List of ASS gotchas

This is a list of ASS gotchas: odd and unexpected behaviors of the ASS format.

General gotchas

 * Breaking a run on a line with  will reset the position of the text to the baseline at the start of the next run.

libass differences
This is a list of differences between VSFilter and libass.


 * Borders are applied before perspective rotations in libass, but after in VSFilter. This can result in larger borders appearing in VSFilter than in libass, or borders appearing for a 90° rotation when there would be nothing rendered in libass.

Extensions
libass has implemented a number of extensions not present in VSFilter.


 * and  insert literal braces instead of starting or ending an override block.