WebRtc源码分析(1) PeerConnection

ChannelManager

pc/channelmanager.h

// ChannelManager allows the MediaEngine to run on a separate thread, and takes
// care of marshalling calls between threads. It also creates and keeps track of
// voice and video channels; by doing so, it can temporarily(暂时的) pause all the
// channels when a new audio or video device is chosen. The voice and video
// channels are stored in separate vectors, to easily allow operations on just
// voice or just video channels.
// ChannelManager also allows the application to discover what devices it has
// using device manager.

WebRtcSession构造中通过MediaControllerInterface初始化ChannelManager变量channel_manager_ , ChannelManager通过构造传入MediaEngineInterface.

WebRtcSession

pc/webrtcsession.h

// A WebRtcSession manages general session state. This includes negotiation
// of both the application-level and network-level protocols:  the former
// defines what will be sent and the latter defines how it will be sent.  Each
// network-level protocol is represented by a Transport object.  Each Transport
// participates in the network-level negotiation.  The individual streams of
// packets are represented by TransportChannels.  The application-level protocol
// is represented by SessionDecription objects.

MediaControllerInterface

pc/mediacontroller.h

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// The MediaController currently owns shared state between media channels.
// Abstract interface is defined here such that it can be faked/mocked for
// tests, but no other real reason.

实现类MediaController,管理ChannelManager,cricket::ChannelManager* const channel_manager_;,在PeerConnection的Initialize方法中,通过PeerConnectionFactory创建.PeerConnectionFactory中Initialize中真正创建ChannelManager,创建ChannelManager之前,先创建出MediaEngine,实际在PeerConnectionFactory::CreateMediaEngine_w中通过cricket::WebRtcMediaEngineFactory::Create创建.

7> Downloading src/resources/voice_engine/audio_tiny44.wav… 4> Downloading src/resources/voice_engine/audio_tiny48.wav… 2> Downloading src/resources/voice_engine/audio_tiny8.wav… Hook ‘download_from_google_storage –directory –recursive –num_threads=10 –no_auth –quiet –bucket chromium-webrtc-resources src/resources’ took 528.97 secs

WARNING: ‘src/testing/gmock’ has been moved from DEPS to a higher level checkout. The git folder containing all the local branches has been saved to /Users/shenjunwei/soft-source/webrtc/old_src_testing_gmock.git. If you don’t care about its state you can safely remove that folder to free up space.

WARNING: ‘src/testing/gtest’ has been moved from DEPS to a higher level checkout. The git folder containing all the local branches has been saved to /Users/shenjunwei/soft-source/webrtc/old_src_testing_gtest.git. If you don’t care about its state you can safely remove that folder to free up space.