Add mute state field to AudioFrame.

webrtc/voice_engine/file_recorder.cc

Index: webrtc/voice_engine/file_recorder.cc
diff --git a/webrtc/voice_engine/file_recorder.cc b/webrtc/voice_engine/file_recorder.cc
index 9a0edb057ba29bb3006b9a837fa7df7bfbc164e5..cb61c9a852c6407146a34f8b92cd062b85280fe1 100644
--- a/webrtc/voice_engine/file_recorder.cc
+++ b/webrtc/voice_engine/file_recorder.cc
@@ -12,6 +12,7 @@
 
 #include <list>
 
+#include "webrtc/audio/utility/audio_frame_operations.h"
 #include "webrtc/base/platform_thread.h"
 #include "webrtc/common_audio/resampler/include/resampler.h"
 #include "webrtc/common_types.h"
@@ -161,12 +162,10 @@ int32_t FileRecorderImpl::RecordAudioToFile(
     tempAudioFrame.sample_rate_hz_ = incomingAudioFrame.sample_rate_hz_;
     tempAudioFrame.samples_per_channel_ =
         incomingAudioFrame.samples_per_channel_;
-    for (size_t i = 0; i < (incomingAudioFrame.samples_per_channel_); i++) {
-      // Sample value is the average of left and right buffer rounded to
-      // closest integer value. Note samples can be either 1 or 2 byte.

[hlundin-webrtc, 2017/03/17 14:29:39]

This comment must be off, right? The code could not have worked for 1-byte
samples.

[yujo, 2017/03/17 23:55:55]

Yeah, I thought so too.

-      tempAudioFrame.data_[i] = ((incomingAudioFrame.data_[2 * i] +
-                                  incomingAudioFrame.data_[(2 * i) + 1] + 1) >>
-                                 1);
+    if (!incomingAudioFrame.muted()) {
+      AudioFrameOperations::StereoToMono(
+          incomingAudioFrame.data(), incomingAudioFrame.samples_per_channel_,
+          tempAudioFrame.mutable_data());
     }
   } else if (incomingAudioFrame.num_channels_ == 1 && _moduleFile->IsStereo()) {
     // Recording stereo but incoming audio is mono.
@@ -174,10 +173,10 @@ int32_t FileRecorderImpl::RecordAudioToFile(
     tempAudioFrame.sample_rate_hz_ = incomingAudioFrame.sample_rate_hz_;
     tempAudioFrame.samples_per_channel_ =
         incomingAudioFrame.samples_per_channel_;
-    for (size_t i = 0; i < (incomingAudioFrame.samples_per_channel_); i++) {
-      // Duplicate sample to both channels
-      tempAudioFrame.data_[2 * i] = incomingAudioFrame.data_[i];
-      tempAudioFrame.data_[2 * i + 1] = incomingAudioFrame.data_[i];
+    if (!incomingAudioFrame.muted()) {
+      AudioFrameOperations::MonoToStereo(
+          incomingAudioFrame.data(), incomingAudioFrame.samples_per_channel_,
+          tempAudioFrame.mutable_data());
     }
   }
 
@@ -206,8 +205,9 @@ int32_t FileRecorderImpl::RecordAudioToFile(
     _audioResampler.ResetIfNeeded(ptrAudioFrame->sample_rate_hz_,
                                   codec_info_.plfreq,
                                   ptrAudioFrame->num_channels_);
+    // TODO(yujo): skip resample if frame is muted.
     _audioResampler.Push(
-        ptrAudioFrame->data_,
+        ptrAudioFrame->data(),
         ptrAudioFrame->samples_per_channel_ * ptrAudioFrame->num_channels_,
         reinterpret_cast<int16_t*>(_audioBuffer), MAX_AUDIO_BUFFER_IN_BYTES,
         outLen);