blob: 3756e80401b27b40cdea5a356fc912a741ea1c64 [file] [log] [blame]
* Copyright (c) 2012 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 <atomic>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "api/video/video_bitrate_allocator.h"
#include "api/video/video_rotation.h"
#include "api/video/video_sink_interface.h"
#include "api/video/video_stream_encoder_interface.h"
#include "api/video/video_stream_encoder_observer.h"
#include "api/video/video_stream_encoder_settings.h"
#include "api/video_codecs/video_codec.h"
#include "api/video_codecs/video_encoder.h"
#include "modules/video_coding/utility/frame_dropper.h"
#include "modules/video_coding/utility/quality_scaler.h"
#include "modules/video_coding/video_coding_impl.h"
#include "rtc_base/critical_section.h"
#include "rtc_base/event.h"
#include "rtc_base/experiments/balanced_degradation_settings.h"
#include "rtc_base/experiments/rate_control_settings.h"
#include "rtc_base/race_checker.h"
#include "rtc_base/rate_statistics.h"
#include "rtc_base/synchronization/sequence_checker.h"
#include "rtc_base/task_queue.h"
#include "video/encoder_bitrate_adjuster.h"
#include "video/frame_encode_metadata_writer.h"
#include "video/overuse_frame_detector.h"
namespace webrtc {
// VideoStreamEncoder represent a video encoder that accepts raw video frames as
// input and produces an encoded bit stream.
// Usage:
// Instantiate.
// Call SetSink.
// Call SetSource.
// Call ConfigureEncoder with the codec settings.
// Call Stop() when done.
class VideoStreamEncoder : public VideoStreamEncoderInterface,
private EncodedImageCallback,
// Protected only to provide access to tests.
protected AdaptationObserverInterface {
VideoStreamEncoder(Clock* clock,
uint32_t number_of_cores,
VideoStreamEncoderObserver* encoder_stats_observer,
const VideoStreamEncoderSettings& settings,
std::unique_ptr<OveruseFrameDetector> overuse_detector,
TaskQueueFactory* task_queue_factory);
~VideoStreamEncoder() override;
void SetSource(rtc::VideoSourceInterface<VideoFrame>* source,
const DegradationPreference& degradation_preference) override;
void SetSink(EncoderSink* sink, bool rotation_applied) override;
// TODO(perkj): Can we remove VideoCodec.startBitrate ?
void SetStartBitrate(int start_bitrate_bps) override;
void SetBitrateAllocationObserver(
VideoBitrateAllocationObserver* bitrate_observer) override;
void ConfigureEncoder(VideoEncoderConfig config,
size_t max_data_payload_length) override;
// Permanently stop encoding. After this method has returned, it is
// guaranteed that no encoded frames will be delivered to the sink.
void Stop() override;
void SendKeyFrame() override;
void OnLossNotification(
const VideoEncoder::LossNotification& loss_notification) override;
void OnBitrateUpdated(DataRate target_bitrate,
DataRate target_headroom,
uint8_t fraction_lost,
int64_t round_trip_time_ms) override;
// Used for testing. For example the |ScalingObserverInterface| methods must
// be called on |encoder_queue_|.
rtc::TaskQueue* encoder_queue() { return &encoder_queue_; }
// AdaptationObserverInterface implementation.
// These methods are protected for easier testing.
void AdaptUp(AdaptReason reason) override;
void AdaptDown(AdaptReason reason) override;
class VideoSourceProxy;
class VideoFrameInfo {
VideoFrameInfo(int width, int height, bool is_texture)
: width(width), height(height), is_texture(is_texture) {}
int width;
int height;
bool is_texture;
int pixel_count() const { return width * height; }
struct EncoderRateSettings : public VideoEncoder::RateControlParameters {
EncoderRateSettings(const VideoBitrateAllocation& bitrate,
double framerate_fps,
DataRate bandwidth_allocation,
DataRate encoder_target);
bool operator==(const EncoderRateSettings& rhs) const;
bool operator!=(const EncoderRateSettings& rhs) const;
// This is the scalar target bitrate before the VideoBitrateAllocator, i.e.
// the |target_bitrate| argument of the OnBitrateUpdated() method. This is
// needed because the bitrate allocator may truncate the total bitrate and a
// later call to the same allocator instance, e.g.
// |using last_encoder_rate_setings_->bitrate.get_sum_bps()|, may trick it
// into thinking the available bitrate has decreased since the last call.
DataRate encoder_target;
void ConfigureEncoderOnTaskQueue(VideoEncoderConfig config,
size_t max_data_payload_length);
void ReconfigureEncoder() RTC_RUN_ON(&encoder_queue_);
void ConfigureQualityScaler(const VideoEncoder::EncoderInfo& encoder_info);
// Implements VideoSinkInterface.
void OnFrame(const VideoFrame& video_frame) override;
void OnDiscardedFrame() override;
void MaybeEncodeVideoFrame(const VideoFrame& frame,
int64_t time_when_posted_in_ms);
void EncodeVideoFrame(const VideoFrame& frame,
int64_t time_when_posted_in_ms);
// Indicates wether frame should be dropped because the pixel count is too
// large for the current bitrate configuration.
bool DropDueToSize(uint32_t pixel_count) const RTC_RUN_ON(&encoder_queue_);
// Implements EncodedImageCallback.
EncodedImageCallback::Result OnEncodedImage(
const EncodedImage& encoded_image,
const CodecSpecificInfo* codec_specific_info,
const RTPFragmentationHeader* fragmentation) override;
void OnDroppedFrame(EncodedImageCallback::DropReason reason) override;
bool EncoderPaused() const;
void TraceFrameDropStart();
void TraceFrameDropEnd();
// Returns a copy of |rate_settings| with the |bitrate| field updated using
// the current VideoBitrateAllocator, and notifies any listeners of the new
// allocation.
EncoderRateSettings UpdateBitrateAllocationAndNotifyObserver(
const EncoderRateSettings& rate_settings) RTC_RUN_ON(&encoder_queue_);
uint32_t GetInputFramerateFps() RTC_RUN_ON(&encoder_queue_);
void SetEncoderRates(const EncoderRateSettings& rate_settings)
// Class holding adaptation information.
class AdaptCounter final {
// Get number of adaptation downscales for |reason|.
VideoStreamEncoderObserver::AdaptationSteps Counts(int reason) const;
std::string ToString() const;
void IncrementFramerate(int reason);
void IncrementResolution(int reason);
void DecrementFramerate(int reason);
void DecrementResolution(int reason);
void DecrementFramerate(int reason, int cur_fps);
// Gets the total number of downgrades (for all adapt reasons).
int FramerateCount() const;
int ResolutionCount() const;
// Gets the total number of downgrades for |reason|.
int FramerateCount(int reason) const;
int ResolutionCount(int reason) const;
int TotalCount(int reason) const;
std::string ToString(const std::vector<int>& counters) const;
int Count(const std::vector<int>& counters) const;
void MoveCount(std::vector<int>* counters, int from_reason);
// Degradation counters holding number of framerate/resolution reductions
// per adapt reason.
std::vector<int> fps_counters_;
std::vector<int> resolution_counters_;
AdaptCounter& GetAdaptCounter() RTC_RUN_ON(&encoder_queue_);
const AdaptCounter& GetConstAdaptCounter() RTC_RUN_ON(&encoder_queue_);
void UpdateAdaptationStats(AdaptReason reason) RTC_RUN_ON(&encoder_queue_);
VideoStreamEncoderObserver::AdaptationSteps GetActiveCounts(
AdaptReason reason) RTC_RUN_ON(&encoder_queue_);
void RunPostEncode(EncodedImage encoded_image,
int64_t time_sent_us,
int temporal_index);
bool HasInternalSource() const RTC_RUN_ON(&encoder_queue_);
void ReleaseEncoder() RTC_RUN_ON(&encoder_queue_);
rtc::Event shutdown_event_;
const uint32_t number_of_cores_;
// Counts how many frames we've dropped in the initial framedrop phase.
int initial_framedrop_;
const bool initial_framedrop_on_bwe_enabled_;
bool has_seen_first_significant_bwe_change_ = false;
const bool quality_scaling_experiment_enabled_;
const std::unique_ptr<VideoSourceProxy> source_proxy_;
EncoderSink* sink_;
const VideoStreamEncoderSettings settings_;
const RateControlSettings rate_control_settings_;
const std::unique_ptr<OveruseFrameDetector> overuse_detector_
std::unique_ptr<QualityScaler> quality_scaler_ RTC_GUARDED_BY(&encoder_queue_)
VideoStreamEncoderObserver* const encoder_stats_observer_;
// |thread_checker_| checks that public methods that are related to lifetime
// of VideoStreamEncoder are called on the same thread.
rtc::ThreadChecker thread_checker_;
VideoEncoderConfig encoder_config_ RTC_GUARDED_BY(&encoder_queue_);
std::unique_ptr<VideoEncoder> encoder_ RTC_GUARDED_BY(&encoder_queue_)
bool encoder_initialized_;
std::unique_ptr<VideoBitrateAllocator> rate_allocator_
RTC_GUARDED_BY(&encoder_queue_) RTC_PT_GUARDED_BY(&encoder_queue_);
// The maximum frame rate of the current codec configuration, as determined
// at the last ReconfigureEncoder() call.
int max_framerate_ RTC_GUARDED_BY(&encoder_queue_);
// Set when ConfigureEncoder has been called in order to lazy reconfigure the
// encoder on the next frame.
bool pending_encoder_reconfiguration_ RTC_GUARDED_BY(&encoder_queue_);
// Set when configuration must create a new encoder object, e.g.,
// because of a codec change.
bool pending_encoder_creation_ RTC_GUARDED_BY(&encoder_queue_);
absl::optional<VideoFrameInfo> last_frame_info_
int crop_width_ RTC_GUARDED_BY(&encoder_queue_);
int crop_height_ RTC_GUARDED_BY(&encoder_queue_);
uint32_t encoder_start_bitrate_bps_ RTC_GUARDED_BY(&encoder_queue_);
size_t max_data_payload_length_ RTC_GUARDED_BY(&encoder_queue_);
absl::optional<EncoderRateSettings> last_encoder_rate_settings_
bool encoder_paused_and_dropped_frame_ RTC_GUARDED_BY(&encoder_queue_);
Clock* const clock_;
// Counters used for deciding if the video resolution or framerate is
// currently restricted, and if so, why, on a per degradation preference
// basis.
// TODO(sprang): Replace this with a state holding a relative overuse measure
// instead, that can be translated into suitable down-scale or fps limit.
std::map<const DegradationPreference, AdaptCounter> adapt_counters_
// Set depending on degradation preferences.
DegradationPreference degradation_preference_ RTC_GUARDED_BY(&encoder_queue_);
const BalancedDegradationSettings balanced_settings_;
struct AdaptationRequest {
// The pixel count produced by the source at the time of the adaptation.
int input_pixel_count_;
// Framerate received from the source at the time of the adaptation.
int framerate_fps_;
// Indicates if request was to adapt up or down.
enum class Mode { kAdaptUp, kAdaptDown } mode_;
// Stores a snapshot of the last adaptation request triggered by an AdaptUp
// or AdaptDown signal.
absl::optional<AdaptationRequest> last_adaptation_request_
rtc::RaceChecker incoming_frame_race_checker_
std::atomic<int> posted_frames_waiting_for_encode_;
// Used to make sure incoming time stamp is increasing for every frame.
int64_t last_captured_timestamp_ RTC_GUARDED_BY(incoming_frame_race_checker_);
// Delta used for translating between NTP and internal timestamps.
const int64_t delta_ntp_internal_ms_
int64_t last_frame_log_ms_ RTC_GUARDED_BY(incoming_frame_race_checker_);
int captured_frame_count_ RTC_GUARDED_BY(&encoder_queue_);
int dropped_frame_count_ RTC_GUARDED_BY(&encoder_queue_);
absl::optional<VideoFrame> pending_frame_ RTC_GUARDED_BY(&encoder_queue_);
int64_t pending_frame_post_time_us_ RTC_GUARDED_BY(&encoder_queue_);
VideoFrame::UpdateRect accumulated_update_rect_
VideoBitrateAllocationObserver* bitrate_observer_
absl::optional<int64_t> last_parameters_update_ms_
absl::optional<int64_t> last_encode_info_ms_ RTC_GUARDED_BY(&encoder_queue_);
VideoEncoder::EncoderInfo encoder_info_ RTC_GUARDED_BY(&encoder_queue_);
VideoEncoderFactory::CodecInfo codec_info_ RTC_GUARDED_BY(&encoder_queue_);
VideoCodec send_codec_ RTC_GUARDED_BY(&encoder_queue_);
FrameDropper frame_dropper_ RTC_GUARDED_BY(&encoder_queue_);
// If frame dropper is not force disabled, frame dropping might still be
// disabled if VideoEncoder::GetEncoderInfo() indicates that the encoder has a
// trusted rate controller. This is determined on a per-frame basis, as the
// encoder behavior might dynamically change.
bool force_disable_frame_dropper_ RTC_GUARDED_BY(&encoder_queue_);
RateStatistics input_framerate_ RTC_GUARDED_BY(&encoder_queue_);
// Incremented on worker thread whenever |frame_dropper_| determines that a
// frame should be dropped. Decremented on whichever thread runs
// OnEncodedImage(), which is only called by one thread but not necessarily
// the worker thread.
std::atomic<int> pending_frame_drops_;
std::unique_ptr<EncoderBitrateAdjuster> bitrate_adjuster_
// TODO(sprang): Change actually support keyframe per simulcast stream, or
// turn this into a simple bool |pending_keyframe_request_|.
std::vector<VideoFrameType> next_frame_types_ RTC_GUARDED_BY(&encoder_queue_);
FrameEncodeMetadataWriter frame_encode_metadata_writer_;
// Experiment groups parsed from field trials for realtime video ([0]) and
// screenshare ([1]). 0 means no group specified. Positive values are
// experiment group numbers incremented by 1.
const std::array<uint8_t, 2> experiment_groups_;
// TODO(philipel): Remove this lock and run on |encoder_queue_| instead.
rtc::CriticalSection encoded_image_lock_;
int64_t next_frame_id_ RTC_GUARDED_BY(encoded_image_lock_);
// This array is used as a map from simulcast id to an encoder's buffer
// state. For every buffer of the encoder we keep track of the last frame id
// that updated that buffer.
std::array<std::array<int64_t, kMaxEncoderBuffers>, kMaxSimulcastStreams>
encoder_buffer_state_ RTC_GUARDED_BY(encoded_image_lock_);
// All public methods are proxied to |encoder_queue_|. It must must be
// destroyed first to make sure no tasks are run that use other members.
rtc::TaskQueue encoder_queue_;
} // namespace webrtc