webrtc/voice_engine/include/voe_hardware.h

/*
 *  Copyright (c) 2011 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:
//
//  - Audio device handling.
//  - Device information.
//  - CPU load monitoring.
//
// Usage example, omitting error checking:
//
//  using namespace webrtc;
//  VoiceEngine* voe = VoiceEngine::Create();
//  VoEBase* base = VoEBase::GetInterface(voe);
//  VoEHardware* hardware  = VoEHardware::GetInterface(voe);
//  base->Init();
//  ...
//  int n_devices = hardware->GetNumOfPlayoutDevices();
//  ...
//  base->Terminate();
//  base->Release();
//  hardware->Release();
//  VoiceEngine::Delete(voe);
//
#ifndef WEBRTC_VOICE_ENGINE_VOE_HARDWARE_H
#define WEBRTC_VOICE_ENGINE_VOE_HARDWARE_H

#include "webrtc/common_types.h"

namespace webrtc {

class VoiceEngine;

class WEBRTC_DLLEXPORT VoEHardware {
 public:
  // Factory for the VoEHardware sub-API. Increases an internal
  // reference counter if successful. Returns NULL if the API is not
  // supported or if construction fails.
  static VoEHardware* GetInterface(VoiceEngine* voiceEngine);

  // Releases the VoEHardware sub-API and decreases an internal
  // reference counter. Returns the new reference count. This value should
  // be zero for all sub-API:s before the VoiceEngine object can be safely
  // deleted.
  virtual int Release() = 0;

  // Gets the number of audio devices available for recording.
  virtual int GetNumOfRecordingDevices(int& devices) = 0;

  // Gets the number of audio devices available for playout.
  virtual int GetNumOfPlayoutDevices(int& devices) = 0;

  // Gets the name of a specific recording device given by an |index|.
  // On Windows Vista/7, it also retrieves an additional unique ID
  // (GUID) for the recording device.
  virtual int GetRecordingDeviceName(int index,
                                     char strNameUTF8[128],
                                     char strGuidUTF8[128]) = 0;

  // Gets the name of a specific playout device given by an |index|.
  // On Windows Vista/7, it also retrieves an additional unique ID
  // (GUID) for the playout device.
  virtual int GetPlayoutDeviceName(int index,
                                   char strNameUTF8[128],
                                   char strGuidUTF8[128]) = 0;

  // Sets the audio device used for recording.
  virtual int SetRecordingDevice(
      int index,
      StereoChannel recordingChannel = kStereoBoth) = 0;

  // Sets the audio device used for playout.
  virtual int SetPlayoutDevice(int index) = 0;

  // Sets the type of audio device layer to use.
  virtual int SetAudioDeviceLayer(AudioLayers audioLayer) = 0;

  // Gets the currently used (active) audio device layer.
  virtual int GetAudioDeviceLayer(AudioLayers& audioLayer) = 0;

  // Native sample rate controls (samples/sec)
  virtual int SetRecordingSampleRate(unsigned int samples_per_sec) = 0;
  virtual int RecordingSampleRate(unsigned int* samples_per_sec) const = 0;
  virtual int SetPlayoutSampleRate(unsigned int samples_per_sec) = 0;
  virtual int PlayoutSampleRate(unsigned int* samples_per_sec) const = 0;

  virtual bool BuiltInAECIsAvailable() const = 0;
  virtual int EnableBuiltInAEC(bool enable) = 0;

  // To be removed. Don't use.
  virtual bool BuiltInAECIsEnabled() const { return false; }
  virtual int GetRecordingDeviceStatus(bool& isAvailable) { return -1; }
  virtual int GetPlayoutDeviceStatus(bool& isAvailable) { return -1; }
  virtual int ResetAudioDevice() { return -1; }
  virtual int AudioDeviceControl(unsigned int par1,
                                 unsigned int par2,
                                 unsigned int par3) {
    return -1;
  }
  virtual int SetLoudspeakerStatus(bool enable) { return -1; }
  virtual int GetLoudspeakerStatus(bool& enabled) { return -1; }
  virtual int GetCPULoad(int& loadPercent) { return -1; }

 protected:
  VoEHardware() {}
  virtual ~VoEHardware() {}
};

}  // namespace webrtc

#endif  //  WEBRTC_VOICE_ENGINE_VOE_HARDWARE_H