text: /*
   *  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.
   */
  
  #ifndef AUDIO_DEVICE_AUDIO_MIXER_MANAGER_ALSA_LINUX_H_
  #define AUDIO_DEVICE_AUDIO_MIXER_MANAGER_ALSA_LINUX_H_
  
  #include "modules/audio_device/include/audio_device.h"
  #include "modules/audio_device/linux/alsasymboltable_linux.h"
  #include "rtc_base/criticalsection.h"
  #include "typedefs.h"  // NOLINT(build/include)
  
  #include <alsa/asoundlib.h>
  
  namespace webrtc {
  
  class AudioMixerManagerLinuxALSA {
   public:
    int32_t OpenSpeaker(char* deviceName);
    int32_t OpenMicrophone(char* deviceName);
    int32_t SetSpeakerVolume(uint32_t volume);
    int32_t SpeakerVolume(uint32_t& volume) const;
    int32_t MaxSpeakerVolume(uint32_t& maxVolume) const;
    int32_t MinSpeakerVolume(uint32_t& minVolume) const;
    int32_t SpeakerVolumeIsAvailable(bool& available);
    int32_t SpeakerMuteIsAvailable(bool& available);
    int32_t SetSpeakerMute(bool enable);
    int32_t SpeakerMute(bool& enabled) const;
    int32_t MicrophoneMuteIsAvailable(bool& available);
    int32_t SetMicrophoneMute(bool enable);
    int32_t MicrophoneMute(bool& enabled) const;
    int32_t MicrophoneVolumeIsAvailable(bool& available);
    int32_t SetMicrophoneVolume(uint32_t volume);
    int32_t MicrophoneVolume(uint32_t& volume) const;
    int32_t MaxMicrophoneVolume(uint32_t& maxVolume) const;
    int32_t MinMicrophoneVolume(uint32_t& minVolume) const;
    int32_t Close();
    int32_t CloseSpeaker();
    int32_t CloseMicrophone();
    bool SpeakerIsInitialized() const;
    bool MicrophoneIsInitialized() const;
  
   public:
    AudioMixerManagerLinuxALSA();
    ~AudioMixerManagerLinuxALSA();
  
   private:
    int32_t LoadMicMixerElement() const;
    int32_t LoadSpeakerMixerElement() const;
    void GetControlName(char* controlName, char* deviceName) const;
  
   private:
    rtc::CriticalSection _critSect;
    mutable snd_mixer_t* _outputMixerHandle;
    char _outputMixerStr[kAdmMaxDeviceNameSize];
    mutable snd_mixer_t* _inputMixerHandle;
    char _inputMixerStr[kAdmMaxDeviceNameSize];
    mutable snd_mixer_elem_t* _outputMixerElement;
    mutable snd_mixer_elem_t* _inputMixerElement;
  };
  
  }  // namespace webrtc
  
  #endif  // MODULES_AUDIO_DEVICE_MAIN_SOURCE_LINUX_AUDIO_MIXER_MANAGER_ALSA_LINUX_H_
  