multiprocessing ffmpeg

change_fps.py

import multiprocessing, os, Queue, subprocess, sys
from time import sleep

class Worker(multiprocessing.Process):
    '''http://jeetworks.org/node/81 modified example in the comments'''
 
    def __init__(self, work_queue):
 
        # base class initialization
        multiprocessing.Process.__init__(self)
 
        # job management stuff
        self.work_queue = work_queue
        self.kill_received = False

    def run(self):
        
        while not self.kill_received:
 
            # fetching a new task
            try:
                n_job, fp = self.work_queue.get_nowait()
            except Queue.Empty:
                break
            
            # the actual processing
            print("Starting " + str(n_job) + " ... " + fp)
            cmd = (
                r"C:\hg\cam_iface\ffmpeg.exe", # path to your ffmpeg here
                '-an',                      # ignore audio
                '-analyzeduration', '0',    # skip auto codec analysis
                '-y',                       # overwrite output file if exists
                '-i', fp,
                '-vf', 'setpts=PTS/3.0',    # speed up fps x3
                '-r', '30',                 # i want video rate
                '-qscale', '5',             # video quality rather high
                fp[:-4] + '_30fps.avi'
                )
            p = subprocess.Popen(cmd)
            stdoutdata, stderrdata = p.communicate() # this makes the process wait till done
            print 'done!'


if __name__ == "__main__":
    ' drop files to this .py file to transcode them'
    work_queue = multiprocessing.Queue()
    for n, fp in enumerate(sys.argv[1:]):
        work_queue.put( (n, fp) )
    
    for i in range( multiprocessing.cpu_count() ):
        worker = Worker(work_queue)
        worker.start()
    
    sleep(10) # handy to have this here for debugging