SMPTE-TT Subtitels (.xml)
The SMPTE-TT Subtitles export option follows the general SMPTE Timed Text specifications - SMPTE ST 2052-1:2010. This documentation defines two subtitle profiles:
Text Only - intended for general use with Subtitles, interoperability and consistent rendering.
Image Based - similar to the Text Only profile but mainly referenced for Forced Narrative Image-Based subtitles.
The profile for the SMPTE-TT compliant output file can be selected from the respective Compatibility drop-down to the top of the configuration window.
It should not be mistaken with the SMPTE-TT CEA-608 Captions export option which is derivative of the general specifications intended for converting CEA-608 data into SMPTE-TT compliant file.