Broadcast-Grade Subtitles: Does it support translation of EBU-STL (.stl) binary subtitle files?
“STL (EBU Tech 3264) is an established, widely used binary subtitle format that cannot be opened with standard text editors and enforces strict byte-length constraints per line.”
Root Cause Analysis
Binary Stream Decoding and Encoding
The Shangyi AI system features a built-in STL binary parser capable of reading both the GSI (General Subtitle Information) block and the TTI (Text and Time Information) block. Once translation is completed in memory, the content is re-encapsulated as an EBU-compliant binary stream, rather than a simple text file.
TV Safe Area and Line Length Constraints
Broadcast standards typically require a maximum of 32–40 characters per line. The AI translation engine is configured with a character counter that automatically performs intelligent line breaking during subtitle generation, ensuring subtitles remain within the TV safe area.
Frame Rate (FPS) Metadata Preservation
The system retains the original file’s frame rate settings (such as 25fps or 29.97fps), ensuring the translated subtitle file remains perfectly synchronized with the video source's timecode, eliminating the need for post-translation TC conversion.
Final Solution Summary
Delivering modern AI-powered translation solutions for the traditional broadcast television industry.