hyperion.ng/include/grabber/V4L2Grabber.h

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#pragma once
// stl includes
#include <string>
#include <vector>
// Qt includes
#include <QObject>
#include <QSocketNotifier>
// util includes
#include <utils/Image.h>
#include <utils/ColorRgb.h>
#include <utils/PixelFormat.h>
#include <utils/VideoMode.h>
#include <utils/ImageResampler.h>
// grabber includes
#include <grabber/VideoStandard.h>
/// Capture class for V4L2 devices
///
/// @see http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html
class V4L2Grabber : public QObject
{
Q_OBJECT
public:
V4L2Grabber(const std::string & device,
int input,
VideoStandard videoStandard, PixelFormat pixelFormat,
int width,
int height,
int frameDecimation,
int horizontalPixelDecimation,
int verticalPixelDecimation);
virtual ~V4L2Grabber();
public slots:
void setCropping(int cropLeft,
int cropRight,
int cropTop,
int cropBottom);
void set3D(VideoMode mode);
void setSignalThreshold(double redSignalThreshold,
double greenSignalThreshold,
double blueSignalThreshold,
int noSignalCounterThreshold);
void start();
void stop();
signals:
void newFrame(const Image<ColorRgb> & image);
private slots:
int read_frame();
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();
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;
PixelFormat _pixelFormat;
int _width;
int _height;
int _lineLength;
int _frameByteSize;
int _frameDecimation;
int _noSignalCounterThreshold;
ColorRgb _noSignalThresholdColor;
int _currentFrame;
int _noSignalCounter;
QSocketNotifier * _streamNotifier;
ImageResampler _imageResampler;
};