Replace the guts of AudioRendererBase with calls to scaling algorithm.

media/filters/null_audio_renderer.cc

 // Copyright (c) 2009 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 <cmath>
 
 #include "media/base/filter_host.h"
 #include "media/filters/null_audio_renderer.h"
 
 namespace media {
 
 // How "long" our buffer should be in terms of milliseconds.  In OnInitialize
 // we calculate the size of one second of audio data and use this number to
 // allocate a buffer to pass to FillBuffer.
 static const size_t kBufferSizeInMilliseconds = 100;
 
 NullAudioRenderer::NullAudioRenderer()
-    : AudioRendererBase(kDefaultMaxQueueSize),
-      playback_rate_(0.0f),
+    : AudioRendererBase(),
       bytes_per_millisecond_(0),
       buffer_size_(0),
       thread_(NULL),
       shutdown_(false) {
 }
 
 NullAudioRenderer::~NullAudioRenderer() {
   Stop();
 }
 
 // static
 bool NullAudioRenderer::IsMediaFormatSupported(
     const MediaFormat& media_format) {
   int channels;
   int sample_rate;
   int sample_bits;
   return ParseMediaFormat(media_format, &channels, &sample_rate, &sample_bits);
 }
 
-void NullAudioRenderer::SetPlaybackRate(float playback_rate) {
-  playback_rate_ = playback_rate;
-}
-
 void NullAudioRenderer::SetVolume(float volume) {
   // Do nothing.
 }
 
 void NullAudioRenderer::ThreadMain() {
   // Loop until we're signaled to stop.
   while (!shutdown_) {
     float sleep_in_milliseconds = 0.0f;
 
     // Only consume buffers when actually playing.
-    if (playback_rate_ > 0.0f)  {
+    if (GetPlaybackRate() > 0.0f)  {
       size_t bytes = FillBuffer(buffer_.get(),
                                 buffer_size_,
-                                playback_rate_,
                                 base::TimeDelta());
 
       // Calculate our sleep duration, taking playback rate into consideration.
       sleep_in_milliseconds =
           floor(bytes / static_cast<float>(bytes_per_millisecond_));
-      sleep_in_milliseconds /= playback_rate_;
+      sleep_in_milliseconds /= GetPlaybackRate();
     } else {
       // If paused, sleep for 10 milliseconds before polling again.
       sleep_in_milliseconds = 10.0f;
     }
 
     // Sleep for at least one millisecond so we don't spin the CPU.
     PlatformThread::Sleep(std::max(1, static_cast<int>(sleep_in_milliseconds)));
   }
 }
 
@@ skipping 20 matching lines @@
 
 void NullAudioRenderer::OnStop() {
   shutdown_ = true;
   if (thread_) {
     PlatformThread::Join(thread_);
     thread_ = NULL;
   }
 }
 
 }  // namespace media