media/audio/linux: Add CrasInputStream.

media/audio/linux/audio_manager_linux.cc

 // Copyright (c) 2012 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/audio_manager_linux.h"
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/logging.h"
 #include "base/nix/xdg_util.h"
 #include "base/process_util.h"
 #include "base/stl_util.h"
 #include "media/audio/audio_output_dispatcher.h"
 #include "media/audio/linux/alsa_input.h"
 #include "media/audio/linux/alsa_output.h"
 #include "media/audio/linux/alsa_wrapper.h"
 #if defined(USE_PULSEAUDIO)
 #include "media/audio/pulse/pulse_output.h"
 #endif
 #if defined(USE_CRAS)
+#include "media/audio/linux/cras_input.h"
 #include "media/audio/linux/cras_output.h"
 #endif
 #include "media/base/limits.h"
 #include "media/base/media_switches.h"
 
 namespace media {
 
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
@@ skipping 259 matching lines @@
 #endif
 #if defined(USE_CRAS)
   }
 #endif
   DCHECK(stream);
   return stream;
 }
 
 AudioInputStream* AudioManagerLinux::MakeInputStream(
     const AudioParameters& params, const std::string& device_id) {
+  AudioInputStream* stream = NULL;
 
+#if defined(USE_CRAS)
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseCras)) {
+    stream = new CrasInputStream(params, this);

[no longer working on chromium, 2012/06/20 10:45:26]

btw, do you support device selection? or any plan to support it?

[dgreid, 2012/06/20 17:14:25]

The hope is that ChromeOS automatically selecting the most recently attached
device will satisfy most use cases.  Therefor there is not UI exposed to switch
devices, but it works from the command line, so adding it won't be difficult if
necessary. 

+  } else {

[no longer working on chromium, 2012/06/20 10:45:26]

Why do we need the else case, it is a bit hard to read.
Do we really need to DCHECK below, if not, how about changing it to:
#if defined(USE_CRAS)
if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseCras)) {
  return new CrasInputStream(params, this);
#endif

[dgreid, 2012/06/20 17:14:25]

Good suggestion, I also took the opportunity to modify the related
MakeOutputStream().

+#endif
   std::string device_name = (device_id == AudioManagerBase::kDefaultDeviceId) ?
       AlsaPcmInputStream::kAutoSelectDevice : device_id;
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAlsaInputDevice)) {
     device_name = CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
         switches::kAlsaInputDevice);
   }
 
-  return new AlsaPcmInputStream(this, device_name, params, wrapper_.get());
+  stream = new AlsaPcmInputStream(this, device_name, params, wrapper_.get());
+#if defined(USE_CRAS)
+  }
+#endif
+
+  DCHECK(stream);
+  return stream;
 }
 
 AudioManager* CreateAudioManager() {
   return new AudioManagerLinux();
 }
 
 }  // namespace media