Merge AudioRendererImpl and AudioRendererBase; add NullAudioSink

content/renderer/media/audio_hardware.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/renderer/media/audio_hardware.h"
 
 #include "base/logging.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 
@@ skipping 30 matching lines @@
   if (!output_buffer_size) {
     uint32 buffer_size = 0;
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareBufferSize(&buffer_size));
     output_buffer_size = buffer_size;
   }
 
   return output_buffer_size;
 }
 
-size_t GetHighLatencyOutputBufferSize(int sample_rate) {
-  // TODO(vrk/crogers): The buffer sizes that this function computes is probably
-  // overly conservative. However, reducing the buffer size to 2048-8192 bytes
-  // caused crbug.com/108396. This computation should be revisited while making
-  // sure crbug.com/108396 doesn't happen again.
-
-  // The minimum number of samples in a hardware packet.
-  // This value is selected so that we can handle down to 5khz sample rate.
-  static const size_t kMinSamplesPerHardwarePacket = 1024;
-
-  // The maximum number of samples in a hardware packet.
-  // This value is selected so that we can handle up to 192khz sample rate.
-  static const size_t kMaxSamplesPerHardwarePacket = 64 * 1024;
-
-  // This constant governs the hardware audio buffer size, this value should be
-  // chosen carefully.
-  // This value is selected so that we have 8192 samples for 48khz streams.
-  static const size_t kMillisecondsPerHardwarePacket = 170;
-
-  // Select the number of samples that can provide at least
-  // |kMillisecondsPerHardwarePacket| worth of audio data.
-  size_t samples = kMinSamplesPerHardwarePacket;
-  while (samples <= kMaxSamplesPerHardwarePacket &&
-         samples * base::Time::kMillisecondsPerSecond <
-         sample_rate * kMillisecondsPerHardwarePacket) {
-    samples *= 2;
-  }
-  return samples;
-}
-
 ChannelLayout GetInputChannelLayout() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   if (input_channel_layout == CHANNEL_LAYOUT_NONE) {
     ChannelLayout layout = CHANNEL_LAYOUT_NONE;
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareInputChannelLayout(&layout));
     input_channel_layout = layout;
   }
 
   return input_channel_layout;
 }
 
 void ResetCache() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   output_sample_rate = 0.0;
   input_sample_rate = 0.0;
   output_buffer_size = 0;
   input_channel_layout = CHANNEL_LAYOUT_NONE;
 }
 
 }  // namespace audio_hardware