Handy as they are, subtitles can turn extremely irritating if they’re out of sync with the video. They distract you, and you end up understanding even less than what you’d have without the subs. Thankfully, if you’re using VLC player to watch the videos, you can make use of a nifty feature in the program to sync the subtitle with the video! Do note that it’ll only temporarily sync the subtitles with the video, and the sync will be gone the next time you watch the video.
Anyway, lets get started with how to implement it. I’m assuming that you’ve already loaded the video and subtitle files into VLC (you can just drag them both into its interface). Now, carefully take a look at the video and the subs, and see whether the subs are lagging behind or running ahead of the video. If you’re watching a foreign movie, it may seem like a very difficult job, but just try a little hard and you should be able to make this out. For example, if you see a girl screaming and running around wildly, and the subs show “Help me! Help me!” 3 seconds after that scene, this means that the titles are 3 seconds behind the movie.
Once you’ve figured out the lag / lead of the subtitle, it’s time to sync it with the video. In VLC, navigate to Tools > Track Synchronization, where you’ll find the Subtitles/Video section. Now comes the important part – syncing the subtitle. If the subtitle is lagging behind the video, you’ve to provide a negative value to ‘Advance of subtitles over video’. Say the subs display 3 seconds after the video, the value you got to enter is –3.000 s. Note that you can adjust the sync time to up to a thousandth of a second, although adjusting to the tenths does the job in all cases. Similarly if the subtitle is ahead of the video, enter the required positive number of seconds. Hit the Refresh button at the top right corner of the window, and you should see the change immediately.
You can also use the g/h keys to delay/advance the subtitle by 50 milli-seconds each! So if you want to slow the subtitle down by 0.5 seconds, hit g ten times.
There’s another option called ‘Speed of the subtitles’ in there. Normally, the subtitles should run for the same time as that of the video. However in rare cases, if you do come across a subtitle that wraps up faster (or slower) than the video, you can make use of that particular option. If the subtitle advances too slowly (starts with proper sync, but then increasingly lags behind), increase the “fps” (frames per second) value to something above 1.0, the value depending upon the relative speed of the subtitle. Similarly for fast subtitles, decrease the fps value so that they’ll keep in pace with the video and won’t run ahead faster.
As I said, both these features are only temporary and last as long as the video is open in VLC. If you want a permanent solution, you should instead look for perfectly syncing subtitles. Sublight is one useful tool that’ll help you get them. Sublight even has a built-in syncing tool that’ll permanently sync de-synced subtitles with their respective videos.
Of course, if for any reason you cannot, or do not want to, use Sublight, VLC’s swift little trick has always got you covered. :)