srt_resync

#!/usr/bin/env python
#Python 2 compatible (tested with 2.6.6)
#This script assumes a lot, and doesn't follow many DRY guidelines. There's a lot of room for improvement.
#It also only works with positive offsets, as it was what I needed. Might update it to work with negative offsets.
#Created to resync some Curb Your Enthusiasm subtitles. Great show by the way. :)

"""
srt_resync.py: Give it 2 parameters: first the path to the file, and second an offset in positive seconds (can be fractional).
The script produces a file with the same name with "-resync" appended to the end of the filename (before the extension)
"""

__author__ = "Nuno Melo";
__copyright__ = "Copyleft 2012";
__credits__ = ["Nuno Melo"];
__license__ = "WTFPL";
__version__ = "1.0b";

import re, sys, math, os;

HOURS_IN_SECONDS = 59*59;
MINUTES_IN_SECONDS = 59;

LINE_BREAK = "\n";

args = sys.argv;

def resync(time, hours, minutes, seconds, ms):
    tokens = time.split(':');
    new_hours = int(tokens[0]) + hours;
    new_minutes = int(tokens[1]) + minutes;
    tokens = tokens[2].split(',');
    new_seconds = int(tokens[0]) + seconds;
    new_ms = int(tokens[1]) + ms;
    while new_ms-999 >= 0:
        new_ms -= 999;
        new_seconds += 1;
    while new_seconds-59 >= 0:
        new_seconds -= 59;
        new_minutes += 1;
    while new_minutes-59 >= 0:
        new_minutes -= 59;
        new_hours += 1;
    return "%s:%s:%s,%s" % (str(new_hours).zfill(2), str(new_minutes).zfill(2), str(new_seconds).zfill(2), str(new_ms).zfill(3));


if len(args) == 3:
    srtf = args[1];
    try:
        diff = float(args[2]);
    except ValueError:
        print "Usage: python %s file_path number_seconds" % args[0];
        sys.exit(1);

    #get actual numbers
    hours = 0;
    minutes = 0;
    seconds = 0;
    ms = 0;
    while diff-HOURS_IN_SECONDS >= 0:
        hours += 1;
        diff -= HOURS_IN_SECONDS;
    while diff-MINUTES_IN_SECONDS >= 0:
        minutes += 1;
        diff -= MINUTES_IN_SECONDS;
    seconds = int(diff);
    ms = int((diff-seconds)*999);

    try:
        f = open(args[1], 'r');
    except IOError:
        print "File does not exist. Exiting...";
        sys.exit(1);

    data = f.read();

    lines = re.findall(r"([0-9]{1,3})(?:\r)?\n?([0-9]{2}:[0-9]{2}:[0-9]{2},[0-9]{3}) --> ([0-9]{2}:[0-9]{2}:[0-9]{2},[0-9]{3})(?:\r)?\n(.*?(?:\r)?\n(?:\r)?\n)", data, re.DOTALL);

    file_ext = os.path.splitext(args[1])[1];
    new_file = args[1].replace(file_ext, "-resync" + file_ext);
    out = open(new_file, 'w');

    for nuple in lines:
        new_start = resync(nuple[1], hours, minutes, seconds, ms);
        new_end = resync(nuple[2], hours, minutes, seconds, ms);
        out.write(nuple[0] + LINE_BREAK);
        out.write(new_start + " --> " + new_end + LINE_BREAK);
        out.write(re.sub('(?:\r)\n', LINE_BREAK, nuple[3]));


    f.close();
    out.close();

    print "Resynced %s." % args[1];
else:
    print "Usage: python %s file_path number_seconds" % args[0];