创建 OpenCV 视频小部件以在 Kivy 中使用

Question

我有 2 到 4 个 rtsp 流，我想在 Kivy 的框布局中显示，但我似乎无法弄清楚如何使用 kv 语言来实现这一点。我可以使用此代码显示一个摄像头：

class KivyCamera(Image):
    def __init__(self, capture, fps, **kwargs):
        super(KivyCamera, self).__init__(**kwargs)
        self.capture = capture
        Clock.schedule_interval(self.update, 1.0 / fps)

    def update(self, dt):
        ret, frame = self.capture.read()
        if ret:
            # convert it to texture
            buf1 = cv2.flip(frame, 0)
            buf = buf1.tostring()
            image_texture = Texture.create(
                size=(frame.shape[1], frame.shape[0]), colorfmt='bgr')
            image_texture.blit_buffer(buf, colorfmt='bgr', bufferfmt='ubyte')
            # display image from the texture
            self.texture = image_texture


class CamApp(App):
    def build(self):
        self.capture = cv2.VideoCapture('stream address removed for stack overflow')
        self.my_camera = KivyCamera(capture=self.capture, fps=30)
        return self.my_camera

    def on_stop(self):
        #without this, app will not exit even if the window is closed
        self.capture.release()


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

然而，这仅使用 .py。我希望能够使用 kv 语言创建 KivyCamera 实例并为每个实例设置不同的 capture 值。

例如：

BoxLayout:
        orientation: 'horizontal'

        KivyCamera:
            capture: 'myvalue'
            pos_hint: {'left': 1}

        KivyCamera:
            capture: 'anothervalue'
            pos_hint: {'right': 1}

Answer 1

您可以将属性设置为 fps 和源（索引、文件名等）而不是 VideoCapture：

main.py

from kivy.app import App
from kivy.uix.image import Image
from kivy.clock import Clock
from kivy.graphics.texture import Texture
from kivy.properties import ObjectProperty, NumericProperty

import cv2

class KivyCamera(Image):
    source = ObjectProperty()
    fps = NumericProperty(30)

    def __init__(self, **kwargs):
        super(KivyCamera, self).__init__(**kwargs)
        self._capture = None
        if self.source is not None:
            self._capture = cv2.VideoCapture(self.source)
        Clock.schedule_interval(self.update, 1.0 / self.fps)

    def on_source(self, *args):
        if self._capture is not None:
            self._capture.release()
        self._capture = cv2.VideoCapture(self.source)

    @property
    def capture(self):
        return self._capture

    def update(self, dt):
        ret, frame = self.capture.read()
        if ret:
            buf1 = cv2.flip(frame, 0)
            buf = buf1.tostring()
            image_texture = Texture.create(
                size=(frame.shape[1], frame.shape[0]), colorfmt="bgr"
            )
            image_texture.blit_buffer(buf, colorfmt="bgr", bufferfmt="ubyte")
            self.texture = image_texture


class CamApp(App):
    pass


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

cam.kv

BoxLayout:
    orientation: 'horizontal'

    KivyCamera:
        source: "stream address removed for stack overflow"

创建 OpenCV 视频小部件以在 Kivy 中使用

Create OpenCV Video Widgets to use in Kivy

python

opencv

rtsp

kivy