Initialize values before calling ALSA APIs

chrome/browser/chromeos/audio_mixer_alsa.cc

 // Copyright (c) 2010 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 "chrome/browser/chromeos/audio_mixer_alsa.h"
 
 #include <alsa/asoundlib.h>
 
 #include "base/logging.h"
 #include "base/task.h"
@@ skipping 234 matching lines @@
     LOG(ERROR) << "ALSA mixer " << card << " load error: %s"
                << snd_strerror(err);
     snd_mixer_close(handle);
     return false;
   }
 
   VLOG(1) << "Opened ALSA mixer " << card << " OK";
 
   elem_master_ = FindElementWithName_Locked(handle, kMasterVolume);
   if (elem_master_) {
-    alsa_long_t long_lo, long_hi;
+    alsa_long_t long_lo = static_cast<alsa_long_t>(kDefaultMinVolume * 100);
+    alsa_long_t long_hi = static_cast<alsa_long_t>(kDefaultMaxVolume * 100);
     snd_mixer_selem_get_playback_dB_range(elem_master_, &long_lo, &long_hi);
     min_volume_ = static_cast<double>(long_lo) / 100.0;
     max_volume_ = static_cast<double>(long_hi) / 100.0;
   } else {
     LOG(ERROR) << "Cannot find 'Master' ALSA mixer element on " << card;
     snd_mixer_close(handle);
     return false;
   }
 
   elem_pcm_ = FindElementWithName_Locked(handle, kPCMVolume);
   if (elem_pcm_) {
-    alsa_long_t long_lo, long_hi;
+    alsa_long_t long_lo = static_cast<alsa_long_t>(kDefaultMinVolume * 100);
+    alsa_long_t long_hi = static_cast<alsa_long_t>(kDefaultMaxVolume * 100);
     snd_mixer_selem_get_playback_dB_range(elem_pcm_, &long_lo, &long_hi);
     min_volume_ += static_cast<double>(long_lo) / 100.0;
     max_volume_ += static_cast<double>(long_hi) / 100.0;
   }
 
   VLOG(1) << "ALSA volume range is " << min_volume_ << " dB to "
           << max_volume_ << " dB";
 
   alsa_mixer_ = handle;
   mixer_state_ = READY;
@@ skipping 128 matching lines @@
 
   alsa_long_t value = static_cast<alsa_long_t>(rounding_bias +
       (new_vol - db_lo) / db_step) + vol_lo;
   snd_mixer_selem_set_playback_volume_all(elem, value);
 
   VLOG(1) << "Set volume " << snd_mixer_selem_get_name(elem)
           << " to " << new_vol << " ==> " << (value - vol_lo) * db_step + db_lo
           << " dB";
 
   if (actual_vol) {
-    alsa_long_t volume;
+    alsa_long_t volume = vol_lo;
     snd_mixer_selem_get_playback_volume(
         elem,
         static_cast<snd_mixer_selem_channel_id_t>(0),
         &volume);
     *actual_vol = db_lo + (volume - vol_lo) * db_step;
 
     VLOG(1) << "Actual volume " << snd_mixer_selem_get_name(elem)
             << " now " << *actual_vol << " dB";
   }
   return true;
 }
 
 bool AudioMixerAlsa::GetElementMuted_Locked(snd_mixer_elem_t* elem) const {
-  int enabled;
+  int enabled = 0;
   snd_mixer_selem_get_playback_switch(
       elem,
       static_cast<snd_mixer_selem_channel_id_t>(0),
       &enabled);
   return (enabled) ? false : true;
 }
 
 void AudioMixerAlsa::SetElementMuted_Locked(snd_mixer_elem_t* elem, bool mute) {
   int enabled = mute ? 0 : 1;
   snd_mixer_selem_set_playback_switch_all(elem, enabled);
 
   VLOG(1) << "Set playback switch " << snd_mixer_selem_get_name(elem)
           << " to " << enabled;
 }
 
 }  // namespace chromeos