Fawkes API
Fawkes Development Version
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General Video4Linux camera implementation. More...
#include <>>
Public Member Functions | |
V4LCamera (const char *device_name="/dev/video0") | |
Constructor. More... | |
V4LCamera (const CameraArgumentParser *cap) | |
Constructor. More... | |
virtual | ~V4LCamera () |
Destructor. More... | |
virtual void | open () |
Open the camera. More... | |
virtual void | start () |
Start image transfer from the camera. More... | |
virtual void | stop () |
Stop image transfer from the camera. More... | |
virtual void | close () |
Close camera. More... | |
virtual void | flush () |
Flush image queue. More... | |
virtual void | capture () |
Capture an image. More... | |
virtual void | print_info () |
Print out camera information. More... | |
virtual bool | ready () |
Camera is ready for taking pictures. More... | |
virtual unsigned char * | buffer () |
Get access to current image buffer. More... | |
virtual unsigned int | buffer_size () |
Size of buffer. More... | |
virtual void | dispose_buffer () |
Dispose current buffer. More... | |
virtual unsigned int | pixel_width () |
Width of image in pixels. More... | |
virtual unsigned int | pixel_height () |
Height of image in pixels. More... | |
virtual colorspace_t | colorspace () |
Colorspace of returned image. More... | |
virtual void | set_image_number (unsigned int n) |
Set image number to retrieve. More... | |
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virtual | ~Camera () |
Virtual empty destructor. More... | |
virtual fawkes::Time * | capture_time () |
Get the Time of the last successfully captured image. More... | |
General Video4Linux camera implementation.
Maintains backwards compatibility. Chooses on the fly whether v4l1 or v4l2 is needed for a given device.
firevision::V4LCamera::V4LCamera | ( | const char * | device_name = "/dev/video0" | ) |
firevision::V4LCamera::V4LCamera | ( | const CameraArgumentParser * | cap | ) |
Constructor.
Initialize camera with parameters from camera argument parser. Supported arguments:
cap | camera argument parser |
Definition at line 69 of file v4l.cpp.
References firevision::CameraArgumentParser::get(), and firevision::CameraArgumentParser::has().
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Get access to current image buffer.
This will return a pointer to the current buffer. The buffer contains an image of the given colorspace, width and height.
Implements firevision::Camera.
Definition at line 174 of file v4l.cpp.
References firevision::Camera::buffer().
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Size of buffer.
Gets the size in bytes of the buffer returned by buffer().
Implements firevision::Camera.
Definition at line 180 of file v4l.cpp.
References firevision::Camera::buffer_size().
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Capture an image.
Although cameras shall operate with a continuous image flow where possible sometimes capturing an image means copying a buffer or advancing a buffer list pointer. This shall be done in this method. For a camera-using application it is mandatory to call capture() just before accessing the image buffer.
Implements firevision::Camera.
Definition at line 154 of file v4l.cpp.
References firevision::Camera::capture().
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Close camera.
This closes the camera device. The camera must have been stopped before calling close().
Implements firevision::Camera.
Definition at line 140 of file v4l.cpp.
References firevision::Camera::close().
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Colorspace of returned image.
Implements firevision::Camera.
Definition at line 211 of file v4l.cpp.
References firevision::Camera::colorspace().
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Dispose current buffer.
Some cameras need disposal of the current buffer (for example to free space in a queue to retrieve the next image). This is done with this method. It has to be called after all work has been done on the image as desired. After dispose_buffer() has been called no further access may happen to the image buffer or undesired behavior may happen.
Implements firevision::Camera.
Definition at line 186 of file v4l.cpp.
References firevision::Camera::dispose_buffer().
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Flush image queue.
Some cameras may have an image buffer queue. With this it can happen that if the processing of an image took longer than desired it is needed to flush this buffer queue.
Implements firevision::Camera.
Definition at line 147 of file v4l.cpp.
References firevision::Camera::flush().
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Open the camera.
The camera is opened, but image transfer not yet started. This can be used to detect general problems with the camera while delaying the real transfer startup until it is needed.
Implements firevision::Camera.
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Height of image in pixels.
Implements firevision::Camera.
Definition at line 202 of file v4l.cpp.
References firevision::Camera::pixel_height().
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Width of image in pixels.
Implements firevision::Camera.
Definition at line 193 of file v4l.cpp.
References firevision::Camera::pixel_width().
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Print out camera information.
Shall print out camera information and current setup information on stdout.
Implements firevision::Camera.
Definition at line 161 of file v4l.cpp.
References firevision::Camera::print_info().
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Camera is ready for taking pictures.
The camera has been opened and started correctly and may now provide images.
Implements firevision::Camera.
Definition at line 168 of file v4l.cpp.
References firevision::Camera::ready().
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Set image number to retrieve.
If a camera is able to retrieve several images this method can be used to select the image to be retrieved with the next call to capture().
n | image number to set |
Implements firevision::Camera.
Definition at line 217 of file v4l.cpp.
References firevision::Camera::set_image_number().
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Start image transfer from the camera.
For many cameras opening the camera and starting transmission of images are two tasks. This method will simply initiate the transfer after the camera as been opened. And exception shall be thrown if the camera has not been opened.
Implements firevision::Camera.
Definition at line 122 of file v4l.cpp.
References firevision::Camera::start().
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Stop image transfer from the camera.
This will stop the image transfer initiated with start(). This can be used to start and stop the image transfer at will without opening and closing operations inbetween.
Implements firevision::Camera.
Definition at line 131 of file v4l.cpp.
References firevision::Camera::stop().