No attribute 'blit buffer' on OpenCV Kivy Android Application

Question

I tried to build my Kivy and Python files to become an APK file, however it gives me a "NoneType" object has no attribute 'blit buffer' error. I followed the solution in this link and I tried to re-build it again, but it is giving me the same error on the logcat.

I executed the android clean first before re-building the application, however no luck.

Here's my main.py:

import kivy

from kivy.app import App
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.graphics.texture import Texture
from kivy.uix.image import Image
from kivy.uix.camera import Camera
from kivy.lang import Builder
from kivy.clock import Clock
from kivy.logger import Logger
from kivy.properties import ObjectProperty, NumericProperty

import numpy as np
import cv2

class CamApp(App):
    pass

class AndroidCamera(Camera):
    camera_resolution = (640, 480)
    counter = 0

    def on_tex(self, *l):
        if self._camera._buffer is None:
            return None
        frame = self.frame_from_buf()
        self.frame_to_screen(frame)
        super(AndroidCamera, self).on_tex(*l)
        self.texture = Texture.create(size=self.camera_resolution, colorfmt='rgb')
        self.texture_size = list(self.texture.size)

    def frame_from_buf(self):
        w, h = self.resolution
        frame = np.frombuffer(self._camera._buffer.tostring(), 'uint8').reshape((h + h // 2, w))    # TODO: try to understand why the frame size has nothing to do with the original resolution
        print(f'{frame.shape = }')
        frame_bgr = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_NV21)
        return frame_bgr

    def frame_to_screen(self, frame):
        frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
        cv2.putText(frame_rgb, str(self.counter), (20, 50), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 255, 0), 2, cv2.LINE_AA)
        self.counter += 1
        flipped = np.flip(frame_rgb, 0)
        buf = flipped.tostring()
        self.texture.blit_buffer(buf, colorfmt='rgb', bufferfmt='ubyte')

class MyLayout(BoxLayout):
    pass

class MyApp(App):
    def build(self):
        return MyLayout()

if __name__ == '__main__':
    Builder.load_file("myapplayout.kv")
    MyApp().run()

Here's my myapplayout.kv:

<MyLayout>
    orientation: 'horizontal'
    size: root.width, root.height

    AndroidCamera:
        index: 0
        resolution: self.camera_resolution
        allow_stretch: True
        play: True

I specified python3, kivy, opencv, and numpy in the requirements section of the buildozer and as well as the CAMERA in the android permission section.

No attribute 'blit buffer' on OpenCV Kivy Android Application

0 Answers0