Adding microphone volume support to chrome.

media/audio/linux/alsa_wrapper.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/linux/alsa_wrapper.h"
 
 #include <alsa/asoundlib.h>
 
 AlsaWrapper::AlsaWrapper() {
 }
@@ skipping 144 matching lines @@
 }
 
 const char* AlsaWrapper::StrError(int errnum) {
   return snd_strerror(errnum);
 }
 
 int AlsaWrapper::PcmStart(snd_pcm_t* handle) {
   return snd_pcm_start(handle);
 }
 
+int AlsaWrapper::MixerOpen(snd_mixer_t** mixer, int mode) {
+  return snd_mixer_open(mixer, mode);
+}
+
+int AlsaWrapper::MixerAttach(snd_mixer_t* mixer, const char *name) {
+  return snd_mixer_attach(mixer, name);
+}
+
+int AlsaWrapper::MixerElementRegister(snd_mixer_t* mixer,
+                                      struct snd_mixer_selem_regopt* options,
+                                      snd_mixer_class_t** classp) {
+  return snd_mixer_selem_register(mixer, options, classp);
+}
+
+void AlsaWrapper::MixerFree(snd_mixer_t* mixer) {
+  snd_mixer_free(mixer);
+}
+
+int AlsaWrapper::MixerDetach(snd_mixer_t* mixer, const char* name) {
+  return snd_mixer_detach(mixer, name);
+}
+
+int AlsaWrapper::MixerClose(snd_mixer_t* mixer) {
+  return snd_mixer_close(mixer);
+}
+
+int AlsaWrapper::MixerLoad(snd_mixer_t *mixer) {

[tommi (sloooow) - chröme, 2012/02/24 12:07:34]

please fix all  "foo *bar" and convert them to "foo* bar"

[no longer working on chromium, 2012/02/24 15:05:55]

Done.

+  return snd_mixer_load(mixer);
+}
+
+snd_mixer_elem_t* AlsaWrapper::MixerFirstElem(snd_mixer_t *mixer) {
+  return snd_mixer_first_elem(mixer);
+}
+
+snd_mixer_elem_t* AlsaWrapper::MixerNextElem(snd_mixer_elem_t *elem) {
+  return snd_mixer_elem_next(elem);
+}
+
+int AlsaWrapper::MixerSelemIsActive(snd_mixer_elem_t *elem) {
+  return snd_mixer_selem_is_active(elem);
+}
+
+const char* AlsaWrapper::MixerSelemName(snd_mixer_elem_t *elem) {
+  return snd_mixer_selem_get_name(elem);

[tommi (sloooow) - chröme, 2012/02/24 12:07:34]

just checking, but the returned string must not be deallocated, correct?

[no longer working on chromium, 2012/02/24 15:05:55]

Really good question. Since the returned value is const char*, and ALSA document
does not specify we need to free the memory after using it, so I suppose ALSA
has the ownership of the memory, I will double check it by using valgrind.

+}
+
+int AlsaWrapper::MixerSelemSetCaptureVolumeAll(
+    snd_mixer_elem_t *elem, long value) {
+  return snd_mixer_selem_set_capture_volume_all(elem, value);
+}
+
+int AlsaWrapper::MixerSelemGetCaptureVolume(
+    snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value) {
+  return snd_mixer_selem_get_capture_volume(elem, channel, value);
+}
+
+int AlsaWrapper::MixerSelemHasCaptureVolume(snd_mixer_elem_t *elem) {
+  return snd_mixer_selem_has_capture_volume(elem);
+}
+
+int AlsaWrapper::MixerSelemGetCaptureVolumeRange(snd_mixer_elem_t *elem,
+                                                 long *min, long *max) {
+  return snd_mixer_selem_get_capture_volume_range(elem, min, max);
+}