Vertiggo's Subtitle Guide (if all you have is mkvmerge)

[vertigoanduminas]

It's become obvious that many people are in need of some pointers when it comes to adapting subtitles to films, as I have been asked several times personally and have had to adjust many subtitles for my own use. I will attempt to break this process down as carefully as possible so anyone can understand and perform it.

First, what is needed? For muxing I use mkvmerge GUI which installs with mkvtoolnix from here:

http://www.bunkus.org/videotools/mkvtoolnix/downloads.html#windows

For subtitle files I look here first, and then Google if I find nothing:

http://www.opensubtitles.org/en/search/sublang-en

For playing the files I always use Zoomplayer, as it has thousands of options (if you want them) and a simple method of jumping to precise frames:

http://www.inmatrix.com/files/zoomplayer_download.shtml

1 - In mkvmerge, add the .mkv for video and audio tracks, and the .srt for subtitles. (The first time you do this don't bother with the delay and stretch values, these are just included for mention later)

2 - Now play the resulting .mkv and select a subtitle at each end of the film (preferrably the first and last subtitles you can be sure of). You need to be able to know exactly which frame they should begin on and they should be as far apart as possible. In Obitaemyy ostrov I chose these two because I knew exactly which bits of Russian audio they correspond with in the film. (it's always easier with names or if you can match someone's reaction in the video track to what they should be saying):

13
00:02:20,474 --> 00:02:25,062
Maxim, where are you? Maxim?

1296
01:54:05,429 --> 01:54:06,013
Mak

These are copied from the original subtitle file, so the times will be slightly incorrect.

3 - Using Zoomplayer's scene cut editor (right click>open interface>scene cut editor), "get current position" for each subtitle exactly where it shows up, and each spot the corresponding audio/video track. For example, I played this film at 0:2:18 until the words "Maxim, where are you? Maxim?" showed up, and that was my first subtitle time. Then I played it until the audio track begins to say those words (Maxim, bla bla bla? Maxim?) and that was my first audio time. I did the same thing for the "Mak" selection near the end of the film and then I had a ratio I could work with. The recorded times looked something like this (I forget the exact numbers):

Subtitle 1 00:02:20,474
Audio 1 00:02:20,742
Subtitle 2 01:54:05,429
Audio 2 01:54:07,243

From this data I knew that the subtitles were set a little early, and that they also needed to stretch to match the audio.

4 - For this movie, use a subtitle delay of 300 milliseconds and if the first subtitles are still off, adjust the value until the first subtitles line up with the first audio/video.

5 - Once you have the first subs lined up, you need to stretch. My stretch settings for Obitaemyy ostrov were 6707/6704, which was

(Audio 2 - Audio 1) / (Subtitle 2 - Subtitle 1) or
(01:54:07,243 - 00:02:20,742) / (01:54:04,429 - 00:02:20,474)
(6847 - 140) / (6844 - 140) = 6707/6704

I add up the hours, minutes and seconds to find out exactly how many seconds each time equates to and do the math. Once you've run mkvmerge with the delay of 300ms and stretch of 6707/6704, your resulting .mkv should view perfectly. If it doesn't, you have to adjust the stretch and delay until it does.

Bottom line is, the nearer the beginning your first subtitle is, the more fixed it will be when stretching, so it will save tries, and the later in the film your second subtitle is, the more accurate your ratio will be of subtitle to audio, and stretching will be easier.

Please make a note of anything I'm not clear on, so I can update this guide or clarify things.

[AlanHK]

I think it's a lot easier to adjust subtitles using Subtitle Workshop.
Basically the same procedure, but it handles all the calculations, with three clicks.

2.2.2 Method 2: synchronize using two points
This method will work very well in most cases. It works by taking two points of the subtitle file and two points of the video, and calculate the times using a linear algorithm. The first pair of points will be called "First sync points" and the last pair of points will be called "Last sync points". Each pair of points consist in one point in the subtitle and one point in the video, the point in the subtitle has the wrong times and the point of the video has the right times. After selecting the first sync points and last sync points Subtitle Workshop calculates the rest of the times appropriately. The closer first sync points are to the beginning and last sync points are to the end, the most accuracy you get. Note: if the point of the subtitle selected in the first sync points corresponds to the first subtitle, and the point of the subtitle selected in the last sync points corresponds to the last subtitle, then the first formula (first and last dialogs) will be used.

After understanding this basics you have to do this:
First of all, select the subtitle you want to mark as first point. The first point in the subtitle will always be the selected subtitle's initial time.
Play the video until you find the right time for that subtitle (this will be the first point in the video), when you do, click the "Mark as first sync point" button or press the [Ctrl]+[1] keys.
Now select the subtitle you want to mark as last sync point. The last sync point will be the selected subtitle's initial time.
Play the video until you find the right time for that subtitle (this will be the last point in the video), when you do, click the "Mark as last sync point" button or press the [Ctrl]+[2] keys.
After doing this you will get a confirmation message, click "Yes" and the subtitle will be instantly synchronized.

Also, you shouldn't use "CODE" tags for your links.