Convert WebAudio file handlers to use AudioBus.

media/base/audio_bus.h

 // 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.
 
 #ifndef MEDIA_BASE_AUDIO_BUS_H_
 #define MEDIA_BASE_AUDIO_BUS_H_
 
 #include <vector>
 
 #include "base/memory/aligned_memory.h"
@@ skipping 31 matching lines @@
   static scoped_ptr<AudioBus> WrapMemory(int channels, int frames, void* data);
   static scoped_ptr<AudioBus> WrapMemory(const AudioParameters& params,
                                          void* data);
   // Returns the required memory size to use the WrapMemory() method.
   static int CalculateMemorySize(const AudioParameters& params);
 
   // Helper methods for converting an AudioBus from and to interleaved integer
   // data.  Expects interleaving to be [ch0, ch1, ..., chN, ch0, ch1, ...] with
   // |bytes_per_sample| per value.  Values are scaled and bias corrected during
   // conversion.  ToInterleaved() will also clip values to format range.
-  // Handles uint8, int16, and int32 currently.
+  // Handles uint8, int16, and int32 currently.  FromInterleaved() will zero out
+  // any unfilled frames when |frames| is less than frames().
   void FromInterleaved(const void* source, int frames, int bytes_per_sample);
   void ToInterleaved(int frames, int bytes_per_sample, void* dest) const;
 
+  // Similar to FromInterleaved() above, but meant for streaming sources.  Does
+  // not zero out remaining frames, the caller is responsible for doing so using
+  // ZeroFramesPartial().  Frames are deinterleaved from the start of |source|
+  // to channel(x)[start_frame].
+  void FromInterleavedPartial(const void* source, int start_frame, int frames,
+                              int bytes_per_sample);
+
   // Helper method for copying channel data from one AudioBus to another.  Both
   // AudioBus object must have the same frames() and channels().
   void CopyTo(AudioBus* dest) const;
 
   // Returns a raw pointer to the requested channel.  Pointer is guaranteed to
   // have a 16-byte alignment.
   float* channel(int channel) { return channel_data_[channel]; }
   const float* channel(int channel) const { return channel_data_[channel]; }
 
   int channels() const { return channel_data_.size(); }
   int frames() const { return frames_; }
 
   // Helper method for zeroing out all channels of audio data.
   void Zero();
   void ZeroFrames(int frames);
+  void ZeroFramesPartial(int start_frame, int frames);
 
  private:
   friend class scoped_ptr<AudioBus>;
   ~AudioBus();
 
   AudioBus(int channels, int frames);
   AudioBus(int channels, int frames, float* data);
   AudioBus(int frames, const std::vector<float*>& channel_data);
 
   // Helper method for building |channel_data_| from a block of memory.  |data|
   // must be at least BlockSize() bytes in size.
   void BuildChannelData(int channels, int aligned_frame, float* data);
 
   // Contiguous block of channel memory.
   scoped_ptr_malloc<float, base::ScopedPtrAlignedFree> data_;
 
   std::vector<float*> channel_data_;
   int frames_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioBus);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_BUS_H_