Jetson Inference: gstCamera Class Reference - Jetson Inference

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gstCamera Class Reference Utilities Library (jetson-utils) » Camera Capture

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

#include <gstCamera.h>

Inheritance diagram for gstCamera:

Public Member Functions

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

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 | | |

Detailed Description

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.

NotegstCamera 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 alsovideoSource

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 |

Capture the next image frame from the camera.

◆CaptureRGBA()

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). |

Returnstrue 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.

NoteClose() 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 |

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. |

ReturnsA pointer to the created gstCamera device, or NULL if there was an error.

◆Create() [2/3]

| static |

Create a MIPI CSI or V4L2 camera device.

◆Create() [3/3]

| 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. |

ReturnsA 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.

Returnstrue on success, false if an error occurred opening the stream.

Reimplemented from videoSource.

◆SetZeroCopy()

| 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.

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

jetson-utils/gstCamera.h
gstCamera
Generated on Fri Mar 17 2023 14:29:30 for Jetson Inference by 1.8.17