Adds Analog Gain Control (AGC) to the WebRTC client.

content/browser/renderer_host/media/audio_input_renderer_host.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 "content/browser/renderer_host/media/audio_input_renderer_host.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
@@ skipping 158 matching lines @@
 bool AudioInputRendererHost::OnMessageReceived(const IPC::Message& message,
                                                bool* message_was_ok) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP_EX(AudioInputRendererHost, message, *message_was_ok)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_StartDevice, OnStartDevice)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_CreateStream, OnCreateStream)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_RecordStream, OnRecordStream)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_CloseStream, OnCloseStream)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_GetVolume, OnGetVolume)
     IPC_MESSAGE_HANDLER(AudioInputHostMsg_SetVolume, OnSetVolume)
+    IPC_MESSAGE_HANDLER(AudioInputHostMsg_SetAutomaticGainControl,
+        OnSetAutomaticGainControl)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
   return handled;
 }
 void AudioInputRendererHost::OnStartDevice(int stream_id, int session_id) {
   VLOG(1) << "AudioInputRendererHost::OnStartDevice(stream_id="
           << stream_id << ", session_id = " << session_id << ")";
 
   // Get access to the AudioInputDeviceManager to start the device.
   media_stream::AudioInputDeviceManager* audio_input_man =
       media_stream::MediaStreamManager::GetForResourceContext(
           resource_context_, audio_manager_)->audio_input_device_manager();
 
   // Add the session entry to the map.
   session_entries_[session_id] = stream_id;
 
   // Start the device with the session_id. If the device is started
   // successfully, OnDeviceStarted() callback will be triggered.
   audio_input_man->Start(session_id, this);
 }
 
 void AudioInputRendererHost::OnCreateStream(int stream_id,
                                             const AudioParameters& params,
-                                            const std::string& device_id) {
+                                            const std::string& device_id,
+                                            bool automatic_gain_control) {
   VLOG(1) << "AudioInputRendererHost::OnCreateStream(stream_id="
           << stream_id << ")";
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(LookupById(stream_id) == NULL);
 
   AudioParameters audio_params(params);
 
   DCHECK_GT(audio_params.samples_per_packet, 0);
   uint32 packet_size = audio_params.GetPacketSize();
 
   // Create a new AudioEntry structure.
   scoped_ptr<AudioEntry> entry(new AudioEntry());
 
+  uint32 mem_size = AudioInputBuffer::kSizeOfStructMinusArr + packet_size;

[tommi (sloooow) - chröme, 2012/03/16 13:31:05]

nit: change kSizeOfStructMinusArr -> kSizeOfStructMinusArray.
If I wrote it as "Arr" on the white board, it was just me being lazy :)

I wonder if we can use more specific term than 'array'.  What about using the
word 'Packet' to be consistent with audio_params.GetPacketSize()?

[henrika (OOO until Aug 14), 2012/03/21 10:16:04]

Done.

+
   // Create the shared memory and share it with the renderer process
   // using a new SyncWriter object.
-  if (!entry->shared_memory.CreateAndMapAnonymous(packet_size)) {
+  if (!entry->shared_memory.CreateAndMapAnonymous(mem_size)) {
     // If creation of shared memory failed then send an error message.
     SendErrorMessage(stream_id);
     return;
   }
 
   scoped_ptr<AudioInputSyncWriter> writer(
       new AudioInputSyncWriter(&entry->shared_memory));
 
   if (!writer->Init()) {
     SendErrorMessage(stream_id);
@@ skipping 11 matching lines @@
       this,
       audio_params,
       device_id,
       entry->writer.get());
 
   if (!entry->controller) {
     SendErrorMessage(stream_id);
     return;
   }
 
+  // Set the initial AGC state for the audio input stream.
+  entry->controller->SetAutomaticGainControl(automatic_gain_control);
+
   // If we have created the controller successfully create a entry and add it
   // to the map.
   entry->stream_id = stream_id;
 
   audio_entries_.insert(std::make_pair(stream_id, entry.release()));
 }
 
 void AudioInputRendererHost::OnRecordStream(int stream_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
@@ skipping 22 matching lines @@
 
 void AudioInputRendererHost::OnSetVolume(int stream_id, double volume) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   AudioEntry* entry = LookupById(stream_id);
   if (!entry) {
     SendErrorMessage(stream_id);
     return;
   }
 
-  // TODO(henrika): TBI.
+  entry->controller->SetVolume(volume);
+}
+
+void AudioInputRendererHost::OnGetVolume(int stream_id) {
   NOTIMPLEMENTED();

[tommi (sloooow) - chröme, 2012/03/16 13:31:05]

Do we need to implement this at some point or never?
(when is it called?)

[scherkus (not reviewing), 2012/03/20 13:49:41]

AFAIK GetVolume() is completely unused

[henrika (OOO until Aug 14), 2012/03/21 10:16:04]

Yeah, you are correct. I might as well drop it actually. Better to add it
if/when we need it.

 }
 
-void AudioInputRendererHost::OnGetVolume(int stream_id) {
+void AudioInputRendererHost::OnSetAutomaticGainControl(int stream_id,
+                                                       bool enabled) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   AudioEntry* entry = LookupById(stream_id);
   if (!entry) {
     SendErrorMessage(stream_id);
     return;
   }
 
-  // TODO(henrika): TBI.
-  NOTIMPLEMENTED();
+  entry->controller->SetAutomaticGainControl(enabled);
 }
 
 void AudioInputRendererHost::SendErrorMessage(int stream_id) {
   Send(new AudioInputMsg_NotifyStreamStateChanged(stream_id,
                                                   kAudioStreamError));
 }
 
 void AudioInputRendererHost::DeleteEntries() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
@@ skipping 119 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   for (SessionEntryMap::iterator it = session_entries_.begin();
        it != session_entries_.end(); ++it) {
     if (stream_id == it->second) {
       return it->first;
     }
   }
   return 0;
 }