Rename AudioRendererBase and AudioRendererAlgorithmBase

media/filters/audio_renderer_algorithm_base.cc

Index: media/filters/audio_renderer_algorithm_base.cc
diff --git a/media/filters/audio_renderer_algorithm_base.cc b/media/filters/audio_renderer_algorithm_base.cc
deleted file mode 100644
index 990c477727e1a8bf09f32f113bb19ffdfd349722..0000000000000000000000000000000000000000
--- a/media/filters/audio_renderer_algorithm_base.cc
+++ /dev/null
@@ -1,444 +0,0 @@
-// 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/filters/audio_renderer_algorithm_base.h"
-
-#include <algorithm>
-#include <cmath>
-
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "media/audio/audio_util.h"
-#include "media/base/buffers.h"
-
-namespace media {
-
-// The starting size in bytes for |audio_buffer_|.
-// Previous usage maintained a deque of 16 Buffers, each of size 4Kb. This
-// worked well, so we maintain this number of bytes (16 * 4096).
-static const int kStartingBufferSizeInBytes = 65536;
-
-// The maximum size in bytes for the |audio_buffer_|. Arbitrarily determined.
-// This number represents 3 seconds of 96kHz/16 bit 7.1 surround sound.
-static const int kMaxBufferSizeInBytes = 4608000;
-
-// Duration of audio segments used for crossfading (in seconds).
-static const double kWindowDuration = 0.08;
-
-// Duration of crossfade between audio segments (in seconds).
-static const double kCrossfadeDuration = 0.008;
-
-// Max/min supported playback rates for fast/slow audio. Audio outside of these
-// ranges are muted.
-// Audio at these speeds would sound better under a frequency domain algorithm.
-static const float kMinPlaybackRate = 0.5f;
-static const float kMaxPlaybackRate = 4.0f;
-
-AudioRendererAlgorithmBase::AudioRendererAlgorithmBase()
-    : channels_(0),
-      samples_per_second_(0),
-      bytes_per_channel_(0),
-      playback_rate_(0.0f),
-      audio_buffer_(0, kStartingBufferSizeInBytes),
-      bytes_in_crossfade_(0),
-      bytes_per_frame_(0),
-      index_into_window_(0),
-      crossfade_frame_number_(0),
-      muted_(false),
-      needs_more_data_(false),
-      window_size_(0) {
-}
-
-AudioRendererAlgorithmBase::~AudioRendererAlgorithmBase() {}
-
-bool AudioRendererAlgorithmBase::ValidateConfig(
-    int channels,
-    int samples_per_second,
-    int bits_per_channel) {
-  bool status = true;
-
-  if (channels <= 0 || channels > 8) {
-    DVLOG(1) << "We only support audio with between 1 and 8 channels.";
-    status = false;
-  }
-
-  if (samples_per_second <= 0 || samples_per_second > 256000) {
-    DVLOG(1) << "We only support sample rates between 1 and 256000Hz.";
-    status = false;
-  }
-
-  if (bits_per_channel != 8 && bits_per_channel != 16 &&
-      bits_per_channel != 32) {
-    DVLOG(1) << "We only support 8, 16, 32 bit audio.";
-    status = false;
-  }
-
-  return status;
-}
-
-void AudioRendererAlgorithmBase::Initialize(
-    int channels,
-    int samples_per_second,
-    int bits_per_channel,
-    float initial_playback_rate,
-    const base::Closure& callback) {
-  DCHECK(!callback.is_null());
-  DCHECK(ValidateConfig(channels, samples_per_second, bits_per_channel));
-
-  channels_ = channels;
-  samples_per_second_ = samples_per_second;
-  bytes_per_channel_ = bits_per_channel / 8;
-  bytes_per_frame_ = bytes_per_channel_ * channels_;
-  request_read_cb_ = callback;
-  SetPlaybackRate(initial_playback_rate);
-
-  window_size_ =
-      samples_per_second_ * bytes_per_channel_ * channels_ * kWindowDuration;
-  AlignToFrameBoundary(&window_size_);
-
-  bytes_in_crossfade_ =
-      samples_per_second_ * bytes_per_channel_ * channels_ * kCrossfadeDuration;
-  AlignToFrameBoundary(&bytes_in_crossfade_);
-
-  crossfade_buffer_.reset(new uint8[bytes_in_crossfade_]);
-}
-
-int AudioRendererAlgorithmBase::FillBuffer(
-    uint8* dest, int requested_frames) {
-  DCHECK_NE(bytes_per_frame_, 0);
-
-  if (playback_rate_ == 0.0f)
-    return 0;
-
-  int total_frames_rendered = 0;
-  uint8* output_ptr = dest;
-  while (total_frames_rendered < requested_frames) {
-    if (index_into_window_ == window_size_)
-      ResetWindow();
-
-    bool rendered_frame = true;
-    if (playback_rate_ > 1.0)
-      rendered_frame = OutputFasterPlayback(output_ptr);
-    else if (playback_rate_ < 1.0)
-      rendered_frame = OutputSlowerPlayback(output_ptr);
-    else
-      rendered_frame = OutputNormalPlayback(output_ptr);
-
-    if (!rendered_frame) {
-      needs_more_data_ = true;
-      break;
-    }
-
-    output_ptr += bytes_per_frame_;
-    total_frames_rendered++;
-  }
-  return total_frames_rendered;
-}
-
-void AudioRendererAlgorithmBase::ResetWindow() {
-  DCHECK_LE(index_into_window_, window_size_);
-  index_into_window_ = 0;
-  crossfade_frame_number_ = 0;
-}
-
-bool AudioRendererAlgorithmBase::OutputFasterPlayback(uint8* dest) {
-  DCHECK_LT(index_into_window_, window_size_);
-  DCHECK_GT(playback_rate_, 1.0);
-
-  if (audio_buffer_.forward_bytes() < bytes_per_frame_)
-    return false;
-
-  // The audio data is output in a series of windows. For sped-up playback,
-  // the window is comprised of the following phases:
-  //
-  //  a) Output raw data.
-  //  b) Save bytes for crossfade in |crossfade_buffer_|.
-  //  c) Drop data.
-  //  d) Output crossfaded audio leading up to the next window.
-  //
-  // The duration of each phase is computed below based on the |window_size_|
-  // and |playback_rate_|.
-  int input_step = window_size_;
-  int output_step = ceil(window_size_ / playback_rate_);
-  AlignToFrameBoundary(&output_step);
-  DCHECK_GT(input_step, output_step);
-
-  int bytes_to_crossfade = bytes_in_crossfade_;
-  if (muted_ || bytes_to_crossfade > output_step)
-    bytes_to_crossfade = 0;
-
-  // This is the index of the end of phase a, beginning of phase b.
-  int outtro_crossfade_begin = output_step - bytes_to_crossfade;
-
-  // This is the index of the end of phase b, beginning of phase c.
-  int outtro_crossfade_end = output_step;
-
-  // This is the index of the end of phase c, beginning of phase d.
-  // This phase continues until |index_into_window_| reaches |window_size_|, at
-  // which point the window restarts.
-  int intro_crossfade_begin = input_step - bytes_to_crossfade;
-
-  // a) Output a raw frame if we haven't reached the crossfade section.
-  if (index_into_window_ < outtro_crossfade_begin) {
-    CopyWithAdvance(dest);
-    index_into_window_ += bytes_per_frame_;
-    return true;
-  }
-
-  // b) Save outtro crossfade frames into intermediate buffer, but do not output
-  //    anything to |dest|.
-  while (index_into_window_ < outtro_crossfade_end) {
-    if (audio_buffer_.forward_bytes() < bytes_per_frame_)
-      return false;
-
-    // This phase only applies if there are bytes to crossfade.
-    DCHECK_GT(bytes_to_crossfade, 0);
-    uint8* place_to_copy = crossfade_buffer_.get() +
-        (index_into_window_ - outtro_crossfade_begin);
-    CopyWithAdvance(place_to_copy);
-    index_into_window_ += bytes_per_frame_;
-  }
-
-  // c) Drop frames until we reach the intro crossfade section.
-  while (index_into_window_ < intro_crossfade_begin) {
-    if (audio_buffer_.forward_bytes() < bytes_per_frame_)
-      return false;
-
-    DropFrame();
-    index_into_window_ += bytes_per_frame_;
-  }
-
-  // Return if we have run out of data after Phase c).
-  if (audio_buffer_.forward_bytes() < bytes_per_frame_)
-    return false;
-
-  // Phase d) doesn't apply if there are no bytes to crossfade.
-  if (bytes_to_crossfade == 0) {
-    DCHECK_EQ(index_into_window_, window_size_);
-    return false;
-  }
-
-  // d) Crossfade and output a frame.
-  DCHECK_LT(index_into_window_, window_size_);
-  int offset_into_buffer = index_into_window_ - intro_crossfade_begin;
-  memcpy(dest, crossfade_buffer_.get() + offset_into_buffer,
-         bytes_per_frame_);
-  scoped_array<uint8> intro_frame_ptr(new uint8[bytes_per_frame_]);
-  audio_buffer_.Read(intro_frame_ptr.get(), bytes_per_frame_);
-  OutputCrossfadedFrame(dest, intro_frame_ptr.get());
-  index_into_window_ += bytes_per_frame_;
-  return true;
-}
-
-bool AudioRendererAlgorithmBase::OutputSlowerPlayback(uint8* dest) {
-  DCHECK_LT(index_into_window_, window_size_);
-  DCHECK_LT(playback_rate_, 1.0);
-  DCHECK_NE(playback_rate_, 0.0);
-
-  if (audio_buffer_.forward_bytes() < bytes_per_frame_)
-    return false;
-
-  // The audio data is output in a series of windows. For slowed down playback,
-  // the window is comprised of the following phases:
-  //
-  //  a) Output raw data.
-  //  b) Output and save bytes for crossfade in |crossfade_buffer_|.
-  //  c) Output* raw data.
-  //  d) Output* crossfaded audio leading up to the next window.
-  //
-  // * Phases c) and d) do not progress |audio_buffer_|'s cursor so that the
-  // |audio_buffer_|'s cursor is in the correct place for the next window.
-  //
-  // The duration of each phase is computed below based on the |window_size_|
-  // and |playback_rate_|.
-  int input_step = ceil(window_size_ * playback_rate_);
-  AlignToFrameBoundary(&input_step);
-  int output_step = window_size_;
-  DCHECK_LT(input_step, output_step);
-
-  int bytes_to_crossfade = bytes_in_crossfade_;
-  if (muted_ || bytes_to_crossfade > input_step)
-    bytes_to_crossfade = 0;
-
-  // This is the index of the end of phase a, beginning of phase b.
-  int intro_crossfade_begin = input_step - bytes_to_crossfade;
-
-  // This is the index of the end of phase b, beginning of phase c.
-  int intro_crossfade_end = input_step;
-
-  // This is the index of the end of phase c,  beginning of phase d.
-  // This phase continues until |index_into_window_| reaches |window_size_|, at
-  // which point the window restarts.
-  int outtro_crossfade_begin = output_step - bytes_to_crossfade;
-
-  // a) Output a raw frame.
-  if (index_into_window_ < intro_crossfade_begin) {
-    CopyWithAdvance(dest);
-    index_into_window_ += bytes_per_frame_;
-    return true;
-  }
-
-  // b) Save the raw frame for the intro crossfade section, then output the
-  //    frame to |dest|.
-  if (index_into_window_ < intro_crossfade_end) {
-    int offset = index_into_window_ - intro_crossfade_begin;
-    uint8* place_to_copy = crossfade_buffer_.get() + offset;
-    CopyWithoutAdvance(place_to_copy);
-    CopyWithAdvance(dest);
-    index_into_window_ += bytes_per_frame_;
-    return true;
-  }
-
-  int audio_buffer_offset = index_into_window_ - intro_crossfade_end;
-
-  if (audio_buffer_.forward_bytes() < audio_buffer_offset + bytes_per_frame_)
-    return false;
-
-  // c) Output a raw frame into |dest| without advancing the |audio_buffer_|
-  //    cursor. See function-level comment.
-  DCHECK_GE(index_into_window_, intro_crossfade_end);
-  CopyWithoutAdvance(dest, audio_buffer_offset);
-
-  // d) Crossfade the next frame of |crossfade_buffer_| into |dest| if we've
-  //    reached the outtro crossfade section of the window.
-  if (index_into_window_ >= outtro_crossfade_begin) {
-    int offset_into_crossfade_buffer =
-        index_into_window_ - outtro_crossfade_begin;
-    uint8* intro_frame_ptr =
-        crossfade_buffer_.get() + offset_into_crossfade_buffer;
-    OutputCrossfadedFrame(dest, intro_frame_ptr);
-  }
-
-  index_into_window_ += bytes_per_frame_;
-  return true;
-}
-
-bool AudioRendererAlgorithmBase::OutputNormalPlayback(uint8* dest) {
-  if (audio_buffer_.forward_bytes() >= bytes_per_frame_) {
-    CopyWithAdvance(dest);
-    index_into_window_ += bytes_per_frame_;
-    return true;
-  }
-  return false;
-}
-
-void AudioRendererAlgorithmBase::CopyWithAdvance(uint8* dest) {
-  CopyWithoutAdvance(dest);
-  DropFrame();
-}
-
-void AudioRendererAlgorithmBase::CopyWithoutAdvance(uint8* dest) {
-  CopyWithoutAdvance(dest, 0);
-}
-
-void AudioRendererAlgorithmBase::CopyWithoutAdvance(
-    uint8* dest, int offset) {
-  if (muted_) {
-    memset(dest, 0, bytes_per_frame_);
-    return;
-  }
-  int copied = audio_buffer_.Peek(dest, bytes_per_frame_, offset);
-  DCHECK_EQ(bytes_per_frame_, copied);
-}
-
-void AudioRendererAlgorithmBase::DropFrame() {
-  audio_buffer_.Seek(bytes_per_frame_);
-
-  if (!IsQueueFull())
-    request_read_cb_.Run();
-}
-
-void AudioRendererAlgorithmBase::OutputCrossfadedFrame(
-    uint8* outtro, const uint8* intro) {
-  DCHECK_LE(index_into_window_, window_size_);
-  DCHECK(!muted_);
-
-  switch (bytes_per_channel_) {
-    case 4:
-      CrossfadeFrame<int32>(outtro, intro);
-      break;
-    case 2:
-      CrossfadeFrame<int16>(outtro, intro);
-      break;
-    case 1:
-      CrossfadeFrame<uint8>(outtro, intro);
-      break;
-    default:
-      NOTREACHED() << "Unsupported audio bit depth in crossfade.";
-  }
-}
-
-template <class Type>
-void AudioRendererAlgorithmBase::CrossfadeFrame(
-    uint8* outtro_bytes, const uint8* intro_bytes) {
-  Type* outtro = reinterpret_cast<Type*>(outtro_bytes);
-  const Type* intro = reinterpret_cast<const Type*>(intro_bytes);
-
-  int frames_in_crossfade = bytes_in_crossfade_ / bytes_per_frame_;
-  float crossfade_ratio =
-      static_cast<float>(crossfade_frame_number_) / frames_in_crossfade;
-  for (int channel = 0; channel < channels_; ++channel) {
-    *outtro *= 1.0 - crossfade_ratio;
-    *outtro++ += (*intro++) * crossfade_ratio;
-  }
-  crossfade_frame_number_++;
-}
-
-void AudioRendererAlgorithmBase::SetPlaybackRate(float new_rate) {
-  DCHECK_GE(new_rate, 0.0);
-  playback_rate_ = new_rate;
-  muted_ =
-      playback_rate_ < kMinPlaybackRate || playback_rate_ > kMaxPlaybackRate;
-
-  ResetWindow();
-}
-
-void AudioRendererAlgorithmBase::AlignToFrameBoundary(int* value) {
-  (*value) -= ((*value) % bytes_per_frame_);
-}
-
-void AudioRendererAlgorithmBase::FlushBuffers() {
-  ResetWindow();
-
-  // Clear the queue of decoded packets (releasing the buffers).
-  audio_buffer_.Clear();
-  request_read_cb_.Run();
-}
-
-base::TimeDelta AudioRendererAlgorithmBase::GetTime() {
-  return audio_buffer_.current_time();
-}
-
-void AudioRendererAlgorithmBase::EnqueueBuffer(Buffer* buffer_in) {
-  DCHECK(!buffer_in->IsEndOfStream());
-  audio_buffer_.Append(buffer_in);
-  needs_more_data_ = false;
-
-  // If we still don't have enough data, request more.
-  if (!IsQueueFull())
-    request_read_cb_.Run();
-}
-
-bool AudioRendererAlgorithmBase::NeedsMoreData() {
-  return needs_more_data_ || IsQueueEmpty();
-}
-
-bool AudioRendererAlgorithmBase::IsQueueEmpty() {
-  return audio_buffer_.forward_bytes() == 0;
-}
-
-bool AudioRendererAlgorithmBase::IsQueueFull() {
-  return audio_buffer_.forward_bytes() >= audio_buffer_.forward_capacity();
-}
-
-int AudioRendererAlgorithmBase::QueueCapacity() {
-  return audio_buffer_.forward_capacity();
-}
-
-void AudioRendererAlgorithmBase::IncreaseQueueCapacity() {
-  audio_buffer_.set_forward_capacity(
-      std::min(2 * audio_buffer_.forward_capacity(), kMaxBufferSizeInBytes));
-}
-
-}  // namespace media