1 /*
2  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  *
10  */
11 
12 #ifndef MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
13 #define MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
14 
15 #include <memory>
16 #include <stack>
17 #include <string>
18 #include <utility>
19 #include <vector>
20 
21 #include "absl/types/optional.h"
22 #include "api/fec_controller_override.h"
23 #include "api/video_codecs/sdp_video_format.h"
24 #include "api/video_codecs/video_encoder.h"
25 #include "modules/video_coding/include/video_codec_interface.h"
26 #include "modules/video_coding/utility/framerate_controller.h"
27 #include "rtc_base/atomic_ops.h"
28 #include "rtc_base/synchronization/sequence_checker.h"
29 #include "rtc_base/system/rtc_export.h"
30 
31 namespace webrtc {
32 
33 class SimulcastRateAllocator;
34 class VideoEncoderFactory;
35 
36 // SimulcastEncoderAdapter implements simulcast support by creating multiple
37 // webrtc::VideoEncoder instances with the given VideoEncoderFactory.
38 // The object is created and destroyed on the worker thread, but all public
39 // interfaces should be called from the encoder task queue.
40 class RTC_EXPORT SimulcastEncoderAdapter : public VideoEncoder {
41  public:
42   // TODO(bugs.webrtc.org/11000): Remove when downstream usage is gone.
43   SimulcastEncoderAdapter(VideoEncoderFactory* primarty_factory,
44                           const SdpVideoFormat& format);
45   // |primary_factory| produces the first-choice encoders to use.
46   // |fallback_factory|, if non-null, is used to create fallback encoder that
47   // will be used if InitEncode() fails for the primary encoder.
48   SimulcastEncoderAdapter(VideoEncoderFactory* primary_factory,
49                           VideoEncoderFactory* fallback_factory,
50                           const SdpVideoFormat& format);
51   ~SimulcastEncoderAdapter() override;
52 
53   // Implements VideoEncoder.
54   void SetFecControllerOverride(
55       FecControllerOverride* fec_controller_override) override;
56   int Release() override;
57   int InitEncode(const VideoCodec* codec_settings,
58                  const VideoEncoder::Settings& settings) override;
59   int Encode(const VideoFrame& input_image,
60              const std::vector<VideoFrameType>* frame_types) override;
61   int RegisterEncodeCompleteCallback(EncodedImageCallback* callback) override;
62   void SetRates(const RateControlParameters& parameters) override;
63   void OnPacketLossRateUpdate(float packet_loss_rate) override;
64   void OnRttUpdate(int64_t rtt_ms) override;
65   void OnLossNotification(const LossNotification& loss_notification) override;
66 
67   // Eventual handler for the contained encoders' EncodedImageCallbacks, but
68   // called from an internal helper that also knows the correct stream
69   // index.
70   EncodedImageCallback::Result OnEncodedImage(
71       size_t stream_idx,
72       const EncodedImage& encoded_image,
73       const CodecSpecificInfo* codec_specific_info);
74 
75   EncoderInfo GetEncoderInfo() const override;
76 
77  private:
78   struct StreamInfo {
StreamInfoStreamInfo79     StreamInfo(std::unique_ptr<VideoEncoder> encoder,
80                std::unique_ptr<EncodedImageCallback> callback,
81                std::unique_ptr<FramerateController> framerate_controller,
82                uint16_t width,
83                uint16_t height,
84                bool send_stream)
85         : encoder(std::move(encoder)),
86           callback(std::move(callback)),
87           framerate_controller(std::move(framerate_controller)),
88           width(width),
89           height(height),
90           key_frame_request(false),
91           send_stream(send_stream) {}
92     std::unique_ptr<VideoEncoder> encoder;
93     std::unique_ptr<EncodedImageCallback> callback;
94     std::unique_ptr<FramerateController> framerate_controller;
95     uint16_t width;
96     uint16_t height;
97     bool key_frame_request;
98     bool send_stream;
99   };
100 
101   enum class StreamResolution {
102     OTHER,
103     HIGHEST,
104     LOWEST,
105   };
106 
107   // Populate the codec settings for each simulcast stream.
108   void PopulateStreamCodec(const webrtc::VideoCodec& inst,
109                            int stream_index,
110                            uint32_t start_bitrate_kbps,
111                            StreamResolution stream_resolution,
112                            webrtc::VideoCodec* stream_codec);
113 
114   bool Initialized() const;
115 
116   void DestroyStoredEncoders();
117 
118   volatile int inited_;  // Accessed atomically.
119   VideoEncoderFactory* const primary_encoder_factory_;
120   VideoEncoderFactory* const fallback_encoder_factory_;
121   const SdpVideoFormat video_format_;
122   VideoCodec codec_;
123   std::vector<StreamInfo> streaminfos_;
124   EncodedImageCallback* encoded_complete_callback_;
125 
126   // Used for checking the single-threaded access of the encoder interface.
127   SequenceChecker encoder_queue_;
128 
129   // Store encoders in between calls to Release and InitEncode, so they don't
130   // have to be recreated. Remaining encoders are destroyed by the destructor.
131   std::stack<std::unique_ptr<VideoEncoder>> stored_encoders_;
132 
133   const absl::optional<unsigned int> experimental_boosted_screenshare_qp_;
134   const bool boost_base_layer_quality_;
135   const bool prefer_temporal_support_on_base_layer_;
136 };
137 
138 }  // namespace webrtc
139 
140 #endif  // MEDIA_ENGINE_SIMULCAST_ENCODER_ADAPTER_H_
141