blob: 6e93da574cdba684f833829b218e14254238fec4 [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.
// This sub-API supports the following functionalities:
// - Enables full duplex VoIP sessions via RTP using G.711 (mu-Law or A-Law).
// - Initialization and termination.
// - Trace information on text files or via callbacks.
// - Multi-channel support (mixing, sending to multiple destinations etc.).
// To support other codecs than G.711, the VoECodec sub-API must be utilized.
// Usage example, omitting error checking:
// using namespace webrtc;
// VoiceEngine* voe = VoiceEngine::Create();
// VoEBase* base = VoEBase::GetInterface(voe);
// base->Init();
// int ch = base->CreateChannel();
// base->StartPlayout(ch);
// ...
// base->DeleteChannel(ch);
// base->Terminate();
// base->Release();
// VoiceEngine::Delete(voe);
#include "webrtc/api/audio_codecs/audio_decoder_factory.h"
#include "webrtc/common_types.h"
#include "webrtc/modules/audio_coding/include/audio_coding_module.h"
#include "webrtc/rtc_base/scoped_ref_ptr.h"
namespace webrtc {
class AudioDeviceModule;
class AudioProcessing;
class AudioTransport;
namespace voe {
class TransmitMixer;
} // namespace voe
// VoiceEngineObserver
class WEBRTC_DLLEXPORT VoiceEngineObserver {
// This method will be called after the occurrence of any runtime error
// code, or warning notification, when the observer interface has been
// installed using VoEBase::RegisterVoiceEngineObserver().
virtual void CallbackOnError(int channel, int errCode) = 0;
virtual ~VoiceEngineObserver() {}
// VoiceEngine
class WEBRTC_DLLEXPORT VoiceEngine {
// Creates a VoiceEngine object, which can then be used to acquire
// sub-APIs. Returns NULL on failure.
static VoiceEngine* Create();
// Deletes a created VoiceEngine object and releases the utilized resources.
// Note that if there are outstanding references held via other interfaces,
// the voice engine instance will not actually be deleted until those
// references have been released.
static bool Delete(VoiceEngine*& voiceEngine);
// Specifies the amount and type of trace information which will be
// created by the VoiceEngine.
static int SetTraceFilter(unsigned int filter);
// Sets the name of the trace file and enables non-encrypted trace messages.
static int SetTraceFile(const char* fileNameUTF8,
bool addFileCounter = false);
// Installs the TraceCallback implementation to ensure that the user
// receives callbacks for generated trace messages.
static int SetTraceCallback(TraceCallback* callback);
static std::string GetVersionString();
VoiceEngine() {}
~VoiceEngine() {}
// VoEBase
struct ChannelConfig {
AudioCodingModule::Config acm_config;
bool enable_voice_pacing = false;
// Factory for the VoEBase sub-API. Increases an internal reference
// counter if successful. Returns NULL if the API is not supported or if
// construction fails.
static VoEBase* GetInterface(VoiceEngine* voiceEngine);
// Releases the VoEBase sub-API and decreases an internal reference
// counter. Returns the new reference count. This value should be zero
// for all sub-APIs before the VoiceEngine object can be safely deleted.
virtual int Release() = 0;
// Installs the observer class to enable runtime error control and
// warning notifications. Returns -1 in case of an error, 0 otherwise.
virtual int RegisterVoiceEngineObserver(VoiceEngineObserver& observer) = 0;
// Removes and disables the observer class for runtime error control
// and warning notifications. Returns 0.
virtual int DeRegisterVoiceEngineObserver() = 0;
// Initializes all common parts of the VoiceEngine; e.g. all
// encoders/decoders, the sound card and core receiving components.
// This method also makes it possible to install some user-defined external
// modules:
// - The Audio Device Module (ADM) which implements all the audio layer
// functionality in a separate (reference counted) module.
// - The AudioProcessing module handles capture-side processing.
// - An AudioDecoderFactory - used to create audio decoders.
// If NULL is passed for either of ADM or AudioDecoderFactory, VoiceEngine
// will create its own. Returns -1 in case of an error, 0 otherwise.
// TODO(ajm): Remove default NULLs.
virtual int Init(AudioDeviceModule* external_adm = NULL,
AudioProcessing* external_apm = nullptr,
const rtc::scoped_refptr<AudioDecoderFactory>&
decoder_factory = nullptr) = 0;
// This method is WIP - DO NOT USE!
// Returns NULL before Init() is called.
virtual AudioDeviceModule* audio_device_module() = 0;
// This method is WIP - DO NOT USE!
// Returns NULL before Init() is called.
virtual voe::TransmitMixer* transmit_mixer() = 0;
// Terminates all VoiceEngine functions and releases allocated resources.
// Returns 0.
virtual int Terminate() = 0;
// Creates a new channel and allocates the required resources for it.
// The second version accepts a |config| struct which includes an Audio Coding
// Module config and an option to enable voice pacing. Note that the
// decoder_factory member of the ACM config will be ignored (the decoder
// factory set through Init() will always be used).
// Returns channel ID or -1 in case of an error.
virtual int CreateChannel() = 0;
virtual int CreateChannel(const ChannelConfig& config) = 0;
// Deletes an existing channel and releases the utilized resources.
// Returns -1 in case of an error, 0 otherwise.
virtual int DeleteChannel(int channel) = 0;
// Prepares and initiates the VoiceEngine for reception of
// incoming RTP/RTCP packets on the specified |channel|.
virtual int StartReceive(int channel) = 0;
// Stops receiving incoming RTP/RTCP packets on the specified |channel|.
virtual int StopReceive(int channel) { return 0; }
// Starts forwarding the packets to the mixer/soundcard for a
// specified |channel|.
virtual int StartPlayout(int channel) = 0;
// Stops forwarding the packets to the mixer/soundcard for a
// specified |channel|.
virtual int StopPlayout(int channel) = 0;
// Starts sending packets to an already specified IP address and
// port number for a specified |channel|.
virtual int StartSend(int channel) = 0;
// Stops sending packets from a specified |channel|.
virtual int StopSend(int channel) = 0;
// Gets the version information for VoiceEngine and its components.
virtual int GetVersion(char version[1024]) = 0;
// Gets the last VoiceEngine error code.
virtual int LastError() = 0;
// TODO(xians): Make the interface pure virtual after libjingle
// implements the interface in its FakeWebRtcVoiceEngine.
virtual AudioTransport* audio_transport() { return NULL; }
// Associate a send channel to a receive channel.
// Used for obtaining RTT for a receive-only channel.
// One should be careful not to crate a circular association, e.g.,
// 1 <- 2 <- 1.
virtual int AssociateSendChannel(int channel, int accociate_send_channel) = 0;
VoEBase() {}
virtual ~VoEBase() {}
} // namespace webrtc