Move V4L2 grabber code to separate library

Former-commit-id: f3003eb0142af3d085ccf93fff1b297ebc2321fc

include/grabber/V4L2Grabber.h

@@ -0,0 +1,120 @@
+#pragma once
+
+// stl includes
+#include <string>
+#include <vector>
+
+// util includes
+#include <utils/Image.h>
+#include <utils/ColorRgb.h>
+
+/// Capture class for V4L2 devices
+///
+/// @see http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html
+class V4L2Grabber
+{
+public:
+	typedef void (*ImageCallback)(void * arg, const Image<ColorRgb> & image);
+
+	enum VideoStandard {
+		PAL, NTSC, NO_CHANGE
+	};
+
+	enum Mode3D {
+		MODE_NONE, MODE_3DSBS, MODE_3DTAB
+	};
+
+public:
+	V4L2Grabber(
+			const std::string & device,
+			int input,
+			VideoStandard videoStandard,
+			int width,
+			int height,
+			int frameDecimation,
+			int horizontalPixelDecimation,
+			int verticalPixelDecimation);
+	virtual ~V4L2Grabber();
+
+	void setCropping(int cropLeft,
+					 int cropRight,
+					 int cropTop,
+					 int cropBottom);
+
+	void set3D(Mode3D mode);
+
+	void setCallback(ImageCallback callback, void * arg);
+
+	void start();
+
+	void capture(int frameCount = -1);
+
+	void stop();
+
+private:
+	void open_device();
+
+	void close_device();
+
+	void init_read(unsigned int buffer_size);
+
+	void init_mmap();
+
+	void init_userp(unsigned int buffer_size);
+
+	void init_device(VideoStandard videoStandard, int input);
+
+	void uninit_device();
+
+	void start_capturing();
+
+	void stop_capturing();
+
+	int read_frame();
+
+	bool process_image(const void *p, int size);
+
+	void process_image(const uint8_t *p);
+
+	int xioctl(int request, void *arg);
+
+	void throw_exception(const std::string &error);
+
+	void throw_errno_exception(const std::string &error);
+
+private:
+	enum io_method {
+			IO_METHOD_READ,
+			IO_METHOD_MMAP,
+			IO_METHOD_USERPTR
+	};
+
+	struct buffer {
+			void   *start;
+			size_t  length;
+	};
+
+private:
+	const std::string _deviceName;
+	const io_method _ioMethod;
+	int _fileDescriptor;
+	std::vector<buffer> _buffers;
+
+	uint32_t _pixelFormat;
+	int _width;
+	int _height;
+	int _cropLeft;
+	int _cropRight;
+	int _cropTop;
+	int _cropBottom;
+	int _frameDecimation;
+	int _horizontalPixelDecimation;
+	int _verticalPixelDecimation;
+
+	Mode3D _mode3D;
+
+	int _currentFrame;
+
+	ImageCallback _callback;
+	void * _callbackArg;
+};