Aegisub is an open-source application carefully designed to help you create, modify, correct, and synchronize subtitles in any language for your favorite movies and other video files. This feature-rich tool comes with all the functions required to produce high-quality professional subtitles in the most intuitive and straightforward way.
Aegisub can open and create subtitles files in all the most popular formats, such as SRT, ASS, SSA, and SUB, an advantage that will also allow you to convert your subtitle files between formats. It also offers you various tools to guarantee the quality of your subtitles, such as a spell checker (complete with a thesaurus), a translation assistant, a duplicate lines finder, a translation assistant, etc.
When creating your own subtitles from scratch, you can make use of the program’s video player to sync images and text in the most intuitive way. The program’s audio player is also a great help when synchronizing subtitles accurately with specific speech fragments. You will also find easy-to-use features to correct the most common syncing problems that arise when adding external subtitle files to an existing movie. The “Shift Times” feature will let you adjust one or more timestamps accurately (down to the centisecond), either forwards or backwards, and to selected lines only or to the entire set of subtitles. Other time correction tools will check the start and end times of each line and will make sure that none of them overlap each other, that the time between lines is correct, etc.
Aegisub includes tools to modify the appearance of your subtitles in the way that better fits your preferences. You can not only change the font type, color, or size, but also place the subtitles anywhere on the screen, horizontally or vertically, centered or aligned to the left or the right, add a shadow effect to the letters, etc. You can even open ASSDraw3 (it installs automatically together with Aegisub) and design your own banners and posters and use them together with your subtitles.
This high-end subtitle tool offers you more features than those noted in this review, but those are for you to discover. Being a free open-source utility, there is no reason for anyone interested in creating their own subtitles or in editing existing ones to not download and install Aegisub on their computer. There is no better way to learn what this program can do for your subtitles than to start creating your own with it.