00001 // This is core/vidl/vidl_v4l2_istream.h 00002 #ifndef vidl_v4l2_istream_h_ 00003 #define vidl_v4l2_istream_h_ 00004 //: 00005 // \file 00006 // \brief Adapter for class vidl_istream 00007 // 00008 // \author Antonio Garrido 00009 // \verbatim 00010 // Modifications 00011 // 30 Apr 2008 Created (A. Garrido) 00012 //\endverbatim 00013 00014 #include "vidl_istream.h" 00015 #include "vidl_v4l2_device.h" 00016 #include "vidl_v4l2_pixel_format.h" 00017 00018 //: A video input stream using a v4l2 device 00019 class vidl_v4l2_istream: public vidl_istream 00020 { 00021 //vidl_v4l2_device_sptr dev; 00022 vidl_v4l2_device& dev; 00023 mutable vidl_frame_sptr cur_frame_; 00024 unsigned int frame_number_; 00025 00026 void update_frame(); 00027 00028 public: 00029 //: Constructor 00030 vidl_v4l2_istream(vidl_v4l2_device& device); 00031 00032 //: Destructor 00033 virtual ~vidl_v4l2_istream() {dev.stop_capturing();} 00034 00035 //: Return true if the stream is open for reading. 00036 virtual bool is_open() const { return true; } 00037 00038 //: Return true if the stream is in a valid state 00039 virtual bool is_valid() const { return cur_frame_ && dev; } 00040 00041 //: Return true if the stream support seeking 00042 virtual bool is_seekable() const {return false;} 00043 00044 //: Return the current frame number. 00045 virtual unsigned int frame_number() const{return frame_number_;} 00046 00047 //: Return the number of frames if known 00048 // returns -1 for non-seekable streams 00049 virtual int num_frames() const { return -1; } 00050 00051 //: Return the width of each frame 00052 virtual unsigned int width() const { return (unsigned int) dev.get_width(); } 00053 00054 //: Return the height of each frame 00055 virtual unsigned int height() const { return (unsigned int) dev.get_height(); } 00056 00057 //: Return the pixel format 00058 virtual vidl_pixel_format format() const { return v4l2_to_vidl(dev.get_v4l2_format()); } 00059 00060 //: Return the frame rate (0.0 if unspecified) 00061 virtual double frame_rate() const { return dev.get_frame_rate(); } 00062 00063 //: Return the duration in seconds (0.0 if unknown) 00064 virtual double duration() const { return 0.0; } 00065 00066 //: Return the current frame number. does this works? 00067 unsigned int frame_number_device() const { return dev.sequence(); } 00068 00069 //: Close the stream 00070 virtual void close() { dev.stop_capturing(); } // why to close? 00071 00072 //: Advance to the next frame (but don't acquire an image) 00073 virtual bool advance(); 00074 00075 //: Read the next frame from the stream (advance and acquire) 00076 virtual vidl_frame_sptr read_frame(); 00077 00078 //: Return the current frame in the stream 00079 virtual vidl_frame_sptr current_frame() { return cur_frame_; } 00080 00081 //: Seek to the given frame number 00082 // \returns true if successful 00083 virtual bool seek_frame(unsigned int /*frame_number*/) { return false; } 00084 }; 00085 00086 00087 #endif // vidl_v4l2_istream_h_
1.7.5.1