Posted by chantra on April 18th, 2006
In a previous article I introduced subtitleeditor and explained how-to create a new subtitle from scratch. This article is going to explain how you can synchronise subtitles with subtitle editor. From changing the framerate to moving subtitles or scaling, here we go.
Subtitle editor make subtitle synchronisation real easy. There is three main reasons for subtitles not being synchronised:
- The framerate of the movie, and the one the subtitles are made for, are different. This causes the subtitles and the movie to go at different speeds, therefore, while watching the movie, sound and subtitles become un-synchronised.
- The subtitles and the movie are synchro, but one is delayed compared to the other one. This is really simple to fix.
- A combination of the first two reasons. This is a pain to fix, but this is where scaling gets interesting.
Sometimes, framerate needs to be changed in order to synchronise the audio and the subtitles. When the framerate is not appropriate to the movie, the delay increase meanwhile the movie runs. For instance, let say that when the movie starts, subtitles are delayed from 1 second, when the movie stops, they are delayed from 1 minute. This means that framerate are different on the movie and the subtitles.
Using mplayer, you can get the framerate on the movie:
check for a line like:
VIDEO: [DIVX] 352x216 24bpp 25.000 fps 1044.1 kbps (127.5 kbyte/s)
another way to do this, is to pass the mouse over a movie file in konqueror, a pop-up then open, telling which framerate the movie was made at.
Basically, if subtitles run faster than the movie, the subtitles'framerate is higher than the one for the movie.
Now, let's get back to it.
Changing framerate is made pretty easily. Firt of all open a subtitles file (Ctrl+O), then go to Edit->Change FPS, then choose among the list which source framerate it is supposed to be, and choose which final framerate you want them to be. Press OK, Save it and it is done.
Nota: since subtitleeditor-0.8.0, you need to go to Tools->Change FPS.
Another common trouble with subtitles is when subtitles are simply delayed, they are synchronise but delayed. For instance, the subtitles are delayed from 1 minute at the beginning of the movie, and still delay from 1 minute at the end.
This is far easier to correct than when the framerate is not correct.
Dealing with this is real simple. Start the movie, note somewhere at what time the first subtitle should be displayed.
Now, open your subtitles file (Ctrl+O), select the first line you want to move and then Edit->Move Subtitle.
You can define at what time the selected subtitle has to start at. Once you entered the correct time (the one you noted aside above), press OK, all subsequents subtitles frame will be displaced from the approriate timing (let say you added 30 seconds from the original timing, all subtitles frame coming after will be move from 30 seconds).
Save it and enjoy your movie with proper subtitles
Scaling subtitles helps you synchronizing subtitles with wrong framerate and delay. The basic idea is to determine the time when the first subtitle should be displayed, and the time the last subtitle should be shown. You could basically choose any pairs of subtitles to do this, but to get a better result, you should definitely go for the first and last one.
To get to that fonctionnality, go to Editor->Scale, then supply the right values for the first subtitle and the last one (note that you can choose different subtitles entries than the predifined first and last).
Nota: Since subtitleeditor-0.8.0, you have to go to Tools->Scale.
It is as simple as that!
Finally linux get it's first real subtitles editor, this was a long time needed tool for people loving watching movies undubbed.