import zipfile
import os
import random
import string
import shutil

def gen_random_string(_len):
    result = ""

    for i in range(_len) :
        result += random.choice(string.ascii_letters)
    return result

def find_file(base_dir,_ext):

    return_list = []

    for (path, dir, files) in os.walk(base_dir):
        for filename in files:
            ext = os.path.splitext(filename)[-1]
            if ext == _ext:
                return_list.append(os.path.join(path,filename))
    return return_list



current_dir = os.getcwd()
pptx_files = find_file(current_dir, ".pptx")

for pptx_file in pptx_files:
    tmp_extract_dir_name = os.path.join(current_dir, gen_random_string(10))


    pptx = zipfile.ZipFile(pptx_file)
    pptx.extractall(tmp_extract_dir_name)
    pptx.close()

    sound_list = find_file(tmp_extract_dir_name, ".mp3")

    for mp3 in sound_list:
        tmp_out_name = os.path.join(os.path.dirname(mp3), gen_random_string(10) + ".mp3")

        os.system("ffmpeg -y -i \"%s\" -filter:a \"atempo=%f\" -vn \"%s\""%(mp3,1.5,tmp_out_name))
        os.remove(mp3)
        os.rename(tmp_out_name,mp3)


    out_fname = os.path.splitext(pptx_file)[0] + "_FAST"
    shutil.make_archive(out_fname, 'zip', tmp_extract_dir_name)
    os.rename(out_fname + ".zip", out_fname + ".pptx")