Example of using input from a Blackmagic Decklink or Ultrastudio card in kivy with the use of OpenCV and GStreamer.

kivy_decklink.py

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivy.clock import Clock
from kivy.graphics.texture import Texture

import cv2
import numpy as np

class CamApp(App):

    def build(self):
        self.img1 = Image()
        layout = BoxLayout()
        layout.add_widget(self.img1)

        self.capture = cv2.VideoCapture('decklinksrc mode=7 connection=0 ! videoconvert ! appsink')

        Clock.schedule_interval(self.update, 1.0/33.0)
        return layout

    def update(self, dt):
        ret, frame = self.capture.read()
        
        if frame:
            buf1 = cv2.flip(frame, 0)
            buf = buf1.tostring()
            texture1 = Texture.create(size=(frame.shape[1], frame.shape[0]), colorfmt='bgr')
            texture1.blit_buffer(buf, colorfmt='bgr', bufferfmt='ubyte')
    
            self.img1.texture = texture1
        else:
            print("No frame read.")

if __name__ == '__main__':
    CamApp().run()

hello , when i'm trying run your script , i'm getting error AttributeError: 'NoneType' object has no attribute 'tostring' .

I guess frame was None because there was an issue with your decklink settings (line 18). The code now checks for a valid frame and prints an error if there was none.

m not able to import cv2 please help it works with other codes but not with kivy

Hello, I would like to ask a question, can I use this code with blackmagic design intensity pro 4k and what should change the code to make it work? Thank you