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

content/browser/renderer_host/media/audio_input_sync_writer.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_sync_writer.h"
 
 #include <algorithm>
 
 #include "base/process_util.h"
 #include "base/shared_memory.h"
 
 AudioInputSyncWriter::AudioInputSyncWriter(base::SharedMemory* shared_memory)
     : shared_memory_(shared_memory) {
 }
 
 AudioInputSyncWriter::~AudioInputSyncWriter() {}
 
+// TODO(henrika): Combine into one method (including Write).
 void AudioInputSyncWriter::UpdateRecordedBytes(uint32 bytes) {
   socket_->Send(&bytes, sizeof(bytes));
 }
 
-uint32 AudioInputSyncWriter::Write(const void* data, uint32 size) {
-  uint32 write_size = std::min(size, shared_memory_->created_size());
-  // Copy audio input samples from recorded data to shared memory.
-  memcpy(shared_memory_->memory(), data, write_size);
-  return write_size;
+uint32 AudioInputSyncWriter::Write(const void* data, uint32 size,
+    double volume) {
+  AudioInputBuffer* buffer =
+      reinterpret_cast<AudioInputBuffer*>(shared_memory_->memory());
+  buffer->volume = volume;
+  buffer->size = size;
+  memcpy(buffer->audio, data, size);
+
+  return size;
 }
 
 void AudioInputSyncWriter::Close() {
   socket_->Close();
 }
 
 bool AudioInputSyncWriter::Init() {
   socket_.reset(new base::CancelableSyncSocket());
   foreign_socket_.reset(new base::CancelableSyncSocket());
   return base::CancelableSyncSocket::CreatePair(socket_.get(),
@@ skipping 15 matching lines @@
 
 bool AudioInputSyncWriter::PrepareForeignSocketHandle(
     base::ProcessHandle process_handle,
     base::FileDescriptor* foreign_handle) {
   foreign_handle->fd = foreign_socket_->handle();
   foreign_handle->auto_close = false;
   return (foreign_handle->fd != -1);
 }
 
 #endif