#
# The Python Imaging Library
# $Id$
#
# split an animation into a number of frame files
#

from PIL import Image
import os, string, sys

class Interval:

    def __init__(self, interval = "0"):

        self.setinterval(interval)

    def setinterval(self, interval):

        self.hilo = []

        for s in string.split(interval, ","):
            if not string.strip(s):
                continue
            try:
                v = string.atoi(s)
                if v < 0:
                    lo, hi = 0, -v
                else:
                    lo = hi = v
            except ValueError:
                i = string.find(s, "-")
                lo, hi = string.atoi(s[:i]), string.atoi(s[i+1:])

            self.hilo.append((hi, lo))

        if not self.hilo:
            self.hilo = [(sys.maxint, 0)]

    def __getitem__(self, index):

        for hi, lo in self.hilo:
            if hi >= index >= lo:
                return 1
        return 0

# --------------------------------------------------------------------
# main program

html = 0

if sys.argv[1:2] == ["-h"]:
    html = 1
    del sys.argv[1]

if not sys.argv[2:]:
    print
    print "Syntax: python explode.py infile template [range]"
    print
    print "The template argument is used to construct the names of the"
    print "individual frame files.  The frames are numbered file001.ext,"
    print "file002.ext, etc.  You can insert %d to control the placement"
    print "and syntax of the frame number."
    print
    print "The optional range argument specifies which frames to extract."
    print "You can give one or more ranges like 1-10, 5, -15 etc.  If"
    print "omitted, all frames are extracted."
    sys.exit(1)

infile = sys.argv[1]
outfile = sys.argv[2]

frames = Interval(string.join(sys.argv[3:], ","))

try:
    # check if outfile contains a placeholder
    outfile % 1
except TypeError:
    file, ext = os.path.splitext(outfile)
    outfile = file + "%03d" + ext

ix = 1

im = Image.open(infile)

if html:
    file, ext = os.path.splitext(outfile)
    html = open(file+".html", "w")
    html.write("<html>\n<body>\n")

while 1:

    if frames[ix]:
        im.save(outfile % ix)
        print outfile % ix

        if html:
            html.write("<img src='%s'><br>\n" % outfile % ix)

    try:
        im.seek(ix)
    except EOFError:
        break

    ix = ix + 1

if html:
    html.write("</body>\n</html>\n")
