Embed ablum cover into MP3 file using FFmpeg

ffcover.py

#!/usr/bin/env python2.7

from optparse import OptionParser
from subprocess import call
import os.path
import os
import tempfile

img_max_width_or_height = 256

def ffcover(filename, cover, right):
	cwd = os.path.dirname(filename)
	tmpfile = tempfile.mktemp(dir=cwd)
	if right:
		axis_x = 'iw-min(iw,ih)'
		axis_y = 'ih-min(iw,ih)'
	else:
		axis_x='0'
		axis_y='0'
	cmd = [ 'ffmpeg', '-hide_banner', '-y', '-i', filename, '-i', cover, 
			'-map', '0:a', '-map', '1:v', 
			'-c:a', 'copy', '-id3v2_version', '3', 
			'-c:v', 'mjpeg',
			'-filter:v',
			'scale=\'if(eq(if(gte(iw,ih),iw,-2),-2),-2,min(iw,{0})):if(eq(if(gt(ih,iw),ih,-2),-2),-2,min(ih,{0}))\',crop=\'min(iw,ih):min(iw,ih):{1}:{2}\''.format(img_max_width_or_height, axis_x, axis_y), 
			'-metadata:s:v', 'title=Album Cover', 
			'-metadata:s:v', 'comment=Cover (Front)',
			'-f', 'mp3', 
			tmpfile ]
	try:
		ret = call(cmd,stdout=open(os.devnull, 'w'), stderr=open(os.devnull, 'w'))
		if ret == 0:
			os.rename(tmpfile, filename)
	finally:
		if os.path.exists(tmpfile):
			os.remove(tmpfile)

if __name__=='__main__':
	parser = OptionParser('ffcover.py -c COVER FILE1 [FILE2 ...]')
	parser.add_option('-c', metavar='FILE', dest='cover', help='Cover file.')
	parser.add_option('-r', action='store_true', dest='right')
	opts,  args = parser.parse_args()
	for f in args:
		ffcover(f, opts.cover, opts.right)