python+opencv打开USB摄像头存储MP4文件

USB摄像头存储MP4文件

import cv2
import os
import time


"打开摄像头，设置分辨率"
my_camera = cv2.VideoCapture(0)
my_camera.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
my_camera.set(cv2.CAP_PROP_FRAME_HEIGHT, 320)

"设置视频格式"
write_ok = False
frame_size = (int(my_camera.get(cv2.CAP_PROP_FRAME_WIDTH)), int(my_camera.get(cv2.CAP_PROP_FRAME_HEIGHT)))
frame_fps = 30
video_format = cv2.VideoWriter_fourcc('m', 'p', '4', 'v')

"设置录制的视频文件名"
video_file_fp = cv2.VideoWriter()
video_file_fp.open('camera_video.mp4', video_format, frame_fps, frame_size, True)

start_time = time.time()
video_time_length = 100
print('Start to record video')

"循环录制视频文件，并给视频加上时间戳"
while(True):
    sucess, video_frame=my_camera.read()
    time_str=time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())
    cv2.putText(video_frame,time_str, (5,340), cv2.FONT_HERSHEY_SIMPLEX, 1, (255,255,255), 2)
    video_file_fp.write(video_frame)
    cv2.imshow('frame', video_frame)

    cur_time = time.time()      #录制10秒后自动结束或者按ESC键退出
    if cur_time-start_time>video_time_length:
        print('End the video with '+str(video_time_length)+' s')
        break
    if cv2.waitKey(1) &0xff == 27:   #esc key
        break

"关闭录制"
video_file_fp.release()
my_camera.release()
cv2.destroyAllWindows()

"显示录制的视频文件大小"
mp4_file_size=os.path.getsize('camera_video.mp4')
print(int(mp4_file_size/1024), 'KBytes')