Add comments and options
diff --git a/Demo/sgi/video/Vinfo.py b/Demo/sgi/video/Vinfo.py
index 3293e41..2aec803 100755
--- a/Demo/sgi/video/Vinfo.py
+++ b/Demo/sgi/video/Vinfo.py
@@ -1,12 +1,53 @@
+#! /usr/local/python
+
+# Print some info about a CMIF movie file
+
+
+# Usage:
+#
+# Vinfo [-d] [-q] [-s] [file] ...
+
+
+# Options:
+#
+# -d       : print deltas between frames instead of frame times
+# -q       : quick: don't read the frames
+# -s       : don't print times (but do count frames and print the total)
+# file ... : file(s) to inspect; default film.video
+
+
 import sys
+sys.path.append('/ufs/guido/src/video')
 import VFile
+import getopt
+
+
+# Global options
+
+short = 0
+quick = 0
+diffs = 0
+
+
+# Main program -- mostly command line parsing
 
 def main():
-	if sys.argv[1:]:
-		for filename in sys.argv[1:]:
-			process(filename)
-	else:
-		process('film.video')
+	global short, quick, diffs
+	opts, args = getopt.getopt(sys.argv[1:], 'dqs')
+	for opt, arg in opts:
+		if opt == '-q':
+			quick = 1
+		elif opt == '-d':
+			diffs = 1
+		elif opt == '-s':
+			short = 1
+	if not args:
+		args = ['film.video']
+	for filename in args:
+		process(filename)
+
+
+# Process one file
 
 def process(filename):
 	vin = VFile.VinFile().init(filename)
@@ -17,22 +58,37 @@
 	print 'Bits:    ', vin.c0bits, vin.c1bits, vin.c2bits
 	print 'Format:  ', vin.format
 	print 'Offset:  ', vin.offset
-	print 'Frame times:',
+	if quick:
+		vin.close()
+		return
+	if not short:
+		print 'Frame times:',
 	n = 0
 	t = 0
+	told = 0
 	while 1:
 		try:
 			t, data, cdata = vin.getnextframe()
 		except EOFError:
-			print
+			if not short:
+				print
 			break
-		if n%8 == 0:
-			sys.stdout.write('\n')
-		sys.stdout.write('\t' + `t`)
+		if not short:
+			if n%8 == 0:
+				sys.stdout.write('\n')
+			if delta:
+				sys.stdout.write('\t' + `t - told`)
+				told = t
+			else:
+				sys.stdout.write('\t' + `t`)
 		n = n+1
 	print 'Total', n, 'frames in', t*0.001, 'sec.',
 	if t:
 		print '-- average', int(n*10000.0/t)*0.1, 'frames/sec',
 	print
+	vin.close()
+
+
+# Don't forget to call the main program
 
 main()