Home | History | Annotate | Download | only in mac 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
      6 #define MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
      7 
      8 #include <AudioToolbox/AudioFormat.h>
      9 #include <AudioToolbox/AudioQueue.h>
     10 
     11 #include "base/cancelable_callback.h"
     12 #include "base/compiler_specific.h"
     13 #include "base/time/time.h"
     14 #include "media/audio/audio_io.h"
     15 #include "media/audio/audio_parameters.h"
     16 
     17 namespace media {
     18 
     19 class AudioBus;
     20 class AudioManagerMac;
     21 
     22 // Implementation of AudioInputStream for Mac OS X using the audio queue service
     23 // present in OS 10.5 and later. Design reflects PCMQueueOutAudioOutputStream.
     24 class PCMQueueInAudioInputStream : public AudioInputStream {
     25  public:
     26   // Parameters as per AudioManager::MakeAudioInputStream.
     27   PCMQueueInAudioInputStream(AudioManagerMac* manager,
     28                              const AudioParameters& params);
     29   virtual ~PCMQueueInAudioInputStream();
     30 
     31   // Implementation of AudioInputStream.
     32   virtual bool Open() OVERRIDE;
     33   virtual void Start(AudioInputCallback* callback) OVERRIDE;
     34   virtual void Stop() OVERRIDE;
     35   virtual void Close() OVERRIDE;
     36   virtual double GetMaxVolume() OVERRIDE;
     37   virtual void SetVolume(double volume) OVERRIDE;
     38   virtual double GetVolume() OVERRIDE;
     39   virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
     40   virtual bool GetAutomaticGainControl() OVERRIDE;
     41 
     42  private:
     43   // Issue the OnError to |callback_|;
     44   void HandleError(OSStatus err);
     45 
     46   // Allocates and prepares the memory that will be used for recording.
     47   bool SetupBuffers();
     48 
     49   // Sends a buffer to the audio driver for recording.
     50   OSStatus QueueNextBuffer(AudioQueueBufferRef audio_buffer);
     51 
     52   // Callback from OS, delegates to non-static version below.
     53   static void HandleInputBufferStatic(
     54       void* data,
     55       AudioQueueRef audio_queue,
     56       AudioQueueBufferRef audio_buffer,
     57       const AudioTimeStamp* start_time,
     58       UInt32 num_packets,
     59       const AudioStreamPacketDescription* desc);
     60 
     61   // Handles callback from OS. Will be called on OS internal thread.
     62   void HandleInputBuffer(AudioQueueRef audio_queue,
     63                          AudioQueueBufferRef audio_buffer,
     64                          const AudioTimeStamp* start_time,
     65                          UInt32 num_packets,
     66                          const AudioStreamPacketDescription* packet_desc);
     67 
     68   static const int kNumberBuffers = 3;
     69 
     70   // Manager that owns this stream, used for closing down.
     71   AudioManagerMac* manager_;
     72   // We use the callback mostly to periodically supply the recorded audio data.
     73   AudioInputCallback* callback_;
     74   // Structure that holds the stream format details such as bitrate.
     75   AudioStreamBasicDescription format_;
     76   // Handle to the OS audio queue object.
     77   AudioQueueRef audio_queue_;
     78   // Size of each of the buffers in |audio_buffers_|
     79   uint32 buffer_size_bytes_;
     80   // True iff Start() has been called successfully.
     81   bool started_;
     82   // Used to determine if we need to slow down |callback_| calls.
     83   base::TimeTicks last_fill_;
     84   // Used to defer Start() to workaround http://crbug.com/160920.
     85   base::CancelableClosure deferred_start_cb_;
     86 
     87   scoped_ptr<media::AudioBus> audio_bus_;
     88 
     89   DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
     90 };
     91 
     92 }  // namespace media
     93 
     94 #endif  // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
     95