1 files changed, 979 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_device/linux/audio_mixer_manager_alsa_linux.cc b/third_party/libwebrtc/modules/audio_device/linux/audio_mixer_manager_alsa_linux.cc
new file mode 100644
index 0000000000..e7e7033173
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_device/linux/audio_mixer_manager_alsa_linux.cc
@@ -0,0 +1,979 @@
+/*
+ *  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.
+ */
+
+#include "modules/audio_device/linux/audio_mixer_manager_alsa_linux.h"
+
+#include "modules/audio_device/linux/audio_device_alsa_linux.h"
+#include "rtc_base/logging.h"
+
+// Accesses ALSA functions through our late-binding symbol table instead of
+// directly. This way we don't have to link to libasound, which means our binary
+// will work on systems that don't have it.
+#define LATE(sym)                                                            \
+  LATESYM_GET(webrtc::adm_linux_alsa::AlsaSymbolTable, GetAlsaSymbolTable(), \
+              sym)
+
+namespace webrtc {
+
+AudioMixerManagerLinuxALSA::AudioMixerManagerLinuxALSA()
+    : _outputMixerHandle(NULL),
+      _inputMixerHandle(NULL),
+      _outputMixerElement(NULL),
+      _inputMixerElement(NULL) {
+  RTC_DLOG(LS_INFO) << __FUNCTION__ << " created";
+
+  memset(_outputMixerStr, 0, kAdmMaxDeviceNameSize);
+  memset(_inputMixerStr, 0, kAdmMaxDeviceNameSize);
+}
+
+AudioMixerManagerLinuxALSA::~AudioMixerManagerLinuxALSA() {
+  RTC_DLOG(LS_INFO) << __FUNCTION__ << " destroyed";
+  Close();
+}
+
+// ============================================================================
+//                                    PUBLIC METHODS
+// ============================================================================
+
+int32_t AudioMixerManagerLinuxALSA::Close() {
+  RTC_DLOG(LS_VERBOSE) << __FUNCTION__;
+
+  MutexLock lock(&mutex_);
+
+  CloseSpeakerLocked();
+  CloseMicrophoneLocked();
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::CloseSpeaker() {
+  MutexLock lock(&mutex_);
+  return CloseSpeakerLocked();
+}
+
+int32_t AudioMixerManagerLinuxALSA::CloseSpeakerLocked() {
+  RTC_DLOG(LS_VERBOSE) << __FUNCTION__;
+
+  int errVal = 0;
+
+  if (_outputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "Closing playout mixer";
+    LATE(snd_mixer_free)(_outputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error freeing playout mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    errVal = LATE(snd_mixer_detach)(_outputMixerHandle, _outputMixerStr);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error detaching playout mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    errVal = LATE(snd_mixer_close)(_outputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error snd_mixer_close(handleMixer) errVal="
+                        << errVal;
+    }
+    _outputMixerHandle = NULL;
+    _outputMixerElement = NULL;
+  }
+  memset(_outputMixerStr, 0, kAdmMaxDeviceNameSize);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::CloseMicrophone() {
+  MutexLock lock(&mutex_);
+  return CloseMicrophoneLocked();
+}
+
+int32_t AudioMixerManagerLinuxALSA::CloseMicrophoneLocked() {
+  RTC_DLOG(LS_VERBOSE) << __FUNCTION__;
+
+  int errVal = 0;
+
+  if (_inputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer";
+
+    LATE(snd_mixer_free)(_inputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error freeing record mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer 2";
+
+    errVal = LATE(snd_mixer_detach)(_inputMixerHandle, _inputMixerStr);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error detaching record mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer 3";
+
+    errVal = LATE(snd_mixer_close)(_inputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error snd_mixer_close(handleMixer) errVal="
+                        << errVal;
+    }
+
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer 4";
+    _inputMixerHandle = NULL;
+    _inputMixerElement = NULL;
+  }
+  memset(_inputMixerStr, 0, kAdmMaxDeviceNameSize);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::OpenSpeaker(char* deviceName) {
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::OpenSpeaker(name="
+                      << deviceName << ")";
+
+  MutexLock lock(&mutex_);
+
+  int errVal = 0;
+
+  // Close any existing output mixer handle
+  //
+  if (_outputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "Closing playout mixer";
+
+    LATE(snd_mixer_free)(_outputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error freeing playout mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    errVal = LATE(snd_mixer_detach)(_outputMixerHandle, _outputMixerStr);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error detaching playout mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    errVal = LATE(snd_mixer_close)(_outputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error snd_mixer_close(handleMixer) errVal="
+                        << errVal;
+    }
+  }
+  _outputMixerHandle = NULL;
+  _outputMixerElement = NULL;
+
+  errVal = LATE(snd_mixer_open)(&_outputMixerHandle, 0);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_open(&_outputMixerHandle, 0) - error";
+    return -1;
+  }
+
+  char controlName[kAdmMaxDeviceNameSize] = {0};
+  GetControlName(controlName, deviceName);
+
+  RTC_LOG(LS_VERBOSE) << "snd_mixer_attach(_outputMixerHandle, " << controlName
+                      << ")";
+
+  errVal = LATE(snd_mixer_attach)(_outputMixerHandle, controlName);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_attach(_outputMixerHandle, " << controlName
+                      << ") error: " << LATE(snd_strerror)(errVal);
+    _outputMixerHandle = NULL;
+    return -1;
+  }
+  strcpy(_outputMixerStr, controlName);
+
+  errVal = LATE(snd_mixer_selem_register)(_outputMixerHandle, NULL, NULL);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR)
+        << "snd_mixer_selem_register(_outputMixerHandle, NULL, NULL), "
+           "error: "
+        << LATE(snd_strerror)(errVal);
+    _outputMixerHandle = NULL;
+    return -1;
+  }
+
+  // Load and find the proper mixer element
+  if (LoadSpeakerMixerElement() < 0) {
+    return -1;
+  }
+
+  if (_outputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "the output mixer device is now open ("
+                        << _outputMixerHandle << ")";
+  }
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::OpenMicrophone(char* deviceName) {
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::OpenMicrophone(name="
+                      << deviceName << ")";
+
+  MutexLock lock(&mutex_);
+
+  int errVal = 0;
+
+  // Close any existing input mixer handle
+  //
+  if (_inputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer";
+
+    LATE(snd_mixer_free)(_inputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error freeing record mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer";
+
+    errVal = LATE(snd_mixer_detach)(_inputMixerHandle, _inputMixerStr);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error detaching record mixer: "
+                        << LATE(snd_strerror)(errVal);
+    }
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer";
+
+    errVal = LATE(snd_mixer_close)(_inputMixerHandle);
+    if (errVal < 0) {
+      RTC_LOG(LS_ERROR) << "Error snd_mixer_close(handleMixer) errVal="
+                        << errVal;
+    }
+    RTC_LOG(LS_VERBOSE) << "Closing record mixer";
+  }
+  _inputMixerHandle = NULL;
+  _inputMixerElement = NULL;
+
+  errVal = LATE(snd_mixer_open)(&_inputMixerHandle, 0);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_open(&_inputMixerHandle, 0) - error";
+    return -1;
+  }
+
+  char controlName[kAdmMaxDeviceNameSize] = {0};
+  GetControlName(controlName, deviceName);
+
+  RTC_LOG(LS_VERBOSE) << "snd_mixer_attach(_inputMixerHandle, " << controlName
+                      << ")";
+
+  errVal = LATE(snd_mixer_attach)(_inputMixerHandle, controlName);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_attach(_inputMixerHandle, " << controlName
+                      << ") error: " << LATE(snd_strerror)(errVal);
+
+    _inputMixerHandle = NULL;
+    return -1;
+  }
+  strcpy(_inputMixerStr, controlName);
+
+  errVal = LATE(snd_mixer_selem_register)(_inputMixerHandle, NULL, NULL);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR)
+        << "snd_mixer_selem_register(_inputMixerHandle, NULL, NULL), "
+           "error: "
+        << LATE(snd_strerror)(errVal);
+
+    _inputMixerHandle = NULL;
+    return -1;
+  }
+  // Load and find the proper mixer element
+  if (LoadMicMixerElement() < 0) {
+    return -1;
+  }
+
+  if (_inputMixerHandle != NULL) {
+    RTC_LOG(LS_VERBOSE) << "the input mixer device is now open ("
+                        << _inputMixerHandle << ")";
+  }
+
+  return 0;
+}
+
+bool AudioMixerManagerLinuxALSA::SpeakerIsInitialized() const {
+  RTC_DLOG(LS_INFO) << __FUNCTION__;
+
+  return (_outputMixerHandle != NULL);
+}
+
+bool AudioMixerManagerLinuxALSA::MicrophoneIsInitialized() const {
+  RTC_DLOG(LS_INFO) << __FUNCTION__;
+
+  return (_inputMixerHandle != NULL);
+}
+
+int32_t AudioMixerManagerLinuxALSA::SetSpeakerVolume(uint32_t volume) {
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::SetSpeakerVolume(volume="
+                      << volume << ")";
+
+  MutexLock lock(&mutex_);
+
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  int errVal = LATE(snd_mixer_selem_set_playback_volume_all)(
+      _outputMixerElement, volume);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error changing master volume: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  return (0);
+}
+
+int32_t AudioMixerManagerLinuxALSA::SpeakerVolume(uint32_t& volume) const {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  long int vol(0);
+
+  int errVal = LATE(snd_mixer_selem_get_playback_volume)(
+      _outputMixerElement, (snd_mixer_selem_channel_id_t)0, &vol);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error getting outputvolume: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::SpeakerVolume() => vol="
+                      << vol;
+
+  volume = static_cast<uint32_t>(vol);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MaxSpeakerVolume(
+    uint32_t& maxVolume) const {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avilable output mixer element exists";
+    return -1;
+  }
+
+  long int minVol(0);
+  long int maxVol(0);
+
+  int errVal = LATE(snd_mixer_selem_get_playback_volume_range)(
+      _outputMixerElement, &minVol, &maxVol);
+
+  RTC_LOG(LS_VERBOSE) << "Playout hardware volume range, min: " << minVol
+                      << ", max: " << maxVol;
+
+  if (maxVol <= minVol) {
+    RTC_LOG(LS_ERROR) << "Error getting get_playback_volume_range: "
+                      << LATE(snd_strerror)(errVal);
+  }
+
+  maxVolume = static_cast<uint32_t>(maxVol);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MinSpeakerVolume(
+    uint32_t& minVolume) const {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  long int minVol(0);
+  long int maxVol(0);
+
+  int errVal = LATE(snd_mixer_selem_get_playback_volume_range)(
+      _outputMixerElement, &minVol, &maxVol);
+
+  RTC_LOG(LS_VERBOSE) << "Playout hardware volume range, min: " << minVol
+                      << ", max: " << maxVol;
+
+  if (maxVol <= minVol) {
+    RTC_LOG(LS_ERROR) << "Error getting get_playback_volume_range: "
+                      << LATE(snd_strerror)(errVal);
+  }
+
+  minVolume = static_cast<uint32_t>(minVol);
+
+  return 0;
+}
+
+// TL: Have done testnig with these but they don't seem reliable and
+// they were therefore not added
+/*
+ // ----------------------------------------------------------------------------
+ //    SetMaxSpeakerVolume
+ // ----------------------------------------------------------------------------
+
+ int32_t AudioMixerManagerLinuxALSA::SetMaxSpeakerVolume(
+     uint32_t maxVolume)
+ {
+
+ if (_outputMixerElement == NULL)
+ {
+ RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+ return -1;
+ }
+
+ long int minVol(0);
+ long int maxVol(0);
+
+ int errVal = snd_mixer_selem_get_playback_volume_range(
+ _outputMixerElement, &minVol, &maxVol);
+ if ((maxVol <= minVol) || (errVal != 0))
+ {
+ RTC_LOG(LS_WARNING) << "Error getting playback volume range: "
+                 << snd_strerror(errVal);
+ }
+
+ maxVol = maxVolume;
+ errVal = snd_mixer_selem_set_playback_volume_range(
+ _outputMixerElement, minVol, maxVol);
+ RTC_LOG(LS_VERBOSE) << "Playout hardware volume range, min: " << minVol
+                 << ", max: " << maxVol;
+ if (errVal != 0)
+ {
+ RTC_LOG(LS_ERROR) << "Error setting playback volume range: "
+               << snd_strerror(errVal);
+ return -1;
+ }
+
+ return 0;
+ }
+
+ // ----------------------------------------------------------------------------
+ //    SetMinSpeakerVolume
+ // ----------------------------------------------------------------------------
+
+ int32_t AudioMixerManagerLinuxALSA::SetMinSpeakerVolume(
+     uint32_t minVolume)
+ {
+
+ if (_outputMixerElement == NULL)
+ {
+ RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+ return -1;
+ }
+
+ long int minVol(0);
+ long int maxVol(0);
+
+ int errVal = snd_mixer_selem_get_playback_volume_range(
+ _outputMixerElement, &minVol, &maxVol);
+ if ((maxVol <= minVol) || (errVal != 0))
+ {
+ RTC_LOG(LS_WARNING) << "Error getting playback volume range: "
+                 << snd_strerror(errVal);
+ }
+
+ minVol = minVolume;
+ errVal = snd_mixer_selem_set_playback_volume_range(
+ _outputMixerElement, minVol, maxVol);
+ RTC_LOG(LS_VERBOSE) << "Playout hardware volume range, min: " << minVol
+                 << ", max: " << maxVol;
+ if (errVal != 0)
+ {
+ RTC_LOG(LS_ERROR) << "Error setting playback volume range: "
+               << snd_strerror(errVal);
+ return -1;
+ }
+
+ return 0;
+ }
+ */
+
+int32_t AudioMixerManagerLinuxALSA::SpeakerVolumeIsAvailable(bool& available) {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  available = LATE(snd_mixer_selem_has_playback_volume)(_outputMixerElement);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::SpeakerMuteIsAvailable(bool& available) {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  available = LATE(snd_mixer_selem_has_playback_switch)(_outputMixerElement);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::SetSpeakerMute(bool enable) {
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::SetSpeakerMute(enable="
+                      << enable << ")";
+
+  MutexLock lock(&mutex_);
+
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+    return -1;
+  }
+
+  // Ensure that the selected speaker destination has a valid mute control.
+  bool available(false);
+  SpeakerMuteIsAvailable(available);
+  if (!available) {
+    RTC_LOG(LS_WARNING) << "it is not possible to mute the speaker";
+    return -1;
+  }
+
+  // Note value = 0 (off) means muted
+  int errVal = LATE(snd_mixer_selem_set_playback_switch_all)(
+      _outputMixerElement, !enable);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error setting playback switch: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  return (0);
+}
+
+int32_t AudioMixerManagerLinuxALSA::SpeakerMute(bool& enabled) const {
+  if (_outputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable output mixer exists";
+    return -1;
+  }
+
+  // Ensure that the selected speaker destination has a valid mute control.
+  bool available =
+      LATE(snd_mixer_selem_has_playback_switch)(_outputMixerElement);
+  if (!available) {
+    RTC_LOG(LS_WARNING) << "it is not possible to mute the speaker";
+    return -1;
+  }
+
+  int value(false);
+
+  // Retrieve one boolean control value for a specified mute-control
+  //
+  int errVal = LATE(snd_mixer_selem_get_playback_switch)(
+      _outputMixerElement, (snd_mixer_selem_channel_id_t)0, &value);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error getting playback switch: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  // Note value = 0 (off) means muted
+  enabled = (bool)!value;
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MicrophoneMuteIsAvailable(bool& available) {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  available = LATE(snd_mixer_selem_has_capture_switch)(_inputMixerElement);
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::SetMicrophoneMute(bool enable) {
+  RTC_LOG(LS_VERBOSE) << "AudioMixerManagerLinuxALSA::SetMicrophoneMute(enable="
+                      << enable << ")";
+
+  MutexLock lock(&mutex_);
+
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  // Ensure that the selected microphone destination has a valid mute control.
+  bool available(false);
+  MicrophoneMuteIsAvailable(available);
+  if (!available) {
+    RTC_LOG(LS_WARNING) << "it is not possible to mute the microphone";
+    return -1;
+  }
+
+  // Note value = 0 (off) means muted
+  int errVal =
+      LATE(snd_mixer_selem_set_capture_switch_all)(_inputMixerElement, !enable);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error setting capture switch: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  return (0);
+}
+
+int32_t AudioMixerManagerLinuxALSA::MicrophoneMute(bool& enabled) const {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer exists";
+    return -1;
+  }
+
+  // Ensure that the selected microphone destination has a valid mute control.
+  bool available = LATE(snd_mixer_selem_has_capture_switch)(_inputMixerElement);
+  if (!available) {
+    RTC_LOG(LS_WARNING) << "it is not possible to mute the microphone";
+    return -1;
+  }
+
+  int value(false);
+
+  // Retrieve one boolean control value for a specified mute-control
+  //
+  int errVal = LATE(snd_mixer_selem_get_capture_switch)(
+      _inputMixerElement, (snd_mixer_selem_channel_id_t)0, &value);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error getting capture switch: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  // Note value = 0 (off) means muted
+  enabled = (bool)!value;
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MicrophoneVolumeIsAvailable(
+    bool& available) {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  available = LATE(snd_mixer_selem_has_capture_volume)(_inputMixerElement);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::SetMicrophoneVolume(uint32_t volume) {
+  RTC_LOG(LS_VERBOSE)
+      << "AudioMixerManagerLinuxALSA::SetMicrophoneVolume(volume=" << volume
+      << ")";
+
+  MutexLock lock(&mutex_);
+
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  int errVal =
+      LATE(snd_mixer_selem_set_capture_volume_all)(_inputMixerElement, volume);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error changing microphone volume: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+
+  return (0);
+}
+
+// TL: Have done testnig with these but they don't seem reliable and
+// they were therefore not added
+/*
+ // ----------------------------------------------------------------------------
+ //    SetMaxMicrophoneVolume
+ // ----------------------------------------------------------------------------
+
+ int32_t AudioMixerManagerLinuxALSA::SetMaxMicrophoneVolume(
+     uint32_t maxVolume)
+ {
+
+ if (_inputMixerElement == NULL)
+ {
+ RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+ return -1;
+ }
+
+ long int minVol(0);
+ long int maxVol(0);
+
+ int errVal = snd_mixer_selem_get_capture_volume_range(_inputMixerElement,
+  &minVol, &maxVol);
+ if ((maxVol <= minVol) || (errVal != 0))
+ {
+ RTC_LOG(LS_WARNING) << "Error getting capture volume range: "
+                 << snd_strerror(errVal);
+ }
+
+ maxVol = (long int)maxVolume;
+ printf("min %d max %d", minVol, maxVol);
+ errVal = snd_mixer_selem_set_capture_volume_range(_inputMixerElement, minVol,
+ maxVol); RTC_LOG(LS_VERBOSE) << "Capture hardware volume range, min: " <<
+ minVol
+                 << ", max: " << maxVol;
+ if (errVal != 0)
+ {
+ RTC_LOG(LS_ERROR) << "Error setting capture volume range: "
+               << snd_strerror(errVal);
+ return -1;
+ }
+
+ return 0;
+ }
+
+ // ----------------------------------------------------------------------------
+ //    SetMinMicrophoneVolume
+ // ----------------------------------------------------------------------------
+
+ int32_t AudioMixerManagerLinuxALSA::SetMinMicrophoneVolume(
+ uint32_t minVolume)
+ {
+
+ if (_inputMixerElement == NULL)
+ {
+ RTC_LOG(LS_WARNING) << "no avaliable output mixer element exists";
+ return -1;
+ }
+
+ long int minVol(0);
+ long int maxVol(0);
+
+ int errVal = snd_mixer_selem_get_capture_volume_range(
+ _inputMixerElement, &minVol, &maxVol);
+ if (maxVol <= minVol)
+ {
+ //maxVol = 255;
+ RTC_LOG(LS_WARNING) << "Error getting capture volume range: "
+                 << snd_strerror(errVal);
+ }
+
+ printf("min %d max %d", minVol, maxVol);
+ minVol = (long int)minVolume;
+ errVal = snd_mixer_selem_set_capture_volume_range(
+ _inputMixerElement, minVol, maxVol);
+ RTC_LOG(LS_VERBOSE) << "Capture hardware volume range, min: " << minVol
+                 << ", max: " << maxVol;
+ if (errVal != 0)
+ {
+ RTC_LOG(LS_ERROR) << "Error setting capture volume range: "
+               << snd_strerror(errVal);
+ return -1;
+ }
+
+ return 0;
+ }
+ */
+
+int32_t AudioMixerManagerLinuxALSA::MicrophoneVolume(uint32_t& volume) const {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  long int vol(0);
+
+  int errVal = LATE(snd_mixer_selem_get_capture_volume)(
+      _inputMixerElement, (snd_mixer_selem_channel_id_t)0, &vol);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "Error getting inputvolume: "
+                      << LATE(snd_strerror)(errVal);
+    return -1;
+  }
+  RTC_LOG(LS_VERBOSE)
+      << "AudioMixerManagerLinuxALSA::MicrophoneVolume() => vol=" << vol;
+
+  volume = static_cast<uint32_t>(vol);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MaxMicrophoneVolume(
+    uint32_t& maxVolume) const {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  long int minVol(0);
+  long int maxVol(0);
+
+  // check if we have mic volume at all
+  if (!LATE(snd_mixer_selem_has_capture_volume)(_inputMixerElement)) {
+    RTC_LOG(LS_ERROR) << "No microphone volume available";
+    return -1;
+  }
+
+  int errVal = LATE(snd_mixer_selem_get_capture_volume_range)(
+      _inputMixerElement, &minVol, &maxVol);
+
+  RTC_LOG(LS_VERBOSE) << "Microphone hardware volume range, min: " << minVol
+                      << ", max: " << maxVol;
+  if (maxVol <= minVol) {
+    RTC_LOG(LS_ERROR) << "Error getting microphone volume range: "
+                      << LATE(snd_strerror)(errVal);
+  }
+
+  maxVolume = static_cast<uint32_t>(maxVol);
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::MinMicrophoneVolume(
+    uint32_t& minVolume) const {
+  if (_inputMixerElement == NULL) {
+    RTC_LOG(LS_WARNING) << "no avaliable input mixer element exists";
+    return -1;
+  }
+
+  long int minVol(0);
+  long int maxVol(0);
+
+  int errVal = LATE(snd_mixer_selem_get_capture_volume_range)(
+      _inputMixerElement, &minVol, &maxVol);
+
+  RTC_LOG(LS_VERBOSE) << "Microphone hardware volume range, min: " << minVol
+                      << ", max: " << maxVol;
+  if (maxVol <= minVol) {
+    RTC_LOG(LS_ERROR) << "Error getting microphone volume range: "
+                      << LATE(snd_strerror)(errVal);
+  }
+
+  minVolume = static_cast<uint32_t>(minVol);
+
+  return 0;
+}
+
+// ============================================================================
+//                                 Private Methods
+// ============================================================================
+
+int32_t AudioMixerManagerLinuxALSA::LoadMicMixerElement() const {
+  int errVal = LATE(snd_mixer_load)(_inputMixerHandle);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_load(_inputMixerHandle), error: "
+                      << LATE(snd_strerror)(errVal);
+    _inputMixerHandle = NULL;
+    return -1;
+  }
+
+  snd_mixer_elem_t* elem = NULL;
+  snd_mixer_elem_t* micElem = NULL;
+  unsigned mixerIdx = 0;
+  const char* selemName = NULL;
+
+  // Find and store handles to the right mixer elements
+  for (elem = LATE(snd_mixer_first_elem)(_inputMixerHandle); elem;
+       elem = LATE(snd_mixer_elem_next)(elem), mixerIdx++) {
+    if (LATE(snd_mixer_selem_is_active)(elem)) {
+      selemName = LATE(snd_mixer_selem_get_name)(elem);
+      if (strcmp(selemName, "Capture") == 0)  // "Capture", "Mic"
+      {
+        _inputMixerElement = elem;
+        RTC_LOG(LS_VERBOSE) << "Capture element set";
+      } else if (strcmp(selemName, "Mic") == 0) {
+        micElem = elem;
+        RTC_LOG(LS_VERBOSE) << "Mic element found";
+      }
+    }
+
+    if (_inputMixerElement) {
+      // Use the first Capture element that is found
+      // The second one may not work
+      break;
+    }
+  }
+
+  if (_inputMixerElement == NULL) {
+    // We didn't find a Capture handle, use Mic.
+    if (micElem != NULL) {
+      _inputMixerElement = micElem;
+      RTC_LOG(LS_VERBOSE) << "Using Mic as capture volume.";
+    } else {
+      _inputMixerElement = NULL;
+      RTC_LOG(LS_ERROR) << "Could not find capture volume on the mixer.";
+
+      return -1;
+    }
+  }
+
+  return 0;
+}
+
+int32_t AudioMixerManagerLinuxALSA::LoadSpeakerMixerElement() const {
+  int errVal = LATE(snd_mixer_load)(_outputMixerHandle);
+  if (errVal < 0) {
+    RTC_LOG(LS_ERROR) << "snd_mixer_load(_outputMixerHandle), error: "
+                      << LATE(snd_strerror)(errVal);
+    _outputMixerHandle = NULL;
+    return -1;
+  }
+
+  snd_mixer_elem_t* elem = NULL;
+  snd_mixer_elem_t* masterElem = NULL;
+  snd_mixer_elem_t* speakerElem = NULL;
+  unsigned mixerIdx = 0;
+  const char* selemName = NULL;
+
+  // Find and store handles to the right mixer elements
+  for (elem = LATE(snd_mixer_first_elem)(_outputMixerHandle); elem;
+       elem = LATE(snd_mixer_elem_next)(elem), mixerIdx++) {
+    if (LATE(snd_mixer_selem_is_active)(elem)) {
+      selemName = LATE(snd_mixer_selem_get_name)(elem);
+      RTC_LOG(LS_VERBOSE) << "snd_mixer_selem_get_name " << mixerIdx << ": "
+                          << selemName << " =" << elem;
+
+      // "Master", "PCM", "Wave", "Master Mono", "PC Speaker", "PCM", "Wave"
+      if (strcmp(selemName, "PCM") == 0) {
+        _outputMixerElement = elem;
+        RTC_LOG(LS_VERBOSE) << "PCM element set";
+      } else if (strcmp(selemName, "Master") == 0) {
+        masterElem = elem;
+        RTC_LOG(LS_VERBOSE) << "Master element found";
+      } else if (strcmp(selemName, "Speaker") == 0) {
+        speakerElem = elem;
+        RTC_LOG(LS_VERBOSE) << "Speaker element found";
+      }
+    }
+
+    if (_outputMixerElement) {
+      // We have found the element we want
+      break;
+    }
+  }
+
+  // If we didn't find a PCM Handle, use Master or Speaker
+  if (_outputMixerElement == NULL) {
+    if (masterElem != NULL) {
+      _outputMixerElement = masterElem;
+      RTC_LOG(LS_VERBOSE) << "Using Master as output volume.";
+    } else if (speakerElem != NULL) {
+      _outputMixerElement = speakerElem;
+      RTC_LOG(LS_VERBOSE) << "Using Speaker as output volume.";
+    } else {
+      _outputMixerElement = NULL;
+      RTC_LOG(LS_ERROR) << "Could not find output volume in the mixer.";
+      return -1;
+    }
+  }
+
+  return 0;
+}
+
+void AudioMixerManagerLinuxALSA::GetControlName(char* controlName,
+                                                char* deviceName) const {
+  // Example
+  // deviceName: "front:CARD=Intel,DEV=0"
+  // controlName: "hw:CARD=Intel"
+  char* pos1 = strchr(deviceName, ':');
+  char* pos2 = strchr(deviceName, ',');
+  if (!pos2) {
+    // Can also be default:CARD=Intel
+    pos2 = &deviceName[strlen(deviceName)];
+  }
+  if (pos1 && pos2) {
+    strcpy(controlName, "hw");
+    int nChar = (int)(pos2 - pos1);
+    strncpy(&controlName[2], pos1, nChar);
+    controlName[2 + nChar] = '\0';
+  } else {
+    strcpy(controlName, deviceName);
+  }
+}
+
+}  // namespace webrtc