Added support for multiple sampling rates on Windows.

remoting/host/audio_capturer_win.cc

Index: remoting/host/audio_capturer_win.cc
diff --git a/remoting/host/audio_capturer_win.cc b/remoting/host/audio_capturer_win.cc
index 55bc0855b887d8a05e8a870f8e0093da4fb11942..8a256454fac9362d4a5774fb85a00c1cc1cd4328 100644
--- a/remoting/host/audio_capturer_win.cc
+++ b/remoting/host/audio_capturer_win.cc
@@ -23,7 +23,6 @@
 namespace {
 const int kChannels = 2;
 const int kBitsPerSample = 16;
-const int kSamplesPerSecond = 44100;
 const int kBitsPerByte = 8;
 // Conversion factor from 100ns to 1ms.
 const int kHnsToMs = 10000;
@@ -48,6 +47,8 @@ class AudioCapturerWin : public AudioCapturer {
 
   PacketCapturedCallback callback_;
 
+  AudioPacket::SamplingRate sampling_rate_;
+
   scoped_ptr<base::RepeatingTimer<AudioCapturerWin> > capture_timer_;
   base::TimeDelta audio_device_period_;
 
@@ -62,8 +63,9 @@ class AudioCapturerWin : public AudioCapturer {
   DISALLOW_COPY_AND_ASSIGN(AudioCapturerWin);
 };
 
-AudioCapturerWin::AudioCapturerWin() {
-  thread_checker_.DetachFromThread();
+AudioCapturerWin::AudioCapturerWin()
+    : sampling_rate_(AudioPacket::SAMPLING_RATE_INVALID) {
+      thread_checker_.DetachFromThread();
 }
 
 AudioCapturerWin::~AudioCapturerWin() {
@@ -131,13 +133,19 @@ bool AudioCapturerWin::Start(const PacketCapturedCallback& callback) {
     case WAVE_FORMAT_IEEE_FLOAT:
       // Intentional fall-through.
     case WAVE_FORMAT_PCM:
+      if (!AudioCapturer::IsValidSampleRate(wave_format_ex_->nSamplesPerSec)) {
+        LOG(ERROR) << "Host sampling rate is neither 44.1 kHz nor 48 kHz.";
+        return false;
+      }
+      sampling_rate_ = static_cast<AudioPacket::SamplingRate>(
+          wave_format_ex_->nSamplesPerSec);
+
       wave_format_ex_->wFormatTag = WAVE_FORMAT_PCM;
       wave_format_ex_->nChannels = kChannels;
-      wave_format_ex_->nSamplesPerSec = kSamplesPerSecond;
       wave_format_ex_->wBitsPerSample = kBitsPerSample;
       wave_format_ex_->nBlockAlign = kChannels * kBitsPerSample / kBitsPerByte;
       wave_format_ex_->nAvgBytesPerSec =
-          kSamplesPerSecond * kChannels * kBitsPerSample / kBitsPerByte;
+          sampling_rate_ * kChannels * kBitsPerSample / kBitsPerByte;
       break;
     case WAVE_FORMAT_EXTENSIBLE: {
       PWAVEFORMATEXTENSIBLE wave_format_extensible =
@@ -145,16 +153,24 @@ bool AudioCapturerWin::Start(const PacketCapturedCallback& callback) {
           static_cast<WAVEFORMATEX*>(wave_format_ex_));
       if (IsEqualGUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT,
                       wave_format_extensible->SubFormat)) {
+        if (!AudioCapturer::IsValidSampleRate(
+                wave_format_extensible->Format.nSamplesPerSec)) {
+          LOG(ERROR) << "Host sampling rate is neither 44.1 kHz nor 48 kHz.";
+          return false;
+        }
+        sampling_rate_ = static_cast<AudioPacket::SamplingRate>(
+            wave_format_extensible->Format.nSamplesPerSec);
+
         wave_format_extensible->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
         wave_format_extensible->Samples.wValidBitsPerSample = kBitsPerSample;
 
         wave_format_extensible->Format.nChannels = kChannels;
-        wave_format_extensible->Format.nSamplesPerSec = kSamplesPerSecond;
+        wave_format_extensible->Format.nSamplesPerSec = sampling_rate_;
         wave_format_extensible->Format.wBitsPerSample = kBitsPerSample;
         wave_format_extensible->Format.nBlockAlign =
             kChannels * kBitsPerSample / kBitsPerByte;
         wave_format_extensible->Format.nAvgBytesPerSec =
-            kSamplesPerSecond * kChannels * kBitsPerSample / kBitsPerByte;
+            sampling_rate_ * kChannels * kBitsPerSample / kBitsPerByte;
       } else {
         LOG(ERROR) << "Failed to force 16-bit samples";
         return false;
@@ -162,7 +178,7 @@ bool AudioCapturerWin::Start(const PacketCapturedCallback& callback) {
       break;
     }
     default:
-      LOG(ERROR) << "Failed to force 16-bit samples";
+      LOG(ERROR) << "Failed to force 16-bit PCM";
       return false;
   }
 
@@ -221,6 +237,7 @@ bool AudioCapturerWin::IsRunning() {
 }
 
 void AudioCapturerWin::DoCapture() {
+  DCHECK(AudioCapturer::IsValidSampleRate(sampling_rate_));
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(IsRunning());
 
@@ -249,6 +266,7 @@ void AudioCapturerWin::DoCapture() {
 
     scoped_ptr<AudioPacket> packet = scoped_ptr<AudioPacket>(new AudioPacket());
     packet->set_data(data, frames * wave_format_ex_->nBlockAlign);
+    packet->set_sampling_rate(sampling_rate_);
 
     callback_.Run(packet.Pass());