Create a copy of talk/sound under webrtc/sound.

BUG=3379
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/22379004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@6986 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/sound/alsasoundsystem.h b/sound/alsasoundsystem.h
new file mode 100644
index 0000000..f95e686
--- /dev/null
+++ b/sound/alsasoundsystem.h
@@ -0,0 +1,103 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SOUND_ALSASOUNDSYSTEM_H_
+#define WEBRTC_SOUND_ALSASOUNDSYSTEM_H_
+
+#include "webrtc/sound/alsasymboltable.h"
+#include "webrtc/sound/soundsysteminterface.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace rtc {
+
+class AlsaStream;
+class AlsaInputStream;
+class AlsaOutputStream;
+
+// Sound system implementation for ALSA, the predominant sound device API on
+// Linux (but typically not used directly by applications anymore).
+class AlsaSoundSystem : public SoundSystemInterface {
+  friend class AlsaStream;
+  friend class AlsaInputStream;
+  friend class AlsaOutputStream;
+ public:
+  static SoundSystemInterface *Create() {
+    return new AlsaSoundSystem();
+  }
+
+  AlsaSoundSystem();
+
+  virtual ~AlsaSoundSystem();
+
+  virtual bool Init();
+  virtual void Terminate();
+
+  virtual bool EnumeratePlaybackDevices(SoundDeviceLocatorList *devices);
+  virtual bool EnumerateCaptureDevices(SoundDeviceLocatorList *devices);
+
+  virtual bool GetDefaultPlaybackDevice(SoundDeviceLocator **device);
+  virtual bool GetDefaultCaptureDevice(SoundDeviceLocator **device);
+
+  virtual SoundOutputStreamInterface *OpenPlaybackDevice(
+      const SoundDeviceLocator *device,
+      const OpenParams &params);
+  virtual SoundInputStreamInterface *OpenCaptureDevice(
+      const SoundDeviceLocator *device,
+      const OpenParams &params);
+
+  virtual const char *GetName() const;
+
+ private:
+  bool IsInitialized() { return initialized_; }
+
+  bool EnumerateDevices(SoundDeviceLocatorList *devices,
+                        bool capture_not_playback);
+
+  bool GetDefaultDevice(SoundDeviceLocator **device);
+
+  static size_t FrameSize(const OpenParams &params);
+
+  template <typename StreamInterface>
+  StreamInterface *OpenDevice(
+      const SoundDeviceLocator *device,
+      const OpenParams &params,
+      snd_pcm_stream_t type,
+      StreamInterface *(AlsaSoundSystem::*start_fn)(
+          snd_pcm_t *handle,
+          size_t frame_size,
+          int wait_timeout_ms,
+          int flags,
+          int freq));
+
+  SoundOutputStreamInterface *StartOutputStream(
+      snd_pcm_t *handle,
+      size_t frame_size,
+      int wait_timeout_ms,
+      int flags,
+      int freq);
+
+  SoundInputStreamInterface *StartInputStream(
+      snd_pcm_t *handle,
+      size_t frame_size,
+      int wait_timeout_ms,
+      int flags,
+      int freq);
+
+  const char *GetError(int err);
+
+  bool initialized_;
+  AlsaSymbolTable symbol_table_;
+
+  DISALLOW_COPY_AND_ASSIGN(AlsaSoundSystem);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_SOUND_ALSASOUNDSYSTEM_H_