4.0

Subtitles
The Blu-ray Disc specification allows for two types of subtitles: image based and text based. DoStudio
Authoring supports image-based subtitles.
DoStudio Authoring does not include a built-in subtitling application, so you must create your subtitle files
separately and import them into your project. This section will describe the required format for subtitle files,
recommended tools for creating subtitle files, and how to import them to your project.
Creating subtitle files
DoStudio Authoring imports image-based subtitles and multiplexes them with your audio/video assets
when you compile your project. The details of the subtitle format are quite simple, yet as any professional
DVD author knows all too well, the task of successfully creating subtitles can be rather tedious.
DoStudio Authoring subtitles are comprised of a series of 8-bit .png files governed by a simple XML script.
The XML script has the file extension .dost. The 8-bit .png files can be sized at 1920 x 1080 pixels, which is
the full size of the HD Blu-ray Disc canvas, or they can be smaller than the screen size and positioned using
the XML. An author could create these images manually using the "Save for Web" feature in Photoshop
(select PNG-8 128 dithered (indexed color)); however, there are subtitling tools that can create .dost files for
you. For more information, see "Subtitling tools" on page 59.
The timecode in the .dost file must match the timecode of the title in DoStudio Authoring in order for the
subtitles to display properly. A title's timecode always starts at 00:00:00:00.
The format for the .dost file is as follows:
When using subtitles it is important to know the characteristics of the subtitle files and the requirements of
DoStudio Authoring.
The most important characteristic is the size of the subtitle files. DoStudio Authoring supports the following
image-based subtitle types:
n Full-raster images
n Images cropped to the minimum size
n Images cropped to a common size
Chapter 6
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