137 lines
6.1 KiB
C++
137 lines
6.1 KiB
C++
/*
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* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef API_VIDEO_VIDEO_STREAM_ENCODER_INTERFACE_H_
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#define API_VIDEO_VIDEO_STREAM_ENCODER_INTERFACE_H_
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#include <vector>
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#include "api/adaptation/resource.h"
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#include "api/fec_controller_override.h"
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#include "api/rtp_parameters.h" // For DegradationPreference.
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#include "api/scoped_refptr.h"
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#include "api/units/data_rate.h"
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#include "api/video/video_bitrate_allocator.h"
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#include "api/video/video_sink_interface.h"
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#include "api/video/video_source_interface.h"
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#include "api/video_codecs/video_encoder.h"
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#include "api/video_codecs/video_encoder_config.h"
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namespace webrtc {
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// This interface represents a class responsible for creating and driving the
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// encoder(s) for a single video stream. It is also responsible for adaptation
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// decisions related to video quality, requesting reduced frame rate or
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// resolution from the VideoSource when needed.
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// TODO(bugs.webrtc.org/8830): This interface is under development. Changes
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// under consideration include:
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//
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// 1. Taking out responsibility for adaptation decisions, instead only reporting
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// per-frame measurements to the decision maker.
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//
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// 2. Moving responsibility for simulcast and for software fallback into this
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// class.
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class VideoStreamEncoderInterface : public rtc::VideoSinkInterface<VideoFrame> {
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public:
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// Interface for receiving encoded video frames and notifications about
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// configuration changes.
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class EncoderSink : public EncodedImageCallback {
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public:
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virtual void OnEncoderConfigurationChanged(
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std::vector<VideoStream> streams,
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bool is_svc,
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VideoEncoderConfig::ContentType content_type,
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int min_transmit_bitrate_bps) = 0;
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};
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// If the resource is overusing, the VideoStreamEncoder will try to reduce
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// resolution or frame rate until no resource is overusing.
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// TODO(https://crbug.com/webrtc/11565): When the ResourceAdaptationProcessor
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// is moved to Call this method could be deleted altogether in favor of
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// Call-level APIs only.
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virtual void AddAdaptationResource(rtc::scoped_refptr<Resource> resource) = 0;
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virtual std::vector<rtc::scoped_refptr<Resource>>
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GetAdaptationResources() = 0;
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// Sets the source that will provide video frames to the VideoStreamEncoder's
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// OnFrame method. |degradation_preference| control whether or not resolution
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// or frame rate may be reduced. The VideoStreamEncoder registers itself with
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// |source|, and signals adaptation decisions to the source in the form of
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// VideoSinkWants.
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// TODO(nisse): When adaptation logic is extracted from this class,
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// it no longer needs to know the source.
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virtual void SetSource(
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rtc::VideoSourceInterface<VideoFrame>* source,
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const DegradationPreference& degradation_preference) = 0;
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// Sets the |sink| that gets the encoded frames. |rotation_applied| means
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// that the source must support rotation. Only set |rotation_applied| if the
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// remote side does not support the rotation extension.
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virtual void SetSink(EncoderSink* sink, bool rotation_applied) = 0;
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// Sets an initial bitrate, later overriden by OnBitrateUpdated. Mainly
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// affects the resolution of the initial key frame: If incoming frames are
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// larger than reasonable for the start bitrate, and scaling is enabled,
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// VideoStreamEncoder asks the source to scale down and drops a few initial
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// frames.
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// TODO(nisse): This is a poor interface, and mixes bandwidth estimation and
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// codec configuration in an undesired way. For the actual send bandwidth, we
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// should always be somewhat conservative, but we may nevertheless want to let
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// the application configure a more optimistic quality for the initial
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// resolution. Should be replaced by a construction time setting.
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virtual void SetStartBitrate(int start_bitrate_bps) = 0;
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// Request a key frame. Used for signalling from the remote receiver.
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virtual void SendKeyFrame() = 0;
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// Inform the encoder that a loss has occurred.
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virtual void OnLossNotification(
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const VideoEncoder::LossNotification& loss_notification) = 0;
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// Set the currently estimated network properties. A |target_bitrate|
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// of zero pauses the encoder.
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// |stable_target_bitrate| is a filtered version of |target_bitrate|. It is
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// always less or equal to it. It can be used to avoid rapid changes of
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// expensive encoding settings, such as resolution.
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// |link_allocation| is the bandwidth available for this video stream on the
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// network link. It is always at least |target_bitrate| but may be higher
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// if we are not network constrained.
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virtual void OnBitrateUpdated(DataRate target_bitrate,
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DataRate stable_target_bitrate,
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DataRate link_allocation,
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uint8_t fraction_lost,
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int64_t round_trip_time_ms,
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double cwnd_reduce_ratio) = 0;
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// Register observer for the bitrate allocation between the temporal
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// and spatial layers.
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virtual void SetBitrateAllocationObserver(
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VideoBitrateAllocationObserver* bitrate_observer) = 0;
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// Set a FecControllerOverride, through which the encoder may override
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// decisions made by FecController.
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virtual void SetFecControllerOverride(
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FecControllerOverride* fec_controller_override) = 0;
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// Creates and configures an encoder with the given |config|. The
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// |max_data_payload_length| is used to support single NAL unit
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// packetization for H.264.
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virtual void ConfigureEncoder(VideoEncoderConfig config,
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size_t max_data_payload_length) = 0;
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// Permanently stop encoding. After this method has returned, it is
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// guaranteed that no encoded frames will be delivered to the sink.
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virtual void Stop() = 0;
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};
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} // namespace webrtc
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#endif // API_VIDEO_VIDEO_STREAM_ENCODER_INTERFACE_H_
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