Camera capture and streaming for MIPI CSI and V4L2 devices (deprecated). More...

Classes
class	gstCamera
	MIPI CSI and V4L2 camera capture using GStreamer and `nvarguscamerasrc` or `v4l2src` elements. More...

class	v4l2Camera
	Video4Linux2 (V4L2) camera capture streaming. More...

Detailed Description

Camera capture and streaming for MIPI CSI and V4L2 devices (deprecated).

Deprecated:: See the updated Video Streaming APIs.

Class Documentation

◆ gstCamera

class gstCamera

MIPI CSI and V4L2 camera capture using GStreamer and nvarguscamerasrc or v4l2src elements.

gstCamera supports both MIPI CSI cameras and V4L2-compliant devices like USB webcams.

Examples of MIPI CSI cameras that work out of the box are the OV5693 module from the Jetson TX1/TX2 devkits, and the IMX219 sensor from the Raspberry Pi Camera Module v2.

For MIPI CSI cameras, the GStreamer element nvarguscamerasrc will be used for capture. For V4L2 devices, the GStreamer element v4l2src will be used for camera capture.

gstCamera uses CUDA underneath for any necessary colorspace conversion, and provides the captured image frames in CUDA device memory, or zero-copy shared CPU/GPU memory.

Note: gstCamera now implements the videoSource interface and is intended to be used through that as opposed to directly. videoSource implements additional command-line parsing of videoOptions to construct instances. Some legacy APIs of gstCamera are now marked deprecated.

See also: videoSource

Inheritance diagram for gstCamera:

Public Member Functions
	~gstCamera ()
	Release the camera interface and resources. More...

virtual bool	Open ()
	Begin streaming the camera. More...

virtual void	Close ()
	Stop streaming the camera. More...

virtual bool	Capture (void *image, imageFormat format, uint64_t timeout=DEFAULT_TIMEOUT, int status=NULL)
	Capture the next image frame from the camera. More...

bool	CaptureRGBA (float **image, uint64_t timeout=DEFAULT_TIMEOUT, bool zeroCopy=false)
	Capture the next image frame from the camera and convert it to float4 RGBA format, with pixel intensities ranging between 0.0 and 255.0. More...

void	SetZeroCopy (bool zeroCopy)
	Set whether converted RGB(A) images should use ZeroCopy buffer allocation. More...

virtual uint32_t	GetType () const
	Return the interface type (gstCamera::Type) More...

Public Member Functions inherited from videoSource
virtual	~videoSource ()
	Destroy interface and release all resources. More...

template<typename T >
bool	Capture (T *image, int status)
	Capture the next image from the video stream, using the default timeout of 1000ms. More...

template<typename T >
bool	Capture (T *image, uint64_t timeout=DEFAULT_TIMEOUT, int status=NULL)
	Capture the next image from the video stream. More...

bool	IsStreaming () const
	Check if the device is actively streaming or not. More...

uint32_t	GetWidth () const
	Return the width of the stream, in pixels. More...

uint32_t	GetHeight () const
	Return the height of the stream, in pixels. More...

uint32_t	GetFrameRate () const
	Return the framerate, in Hz or FPS. More...

uint64_t	GetFrameCount () const
	Return the number of frames captured. More...

uint64_t	GetLastTimestamp () const
	Get timestamp of the last captured frame, in nanoseconds. More...

imageFormat	GetRawFormat () const
	Get raw image format. More...

const URI &	GetResource () const
	Return the resource URI of the stream. More...

const videoOptions &	GetOptions () const
	Return the videoOptions of the stream. More...

bool	IsType (uint32_t type) const
	Check if this stream is of a particular type. More...

template<typename T >
bool	IsType () const
	Check if a this stream is of a particular type. More...

const char *	TypeToStr () const
	Convert this stream's class type to string. More...

Static Public Member Functions
static gstCamera *	Create (const videoOptions &options)
	Create a MIPI CSI or V4L2 camera device. More...

static gstCamera *	Create (const char *camera=NULL)
	Create a MIPI CSI or V4L2 camera device. More...

static gstCamera *	Create (uint32_t width, uint32_t height, const char *camera=NULL)
	Create a MIPI CSI or V4L2 camera device. More...

Static Public Member Functions inherited from videoSource
static videoSource *	Create (const videoOptions &options)
	Create videoSource interface from a videoOptions struct that's already been filled out. More...

static videoSource *	Create (const char *URI, const videoOptions &options=videoOptions())
	Create videoSource interface from a resource URI string and optional videoOptions. More...

static videoSource *	Create (const char *URI, const commandLine &cmdLine)
	Create videoSource interface from a resource URI string and parsing command line arguments. More...

static videoSource *	Create (const char URI, const int argc, char *argv)
	Create videoSource interface from a resource URI string and parsing command line arguments. More...

static videoSource *	Create (const int argc, char **argv, int positionArg=-1)
	Create videoSource interface by parsing command line arguments, including the resource URI. More...

static videoSource *	Create (const commandLine &cmdLine, int positionArg=-1)
	Create videoSource interface by parsing command line arguments, including the resource URI. More...

static const char *	Usage ()
	Usage string for command line arguments to Create() More...

static const char *	TypeToStr (uint32_t type)
	Convert a class type to a string. More...

Static Public Attributes
static const uint32_t	Type = (1 << 0)
	Unique type identifier of gstCamera class. More...

static const uint32_t	DefaultWidth = 1280
	Default camera width, unless otherwise specified during Create() More...

static const uint32_t	DefaultHeight = 720
	Default camera height, unless otherwise specified during Create() More...

Static Public Attributes inherited from videoSource
static const uint64_t	DEFAULT_TIMEOUT =1000
	The default Capture timeout (1000ms) More...

Additional Inherited Members
Public Types inherited from videoSource
enum	Status { ERROR = -2, EOS = -1, TIMEOUT = 0, OK = 1 }
	Stream status codes that are optionally returned from Capture() More...

Protected Member Functions inherited from videoSource
	videoSource (const videoOptions &options)

Protected Attributes inherited from videoSource
bool	mStreaming

videoOptions	mOptions

uint64_t	mLastTimestamp

imageFormat	mRawFormat

Constructor & Destructor Documentation

◆ ~gstCamera()

gstCamera::~gstCamera ( )

Release the camera interface and resources.

Destroying the camera will also Close() the stream if it is still open.

Member Function Documentation

◆ Capture()

virtual bool gstCamera::Capture	(	void **	image,
		imageFormat	format,
		uint64_t	timeout = `DEFAULT_TIMEOUT`,
		int *	status = `NULL`
	)

virtual

Capture the next image frame from the camera.

See also: videoSource::Capture

Implements videoSource.

◆ CaptureRGBA()

bool gstCamera::CaptureRGBA	(	float **	image,
		uint64_t	timeout = `DEFAULT_TIMEOUT`,
		bool	zeroCopy = `false`
	)

Capture the next image frame from the camera and convert it to float4 RGBA format, with pixel intensities ranging between 0.0 and 255.0.

Deprecated:: CaptureRGBA() has been deprecated and is only provided for legacy compatibility. Please use the updated Capture() function instead.

Internally, CaptureRGBA() first calls Capture() and then ConvertRGBA(). The ConvertRGBA() function uses CUDA, so if you want to capture from a different thread than your CUDA device, use the Capture() and ConvertRGBA() functions.

Parameters

[out]	image	Pointer that gets returned to the image in GPU address space, or if the zeroCopy parameter is true, then the pointer is valid in both CPU and GPU address spaces. Do not manually free the image memory, it is managed internally. The image is in float4 RGBA format. The size of the image is: `GetWidth() * GetHeight() * sizeof(float) * 4`
[in]	timeout	The time in milliseconds for the calling thread to wait to return if a new camera frame isn't recieved by that time. If timeout is 0, the calling thread will return immediately if a new frame isn't already available. If timeout is UINT64_MAX, the calling thread will wait indefinetly for a new frame to arrive.
[in]	zeroCopy	If `true`, the image will reside in shared CPU/GPU memory. If `false`, the image will only be accessible from the GPU. You would need to set zeroCopy to `true` if you wanted to access the image pixels from the CPU. Since this isn't generally the case, the default is `false` (GPU only).

Returns: true if a frame was successfully captured, otherwise false if a timeout or error occurred, or if timeout was 0 and a frame wasn't ready.

◆ Close()

virtual void gstCamera::Close ( )

virtual

Stop streaming the camera.

Note: Close() is automatically called by the camera's destructor when it gets deleted, so you do not explicitly need to call Close() before exiting the program if you delete your camera object.

Reimplemented from videoSource.

◆ Create() [1/3]

static gstCamera* gstCamera::Create ( const char * camera = NULL )

static

Create a MIPI CSI or V4L2 camera device.

gstCamera will use the nvarguscamerasrc GStreamer element for MIPI CSI cameras, and the v4l2src GStreamer element for capturing V4L2 cameras, like USB webcams.

The camera will be created with a resolution indicated by gstCamera::DefaultWidth and gstCamera::DefaultHeight (1280x720 by default).

Parameters

camera Camera device to use. If using MIPI CSI, this string can be NULL to default to CSI camera 0, otherwise the string should contain the device index of the CSI camera (e.g. "0" for CSI camera 0 or "1" for CSI camera 1, ect). If using V4L2, the string should contain the /dev/video node to use (e.g. "/dev/video0" for V4L2 camera 0). By default, camera parameter is NULL and MIPI CSI camera 0 is used.

Returns: A pointer to the created gstCamera device, or NULL if there was an error.

◆ Create() [2/3]

static gstCamera* gstCamera::Create ( const videoOptions & options )

static

Create a MIPI CSI or V4L2 camera device.

◆ Create() [3/3]

static gstCamera* gstCamera::Create	(	uint32_t	width,
		uint32_t	height,
		const char *	camera = `NULL`
	)

static

Create a MIPI CSI or V4L2 camera device.

gstCamera will use the nvarguscamerasrc GStreamer element for MIPI CSI cameras, and the v4l2src GStreamer element for capturing V4L2 cameras, like USB webcams.

Parameters

width	desired width (in pixels) of the camera resolution. This should be from a format that the camera supports.
height	desired height (in pixels) of the camera resolution. This should be from a format that the camera supports.
camera	Camera device to use. If using MIPI CSI, this string can be `NULL` to default to CSI camera 0, otherwise the string should contain the device index of the CSI camera (e.g. `"0"` for CSI camera 0 or `"1"` for CSI camera 1, ect). If using V4L2, the string should contain the `/dev/video` node to use (e.g. `"/dev/video0"` for V4L2 camera 0). By default, `camera` parameter is NULL and MIPI CSI camera 0 is used.

Returns: A pointer to the created gstCamera device, or NULL if there was an error.

◆ GetType()

virtual uint32_t gstCamera::GetType ( ) const

inlinevirtual

Return the interface type (gstCamera::Type)

Reimplemented from videoSource.

◆ Open()

virtual bool gstCamera::Open ( )

virtual

Begin streaming the camera.

After Open() is called, frames from the camera will begin to be captured.

Open() is not stricly necessary to call, if you call one of the Capture() functions they will first check to make sure that the stream is opened, and if not they will open it automatically for you.

Returns: true on success, false if an error occurred opening the stream.

Reimplemented from videoSource.

◆ SetZeroCopy()

void gstCamera::SetZeroCopy ( bool zeroCopy )

inline

Set whether converted RGB(A) images should use ZeroCopy buffer allocation.

Has no effect after the first image (in RGB(A) format) was captured.

Member Data Documentation

◆ DefaultHeight

const uint32_t gstCamera::DefaultHeight = 720

static

Default camera height, unless otherwise specified during Create()

◆ DefaultWidth

const uint32_t gstCamera::DefaultWidth = 1280

static

Default camera width, unless otherwise specified during Create()

◆ Type

const uint32_t gstCamera::Type = (1 << 0)

static

Unique type identifier of gstCamera class.

◆ v4l2Camera

class v4l2Camera

Video4Linux2 (V4L2) camera capture streaming.

Note: gstCamera, which convieniently handles both V4L2 and MIPI CSI cameras, is used mostly in lieu of v4l2Camera. v4l2Camera is provided in the event that you would rather interface with V4L2 directly, rather than go through GStreamer.

Public Member Functions
	~v4l2Camera ()
	Destructor. More...

bool	Open ()
	Start streaming. More...

bool	Close ()
	Stop streaming. More...

void *	Capture (size_t timeout=0)
	Return the next image. More...

uint32_t	GetWidth () const
	Get width, in pixels, of camera image. More...

uint32_t	GetHeight () const
	Retrieve height, in pixels, of camera image. More...

uint32_t	GetPitch () const
	Return the size in bytes of one line of the image. More...

uint32_t	GetPixelDepth () const
	Return the bit depth per pixel. More...

Static Public Member Functions
static v4l2Camera *	Create (const char *device_path)
	Create V4L2 interface. More...

Constructor & Destructor Documentation

◆ ~v4l2Camera()

v4l2Camera::~v4l2Camera ( )

Destructor.

Member Function Documentation

◆ Capture()

void* v4l2Camera::Capture ( size_t timeout = 0 )

Return the next image.

◆ Close()

bool v4l2Camera::Close ( )

Stop streaming.

◆ Create()

static v4l2Camera* v4l2Camera::Create ( const char * device_path )

static

Create V4L2 interface.

Parameters

path	Filename of the video device (e.g. /dev/video0)

◆ GetHeight()

uint32_t v4l2Camera::GetHeight ( ) const

inline

Retrieve height, in pixels, of camera image.

◆ GetPitch()

uint32_t v4l2Camera::GetPitch ( ) const

inline

Return the size in bytes of one line of the image.

◆ GetPixelDepth()

uint32_t v4l2Camera::GetPixelDepth ( ) const

inline

Return the bit depth per pixel.

◆ GetWidth()

uint32_t v4l2Camera::GetWidth ( ) const

inline

Get width, in pixels, of camera image.

◆ Open()

bool v4l2Camera::Open ( )

Start streaming.

Classes

Detailed Description

Class Documentation

◆ gstCamera

Public Member Functions

Static Public Member Functions

Static Public Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ ~gstCamera()

Member Function Documentation

◆ Capture()

◆ CaptureRGBA()

◆ Close()

◆ Create() [1/3]

◆ Create() [2/3]

◆ Create() [3/3]

◆ GetType()

◆ Open()

◆ SetZeroCopy()

Member Data Documentation

◆ DefaultHeight

◆ DefaultWidth

◆ Type

◆ v4l2Camera

Public Member Functions

Static Public Member Functions

Constructor & Destructor Documentation

◆ ~v4l2Camera()

Member Function Documentation

◆ Capture()

◆ Close()

◆ Create()

◆ GetHeight()

◆ GetPitch()

◆ GetPixelDepth()

◆ GetWidth()

◆ Open()