- From: Nigel Megitt via GitHub <sysbot+gh@w3.org>
- Date: Wed, 13 Jun 2018 10:37:04 +0000
- To: public-web-and-tv@w3.org
> how the imsc.js library handles this @jpiesing I can't speak for @palemieux obviously but my understanding is that imsc.js does not play back video and therefore does not do any alignment; it merely identifies the times at which the presentation should change. However it _is_ integrated into the [dash.js](https://github.com/Dash-Industry-Forum/dash.js/) player which does need to synchronise the subtitle presentation with the media. I believe it uses Text Track Cues, and from what I've seen they can be up to 250ms late depending on when the _Time Marches On_ algorithm happens to be run, which can be as infrequent as every 250ms, and in my experience often is. As @Daiz points out, that's not nearly accurate enough. -- GitHub Notification of comment by nigelmegitt Please view or discuss this issue at https://github.com/w3c/media-and-entertainment/issues/4#issuecomment-396893004 using your GitHub account
Received on Wednesday, 13 June 2018 10:37:08 UTC