Added an "enable-audio-processor" flag and WebRtcAudioProcessor class

content/renderer/media/webrtc_audio_processor_options.cc

+// Copyright 2013 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 "content/renderer/media/webrtc_audio_processor_options.h"
+
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/path_service.h"
+#include "third_party/libjingle/source/talk/app/webrtc/mediaconstraintsinterface.h"
+#include "third_party/webrtc/modules/audio_processing/include/audio_processing.h"
+
+namespace content {
+
+bool GetPropertyFromConstraints(const MediaConstraintsInterface* constraints,
+                                const std::string& key) {
+  bool value = false;
+  return webrtc::FindConstraint(constraints, key, &value, NULL) && value;
+}
+
+// Extract all these methods to a helper class.

[Henrik Grunell, 2013/11/12 12:46:37]

Comment doesn't seem to make sense. Is this a todo? Old todo?

[no longer working on chromium, 2013/11/12 13:31:56]

Done.

+void EnableEchoCancellation(AudioProcessing* audio_processing) {

[Henrik Grunell, 2013/11/12 12:46:37]

Should we have disable calls? Are all components disabled by default?

[no longer working on chromium, 2013/11/12 13:31:56]

No, all the components are disabled by default.

+#if defined(IOS) || defined(ANDROID)

[Henrik Grunell, 2013/11/12 12:46:37]

Note: In libjingle, for iOS built-in EC and AGC is used. (See
WebRtcVoiceEngine::ApplyOptions.) So when we'll later use the audio processor in
the track, it should likely do the same and not enable them.

[no longer working on chromium, 2013/11/12 13:31:56]

OK, I was not taking this code seriously since chrome does support IOS yet.

Fixed now.

+  // Mobile devices are using AECM.
+  if (audio_processing->echo_control_mobile()->Enable(true))

[Henrik Grunell, 2013/11/12 12:46:37]

Does ordinary EC need to be disabled before enabling the mobile EC?

[no longer working on chromium, 2013/11/12 13:31:56]

We never enable the ordinary EC for mobile.

+    NOTREACHED();

[Henrik Grunell, 2013/11/12 12:46:37]

Can't enabling fail for this and all below calls? If not, should the interface
have void return type? If yes, when?

[no longer working on chromium, 2013/11/12 13:31:56]

After the offline discussion, we agreed that a NOTREACHED() is suitable here.

+
+  if (audio_processing->echo_control_mobile()->set_routing_mode(
+      webrtc::EchoControlMobile::kSpeakerphone))
+    NOTREACHED();

[Henrik Grunell, 2013/11/12 12:46:37]

Do we need to set CN for mobile EC to false or is that default?

[no longer working on chromium, 2013/11/12 13:31:56]

I think the defaults are all false

+#else
+  if (audio_processing->echo_cancellation()->Enable(true))

[Henrik Grunell, 2013/11/12 12:46:37]

Does mobile EC need to be disabled before enabling the ordinary EC?

[no longer working on chromium, 2013/11/12 13:31:56]

We never enable Mobile EC for desktops.

+    NOTREACHED();
+  if (audio_processing->echo_cancellation()->set_suppression_level(
+      webrtc::EchoCancellation::kHighSuppression))

[Henrik Grunell, 2013/11/12 12:46:37]

For mobile, the level should be set to moderate. See
VoEAudioProcessingImpl::SetEcStatus in webrtc and
WebRtcVoiceEngine::ApplyOptions in libjingle.

[no longer working on chromium, 2013/11/12 13:31:56]

Addressed this offline, no need to change anything.

+    NOTREACHED();
+
+  // Enable the metrics for AEC.
+  if (audio_processing->echo_cancellation()->enable_metrics(true))
+    NOTREACHED();
+  if (audio_processing->echo_cancellation()->enable_delay_logging(true))
+    NOTREACHED();
+#endif
+}
+
+void EnableNoiseSuppression(AudioProcessing* audio_processing) {
+  if (audio_processing->noise_suppression()->set_level(
+      webrtc::NoiseSuppression::kHigh))
+    NOTREACHED();
+
+  if (audio_processing->noise_suppression()->Enable(true))
+    NOTREACHED();
+}
+
+void EnableHighPassFilter(AudioProcessing* audio_processing) {

[Henrik Grunell, 2013/11/12 12:46:37]

Isn't this on by default? Since there's no disable this function doesn't make
much sense.

[no longer working on chromium, 2013/11/12 13:31:56]

I think all the processing components are set to false by default:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/webrtc...

+  if (audio_processing->high_pass_filter()->Enable(true))
+     NOTREACHED();
+}
+
+// TODO(xians): stereo swapping
+void EnableTypingDetection(AudioProcessing* audio_processing) {
+  if (audio_processing->voice_detection()->Enable(true))
+    NOTREACHED();
+
+  if (audio_processing->voice_detection()->set_likelihood(
+      webrtc::VoiceDetection::kVeryLowLikelihood))
+    NOTREACHED();
+}
+
+void EnableExperimentalEchoCancellation(AudioProcessing* audio_processing) {
+  webrtc::Config config;
+  config.Set<webrtc::DelayCorrection>(new webrtc::DelayCorrection(true));
+  audio_processing->SetExtraOptions(config);
+}
+
+void StartAecDump(AudioProcessing* audio_processing) {
+  // TODO(xians): Figure out a more suitable directory for the audio dump data.

[Henrik Grunell, 2013/11/12 12:46:37]

Did you check with ajm@ about the locations?

[no longer working on chromium, 2013/11/12 13:31:56]

Not yet, but will do it. But this should not block this CL, we can always change
it when getting answer from ajm.
Also, the code is behind a flag, so there is no impact at all.

+  base::FilePath path;
+#if defined(CHROMEOS)
+  PathService::Get(base::DIR_TEMP, &path);
+#elif defined(ANDROID)
+  path = base::FilePath(FILE_PATH_LITERAL("sdcard"));
+#else
+  PathService::Get(base::DIR_EXE, &path);
+#endif
+  base::FilePath file = path.Append(FILE_PATH_LITERAL("audio.aecdump"));
+  if (audio_processing->StartDebugRecording(file.value().c_str()))
+    DLOG(ERROR) << "Fail to start AEC debug recording";
+}
+
+void StopAecDump(AudioProcessing* audio_processing) {
+  if (audio_processing->StopDebugRecording())
+    DLOG(ERROR) << "Fail to stop AEC debug recording";
+}
+
+}  // namespace content