Adding pulseaudio input support to chrome

media/audio/pulse/pulse_input.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_AUDIO_PULSE_PULSE_INPUT_H_
+#define MEDIA_AUDIO_PULSE_PULSE_INPUT_H_
+
+#include <pulse/pulseaudio.h>
+
+#include <string>
+
+#include "media/audio/audio_device_name.h"
+#include "media/audio/audio_input_stream_impl.h"
+#include "media/audio/audio_io.h"
+#include "media/audio/audio_parameters.h"
+
+namespace media {
+
+class AudioManagerLinux;
+class SeekableBuffer;
+
+class PulseAudioInputStream : public AudioInputStreamImpl {
+ public:
+  PulseAudioInputStream(AudioManagerLinux* audio_manager,
+                        const std::string& device_name,
+                        const AudioParameters& params,
+                        pa_threaded_mainloop* mainloop,
+                        pa_context* context);
+
+  virtual ~PulseAudioInputStream();
+
+  // Implementation of AudioInputStream.
+  virtual bool Open() OVERRIDE;
+  virtual void Start(AudioInputCallback* callback) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual double GetMaxVolume() OVERRIDE;
+  virtual void SetVolume(double volume) OVERRIDE;
+  virtual double GetVolume() OVERRIDE;
+
+ private:
+  // PulseAudio Callbacks.
+  static void ContextStateCallback(pa_context* context, void* user_data);
+  static void ReadCallback(pa_stream* handle, size_t length, void* user_data);
+  static void StreamNotifyCallback(pa_stream* stream, void* user_data);
+  static void VolumeCallback(pa_context* context, const pa_source_info* info,
+                             int error, void* user_data);
+
+  // Helper function to get latency in bytes.
+  int GetHardwareLatencyInBytes();
+
+  // Helper for the ReadCallback.
+  void ReadData();
+
+  // Flag indicating the state of the context has been changed.
+  bool context_state_changed_;
+
+  AudioManagerLinux* audio_manager_;
+  AudioInputCallback* callback_;
+  std::string device_name_;
+  AudioParameters params_;
+  int channels_;
+  double volume_;
+
+  // Flag indicating the code should stop reading from the data source or
+  // writing to the PulseAudio server.  This is set because the device has
+  // entered an unrecoverable error state, or the Stio() has executed.
+  bool stream_started_;
+
+  // Holds the data from the OS.
+  scoped_ptr<media::SeekableBuffer> buffer_;
+
+  // Temporary storage for recorded data. It gets a packet of data from
+  // |buffer_| and deliver the data to OnData() callback.
+  scoped_array<uint8> audio_data_buffer_;
+
+  // PulseAudio API structs.
+  pa_threaded_mainloop* pa_mainloop_; // Weak.
+  pa_context* pa_context_;  // Weak.
+  pa_stream* handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(PulseAudioInputStream);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_