changed the input low latency input impl to use client's requested buffer size on Mac

media/audio/mac/audio_low_latency_input_mac.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.
 //
 // Implementation of AudioInputStream for Mac OS X using the special AUHAL
 // input Audio Unit present in OS 10.4 and later.
 // The AUHAL input Audio Unit is for low-latency audio I/O.
 //
 // Overview of operation:
 //
@@ skipping 27 matching lines @@
 
 #include <AudioUnit/AudioUnit.h>
 #include <CoreAudio/CoreAudio.h>
 
 #include "base/cancelable_callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/agc_audio_stream.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
-#include "media/base/seekable_buffer.h"
 
 namespace media {
 
 class AudioBus;
+class AudioFifo;
 class AudioManagerMac;
 class DataBuffer;
 
 class AUAudioInputStream : public AgcAudioStream<AudioInputStream> {
  public:
   // The ctor takes all the usual parameters, plus |manager| which is the
   // the audio manager who is creating this object.
   AUAudioInputStream(AudioManagerMac* manager,
                      const AudioParameters& input_params,
-                     const AudioParameters& output_params,
                      AudioDeviceID audio_device_id);
   // The dtor is typically called by the AudioManager only and it is usually
   // triggered by calling AudioInputStream::Close().
   virtual ~AUAudioInputStream();
 
   // Implementation of AudioInputStream.
   virtual bool Open() OVERRIDE;
   virtual void Start(AudioInputCallback* callback) OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual void Close() OVERRIDE;
@@ skipping 35 matching lines @@
   void HandleError(OSStatus err);
 
   // Helper function to check if the volume control is avialable on specific
   // channel.
   bool IsVolumeSettableOnChannel(int channel);
 
   // Our creator, the audio manager needs to be notified when we close.
   AudioManagerMac* manager_;
 
   // Contains the desired number of audio frames in each callback.
-  size_t number_of_frames_;
+  const size_t number_of_frames_;
 
   // Pointer to the object that will receive the recorded audio samples.
   AudioInputCallback* sink_;
 
   // Structure that holds the desired output format of the stream.
   // Note that, this format can differ from the device(=input) format.
   AudioStreamBasicDescription format_;
 
   // The special Audio Unit called AUHAL, which allows us to pass audio data
   // directly from a microphone, through the HAL, and to our application.
   // The AUHAL also enables selection of non default devices.
   AudioUnit audio_unit_;
 
   // The UID refers to the current input audio device.
   AudioDeviceID input_device_id_;
 
   // Provides a mechanism for encapsulating one or more buffers of audio data.
   AudioBufferList audio_buffer_list_;
 
   // Temporary storage for recorded data. The InputProc() renders into this
   // array as soon as a frame of the desired buffer size has been recorded.
   scoped_ptr<uint8[]> audio_data_buffer_;
 
   // True after successfull Start(), false after successful Stop().
   bool started_;
 
   // Fixed capture hardware latency in frames.
   double hardware_latency_frames_;
 
-  // Delay due to the FIFO in bytes.
-  int fifo_delay_bytes_;
-
   // The number of channels in each frame of audio data, which is used
   // when querying the volume of each channel.
   int number_of_channels_in_frame_;
 
-  // Accumulates recorded data packets until the requested size has been stored.
-  scoped_ptr<media::SeekableBuffer> fifo_;
-
-   // Intermediate storage of data from the FIFO before sending it to the
-   // client using the OnData() callback.
-  scoped_refptr<media::DataBuffer> data_;
-
-  // The client requests that the recorded data shall be delivered using
-  // OnData() callbacks where each callback contains this amount of bytes.
-  int requested_size_bytes_;
+  // Dynamically allocated FIFO used to accumulates recorded data when
+  // CoreAudio delivers non-requested frame size of data.
+  scoped_ptr<media::AudioFifo> fifo_;
 
   // Used to defer Start() to workaround http://crbug.com/160920.
   base::CancelableClosure deferred_start_cb_;
 
-  // Extra audio bus used for storage of deinterleaved data for the OnData
-  // callback.
+  // Audio bus used for storage of deinterleaved data for the OnData callback.
   scoped_ptr<media::AudioBus> audio_bus_;
 
+  // Audio bus used to convert interleaved data to deinterleaved data before
+  // storing data to FIFO or delivering data via OnData callback.
+  scoped_ptr<media::AudioBus> audio_wrapper_;
+
   DISALLOW_COPY_AND_ASSIGN(AUAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_