批量修改mp3文件播放速度

#coding=utf-8
import sys,os ,shutil
import struct
import glob
import time
import subprocess


def process_audio(file_name,to_file):
    command='ffmpeg -i {} -af atempo=0.85 {} '.format('"'+file_name+'"',to_file.replace(' ','_'))
    print(command)
    os.system(command)

def process_file(file_name,dest_node):
    if not file_name.endswith('.mp3'):
        return;
    process_audio(file_name,dest_node)

def process_dir(folder):
    for sub_node in glob.glob ( folder+'/*' ):
        dest_node=sub_node.replace(node,"../processed/")
        if os.path.isdir(sub_node):
            if not os.path.isdir(dest_node):
                os.mkdir(dest_node)
            process_dir(sub_node)
        else:
            process_file(sub_node,dest_node)

node=sys.argv[1]
if os.path.isdir(node):
    process_dir(node)
if os.path.isfile(node):
    with open(node, 'r') as file_to_read:
        for line in file_to_read.readlines():
            process_file(line)