Jetson Inference: videoSource Class Reference - Jetson Inference

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videoSource Class Referenceabstract Utilities Library (jetson-utils) » Video Streaming

The videoSource API is for capturing frames from video input devices such as MIPI CSI cameras, V4L2 cameras, video/images files from disk, directories containing a sequence of images, and from RTP/RTSP network video streams over UDP/IP. More...

#include <videoSource.h>

Inheritance diagram for videoSource:

Public Types

| | enum | Status { ERROR = -2, EOS = -1, TIMEOUT = 0, OK = 1 } | | | Stream status codes that are optionally returned from Capture()More...
| | |

Public Member Functions

Static Public Member Functions

| | 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

Protected Member Functions

| | | videoSource (const videoOptions &options) | | |

Protected Attributes

Detailed Description

videoSource interfaces are implemented by gstCamera, gstDecoder, and imageLoader. The specific implementation is selected at runtime based on the type of resource URI.

videoSource supports the following protocols and resource URI's:

- `csi://0` for MIPI CSI cameras, where `0` can be replaced with the camera port.
   It is also assumed that if a number with no protocol is specified (e.g. `"0"`),
   this means to use the MIPI CSI camera of that number (`"0"` -> `csi://0`).

- `v4l2:///dev/video0` for V4L2 cameras, where `/dev/video0` can be replaced with
   a different video device (e.g. `v4l2:///dev/video1` for V4L2 video device `1`).
   If no protocol is specified but the string begins with `/dev/video`, then it is
   assumed that the protocol is V4L2 (`/dev/video0` -> `v4l2:///dev/video0`)

- `rtp://@:1234` to recieve an RTP network stream, where `1234` is the port and `@` is shorthand
   for localhost. `@` can also be substituted for the IP address of a multicast group.
   Note that it is important to manually specify the codec of the stream when using RTP,
   as the codec cannot be discovered from the RTP stream itself and need to be provided.
   @see videoOptions for more info about the `--input-codec` option.

- `rtsp://username:password@<remote-host>:1234` to subscribe to an RTSP network stream, where
   `<remote-host>` should be substituted for the remote host's IP address or hostname, and 
   `1234` is the port. For example, `rtsp://192.168.1.2:5000`. The `username` and `password` 
   are optional, and are only used for RTSP streams that require authentication.

- `file:///home/user/my_video.mp4` for disk-based videos, images, and directories of images.
   You can leave off the `file://` protocol identifier and it will be deduced from the path.
   It can be a relative or absolute path. If a directory is specified that contains images,
   those images will be loaded in sequence (sorted alphanumerically). The path can also
   contain wildcard characters, for example `"images/*.jpg"` - however when using wildcards
   from the command line, enclose the string in quotes otherwise the OS will pre-expand them.
   Supported video formats for loading include MKV, MP4, AVI, and FLV. Supported codecs for 
   decoding include H.264, H.265, VP8, VP9, MPEG-2, MPEG-4, and MJPEG. Supported image formats
   for loading include JPG, PNG, TGA, BMP, GIF, PSD, HDR, PIC, and PNM (PPM/PGM binary).

See alsoURI for info about resource URI formats. videoOptions for additional options and command-line arguments.

Member Enumeration Documentation

◆Status

| enum videoSource::Status |

Stream status codes that are optionally returned from Capture()

Enumerator
ERROR

an error occurred

| | EOS |

end-of-stream (EOS)

| | TIMEOUT |

a timeout occurred

| | OK |

frame capture successful

Constructor & Destructor Documentation

◆~videoSource()

| virtual videoSource::~videoSource | ( | | ) | |

| virtual |

Destroy interface and release all resources.

◆videoSource()

| protected |

Member Function Documentation

◆Capture() [1/3]

template<typename T >

| bool videoSource::Capture | ( | T ** | image, | | | | int * | status | | | ) | | |

| inline |

Capture the next image from the video stream, using the default timeout of 1000ms.

The image formats supported by this templated version of Capture() include the following:

uchar3 (IMAGE_RGB8)
uchar4 (IMAGE_RGBA8)
float3 (IMAGE_RGB32F)
float4 (IMAGE_RGBA32F)

The image format will automatically be deduced from these types. If other types are used with this overload, a static compile-time error will be asserted.

Parameters

See alsovideoSource::Status). -2 on ERROR, -1 on EOS, 0 on TIMEOUT, 1 on OK.Returnstrue if a frame was captured, false if there was an error or a timeout occurred.

◆Capture() [2/3]

template<typename T >

| bool videoSource::Capture | ( | T ** | image, | | | | uint64_t | timeout = DEFAULT_TIMEOUT, | | | | int * | status = NULL | | | ) | | |

| inline |

Capture the next image from the video stream.

The image formats supported by this templated version of Capture() include the following:

uchar3 (IMAGE_RGB8)
uchar4 (IMAGE_RGBA8)
float3 (IMAGE_RGB32F)
float4 (IMAGE_RGBA32F)

The image format will automatically be deduced from these types. If other types are used with this overload, a static compile-time error will be asserted.

Parameters

| [out] | image | output pointer that will be set to the memory containing the image. If this interface has it's videoOptions::zeroCopy flag set to true, the memory was allocated in mapped CPU/GPU memory and is be accessible from both CPU and CUDA. Otherwise, it's accessible only from CUDA. | | [in] | timeout | timeout in milliseconds to wait to capture the image before returning. The default is 1000ms. A timeout value of UINT64_MAX will wait forever. A timeout of 0 will return instantly if a frame wasn't immediately ready. | | [out] | status | optional status code returned ( |

See alsovideoSource::Status). -2 on ERROR, -1 on EOS, 0 on TIMEOUT, 1 on OK.Returnstrue if a frame was captured, false if there was an error or a timeout occurred.

◆Capture() [3/3]

| pure virtual |

Capture the next image from the video stream.

The image formats supported by Capture() are IMAGE_RGB8 (uchar3), IMAGE_RGBA8 (uchar4), IMAGE_RGB32F (float3), and IMAGE_RGBA32F (float4).

See alsoimageFormat for more info.Parameters

See alsovideoSource::Status). -2 on ERROR, -1 on EOS, 0 on TIMEOUT, 1 on OK.Returnstrue if a frame was captured, false if there was an error or a timeout occurred.

Implemented in gstCamera, gstDecoder, and imageLoader.

◆Close()

| virtual void videoSource::Close | ( | | ) | |

| virtual |

Stop streaming the device.

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

Reimplemented in gstCamera, gstDecoder, and imageLoader.

◆Create() [1/6]

| static videoSource* videoSource::Create | ( | const char * | URI, | | | | const commandLine & | cmdLine | | | ) | | |

| static |

Create videoSource interface from a resource URI string and parsing command line arguments.

See alsovideoOptions for valid command-line arguments to be parsed. the documentation above and the URI struct for more info about resource URI's.

◆Create() [2/6]

| static |

Create videoSource interface from a resource URI string and parsing command line arguments.

See alsovideoOptions for valid command-line arguments to be parsed. the documentation above and the URI struct for more info about resource URI's.

◆Create() [3/6]

| static videoSource* videoSource::Create | ( | const char * | URI, | | | | const videoOptions & | options = videoOptions() | | | ) | | |

| static |

Create videoSource interface from a resource URI string and optional videoOptions.

See alsothe documentation above and the URI struct for more info about resource URI's.

◆Create() [4/6]

| static videoSource* videoSource::Create | ( | const commandLine & | cmdLine, | | | | int | positionArg = -1 | | | ) | | |

| static |

Create videoSource interface by parsing command line arguments, including the resource URI.

Parameters

| positionArg | indicates the positional argument number in the command line of the resource URI (or -1 if a positional argument isn't used, and should instead be parsed from the --input= option). |

See alsovideoOptions for valid command-line arguments to be parsed. the documentation above and the URI struct for more info about resource URI's.

◆Create() [5/6]

| static |

Create videoSource interface by parsing command line arguments, including the resource URI.

Parameters

See alsovideoOptions for valid command-line arguments to be parsed. the documentation above and the URI struct for more info about resource URI's.

◆Create() [6/6]

| static |

Create videoSource interface from a videoOptions struct that's already been filled out.

It's expected that the supplied videoOptions already contain a valid resource URI.

◆GetFrameCount()

| uint64_t videoSource::GetFrameCount | ( | | ) | const |

| inline |

Return the number of frames captured.

◆GetFrameRate()

| uint32_t videoSource::GetFrameRate | ( | | ) | const |

| inline |

Return the framerate, in Hz or FPS.

◆GetHeight()

| uint32_t videoSource::GetHeight | ( | | ) | const |

| inline |

Return the height of the stream, in pixels.

◆GetLastTimestamp()

| uint64_t videoSource::GetLastTimestamp | ( | | ) | const |

| inline |

Get timestamp of the last captured frame, in nanoseconds.

◆GetOptions()

| const videoOptions& videoSource::GetOptions | ( | | ) | const |

| inline |

Return the videoOptions of the stream.

◆GetRawFormat()

| imageFormat videoSource::GetRawFormat | ( | | ) | const |

| inline |

Get raw image format.

◆GetResource()

| const URI& videoSource::GetResource | ( | | ) | const |

| inline |

Return the resource URI of the stream.

◆GetType()

| virtual uint32_t videoSource::GetType | ( | | ) | const |

| inlinevirtual |

Return the interface type of the stream.

This could be one of the following values:

Reimplemented in gstCamera, gstDecoder, and imageLoader.

◆GetWidth()

| uint32_t videoSource::GetWidth | ( | | ) | const |

| inline |

Return the width of the stream, in pixels.

◆IsStreaming()

| bool videoSource::IsStreaming | ( | | ) | const |

| inline |

Check if the device is actively streaming or not.

Returnstrue if the device is streaming (open), or false if it's closed or has reached EOS (End Of Stream).

◆IsType() [1/2]

template<typename T >

| bool videoSource::IsType | ( | | ) | const |

| inline |

Check if a this stream is of a particular type.

Can be used with gstCamera, gstDecoder, and imageLoader. For example:

if( stream->IsType<gstCamera>() ) gstCamera* camera = (gstCamera*)stream; // safe to cast

◆IsType() [2/2]

| inline |

Check if this stream is of a particular type.

◆Open()

| virtual bool videoSource::Open | ( | | ) | |

| virtual |

Begin streaming the device.

After Open() is called, frames from the device 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 in gstCamera, gstDecoder, and imageLoader.

◆TypeToStr() [1/2]

| const char* videoSource::TypeToStr | ( | | ) | const |

| inline |

Convert this stream's class type to string.

◆TypeToStr() [2/2]

| static |

Convert a class type to a string.

◆Usage()

| static const char* videoSource::Usage | ( | | ) | |

| inlinestatic |

Usage string for command line arguments to Create()

Member Data Documentation

◆DEFAULT_TIMEOUT

| const uint64_t videoSource::DEFAULT_TIMEOUT =1000 |

| static |

The default Capture timeout (1000ms)

◆mLastTimestamp

| uint64_t videoSource::mLastTimestamp |

| protected |

◆mOptions

| videoOptions videoSource::mOptions |

| protected |

◆mRawFormat

| imageFormat videoSource::mRawFormat |

| protected |

◆mStreaming

| bool videoSource::mStreaming |

| protected |

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

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