#pragma once // stl includes #include #include // util includes #include #include /// Capture class for V4L2 devices /// /// @see http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html class V4L2Grabber { public: enum VideoStandard { PAL, NTSC, NO_CHANGE }; public: V4L2Grabber(const std::string & device, int input, VideoStandard videoStandard, int cropHorizontal, int cropVertical, int frameDecimation, int pixelDecimation); virtual ~V4L2Grabber(); 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(); void process_image(const void *p, int size); void process_image(const uint8_t *p); int xioctl(int request, void *arg); void errno_exit(const char *s); 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 _buffers; int _width; int _height; const int _cropWidth; const int _cropHeight; const int _frameDecimation; const int _pixelDecimation; int _currentFrame; };