Both DVD and Blu-ray use bitmap based subpictures for subtitles. In fact the two formats are extremely simmilar, so once you've extracted your DVD subtitles (see our guide for Extracting Content From DVD), the process for converting them is quite simple.
For converting you can use a program called BDSup2Sub, and our DVD to Blu-ray subtitle conversion guide.
You can watch the videos below for a better idea of what the guide covers. All three videos are also included with the guide.
The basic process is simple. First load the extracted subtitles, then check for any errors, and finally save to BDN XML format:
Sometimes there may be additional operations required. For example, maybe you want to make the subtitles larger or smaller or change the display time to match a PAL to NTSC or NTSC to PAL conversion.
BDSup2Sub can handle all those options, as you can see below:
Finally, BDSup2Sub can be used to change the position of subtitles on the screen. This is particularly handy if you want to move subtitles that partially cover the image so they only cover the letterbox.
You may want to use it alongside the resize feature.
Written by: Rich Fiscus @ 1 Sep 2011 21:27