webmifier.py

import os, sys, subprocess, shlex, argparse, multiprocessing

def dir(path):
	if os.path.isdir(path):
		return path
	else:
		raise argparse.ArgumentTypeError("%s is not a valid directory" % (path))

def process_dir(path, dest):
	files = os.listdir(path)
	gifs = []
	for f in files:
		name, ext = os.path.splitext(f)
		if ".gif" in ext.lower():
			gifs.append(
				(os.path.abspath(f), os.path.join(os.path.abspath(dest), name + '.webm'))
			)
	
	return gifs
	
def convert(path):
	inf, out = path
	
	if os.path.lexists(out):
		return
	
	args = shlex.split('ffmpeg -i "%s" -an -c:v libvpx-vp9 -strict experimental -crf 10 -qmin 4 -qmax 20 -b:v 5000k -y "%s"' % (inf, out))
	proc = subprocess.Popen(args)
	proc.wait()
	
if __name__ == '__main__':
	multiprocessing.freeze_support()
	pool = multiprocessing.Pool(multiprocessing.cpu_count())
	
	p = argparse.ArgumentParser()
	p.add_argument("gifpath", type=dir, default=".")
	p.add_argument("destpath", type=str, default="webm")
	args = p.parse_args()

	files = process_dir(args.gifpath, dest=args.destpath)
	print "Found %d gifs ..." % (len(files))

	print "Starting to convert gifs to webm/vp9 with %d threads ..." % (multiprocessing.cpu_count())

	pool.map(convert, files)
	
	print "Done!"