Display Object

The Display object implements video display functionality, capable of outputting image data to a monitor via the HDMI interface. This object includes methods such as display, set_img, set_graph_rect, set_graph_word, and close. Detailed descriptions are provided below:

display

【Function Description】

Initializes the display module and configures display parameters.

【Function Declaration】

Display.display(chn, width, height, vot_intf, vot_out_mode)

【Parameter Description】

Parameter	Description	Value Range
chn	Display output layer	0: Video layer, 2: Graphics layer
width	Width of the input image	Up to 1920
height	Height of the input image	Up to 1080
vot_intf	Video interface output resolution	Default: 0 (1080p)
vot_out_mode	Video output interface	Default: 1 (HDMI output)

【Usage】

#create display object
disp = libsrcampy.Display()

#enable display function, resolution: 1080p, interface: HDMI
ret = disp.display(0, 1920, 1080, 0, 1)

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

The HDMI interface resolution on the development board is obtained from the monitor's EDID. Currently, only the following resolutions are supported: 1920x1080, 1280x720, 1024x600, and 800x480. When enabling the display module, ensure that the configured resolution matches the actual resolution of the connected monitor.

【Reference Code】

None

set_img

【Function Description】

Feeds display data into the display module. The data format must be NV12.

【Function Declaration】

Display.set_img(img)

【Parameter Description】

Parameter	Description	Value Range
img	Image data to be displayed	NV12 format

【Usage】

None

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

This interface must be used only after enabling the display functionality via the display interface. The input data must be in NV12 format.

【Reference Code】

import sys, os, time

import numpy as np
import cv2
from hobot_vio import libsrcampy

def test_display():
    #create display object
    disp = libsrcampy.Display()

    #enable display function
    ret = disp.display(0, 1920, 1080, 0, 1)
    print ("Display display 0 return:%d" % ret)

    fo = open("output.img", "rb")
    img = fo.read()
    fo.close()

    #send image data to display
    ret = disp.set_img(img)
    print ("Display set_img return:%d" % ret)

    time.sleep(3)

    disp.close()
    print("test_display done!!!")

test_display()

set_graph_rect

【Function Description】

Draws a rectangle on the graphics layer of the display module.

【Function Declaration】

Display.set_graph_rect(x0, y0, x1, y1, chn, flush, color, line_width)

【Parameter Description】

Parameter	Description	Value Range
x0	X-coordinate of the top-left corner of the rectangle	Within video frame dimensions
y0	Y-coordinate of the top-left corner of the rectangle	Within video frame dimensions
x1	X-coordinate of the bottom-right corner of the rectangle	Within video frame dimensions
y1	Y-coordinate of the bottom-right corner of the rectangle	Within video frame dimensions
chn	Graphics layer channel number	Range: 2–3, default: 2
flush	Whether to clear the graphics layer buffer	0: No, 1: Yes
color	Rectangle color	ARGB8888 format
line_width	Width of the rectangle border	Range: 1–16, default: 4

【Usage】

#enable graph layer 2
ret = disp.display(2)
print ("Display display 2 return:%d" % ret)

#set osd rectangle
ret = disp.set_graph_rect(100, 100, 1920, 200, chn = 2, flush = 1,  color = 0xffff00ff)

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

This interface must be used only after enabling the display functionality via the display interface.

【Reference Code】

None

set_graph_word

【Function Description】

Draws text characters on the graphics layer of the display module.

【Function Declaration】

Display.set_graph_word(x, y, str, chn, flush, color, line_width)

【Parameter Description】

Parameter	Description	Value Range
x	X-coordinate of the starting position for text	Within video frame dimensions
y	Y-coordinate of the starting position for text	Within video frame dimensions
str	Text string to be drawn	GB2312 encoding
chn	Graphics layer channel number	Range: 2–3, default: 2
flush	Whether to clear the graphics layer buffer	0: No, 1: Yes
color	Text color	ARGB8888 format
line_width	Line width of the text characters	Range: 1–16, default: 1

【Usage】

#enable graph layer 2
ret = disp.display(2)
```print ("Display display 2 return:%d" % ret)

#set osd string
string = "horizon"
ret = disp.set_graph_word(300, 300, string.encode('gb2312'), 2, 0, 0xff00ffff)
print ("Display set_graph_word return:%d" % ret)

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

This API must be used after enabling the display functionality via the display interface.

【Sample Code】

None

close

【Function Description】

Closes the display module.

【Function Declaration】

Display.close()

【Parameter Description】

None

【Usage】

None

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

This API must be used after enabling the display functionality via the display interface.

【Sample Code】

None

bind Interface

【Function Description】

This interface binds the output and input data streams of modules such as Camera, Encoder, Decoder, and Display. Once bound, data automatically flows between the modules without requiring further user intervention. For example, after binding Camera and Display, camera data will be automatically output to the display through the display module without calling additional APIs.

【Function Declaration】

    libsrcampy.bind(src, dst)

【Parameter Description】

Parameter	Description	Value Range
src	Source data module	`Camera`, `Encoder`, `Decoder` modules
dst	Destination data module	`Camera`, `Encoder`, `Decoder`, `Display` modules

【Usage】

#create camera object
cam = libsrcampy.Camera()
ret = cam.open_cam(0, 1, 30, [1920, 1280], [1080, 720])
print("Camera open_cam return:%d" % ret)

#encode start
enc = libsrcampy.Encoder()
ret = enc.encode(0, 1, 1920, 1080)
print("Encoder encode return:%d" % ret)

#bind, input: cam, output: enc
ret = libsrcampy.bind(cam, enc)
print("libsrcampy bind return:%d" % ret)

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

None

【Sample Code】

None

unbind Interface

【Function Description】

Unbinds two previously bound modules.

【Function Declaration】

libsrcampy.unbind(src, dst)

【Parameter Description】

Parameter	Description	Value Range
src	Source data module	`Camera`, `Encoder`, `Decoder` modules
dst	Destination data module	`Camera`, `Encoder`, `Decoder`, `Display` modules

【Usage】

#create camera object
cam = libsrcampy.Camera()
ret = cam.open_cam(0, 1, 30, [1920, 1280], [1080, 720])
print("Camera open_cam return:%d" % ret)

#encode start
enc = libsrcampy.Encoder()
ret = enc.encode(0, 1, 1920, 1080)
print("Encoder encode return:%d" % ret)

#bind, input: cam, output: enc
ret = libsrcampy.bind(cam, enc)
print("libsrcampy bind return:%d" % ret)

#unbind, input: cam, output: enc
ret = libsrcampy.unbind(cam, enc)
print("libsrcampy unbind return:%d" % ret)

【Return Value】

Return Value	Description
0	Success
-1	Failure

【Notes】

None

【Sample Code】

None

display​

set_img​

set_graph_rect​

set_graph_word​

close​

bind Interface​

unbind Interface​

display

set_img

set_graph_rect

set_graph_word

close

bind Interface

unbind Interface