Owen, I am familiar with CADET and tried it a while ago. Cannot recall the experience. Nonetheless, I appreciate your addition and know someone else will, too! Thanks for coming back and adding this tidbit!

Thanks for the detailed background. You definitely know a lot about the topic. I’ll have to find some time to check this out and see how it works. Thanks for the resources!

For captions, this isn’t a big problem, because no captions should be displayed for less than 1/4th of a second. However, for audio description, the issue is not due to VTT audio descriptions having shorter cues (they don’t), but rather the _accuracy_ of when a cue starts is more significant. Audio description is much more likely to “step on” dialog in the video if it isn’t started and ended accurately.

I was involved in research around audio description, including VTT audio description tracks, when I worked at the Video Description Research and Development Center (VDRDC) at the Smith-Kettlewell Eye Research Institute in San Francisco; later on, I help the video.js framework add support for audio description, both as an additional audio track and as a VTT text track.

There are some significant limitations to VTT audio descriptions, not least of which is that the HLS format used by Apple doesn’t support them (metadata doesn’t allow a text track to be marked as audio description; only an audio track can be marked that way, and the iOS player only allows users to turn on audio description if it is a separate audio track). Unfortunately, YouTube hasn’t rolled out broad support for a separate audio description audio track for a video (there is one demo in this video: https://www.youtube.com/watch?v=WaOKSUlf4TM) – generally, you need to upload a whole second video with the audio description added. But some frameworks, like video.js and Brightcove (who use video.js as the core of their player), do support a multiplexed file (in HLS format) with two audio tracks, the original audio and the described version. See https://videojs.com/advanced/?video=elephantsdream for a demo of this.

What a confusing situation! Usually, there are options to turn on captions OR subtitles … they shouldn’t affect each other. That’s odd as Amazon Prime is usually good about accessibility. Thanks for letting me know!

One feature of Apple TV+ I really like is that if you select the ‘seek back’ control it automatically enables captions for a short duration on the assumption that you were just trying to hear what was just said!

Thank you, Kathleen! Knowbility sends the shirt to people who gift $60 or more.