有没有办法在kivy中录制视频？

Question

我在 Kivy 中显示摄像机视频，但找不到录制视频的方法，我尝试使用 OpenCV Videowriter 但由于更新（Clock.schedule_interval(self.update, 1.0/33.0)）它一直在覆盖，所以它保存的视频是一个图像，有没有人有另一种方法。

Answer 1

请查看以下可能有助于您的代码。主要代码取自链接：https://www.codingforentrepreneurs.com/blog/how-to-record-video-in-opencv-python。我只适应了kivy框架（因为问题是kivy解决方案）并调整了frame_per_second使其与查看和写入速度一致。

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
from kivy.properties import StringProperty, NumericProperty

import cv2
import os

# Standard Video Dimensions Sizes
STD_DIMENSIONS =  {
    "480p": (640, 480),
    "720p": (1280, 720),
    "1080p": (1920, 1080),
    "4k": (3840, 2160),
}

# Video Encoding, might require additional installs
# Types of Codes: http://www.fourcc.org/codecs.php
VIDEO_TYPE = {
    'avi': cv2.VideoWriter_fourcc(*'XVID'),
    #'mp4': cv2.VideoWriter_fourcc(*'H264'),
    'mp4': cv2.VideoWriter_fourcc(*'XVID'),
}

class KivyCamera(BoxLayout):
    filename = StringProperty('video.avi')
    frames_per_second = NumericProperty(30.0)
    video_resolution = StringProperty('720p')

    def __init__(self, **kwargs):
        super(KivyCamera, self).__init__(**kwargs)
        self.img1=Image()
        self.add_widget(self.img1)
        self.capture = cv2.VideoCapture(0)
        self.out = cv2.VideoWriter(self.filename, self.get_video_type(self.filename), self.frames_per_second, self.get_dims(self.capture, self.video_resolution))
        Clock.schedule_interval(self.update, 1 / self.frames_per_second)

    def update(self, *args):
        ret, frame = self.capture.read()
        self.out.write(frame)
        buf = cv2.flip(frame, 0).tostring()
        texture = Texture.create(size=(frame.shape[1], frame.shape[0]), colorfmt="bgr")
        texture.blit_buffer(buf, colorfmt="bgr", bufferfmt="ubyte")
        self.img1.texture = texture

    # Set resolution for the video capture
    # Function adapted from https://kirr.co/0l6qmh
    def change_resolution(self, cap, width, height):
        self.capture.set(3, width)
        self.capture.set(4, height)

    # grab resolution dimensions and set video capture to it.
    def get_dims(self, cap, video_resolution='1080p'):
        width, height = STD_DIMENSIONS["480p"]
        if self.video_resolution in STD_DIMENSIONS:
            width, height = STD_DIMENSIONS[self.video_resolution]
        ## change the current caputre device
        ## to the resulting resolution
        self.change_resolution(cap, width, height)
        return width, height

    def get_video_type(self, filename):
        filename, ext = os.path.splitext(filename)
        if ext in VIDEO_TYPE:
          return  VIDEO_TYPE[ext]
        return VIDEO_TYPE['avi']

class CamApp(App):
    def build(self):
        return KivyCamera()

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