Implemented OpenCV demo to demonstrate video device listing and set up code structure for video

src/video_device.h

@@ -0,0 +1,66 @@
+/*  video_device.h
+ *
+ *
+ *  Copyright (C) 2014 Toxic All Rights Reserved.
+ *
+ *  This file is part of Toxic.
+ *
+ *  Toxic is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Toxic is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Toxic.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * You can have multiple sources (Input devices) but only one output device.
+ * Pass buffers to output device via write(); 
+ * Read from running input device(s) via select()/callback combo.
+ */
+
+#ifndef VIDEO_DEVICE_H
+#define VIDEO_DEVICE_H
+
+#define MAX_DEVICES 32
+#include <inttypes.h>
+#include "windows.h"
+
+#include "audio_device.h"
+
+typedef enum VideoDeviceError {
+    vde_None,
+    vde_InternalError = -1,
+    vde_InvalidSelection = -2,
+    vde_FailedStart = -3,
+    vde_Busy = -4,
+    vde_AllDevicesBusy = -5,
+    vde_DeviceNotActive = -6,
+    vde_BufferError = -7,
+    vde_UnsupportedMode = -8,
+    vde_OpenCVError = -9,
+} VideoDeviceError;
+
+#ifdef VIDEO
+VideoDeviceError init_video_devices(ToxAv* av);
+#else
+VideoDeviceError init_video_devices();
+#endif /* VIDEO */
+
+VideoDeviceError terminate_video_devices();
+
+VideoDeviceError set_primary_video_device(DeviceType type, int32_t selection);
+VideoDeviceError open_primary_video_device(DeviceType type);
+/* Start device */
+VideoDeviceError open_video_device(DeviceType type, int32_t selection, uint32_t* device_idx);
+/* Stop device */
+VideoDeviceError close_video_device(DeviceType type, uint32_t device_idx);
+
+#endif /* VIDEO_DEVICE_H */