media/audio/mac/audio_input_mac.h

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