Switch the input code to use AudioBlockFifo

media/audio/pulse/pulse_input.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/pulse/pulse_input.h"
 
 #include <pulse/pulseaudio.h>
 
 #include "base/logging.h"
 #include "media/audio/pulse/audio_manager_pulse.h"
 #include "media/audio/pulse/pulse_util.h"
-#include "media/base/seekable_buffer.h"
 
 namespace media {
 
 using pulse::AutoPulseLock;
 using pulse::WaitForOperationCompletion;
 
+// Number of blocks of buffers used in the |fifo_|.
+const int kNumberOfBlocksBufferInFifo = 2;
+
 PulseAudioInputStream::PulseAudioInputStream(AudioManagerPulse* audio_manager,
                                              const std::string& device_name,
                                              const AudioParameters& params,
                                              pa_threaded_mainloop* mainloop,
                                              pa_context* context)
     : audio_manager_(audio_manager),
       callback_(NULL),
       device_name_(device_name),
       params_(params),
       channels_(0),
       volume_(0.0),
       stream_started_(false),
+      fifo_(params.channels(),
+            params.frames_per_buffer(),
+            kNumberOfBlocksBufferInFifo),
       pa_mainloop_(mainloop),
       pa_context_(context),
       handle_(NULL),
       context_state_changed_(false) {
   DCHECK(mainloop);
   DCHECK(context);
   CHECK(params_.IsValid());
-  audio_bus_ = AudioBus::Create(params_);
 }
 
 PulseAudioInputStream::~PulseAudioInputStream() {
   // All internal structures should already have been freed in Close(),
   // which calls AudioManagerPulse::Release which deletes this object.
   DCHECK(!handle_);
 }
 
 bool PulseAudioInputStream::Open() {
   DCHECK(thread_checker_.CalledOnValidThread());
   AutoPulseLock auto_lock(pa_mainloop_);
   if (!pulse::CreateInputStream(pa_mainloop_, pa_context_, &handle_, params_,
                                 device_name_, &StreamNotifyCallback, this)) {
     return false;
   }
 
   DCHECK(handle_);
 
-  buffer_.reset(new media::SeekableBuffer(0, 2 * params_.GetBytesPerBuffer()));
-  audio_data_buffer_.reset(new uint8[params_.GetBytesPerBuffer()]);
   return true;
 }
 
 void PulseAudioInputStream::Start(AudioInputCallback* callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(callback);
   DCHECK(handle_);
 
   // AGC needs to be started out of the lock.
   StartAgc();
 
   AutoPulseLock auto_lock(pa_mainloop_);
 
   if (stream_started_)
     return;
 
   // Clean up the old buffer.
   pa_stream_drop(handle_);
-  buffer_->Clear();
+  fifo_.Clear();
 
   // Start the streaming.
   callback_ = callback;
   pa_stream_set_read_callback(handle_, &ReadCallback, this);
   pa_stream_readable_size(handle_);
   stream_started_ = true;
 
   pa_operation* operation = pa_stream_cork(handle_, 0, NULL, NULL);
   WaitForOperationCompletion(pa_mainloop_, operation);
 }
@@ skipping 170 matching lines @@
   GetAgcVolume(&normalized_volume);
   normalized_volume = volume_ / GetMaxVolume();
 
   do {
     size_t length = 0;
     const void* data = NULL;
     pa_stream_peek(handle_, &data, &length);
     if (!data || length == 0)
       break;
 
-    buffer_->Append(reinterpret_cast<const uint8*>(data), length);
+    const int number_of_frames = length / params_.GetBytesPerFrame();
+    fifo_.Push(data, number_of_frames, params_.bits_per_sample() / 8);
 
     // Checks if we still have data.
     pa_stream_drop(handle_);
   } while (pa_stream_readable_size(handle_) > 0);
 
-  int packet_size = params_.GetBytesPerBuffer();
-  while (buffer_->forward_bytes() >= packet_size) {
-    buffer_->Read(audio_data_buffer_.get(), packet_size);
-    audio_bus_->FromInterleaved(audio_data_buffer_.get(),
-                                audio_bus_->frames(),
-                                params_.bits_per_sample() / 8);
-    callback_->OnData(
-        this, audio_bus_.get(), hardware_delay, normalized_volume);
+  while (fifo_.available_blocks()) {
+    const AudioBus* audio_bus = fifo_.Consume();
 
-    if (buffer_->forward_bytes() < packet_size)
-      break;
+    // Compensate the audio delay caused by the FIFO.
+    hardware_delay += fifo_.GetAvailableFrames() * params_.GetBytesPerFrame();
+    callback_->OnData(this, audio_bus, hardware_delay, normalized_volume);
 
     // TODO(xians): Remove once PPAPI is using circular buffers.
     DVLOG(1) << "OnData is being called consecutively, sleep 5ms to "
              << "wait until render consumes the data";
     base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(5));
   }
 
   pa_threaded_mainloop_signal(pa_mainloop_, 0);
 }
 
 }  // namespace media