The application reads the subtitles or writes audio to the file according to the SRT or VTT markup of the subtitle file.
To produce text from the subtitles the App use TTS engine installed on the user device.
The resulting audio file (uncompressed with caf extension or compressed with m4a extension) can be used to create an audio track in the desired language for movies (Automatic Voice Over).
The application can automatically control the tempo of speech so as not to lose synchronization with the time stamp of subtitles.