DVD Subtitle converter - synchronizer in details

Subtitles formatted in SRT (SubRip) are calculated in a number of minutes + seconds as where the SUB (MicroDVD) format calculates the display position of a subtitle in a number of frames per second.
Besides, as where the first uses an arrow (-->) to indicate the duration of a displayed subtitle, the second uses two values express in FPS indicated between curly brackets.

Example of .SRT (SubRip) subtitle format :

00:00:05,130 --> 00:00:08,167
<i>I've always been able</i>
<i>to sleep through anything.</i>

00:00:08,383 --> 00:00:12,137
<i>Storms, sirens, you name it.</i>
<i>Last night, I didn't sleep.</i>


Example of .SUB (MicroDVD) subtitle format :

{123}{196} I've always been able | to sleep through anything.
{201}{291} Storms, sirens, you name it. | Last night, I didn't sleep.

Advance / Delay : It often happens that subtitles of a DVD or movie are shifted in time in regards to the voices, either being displayed too soon or too late. To resolve this shifting problem (synchronisation), you can use the option "Advance / Delay subtitle display" expressed in seconds to shift the subtitles in regards to the picture. Use a negative time, for instance -10, to make subtitles appear 10 seconds earlier, use a positive time, for instance +10, to make them appear 10 seconds later.

Stretch : You are probably familiar with a phenomene where the subtitling starts exactly at the right moment where they should start but where they slowly start to desynchronise where, towards the end of the movie, the subtitles may be displayed minutes too early? This is often explained by the fact that your subtitles are for a movie in 24fps while the movie itself counts 25fps. And the subtitles will desynchronise more and more as time passes. Yet it is quite simple to resynchronise your subtitles so they'll fit, there are two possibilities; Either you can first convert into a different format (for instance SRT into SUB) while choosing 25fps, then reconvert the obtained result again into SRT. Or perhaps even more easy; if you know how much time in seconds comes up "missing" towards the end of your movie, you can use the option "Stretch" while indicating to extend for instance 120 seconds in combination with the option "Do not convert" to keep the same format (SRT only). This option may be handy if you are not sure of the original fps rate used for your subtitles but if you do know, roughly, the time missing towards the end of your movie.
Astuce : Look at the timestamp of the last phrase used in your subtitle file and then watch the end of your movie and write down at which actual time this phrase is used. Then take the difference of the two in seconds.

Example :

00:46:57,480 --> 00:47:00,233 <-- 46*60+57 = 2817 seconds
That were the best years of my life.

Then, watch only the end of your movie and write down when this phrase is actually used, for instance at 48m49s <-- 48*60+49 = 2929 seconds

The difference between the two will then be 2929-2817 = 112 seconds to Stretch (it won't be a complete coincidence if 1.039758 is close to 25fps/24fps ?)

Strip : It may also happen that a text supposely being displayed in italics, some DVD readers actually show the <i> and </i> markers as part of the text. You may use the option "Strip <i> / </i>" to delete these

Renumber lines : When the numbered lines in a .SRT subtitle text are not in sequence, for instance when some lines were deleted, use this option to renumber the lines to get again a correct numbered sequence.

Remove empty lines : Removes (delete) empty lines from subtitles.

Do not convert : For those that do not want to convert the format (said otherwise, do SRT into SRT or SUB into SUB) but just only want to modify or manipulate the original format, for instance for easy timeshifting or stretching on an existing SRT or SUB formatted file, you may check the option "Do not convert".

After having clicked the "Convert" button, SUB or SRT formatted text (depends on the input format) will appear below the form. Click "Select all", copy (right-click and copy), open a new file with a text editor (like Notepad), paste the text and save the file as "myfile.sub" or "myfile.srt".