRTC_VIDEO_CODEC_ERROR;
}
RTC_DCHECK(openh264_encoder);
if (kOpenH264EncoderDetailedLogging) {
int trace_level = WELS_LOG_DETAIL;
openh264_encoder->SetOption(ENCODER_OPTION_TRACE_LEVEL, &trace_level);
}
// else WELS_LOG_DEFAULT is used by default.
// Store h264 encoder.
encoders_[i] = openh264_encoder;
// Set internal settings from codec_settings
configurations_[i].simulcast_idx = idx;
configurations_[i].sending = false;
configurations_[i].width = codec_.simulcastStream[idx].width;
configurations_[i].height = codec_.simulcastStream[idx].height;
configurations_[i].max_frame_rate = static_cast<float>(codec_.maxFramerate);
configurations_[i].frame_dropping_on = codec_.GetFrameDropEnabled();
configurations_[i].key_frame_interval = codec_.H264()->keyFrameInterval;
configurations_[i].num_temporal_layers =
std::max(codec_.H264()->numberOfTemporalLayers,
codec_.simulcastStream[idx].numberOfTemporalLayers);
// Create downscaled image buffers.
if (i > 0) {
downscaled_buffers_[i - 1] = I420Buffer::Create(
configurations_[i].width, configurations_[i].height,
configurations_[i].width, configurations_[i].width / 2,
configurations_[i].width / 2);
}
// Codec_settings uses kbits/second; encoder uses bits/second.
configurations_[i].max_bps = codec_.maxBitrate * 1000;
configurations_[i].target_bps = codec_.startBitrate * 1000;
// Create encoder parameters based on the layer configuration.
SEncParamExt encoder_params = CreateEncoderParams(i);
// Initialize.
if (openh264_encoder->InitializeExt(&encoder_params) != 0) {
RTC_LOG(LS_ERROR) << "Failed to initialize OpenH264 encoder";
Release();
ReportError();
return WEBRTC_VIDEO_CODEC_ERROR;
}
// TODO(pbos): Base init params on these values before submitting.
int video_format = EVideoFormatType::videoFormatI420;
openh264_encoder->SetOption(ENCODER_OPTION_DATAFORMAT, &video_format);
// Initialize encoded image. Default buffer size: size of unencoded data.
const size_t new_capacity =
CalcBufferSize(VideoType::kI420, codec_.simulcastStream[idx].width,
codec_.simulcastStream[idx].height);
encoded_images_[i].SetEncodedData(EncodedImageBuffer::Create(new_capacity));
encoded_images_[i]._encodedWidth = codec_.simulcastStream[idx].width;
encoded_images_[i]._encodedHeight = codec_.simulcastStream[idx].height;
encoded_images_[i].set_size(0);
tl0sync_limit_[i] = configurations_[i].num_temporal_layers;
scalability_modes_[i] = ScalabilityModeFromTemporalLayers(
configurations_[i].num_temporal_layers);
if (scalability_modes_[i].has_value()) {
svc_controllers_[i] = CreateScalabilityStructure(*scalability_modes_[i]);
if (svc_controllers_[i] == nullptr) {
RTC_LOG(LS_ERROR) << "Failed to create scalability structure";
Release();
ReportError();
return WEBRTC_VIDEO_CODEC_ERROR;
}
}
}
SimulcastRateAllocator init_allocator(env_, codec_);
VideoBitrateAllocation allocation =
init_allocator.Allocate(VideoBitrateAllocationParameters(
DataRate::KilobitsPerSec(codec_.startBitrate), codec_.maxFramerate));
SetRates(RateControlParameters(allocation, codec_.maxFramerate));
return WEBRTC_VIDEO_CODEC_OK;
}
int32_t H264EncoderImpl::Release() {
while (!encoders_.empty()) {
ISVCEncoder* openh264_encoder = encoders_.back();
if (openh264_encoder) {
RTC_CHECK_EQ(0, openh264_encoder->Uninitialize());
WelsDestroySVCEncoder(openh264_encoder);
}
encoders_.pop_back();
}
downscaled_buffers_.clear();
configurations_.clear();
encoded_images_.clear();
pictures_.clear();
tl0sync_limit_.clear();
svc_controllers_.clear();
scalability_modes_.clear();
return WEBRTC_VIDEO_CODEC_OK;
}
int32_t H264EncoderImpl::RegisterEncodeCompleteCallback(
EncodedImageCallback* callback) {
encoded_image_callback_ = callback;
return WEBRTC_VIDEO_CODEC_OK;
}
void H264EncoderImpl::SetRates(const RateControlParameters& parameters) {
if (encoders_.empty()) {
RTC_LOG(LS_WARNING) << "SetRates() while uninitialized.";
return;
}
if (parameters.framerate_fps < 1.0) {
RTC_LOG(LS_WARNING) << "Invalid frame rate: " << parameters.framerate_fps;
return;
}
if (parameters.bitrate.get_sum_bps() == 0) {
// Encoder paused, turn off all encoding.
for (size_t i = 0; i < configurations_.size(); ++i) {
configurations_[i].SetStreamState(false);
}
return;
}
codec_.maxFramerate = static_cast<uint32_t>(parameters.framerate_fps);
size_t stream_idx = encoders_.size() - 1;
for (size_t i = 0; i < encoders_.size(); ++i, --stream_idx) {
// Update layer config.
configurations_[i].target_bps =
parameters.bitrate.GetSpatialLayerSum(stream_idx);
configurations_[i].max_frame_rate = parameters.framerate_fps;
if (configurations_[i].target_bps) {
configurations_[i].SetStreamState(true);
// Update h264 encoder.
SBitrateInfo target_bitrate;
memset(&target_bitrate, 0, sizeof(SBitrateInfo));
target_bitrate.iLayer = SPATIAL_LAYER_ALL,
target_bitrate.iBitrate = configurations_[i].target_bps;
encoders_[i]->SetOption(ENCODER_OPTION_BITRATE, &target_bitrate);
encoders_[i]->SetOption(ENCODER_OPTION_FRAME_RATE,
&configurations_[i].max_frame_rate);
} else {
configurations_[i].SetStreamState(false);
}
}
}
int32_t H264EncoderImpl::Encode(
const VideoFrame& input_frame,
const std::vector<VideoFrameType>* frame_types) {
if (encoders_.empty()) {
ReportError();
return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
}
if (!encoded_image_callback_) {
RTC_LOG(LS_WARNING)
<< "InitEncode() has been called, but a callback function "
"has not been set with RegisterEncodeCompleteCallback()";
ReportError();
return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
}
rtc::scoped_refptr<I420BufferInterface> frame_buffer =
input_frame.video_frame_buffer()->ToI420();
if (!frame_buffer) {
RTC_LOG(LS_ERROR) << "Failed to convert "
<< VideoFrameBufferTypeToString(
input_frame.video_frame_buffer()->type())
<< " image to I420. Can't encode frame.";
return WEBRTC_VIDEO_CODEC_ENCODER_FAILURE;
}
RTC_CHECK(frame_buffer->type() == VideoFrameBuffer::Type::kI420 ||
frame_buffer->type() == VideoFrameBuffer::Type::kI420A);
bool is_keyframe_needed = false;
for (size_t i = 0; i < configurations_.size(); ++i) {
if (configurations_[i].key_frame_request && configurations_[i].sending) {
// This is legacy behavior, generating a keyframe on all layers
// when generating one for a layer that became active for the first time
// or after being disabled.
is_keyframe_needed = true;
break;
}
}
RTC_DCHECK_EQ(configurations_[0].width, frame_buffer->width());
RTC_DCHECK_EQ(configurations_[0].height, frame_buffer->height());
// Encode image for each layer.
for (size_t i = 0; i < encoders_.size(); ++i) {
// EncodeFrame input.
pictures_[i] = {0};
pictures_[i].iPicWidth = configurations_[i].width;
pictures_[i].iPicHeight = configurations_[i].height;
pictures_[i].iColorFormat = EVideoFormatType::videoFormatI420;
pictures_[i].uiTimeStamp = input_frame.ntp_time_ms();
// Downscale images on second and ongoing layers.
if (i == 0) {
pictures_[i].iStride[0] = frame_buffer->StrideY();
pictures_[i].iStride[1] = frame_buffer->StrideU();
pictures_[i].iStride[2] = frame_buffer->StrideV();
pictures_[i].pData[0] = const_cast<uint8_t*>(frame_buffer->DataY());
pictures_[i].pData[1] = const_cast<uint8_t*>(frame_buffer->DataU());
pictures_[i].pData[2] = const_cast<uint8_t*>(frame_buffer->DataV());
} else {
pictures_[i].iStride[0] = downscaled_buffers_[i - 1]->StrideY();
pictures_[i].iStride[1] = downscaled_buffers_[i - 1]->StrideU();
pictures_[i].iStride[2] = downscaled_buffers_[i - 1]->StrideV();
pictures_[i].pData[0] =
const_cast<uint8_t*>(downscaled_buffers_[i - 1]->DataY());
pictures_[i].pData[1] =
const_cast<uint8_t*>(downscaled_buffers_[i - 1]->DataU());
pictures_[i].pData[2] =
const_cast<uint8_t*>(downscaled_buffers_[i - 1]->DataV());
// Scale the image down a number of times by downsampling factor.
libyuv::I420Scale(pictures_[i - 1].pData[0], pictures_[i - 1].iStride[0],
pictures_[i - 1].pData[1], pictures_[i - 1].iStride[1],
pictures_[i - 1].pData[2], pictures_[i - 1].iStride[2],
configurations_[i - 1].width,
configurations_[i - 1].height, pictures_[i].pData[0],
pictures_[i].iStride[0], pictures_[i].pData[1],
pictures_[i].iStride[1], pictures_[i].pData[2],
pictures_[i].iStride[2], configurations_[i].width,
configurations_[i].height, libyuv::kFilterBox);
}
if (!configurations_[i].sending) {
continue;
}
if (frame_types != nullptr && i < frame_types->size()) {
// Skip frame?
if ((*frame_types)[i] == VideoFrameType::kEmptyFrame) {
continue;
}
}
// Send a key frame either when this layer is configured to require one
// or we have explicitly been asked to.
const size_t simulcast_idx =
static_cast<size_t>(configurations_[i].simulcast_idx);
bool send_key_frame =
is_keyframe_needed ||
(frame_types && simulcast_idx < frame_types->size() &&
(*frame_types)[simulcast_idx] == VideoFrameType::kVideoFrameKey);
if (send_key_frame) {
// API doc says ForceIntraFrame(false) does nothing, but calling this
// function forces a key frame regardless of the `bIDR` argument's value.
// (If every frame is a key frame we get lag/delays.)
encoders_[i]->ForceIntraFrame(true);
configurations_[i].key_frame_request = false;
}
// EncodeFrame output.
SFrameBSInfo info;
memset(&info, 0, sizeof(SFrameBSInfo));
std::vector<ScalableVideoController::LayerFrameConfig> layer_frames;
if (svc_controllers_[i]) {
layer_frames = svc_controllers_[i]->NextFrameConfig(send_key_frame);
RTC_CHECK_EQ(layer_frames.size(), 1);
}
// Encode!
int enc_ret = encoders_[i]->EncodeFrame(&pictures_[i], &info);
if (enc_ret != 0) {
RTC_LOG(LS_ERROR)
<< "OpenH264 frame encoding failed, EncodeFrame returned " << enc_ret
<< ".";
ReportError();
return WEBRTC_VIDEO_CODEC_ERROR;
}
encoded_images_[i]._encodedWidth = configurations_[i].width;
encoded_images_[i]._encodedHeight = configurations_[i].height;
encoded_images_[i].SetRtpTimestamp(input_frame.rtp_timestamp());
encoded_images_[i].SetColorSpace(input_frame.color_space());
encoded_images_[i]._frameType = ConvertToVideoFrameType(info.eFrameType);
encoded_images_[i].SetSimulcastIndex(configurations_[i].simulcast_idx);
// Split encoded image up into fragments. This also updates
// `encoded_image_`.
RtpFragmentize(&encoded_images_[i], &info);
// Encoder can skip frames to save bandwidth in which case
// `encoded_images_[i]._length` == 0.
if (encoded_images_[i].size() > 0) {
// Parse QP.
h264_bitstream_parser_.ParseBitstream(encoded_images_[i]);
encoded_images_[i].qp_ =
h264_bitstream_parser_.GetLastSliceQp().value_or(-1);
// Deliver encoded image.
CodecSpecificInfo codec_specific;
codec_specific.codecType = kVideoCodecH264;
codec_specific.codecSpecific.H264.packetization_mode =
packetization_mode_;
codec_specific.codecSpecific.H264.temporal_idx = kNoTemporalIdx;
codec_specific.codecSpecific.H264.idr_frame =
info.eFrameType == videoFrameTypeIDR;
codec_specific.codecSpecific.H264.base_layer_sync = false;
if (configurations_[i].num_temporal_layers > 1) {
const uint8_t tid = info.sLayerInfo[0].uiTemporalId;
codec_specific.codecSpecific.H264.temporal_idx = tid;
codec_specific.codecSpecific.H264.base_layer_sync =
tid > 0 && tid < tl0sync_limit_[i];
if (svc_controllers_[i]) {
if (encoded_images_[i]._frameType == VideoFrameType::kVideoFrameKey) {
// Reset the ScalableVideoController on key frame
// to reset the expected dependency structure.
layer_frames =
svc_controllers_[i]->NextFrameConfig(/* restart= */ true);
RTC_CHECK_EQ(layer_frames.size(), 1);
RTC_DCHECK_EQ(layer_frames[0].TemporalId(), 0);
RTC_DCHECK_EQ(layer_frames[0].IsKeyframe(), true);
}
if (layer_frames[0].TemporalId() != tid) {
RTC_LOG(LS_WARNING)
<< "Encoder produced a frame with temporal id " << tid
<< ", expected " << layer_frames[0].TemporalId() << ".";
continue;
}
encoded_images_[i].SetTemporalIndex(tid);
}
if (codec_specific.codecSpecific.H264.base_layer_sync) {
tl0sync_limit_[i] = tid;
}
if (tid == 0) {
tl0sync_limit_[i] = configurations_[i].num_temporal_layers;
}
}
if (svc_controllers_[i]) {
codec_specific.generic_frame_info =
svc_controllers_[i]->OnEncodeDone(layer_frames[0]);
if (send_key_frame && codec_specific.generic_frame_info.has_value()) {
codec_specific.template_structure =
svc_controllers_[i]->DependencyStructure();
}
codec_specific.scalability_mode = scalability_modes_[i];
}
encoded_image_callback_->OnEncodedImage(encoded_images_[i],
&codec_specific);
}
}
return WEBRTC_VIDEO_CODEC_OK;
}
// Initialization parameters.
// There are two ways to initialize. There is SEncParamBase (cleared with
// memset(&p, 0, sizeof(SEncParamBase)) used in Initialize, and SEncParamExt
// which is a superset of SEncParamBase (cleared with GetDefaultParams) used
// in InitializeExt.
SEncParamExt H264EncoderImpl::CreateEncoderParams(size_t i) const {
SEncParamExt encoder_params;
encoders_[i]->GetDefaultParams(&encoder_params);
if (codec_.mode == VideoCodecMode::kRealtimeVideo) {
encoder_params.iUsageType = CAMERA_VIDEO_REAL_TIME;
} else if (codec_.mode == VideoCodecMode::kScreensharing) {
encoder_params.iUsageType = SCREEN_CONTENT_REAL_TIME;
} else {
RTC_DCHECK_NOTREACHED();
}
encoder_params.iPicWidth = configurations_[i].width;
encoder_params.iPicHeight = configurations_[i].height;
encoder_params.iTargetBitrate = configurations_[i].target_bps;
// Keep unspecified. WebRTC's max codec bitrate is not the same setting
encoder_params.iMaxBitrate = UNSPECIFIED_BIT_RATE;
// Rate Control mode
encoder_params.iRCMode = RC_BITRATE_MODE;
encoder_params.fMaxFrameRate = configurations_[i].max_frame_rate;
// The following parameters are extension parameters (they're in SEncParamExt,
// not in SEncParamBase).
encoder_params.bEnableFrameSkip = configurations_[i].frame_dropping_on;
// `uiIntraPeriod` - multiple of GOP size
// `keyFrameInterval` - number of frames
encoder_params.uiIntraPeriod = configurations_[i].key_frame_interval;
// Reuse SPS id if possible. This helps to avoid reset of chromium HW decoder
// on each key-frame.
// Note that WebRTC resets encoder on resolution change which makes all
// EParameterSetStrategy modes except INCREASING_ID (default) essentially
// equivalent to CONSTANT_ID.
encoder_params.eSpsPpsIdStrategy = SPS_LISTING;
encoder_params.uiMaxNalSize = 0;
// Threading model: use auto.
// 0: auto (dynamic imp. internal encoder)
// 1: single thread (default value)
// >1: number of threads
encoder_params.iMultipleThreadIdc =
NumberOfThreads(encoder_thread_limit_, encoder_params.iPicWidth,
encoder_params.iPicHeight, number_of_cores_);
// The base spatial layer 0 is the only one we use.
encoder_params.sSpatialLayers[0].iVideoWidth = encoder_params.iPicWidth;
encoder_params.sSpatialLayers[0].iVideoHeight = encoder_params.iPicHeight;
encoder_params.sSpatialLayers[0].fFrameRate = encoder_params.fMaxFrameRate;
encoder_params.sSpatialLayers[0].iSpatialBitrate =
encoder_params.iTargetBitrate;
encoder_params.sSpatialLayers[0].iMaxSpatialBitrate =
encoder_params.iMaxBitrate;
encoder_params.iTemporalLayerNum = configurations_[i].num_temporal_layers;
if (encoder_params.iTemporalLayerNum > 1) {
// iNumRefFrame specifies total number of reference buffers to allocate.
// For N temporal layers we need at least (N - 1) buffers to store last
// encoded frames of all reference temporal layers.
// Note that there is no API in OpenH264 encoder to specify exact set of
// references to be used to prediction of a given frame. Encoder can
// theoretically use all available reference buffers.
encoder_params.iNumRefFrame = encoder_params.iTemporalLayerNum - 1;
}
RTC_LOG(LS_INFO) << "OpenH264 version is " << OPENH264_MAJOR << "."
<< OPENH264_MINOR;
switch (packetization_mode_) {
case H264PacketizationMode::SingleNalUnit:
// Limit the size of the packets produced.
encoder_params.sSpatialLayers[0].sSliceArgument.uiSliceNum = 1;
encoder_params.sSpatialLayers[0].sSliceArgument.uiSliceMode =
SM_SIZELIMITED_SLICE;
encoder_params.sSpatialLayers[0].sSliceArgument.uiSliceSizeConstraint =
static_cast<unsigned int>(max_payload_size_);
RTC_LOG(LS_INFO) << "Encoder is configured with NALU constraint: "
<< max_payload_size_ << " bytes";
break;
case H264PacketizationMode::NonInterleaved:
// When uiSliceMode = SM_FIXEDSLCNUM_SLICE, uiSliceNum = 0 means auto
// design it with cpu core number.
// TODO(sprang): Set to 0 when we understand why the rate controller borks
// when uiSliceNum > 1.
encoder_params.sSpatialLayers[0].sSliceArgument.uiSliceNum = 1;
encoder_params.sSpatialLayers[0].sSliceArgument.uiSliceMode =
SM_FIXEDSLCNUM_SLICE;
break;
}
return encoder_params;
}
void H264EncoderImpl::ReportInit() {
if (has_reported_init_)
return;
RTC_HISTOGRAM_ENUMERATION("WebRTC.Video.H264EncoderImpl.Event",
kH264EncoderEventInit, kH264EncoderEventMax);
has_reported_init_ = true;
}
void H264EncoderImpl::ReportError() {
if (has_reported_error_)
return;
RTC_HISTOGRAM_ENUMERATION("WebRTC.Video.H264EncoderImpl.Event",
kH264EncoderEventError, kH264EncoderEventMax);
has_reported_error_ = true;
}
VideoEncoder::EncoderInfo H264EncoderImpl::GetEncoderInfo() const {
EncoderInfo info;
info.supports_native_handle = false;
info.implementation_name = "OpenH264";
info.scaling_settings =
VideoEncoder::ScalingSettings(kLowH264QpThreshold, kHighH264QpThreshold);
info.is_hardware_accelerated = false;
info.supports_simulcast = true;
info.preferred_pixel_formats = {VideoFrameBuffer::Type::kI420};
return info;
}
void H264EncoderImpl::LayerConfig::SetStreamState(bool send_stream) {
if (send_stream && !sending) {
// Need a key frame if we have not sent this stream before.
key_frame_request = true;
}
sending = send_stream;
}
} // namespace webrtc
#endif // WEBRTC_USE_H264