In our application, we play video-on-demand (VOD) content and display subtitles in different languages. The format we prefer for subtitles is WebVTT. We are planning to enhance caption styling (text color, background color, font weight, etc.) in WebVTT files. In our current flow, subtitles and images are loaded in 6-second chunks.
Below is an example of one of the subtitle parts we use:
WEBVTT
X-TIMESTAMP-MAP=MPEGTS:0,LOCAL:00:00:00.000