Timed Text Display

AMIA | 2022-09-15

with Brendan Coates (he|his)

Overview

What we are gonna learn about

subtitles as text files

link btw preservation and access strategies

Subtitle Files

They're Just Text!

media files have other stuff going on

text is different than word

word docs are actually xml

VTT and SRT are basically the same

VTTs can/ do contain markup tho

which then has to be parsed and rendered
(i.e. decoded)

Types of Markup

CSS class
italics
bold
underline
Ruby
Ruby text
Voice(like CSS)

CSS class detail

Style Guide

make one, share it

Preservation Strategy

1. embed subs in media file
2. store subs separately

embedded subs

self-contained files

separate subs

versioning
styling

Display Strategy

Embedded Subs

can be accessed on web
but not with HTML5 video tag

can be accessed on VLC

Separate Text

easily displayed and styled on web

somewhat more difficult on VLC

Separate Text - html

burned-in subs

always plays and looks great

can't turn them off

User Preferences

subtitle track display order

HTML5 video tag

1. "default" subs track on video

Video.js

1. most recent subs track in browser cache
2. language match for above
3. "default" subs track on video

wrap up

1. subtitles are just text - still decoded

2. styling timed text can make specific content more clear for users

3. if you style your timed text, tell people why/ how