python调用ffmpeg处理视频-提取图片

ffmpeg 使用说明

# usage: 
ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

# options:
-ss:   set the start time offset
-f:    force format
-t:    record or transcode "duration" seconds of audio/video
-r     set frame rate (Hz value, fraction or abbreviation)
-y:    overwrite output files

遍历文件夹中的所有视频文件, 提取特定时间点的图片

import os

# 提取特定时间点（第12s）的图片
# ffmpeg -ss 0:0:12 -i xxx.mp4 -t 0.01 -f image2 yyy.jpg -y
str = 'c:/users/xxxx/ffmpeg/ffmpeg.exe ' + 
      '-ss 0:0:12 -i {} -t 0.01 -f image2 d:/images/{}.jpg -y'

for parent, dirnames, filenames in os.walk('d:/videos/'):
    for filename in filenames:
        video_dir = os.path.join(parent, filename)

        str_cmd = str.format(video_dir, filename)
        print(str_cmd)

        os.popen(str_cmd)

定时提取视频中的图片

import os

# 第12s之后每隔1s钟，定时提取视频中的图片
# ffmpeg -ss 0:0:12 -i xxx.mp4 -r 1 -f image2 yyy_%03d.jpg -y
str = 'c:/users/xxxx/ffmpeg/ffmpeg.exe ' + 
      '-ss 0:0:12 -i xxx.mp4 -r 1 -f image2 d:/images/{}_%03d.jpg -y'

str_cmd = str
print(str_cmd)

os.popen(str_cmd)

定时提取视频中的图片，并截取需要的区域

import os
import time
import cv2
import matplotlib.pyplot as plt

ss = 'c:/users/xxxx/ffmpeg/ffmpeg.exe ' + 
      '-ss {} -i xxx.mp4 -t 0.01 -f image2 d:/images/{}.jpg -y'

for sec in range(60):
    cmd = ss.format(str(sec), str(sec))
    print(cmd)
    os.popen(cmd)
    time.sleep(0.5)

for i in range(60):
    img = cv2.imread('d:/images/{}.jpg'.format(str(i)), 0)

    cut = img[803:835, 533:595]
    # 二值化
    # _, cut1 = cv2.threshold(cut, 50, 220, cv2.THRESH_BINARY)
    cv2.imwrite('d:/cuts/{}.jpg'.format(str(i)), cut)

    plt.subplot(6, 10, i+1)
    plt.imshow(cut)
    # plt.title(i)
    plt.xticks([]), plt.yticks([])

# plt.savefig('yyy.png', dpi=300)
plt.show()