Makeshift add delay to .SRT files.

script.py

subs = SubtitleFile("the grudge.srt")
subs.delay(-1000)
subs.save("new subs.srt")

subdelay.py

# Convert SRT time format string to millisecond integer.
def toMillisecs(srtFormatStr):
    timeCompData = srtFormatStr.split(",")
    timeData = timeCompData[0].split(":")
    milliData = timeCompData[1]
    
    hours     = int(timeData[0]) * 36000000
    minutes   = int(timeData[1]) * 60000
    seconds   = int(timeData[2]) * 1000
    millisecs = int(milliData)
    
    return hours + minutes + seconds + millisecs

# Convert millisecond integer to SRT time format string.
def toSRTFormat(millisecs):
    hours = millisecs // 36000000
    millisecs = millisecs - hours * 3600000
    mins = millisecs // 60000
    millisecs = millisecs - mins * 60000
    secs = millisecs // 1000
    millisecs = millisecs - secs * 1000
    
    if hours < 9: hours = "0" + str(hours)
    if mins  < 9: mins  = "0" + str(mins)
    if secs  < 9: secs  = "0" + str(secs)

    out = ""
    out += str(hours) + ":"
    out += str(mins)  + ":"
    out += str(secs)  + ","
    out += str(millisecs)
    return out

class SubtitleFile:
    def __init__(self, filename):
        self.data = []
        self.read(filename)
        
    def read(self, filename):
        file = open(filename)
        line = "bleh"


        while line != "":
            entry = {"subs": ""}
            
            line = file.readline() # ignore the numeric identifier
            line = file.readline()
            startTime, stopTime = line.split(" --> ")
            entry["startTime"] = toMillisecs(startTime)
            entry["stopTime"] = toMillisecs(stopTime)
            
            line = file.readline()
            
            while line != "\n":
                if line == "":
                    break

                entry["subs"] += line
                line = file.readline()
            print(entry)
            self.data.append(entry)


    def delay(self, delay):
        for i in range(len(self.data)):
            self.data[i]["startTime"] += delay
            self.data[i]["stopTime"] += delay
    
    def save(self, filename):
        index = 1
        file = open(filename, "w")
        
        for i in range(len(self.data)):
            startTime = toSRTFormat(self.data[i]["startTime"])
            stopTime = toSRTFormat(self.data[i]["stopTime"])
            
            file.write(str(index) + "\n")
            file.write(startTime + " --> " + stopTime + "\n")
            file.write(self.data[i]["subs"])
            file.write("\n")
            index += 1
        file.close()