Implementation of 'AudioContext.getOutputTimestamp' method

media/audio/audio_output_device.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 "media/audio/audio_output_device.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <cmath>
@@ skipping 19 matching lines @@
  public:
   AudioThreadCallback(const AudioParameters& audio_parameters,
                       base::SharedMemoryHandle memory,
                       int memory_length,
                       AudioRendererSink::RenderCallback* render_callback);
   ~AudioThreadCallback() override;
 
   void MapSharedMemory() override;
 
   // Called whenever we receive notifications about pending data.
-  void Process(uint32_t pending_data) override;
+  void Process(uint32_t pending_data, const AudioTimestamp& timestamp) override;
 
  private:
   AudioRendererSink::RenderCallback* render_callback_;
   std::unique_ptr<AudioBus> output_bus_;
   uint64_t callback_num_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioThreadCallback);
 };
 
 AudioOutputDevice::AudioOutputDevice(
@@ skipping 359 matching lines @@
   DCHECK_EQ(static_cast<size_t>(memory_length_),
             sizeof(AudioOutputBufferParameters) +
                 AudioBus::CalculateMemorySize(audio_parameters_));
 
   AudioOutputBuffer* buffer =
       reinterpret_cast<AudioOutputBuffer*>(shared_memory_.memory());
   output_bus_ = AudioBus::WrapMemory(audio_parameters_, buffer->audio);
 }
 
 // Called whenever we receive notifications about pending data.
-void AudioOutputDevice::AudioThreadCallback::Process(uint32_t pending_data) {
+void AudioOutputDevice::AudioThreadCallback::Process(
+    uint32_t pending_data,
+    const AudioTimestamp& timestamp) {
   // Convert the number of pending bytes in the render buffer into frames.
   double frames_delayed = static_cast<double>(pending_data) / bytes_per_frame_;
 
   callback_num_++;
   TRACE_EVENT1("audio", "AudioOutputDevice::FireRenderCallback",
                "callback_num", callback_num_);
 
   // When playback starts, we get an immediate callback to Process to make sure
   // that we have some data, we'll get another one after the device is awake and
   // ingesting data, which is what we want to track with this trace.
   if (callback_num_ == 2) {
     TRACE_EVENT_ASYNC_END0("audio", "StartingPlayback", this);
   }
 
   // Read and reset the number of frames skipped.
   AudioOutputBuffer* buffer =
       reinterpret_cast<AudioOutputBuffer*>(shared_memory_.memory());
   uint32_t frames_skipped = buffer->params.frames_skipped;
   buffer->params.frames_skipped = 0;
 
   DVLOG(4) << __FUNCTION__ << " pending_data:" << pending_data
            << " frames_delayed(pre-round):" << frames_delayed
            << " frames_skipped:" << frames_skipped;
 
   // Update the audio-delay measurement, inform about the number of skipped
   // frames, and ask client to render audio.  Since |output_bus_| is wrapping
   // the shared memory the Render() call is writing directly into the shared
   // memory.
   render_callback_->Render(output_bus_.get(), std::round(frames_delayed),
-                           frames_skipped);
+                           frames_skipped, timestamp);
 }
 
 }  // namespace media