Gst-nvdsosd

This plugin draws bounding boxes, text, and region of interest (RoI) polygons. (Polygons are presented as a set of lines.) The plugin accepts an RGBA buffer with attached metadata from the upstream component. It draws bounding boxes, which may be shaded depending on the configuration (e.g. width, color, and opacity) of a given bounding box. It also draws text and RoI polygons at specified locations in the frame. Text and polygon parameters are configurable through metadata.

Inputs and Outputs

• Inputs

  • RGBA buffer

  • NvDsBatchMeta (holds NvDsFrameMeta consisting of bounding boxes, text parameters, and lines parameters)

  • NvDsLineMeta (RoI polygon)

• Control parameters

  • gpu-id (dGPU only)

  • display-clock

  • display-text

  • clock-font

  • clock-font-size

  • x-clock-offset

  • y-clock-offset

  • clock-color

  • process-mode

  • hw-blend-color-attr

  • display-bbox

  • display-mask

• Output

  • RGBA buffer modified in place to overlay bounding boxes, texts, and polygons represented in the metadata

Features

The following table summarizes the features of the plugin.

Gst-nvsosd features

Feature	Description	Release
Supports drawing arrows	Arrows can be drawn by specifying values in NvOSD_ArrowParams in metadata.	DS 5.0
Supports drawing circles	Circles can be drawn by specifying values in NvOSD_CircleParams in metadata.	DS 5.0
Support for blending bounding boxes	Blending boxes can be drawn by specifying bg_color values in NvOSD_RectParams in metadata. For HW mode, hw-blend-color-attr property for OSD needs to be set for blending.	DS 4.0
Supports drawing polygon lines	Lines can be drawn by specifying values in NvOSD_LineParams in metadata.	DS 3.0
Supports drawing text using Pango and Cairo libraries	Text can be drawn by specifying values in NvOSD_TextParams in metadata.	DS 2.0
VIC (Jetson only) and GPU support for drawing bounding boxes	Bounding boxes can be drawn by specifying values in NvOSD_RectParams in metadata.	DS 2.0

Gst Properties

The following table describes the Gst properties of the Gst-nvdsosd plugin.

Gst-nvsosd gst properties

Property	Meaning	Type and Range	Example Notes
gpu-id	Device ID of the GPU to be used for operation (dGPU only)	Integer, 0 to 4,294,967,295	gpu-id=0
display-clock	Indicates whether to display system clock	Boolean	display-clock=0
display-text	Indicates whether to display text	Boolean	display-text=0
clock-font	Name of Pango font to use for the clock	String	clock-font=Arial
clock-font-size	Font size to use for the clock	Integer, 0-60	clock-font-size=2
x-clock-offset	X offset of the clock	Integer, 0 to 4,294,967,295	x-clock-offset=100
y-clock-offset	Y offset of the clock	Integer, 0 to 4,294,967,295	y-clock-offset=50
clock-color	Color of the clock to be set while display, in the order 0xRGBA	Integer, 0 to 4,294,967,295	clock-color=0xff0000ff (Clock is red with alpha=1)
process-mode	Indicates the mode used to draw the objects 0: CPU mode 1: GPU mode (For dGPU only) 2: VIC mode (For Jetson only)	Integer, 0 to 2	process-mode=0
hw-blend-color-attr	Blending color attributes for all classes. To be used for process-mode=2 (VIC based blending). If this property is set, shaded bboxes will be drawn using blending. Property to be set in the form: “Class_ID,R,G,B,A” for each class separated by a “:” Only applicable on Jetson. Note that for HW mode, this property must be set , otherwise objects will not be blended with required colors.	String	hw-blend-color-attr=0,0.0,1.0,0.0,0.3:1,1.0,0.0,0.3.0.3
display-bbox	Control bounding box drawing	Boolean	display-bbox=1
display-mask	Controls instance mask drawing	Boolean	display-mask=1