Moved renderer implementation from media/filters/ to media/renderers/

media/filters/audio_renderer_algorithm.h

Index: media/filters/audio_renderer_algorithm.h
diff --git a/media/filters/audio_renderer_algorithm.h b/media/filters/audio_renderer_algorithm.h
deleted file mode 100644
index 25ac811132869e5914d6a2132588a6ccf794b372..0000000000000000000000000000000000000000
--- a/media/filters/audio_renderer_algorithm.h
+++ /dev/null
@@ -1,205 +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.
-
-// AudioRendererAlgorithm buffers and transforms audio data. The owner of
-// this object provides audio data to the object through EnqueueBuffer() and
-// requests data from the buffer via FillBuffer().
-//
-// This class is *not* thread-safe. Calls to enqueue and retrieve data must be
-// locked if called from multiple threads.
-//
-// AudioRendererAlgorithm uses the Waveform Similarity Overlap and Add (WSOLA)
-// algorithm to stretch or compress audio data to meet playback speeds less than
-// or greater than the natural playback of the audio stream. The algorithm
-// preserves local properties of the audio, therefore, pitch and harmonics are
-// are preserved. See audio_renderer_algorith.cc for a more elaborate
-// description of the algorithm.
-//
-// Audio at very low or very high playback rates are muted to preserve quality.
-
-#ifndef MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_
-#define MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "media/audio/audio_parameters.h"
-#include "media/base/audio_buffer.h"
-#include "media/base/audio_buffer_queue.h"
-
-namespace media {
-
-class AudioBus;
-
-class MEDIA_EXPORT AudioRendererAlgorithm {
- public:
-  AudioRendererAlgorithm();
-  ~AudioRendererAlgorithm();
-
-  // Initializes this object with information about the audio stream.
-  void Initialize(const AudioParameters& params);
-
-  // Tries to fill |requested_frames| frames into |dest| with possibly scaled
-  // data from our |audio_buffer_|. Data is scaled based on |playback_rate|,
-  // using a variation of the Overlap-Add method to combine sample windows.
-  //
-  // Data from |audio_buffer_| is consumed in proportion to the playback rate.
-  //
-  // |dest_offset| is the offset in frames for writing into |dest|.
-  //
-  // Returns the number of frames copied into |dest|.
-  int FillBuffer(AudioBus* dest,
-                 int dest_offset,
-                 int requested_frames,
-                 float playback_rate);
-
-  // Clears |audio_buffer_|.
-  void FlushBuffers();
-
-  // Enqueues a buffer. It is called from the owner of the algorithm after a
-  // read completes.
-  void EnqueueBuffer(const scoped_refptr<AudioBuffer>& buffer_in);
-
-  // Returns true if |audio_buffer_| is at or exceeds capacity.
-  bool IsQueueFull();
-
-  // Returns the capacity of |audio_buffer_| in frames.
-  int QueueCapacity() const { return capacity_; }
-
-  // Increase the capacity of |audio_buffer_| if possible.
-  void IncreaseQueueCapacity();
-
-  // Returns the number of frames left in |audio_buffer_|, which may be larger
-  // than QueueCapacity() in the event that EnqueueBuffer() delivered more data
-  // than |audio_buffer_| was intending to hold.
-  int frames_buffered() { return audio_buffer_.frames(); }
-
-  // Returns the samples per second for this audio stream.
-  int samples_per_second() { return samples_per_second_; }
-
- private:
-  // Within |search_block_|, find the block of data that is most similar to
-  // |target_block_|, and write it in |optimal_block_|. This method assumes that
-  // there is enough data to perform a search, i.e. |search_block_| and
-  // |target_block_| can be extracted from the available frames.
-  void GetOptimalBlock();
-
-  // Read a maximum of |requested_frames| frames from |wsola_output_|. Returns
-  // number of frames actually read.
-  int WriteCompletedFramesTo(
-      int requested_frames, int output_offset, AudioBus* dest);
-
-  // Fill |dest| with frames from |audio_buffer_| starting from frame
-  // |read_offset_frames|. |dest| is expected to have the same number of
-  // channels as |audio_buffer_|. A negative offset, i.e.
-  // |read_offset_frames| < 0, is accepted assuming that |audio_buffer| is zero
-  // for negative indices. This might happen for few first frames. This method
-  // assumes there is enough frames to fill |dest|, i.e. |read_offset_frames| +
-  // |dest->frames()| does not extend to future.
-  void PeekAudioWithZeroPrepend(int read_offset_frames, AudioBus* dest);
-
-  // Run one iteration of WSOLA, if there are sufficient frames. This will
-  // overlap-and-add one block to |wsola_output_|, hence, |num_complete_frames_|
-  // is incremented by |ola_hop_size_|.
-  bool RunOneWsolaIteration(float playback_rate);
-
-  // Seek |audio_buffer_| forward to remove frames from input that are not used
-  // any more. State of the WSOLA will be updated accordingly.
-  void RemoveOldInputFrames(float playback_rate);
-
-  // Update |output_time_| by |time_change|. In turn |search_block_index_| is
-  // updated.
-  void UpdateOutputTime(float playback_rate, double time_change);
-
-  // Is |target_block_| fully within |search_block_|? If so, we don't need to
-  // perform the search.
-  bool TargetIsWithinSearchRegion() const;
-
-  // Do we have enough data to perform one round of WSOLA?
-  bool CanPerformWsola() const;
-
-  // Number of channels in audio stream.
-  int channels_;
-
-  // Sample rate of audio stream.
-  int samples_per_second_;
-
-  // Buffered audio data.
-  AudioBufferQueue audio_buffer_;
-
-  // If muted, keep track of partial frames that should have been skipped over.
-  double muted_partial_frame_;
-
-  // How many frames to have in the queue before we report the queue is full.
-  int capacity_;
-
-  // Book keeping of the current time of generated audio, in frames. This
-  // should be appropriately updated when out samples are generated, regardless
-  // of whether we push samples out when FillBuffer() is called or we store
-  // audio in |wsola_output_| for the subsequent calls to FillBuffer().
-  // Furthermore, if samples from |audio_buffer_| are evicted then this
-  // member variable should be updated based on |playback_rate_|.
-  // Note that this member should be updated ONLY by calling UpdateOutputTime(),
-  // so that |search_block_index_| is update accordingly.
-  double output_time_;
-
-  // The offset of the center frame of |search_block_| w.r.t. its first frame.
-  int search_block_center_offset_;
-
-  // Index of the beginning of the |search_block_|, in frames.
-  int search_block_index_;
-
-  // Number of Blocks to search to find the most similar one to the target
-  // frame.
-  int num_candidate_blocks_;
-
-  // Index of the beginning of the target block, counted in frames.
-  int target_block_index_;
-
-  // Overlap-and-add window size in frames.
-  int ola_window_size_;
-
-  // The hop size of overlap-and-add in frames. This implementation assumes 50%
-  // overlap-and-add.
-  int ola_hop_size_;
-
-  // Number of frames in |wsola_output_| that overlap-and-add is completed for
-  // them and can be copied to output if FillBuffer() is called. It also
-  // specifies the index where the next WSOLA window has to overlap-and-add.
-  int num_complete_frames_;
-
-  // This stores a part of the output that is created but couldn't be rendered.
-  // Output is generated frame-by-frame which at some point might exceed the
-  // number of requested samples. Furthermore, due to overlap-and-add,
-  // the last half-window of the output is incomplete, which is stored in this
-  // buffer.
-  scoped_ptr<AudioBus> wsola_output_;
-
-  // Overlap-and-add window.
-  scoped_ptr<float[]> ola_window_;
-
-  // Transition window, used to update |optimal_block_| by a weighted sum of
-  // |optimal_block_| and |target_block_|.
-  scoped_ptr<float[]> transition_window_;
-
-  // Auxiliary variables to avoid allocation in every iteration.
-
-  // Stores the optimal block in every iteration. This is the most
-  // similar block to |target_block_| within |search_block_| and it is
-  // overlap-and-added to |wsola_output_|.
-  scoped_ptr<AudioBus> optimal_block_;
-
-  // A block of data that search is performed over to find the |optimal_block_|.
-  scoped_ptr<AudioBus> search_block_;
-
-  // Stores the target block, denoted as |target| above. |search_block_| is
-  // searched for a block (|optimal_block_|) that is most similar to
-  // |target_block_|.
-  scoped_ptr<AudioBus> target_block_;
-
-  DISALLOW_COPY_AND_ASSIGN(AudioRendererAlgorithm);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_