用python录制视频

Question

我尝试用Python录制视频。运行下面的代码创建一个 .mp4 文件，但大小为 0KB，当我打开时，出现数据已损坏且无法打开的错误。我尝试使用 VLC、媒体播放器和我在 Windows 11 上获得的所有其他工具打开。也尝试了互联网上可用的所有工具，每次都是同样的问题

 import cv2
    
cap = cv2.VideoCapture(0)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1280)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 720)
fourcc = cv2.VideoWriter_fourcc(*'mp4v')
writer = cv2.VideoWriter('recording.mp4', fourcc, 30.0, (1280, 720))
recording = False

while True:
    ret, frame = cap.read()
    if ret:
        print('working')
        cv2.imshow("video", frame)
        if recording:
            writer.write(frame)
    
    key = cv2.waitKey(1)
    if key == ord('q'):
        break
    elif key == ord('r'):
        recording = not recording
        print(f'recording: {recording}')

# Release the video capture and writer objects
cap.release()
writer.release()
cv2.destroyAllWindows()

Answer 1

您正在手动设置尺寸，但相机可能无法在该分辨率下工作。

要解决此问题，您可以手动将分辨率设置为 1280x720，但不要对捕获结果进行硬编码，而是从相机中检索它

这样，如果相机在所需的分辨率下工作良好，如果不是，它将在默认分辨率下工作。

import cv2
    
cap = cv2.VideoCapture(0)
# set the camera to 1280x720
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1280)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 720)

# but here get the actual resolution
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH) + 0.5)
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT) + 0.5)
size = (width, height)
fourcc = cv2.VideoWriter_fourcc(*'mp4v')

# then use here the actual resolution instead of the hardcoded one
writer = cv2.VideoWriter('recording.mp4', fourcc, 30.0,(width,height)) 

recording = False

while True:
    ret, frame = cap.read()
    if ret:
        print('working')
        cv2.imshow("video", frame)
        if recording:
            writer.write(frame)
    
    key = cv2.waitKey(1)
    if key == ord('q'):
        break
    elif key == ord('r'):
        recording = not recording
        print(f'recording: {recording}')

# Release the video capture and writer objects
cap.release()
writer.release()
cv2.destroyAllWindows()