Sift through MPEG transport footage from prosumer cameras and convert to 1/10th the size for playback

sift_mrs.py

import os
from subprocess import call

root = "."

def crawl_folder(root):
    '''crawl filesystem and apply encoding function'''
    root = os.walk(root) #walk filesystem, return tuples
    for root, dirs, files in root: #for each tuple, check for streamers dict, create dict and encode
        for filename in files:
            if '.MTS' in filename: 
                os.mkdir(root + '/streamers')
                os.chdir(root)
                map(encode, files) #map encode over each dict of files
                break   

def encode(contents):
    if '.mts' in contents.lower(): #check to see if MPEG transit stream
        new_name = contents[:-4]+'_streamer.mp4' 
        command = "ffmpeg -v verbose -i "+ contents +" -acodec copy -vf 'field, scale=iw/2:ih, setsar=1' -vcodec libx264 -g 60 -crf 30 -threads 8 -preset slow -y streamers/" + new_name 
        call(command, shell=True) #calll ffmpeg and place new file in new dict
        #Beware files only play in VLC

if __name__=='__main__':
    crawl_folder(root)