python通过ffmgep从视频中抽帧的方法

import os, sys
from PIL import Image
#open a pipe from a command 
a, b, c = os.popen3(\"ffmpeg -i test.avi\")
out = c.read()
dp = out.index(\"Duration: \")
duration = out[dp+10:dp+out[dp:].index(\",\")]
hh, mm, ss = map(float, duration.split(\":\"))
#total time ss
total = (hh*60 + mm)*60 + ss
for i in xrange(9):
 t = int((i + 1) * total / 10)
 # ffmpeg -i test.mp4 -y -f mjpeg -ss 3 -t 1 test1.jpg 
 os.system(\"ffmpeg -i test.avi -y -f mjpeg -ss %s -t 1  %i.jpg\" % (t, i))
 
\"\"\"
num=int(total-3)
i=0
for t in xrange(0,num,3):
 i = i+1
 # ffmpeg -i test.mp4 -y -f mjpeg -ss 3 -t 1 test1.jpg 
 os.system(\"ffmpeg -i test.avi -y -f mjpeg -ss %s -t 1 %s %i.jpg\" % (t,t, i))
\"\"\"