Adding pulseaudio input support to chrome

media/audio/pulse/pulse_util.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_UTIL_H_
+#define MEDIA_AUDIO_PULSE_PULSE_UTIL_H_
+
+#include <pulse/pulseaudio.h>
+
+#include "base/basictypes.h"
+#include "media/audio/audio_device_name.h"
+#include "media/base/channel_layout.h"
+
+namespace media {
+
+// A helper class that acquires pa_threaded_mainloop_lock() while in scope.
+class AutoPulseLock {
+ public:
+  explicit AutoPulseLock(pa_threaded_mainloop* pa_mainloop)
+      : pa_mainloop_(pa_mainloop) {
+    pa_threaded_mainloop_lock(pa_mainloop_);
+  }
+
+  ~AutoPulseLock() {
+    pa_threaded_mainloop_unlock(pa_mainloop_);
+  }
+
+ private:
+  pa_threaded_mainloop* pa_mainloop_;
+  DISALLOW_COPY_AND_ASSIGN(AutoPulseLock);
+};
+
+// Triggers pa_threaded_mainloop_signal() to avoid deadlocks.
+void StreamSuccessCallback(pa_stream* s, int error, void* mainloop);
+
+// Triggers pa_threaded_mainloop_signal() to avoid deadlocks.
+void ContextStateCallback(pa_context* context, void* user_data);
+
+pa_sample_format_t BitsToPASampleFormat(int bits_per_sample);
+
+pa_channel_map ChannelLayoutToPAChannelMap(ChannelLayout channel_layout);
+
+void WaitForOperationCompletion(pa_threaded_mainloop* pa_mainloop,
+                                pa_operation* operation);
+
+int GetHardwareLatencyInBytes(pa_stream* stream,
+                              int sample_rate,
+                              int bytes_per_frame);
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_PULSE_PULSE_UTIL_H_