Mac audio input implementation

Required for speech input feature

BUG=none
TEST=Added AudioInputStreamMacTest.* unit tests

Review URL: http://codereview.chromium.org/3181041

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57660 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 75 insertions, 0 deletions

diff --git a/media/audio/mac/audio_input_mac.h b/media/audio/mac/audio_input_mac.h
new file mode 100644
index 0000000..9615d18
--- /dev/null
+++ b/media/audio/mac/audio_input_mac.h
@@ -0,0 +1,75 @@
+// Copyright (c) 2010 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_AUDIO_MAC_AUDIO_INPUT_MAC_H_
+#define MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
+
+#include <AudioToolbox/AudioQueue.h>
+#include <AudioToolbox/AudioFormat.h>
+
+#include "media/audio/audio_io.h"
+
+class AudioManagerMac;
+
+// Implementation of AudioInputStream for Mac OS X using the audio queue service
+// present in OS 10.5 and later. Design reflects PCMQueueOutAudioOutputStream.
+class PCMQueueInAudioInputStream : public AudioInputStream {
+ public:
+  // Parameters as per AudioManager::MakeAudioInputStream.
+  PCMQueueInAudioInputStream(AudioManagerMac* manager,
+                             int channels,
+                             int sampling_rate,
+                             char bits_per_sample,
+                             uint32 samples_per_packet);
+  virtual ~PCMQueueInAudioInputStream();
+
+  // Implementation of AudioInputStream.
+  virtual bool Open();
+  virtual void Start(AudioInputCallback* callback);
+  virtual void Stop();
+  virtual void Close();
+
+ private:
+  // Issue the OnError to |callback_|;
+  void HandleError(OSStatus err);
+
+  // Allocates and prepares the memory that will be used for recording.
+  bool SetupBuffers();
+
+  // Sends a buffer to the audio driver for recording.
+  OSStatus QueueNextBuffer(AudioQueueBufferRef audio_buffer);
+
+  // Callback from OS, delegates to non-static version below.
+  static void HandleInputBufferStatic(
+      void* data,
+      AudioQueueRef audio_queue,
+      AudioQueueBufferRef audio_buffer,
+      const AudioTimeStamp* start_time,
+      UInt32 num_packets,
+      const AudioStreamPacketDescription* desc);
+
+  // Handles callback from OS. Will be called on OS internal thread.
+  void HandleInputBuffer(AudioQueueRef audio_queue,
+                         AudioQueueBufferRef audio_buffer,
+                         const AudioTimeStamp* start_time,
+                         UInt32 num_packets,
+                         const AudioStreamPacketDescription* packet_desc);
+
+  static const int kNumberBuffers = 3;
+
+  // Manager that owns this stream, used for closing down.
+  AudioManagerMac* manager_;
+  // We use the callback mostly to periodically supply the recorded audio data.
+  AudioInputCallback* callback_;
+  // Structure that holds the stream format details such as bitrate.
+  AudioStreamBasicDescription format_;
+  // Handle to the OS audio queue object.
+  AudioQueueRef audio_queue_;
+  // Size of each of the buffers in |audio_buffers_|
+  uint32 buffer_size_bytes_;
+
+  DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
+};
+
+#endif  // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_