#include <cam_gst.h>

Public Member Functions
	CamGst (std::string const &device)

	~CamGst ()

void	createDefaultPipeline (bool check_for_valid_params=false, uint32_t width=DEFAULT_WIDTH, uint32_t height=DEFAULT_HEIGHT, uint32_t fps=DEFAULT_FPS, uint32_t bpp=DEFAULT_BPP, base::samples::frame::frame_mode_t mode=base::samples::frame::MODE_UNDEFINED, uint32_t jpeg_quality=DEFAULT_JPEG_QUALITY)

void	deletePipeline ()

bool	startPipeline ()

void	stopPipeline ()

bool	getBuffer (std::vector< uint8_t > &buffer, bool blocking_read=false, int32_t timeout=0)

bool	skipBuffer ()

bool	storeImageToFile (std::vector< uint8_t > const &buffer, std::string const &file_name)

bool	hasNewBuffer ()

bool	isPipelineRunning ()

int	getFileDescriptor ()

Static Public Attributes
static const uint32_t	DEFAULT_WIDTH = 640

static const uint32_t	DEFAULT_HEIGHT = 480

static const uint32_t	DEFAULT_FPS = 10

static const uint32_t	DEFAULT_BPP = 24

static const uint32_t	DEFAULT_JPEG_QUALITY = 85

static const uint32_t	DEFAULT_PIPELINE_TIMEOUT = 4000000

Detailed Description

Allows to create a default GStreamer pipeline, which requests images using v4l2src, converts them to jpegs and gives access to the image data. Successfully tested with the Microsoft LifeCam Cinema Web camera and the Gumstix e-CAM32 camera.

Constructor & Destructor Documentation

camera::CamGst::CamGst ( std::string const & device )

Initialize GStreamer and starts the GMainLoop in its own thread.

Parameters

device	Only used to configure the GStreamer source (e.g. /dev/video0).
cam_config	Pointer to a CamConfig object, used to get a valid image size and fps and for general configurations.

camera::CamGst::~CamGst ( )

Stops the GMainLoop and its thread.

Member Function Documentation

void camera::CamGst::createDefaultPipeline	(	bool	check_for_valid_params = `false`,
		uint32_t	width = `DEFAULT_WIDTH`,
		uint32_t	height = `DEFAULT_HEIGHT`,
		uint32_t	fps = `DEFAULT_FPS`,
		uint32_t	bpp = `DEFAULT_BPP`,
		base::samples::frame::frame_mode_t	mode = `base::samples::frame::MODE_UNDEFINED`,
		uint32_t	jpeg_quality = `DEFAULT_JPEG_QUALITY`
	)

Creates a simple pipeline to write images with the requested format to a buffer.

Parameters

check_for_valid_params If set to true the parameters (width, height, fps) are validated. If they are not valid on the camera valid parameters are used. In addition if you pass 0 for a parameter, the last valid parameter on the camera will be used. E.g. 'createDefaultPipeline(true,0,0,0,80)' would just change the JPEG quality. But for this functionality a CamConfig object has to be created, which uses the same device like GStreamer what should be avoided. In addition using this method within the CamUsb driver is not necessary because all parameters have been validated and set already.
If set to false the pipeline may not be created if the parameters are not supported by the camera (a CamGstException may be thrown).

mode Valid modes: MODE_GRAYSCALE, MODE_RGB, MODE_UYVY, MODE_JPEG. If MODE_UNDEFINED is passed the raw image video/x-raw-yuv will be requested.

Returns: If an error occurs a CamGstException is thrown.

void camera::CamGst::deletePipeline ( )

Deletes pipeline, clears buffer.

bool camera::CamGst::getBuffer	(	std::vector< uint8_t > &	buffer,
		bool	blocking_read = `false`,
		int32_t	timeout = `0`
	)

Allows to request a copy of the new image.

Parameters

buffer	Will receive the image if available.
blocking_read	If true, method will return as soon as a new image is available.
timeout	Max. time to wait for the frame in msec. < 1 means no timeout.

Returns: blocking-read not active: true if a new image is available, otherwise false.
blocking_read active: Returns true as soon as a new image is available or false after 'timeout' msec.

int camera::CamGst::getFileDescriptor ( )

inline

Returns the file descriptor used by GStreamer. The pipeline has to be running, otherwise -1 will be returned.

Returns: The fd or -1 if not available.

bool camera::CamGst::hasNewBuffer ( )

inline

True if a new buffer is available.

bool camera::CamGst::isPipelineRunning ( )

inline

bool camera::CamGst::skipBuffer ( )

Just sets mNewBuffer to false.

Returns: True if a new buffer was available.

bool camera::CamGst::startPipeline ( )

Starts current pipeline in another a intern GStreamer thread. Pipeline has to be already created. Restarting may not work, in this case an error message will be printed and false will be returned.

Warning: Just stopping and starting a pipeline may not work. You should delete and recreate the pipeline instead!

Returns: True if its already running or could be started.

void camera::CamGst::stopPipeline ( )

Warning: Just stopping and starting a pipeline may not work. You should delete and recreate the pipeline instead!

bool camera::CamGst::storeImageToFile	(	std::vector< uint8_t > const &	buffer,
		std::string const &	file_name
	)

Stores the image to a file.

Returns: false if the file could not be opened or not all of the bytes could be written.

Member Data Documentation

const uint32_t camera::CamGst::DEFAULT_BPP = 24

static

const uint32_t camera::CamGst::DEFAULT_FPS = 10

static

const uint32_t camera::CamGst::DEFAULT_HEIGHT = 480

static

const uint32_t camera::CamGst::DEFAULT_JPEG_QUALITY = 85

static

const uint32_t camera::CamGst::DEFAULT_PIPELINE_TIMEOUT = 4000000

static

const uint32_t camera::CamGst::DEFAULT_WIDTH = 640

static

The documentation for this class was generated from the following files:

/build/rock-master-18.09-drivers-camera-usb-0.20180212/src/cam_gst.h
/build/rock-master-18.09-drivers-camera-usb-0.20180212/src/cam_gst.cpp

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation