How to perfectly synchronize Subtitles with movie?

If the sync error remains constant then you have a delay issue.

If you are using version 0.8.2 or above then keys g and h will allow you to adjust the sync delay during playback.

If your subtitles are appearing and disappearing too early then use h to increase the delay until they appear at the correct time.

If your subtitles are appearing and disappearing too late then use g to decrease the delay until they appear at the correct time.

If the sync gets worse (gets more and more ahead or behind) as the playback progresses then you have a timing issue.

This is usually due to a subtitle file being set up for a different frame rate than the video.

You will need to convert the subtitle file to match the frame rate of the video.

As you are using .SRT subtitle files there are some suggestions on tools to re-time them on this SuperUser question: Which is the best subtitle file editor (srt)?

You can use MediaInfo to check the frame rate of both video and subtitle files to help you decide which conversions are required on the subtitle files.

Try Easy Subtitles Synchronizer (ESS). It is a freeware tool that creates, repairs and synchronizes your subtitles easily.

You can easily change synchronization of your subtitles with any modern video player today. However, if you want to permanently setup synchronization you need to do it manually (hard way) or by using some specialized software.

Definitely my own favorite is Subtitle Workshop, and through it you can do much more than just sync your subtitle. It supports practically every single subtitle format you may find and use today.