hyperion.ng/include/grabber/V4L2Grabber.h

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#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;
};