Adds input device selection on Windows.

media/audio/win/wavein_input_win.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/win/wavein_input_win.h"
 
 #include <windows.h>
 #include <mmsystem.h>
 #pragma comment(lib, "winmm.lib")
 
 #include "base/logging.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_util.h"
 #include "media/audio/win/audio_manager_win.h"
+#include "media/audio/win/device_enumeration_win.h"
 
 namespace {
 const int kStopInputStreamCallbackTimeout = 3000; // Three seconds.
 }
 
+using media::AudioDeviceNames;
+
 // Our sound buffers are allocated once and kept in a linked list using the
 // the WAVEHDR::dwUser variable. The last buffer points to the first buffer.
 static WAVEHDR* GetNextBuffer(WAVEHDR* current) {
   return reinterpret_cast<WAVEHDR*>(current->dwUser);
 }
 
 PCMWaveInAudioInputStream::PCMWaveInAudioInputStream(
     AudioManagerWin* manager, const AudioParameters& params, int num_buffers,
-    UINT device_id)
+    const std::string& device_id)
     : state_(kStateEmpty),
       manager_(manager),
       device_id_(device_id),
       wavein_(NULL),
       callback_(NULL),
       num_buffers_(num_buffers),
       buffer_(NULL),
       channels_(params.channels) {
   format_.wFormatTag = WAVE_FORMAT_PCM;
   format_.nChannels = params.channels > 2 ? 2 : params.channels;
@@ skipping 12 matching lines @@
 
 PCMWaveInAudioInputStream::~PCMWaveInAudioInputStream() {
   DCHECK(NULL == wavein_);
 }
 
 bool PCMWaveInAudioInputStream::Open() {
   if (state_ != kStateEmpty)
     return false;
   if (num_buffers_ < 2 || num_buffers_ > 10)
     return false;
-  MMRESULT result = ::waveInOpen(&wavein_, device_id_, &format_,
-                                 reinterpret_cast<DWORD_PTR>(WaveCallback),
-                                 reinterpret_cast<DWORD_PTR>(this),
-                                 CALLBACK_FUNCTION);
+
+  // Convert the stored device id string into an unsigned integer
+  // corresponding to the selected device.
+  UINT device_id = WAVE_MAPPER;
+  if (!GetDeviceId(&device_id)) {
+    return false;
+  }
+
+  // Open the specified input device for recording.
+  MMRESULT result = MMSYSERR_NOERROR;
+  result = ::waveInOpen(&wavein_, device_id, &format_,
+                        reinterpret_cast<DWORD_PTR>(WaveCallback),
+                        reinterpret_cast<DWORD_PTR>(this),
+                        CALLBACK_FUNCTION);
   if (result != MMSYSERR_NOERROR)
     return false;
 
   SetupBuffers();
   state_ = kStateReady;
   return true;
 }
 
 void PCMWaveInAudioInputStream::SetupBuffers() {
   WAVEHDR* last = NULL;
@@ skipping 103 matching lines @@
   DLOG(WARNING) << "PCMWaveInAudio error " << error;
   callback_->OnError(this, error);
 }
 
 void PCMWaveInAudioInputStream::QueueNextPacket(WAVEHDR *buffer) {
   MMRESULT res = ::waveInAddBuffer(wavein_, buffer, sizeof(WAVEHDR));
   if (res != MMSYSERR_NOERROR)
     HandleError(res);
 }
 
+bool PCMWaveInAudioInputStream::GetDeviceId(UINT* device_index) {
+  // Deliver the default input device id (WAVE_MAPPER) if the default
+  // device has been selected.
+  if (device_id_ == AudioManagerBase::kDefaultDeviceId) {
+    *device_index = WAVE_MAPPER;
+    return true;
+  }
+
+  // Get list of all available and active devices.
+  AudioDeviceNames device_names;
+  if (!GetInputDeviceNamesWinXP(&device_names)) {

[tommi (sloooow) - chröme, 2011/12/01 14:11:03]

nit: no need for {} (like the the next statement)

[henrika (OOO until Aug 14), 2011/12/01 16:02:38]

Done.

+    return false;
+  }
+
+  if (device_names.empty())
+    return false;
+
+  // Search the full list of devices and compare with the specified
+  // device id which was specified in the constructor. Stop comparing
+  // when a match is found and return the corresponding index.
+  UINT index = 0;
+  AudioDeviceNames::const_iterator it = device_names.begin();
+  while (it != device_names.end()) {

[no longer working on chromium, 2011/12/01 15:28:03]

what happen if none of the device in the list matches the device_id_? Shall you
return false instead?

[henrika (OOO until Aug 14), 2011/12/01 16:02:38]

Done.

+    if (it->unique_id.compare(device_id_) == 0) {

[no longer working on chromium, 2011/12/01 15:28:03]

we can directly use device_id_ == it->unique_id

[henrika (OOO until Aug 14), 2011/12/01 16:02:38]

I actually prefer the compare() method for std::sting. Hope that is OK.

+      *device_index = index;
+      break;
+    }
+    ++index;
+    ++it;
+  }
+
+  return true;
+}
+
 // Windows calls us back in this function when some events happen. Most notably
 // when it has an audio buffer with recorded data.
 void PCMWaveInAudioInputStream::WaveCallback(HWAVEIN hwi, UINT msg,
                                              DWORD_PTR instance,
                                              DWORD_PTR param1, DWORD_PTR) {
   PCMWaveInAudioInputStream* obj =
       reinterpret_cast<PCMWaveInAudioInputStream*>(instance);
 
   if (msg == WIM_DATA) {
     // WIM_DONE indicates that the driver is done with our buffer. We pass it
@@ skipping 18 matching lines @@
       // waveInPrepareHeader.
       obj->QueueNextPacket(buffer);
     }
   } else if (msg == WIM_CLOSE) {
     // We can be closed before calling Start, so it is possible to have a
     // null callback at this point.
     if (obj->callback_)
       obj->callback_->OnClose(obj);
   }
 }