W3C home > Mailing lists > Public > public-web-and-tv@w3.org > January 2020

Re: [me-media-timed-events] event is not defined (#41)

From: Chris Needham via GitHub <sysbot+gh@w3.org>
Date: Fri, 17 Jan 2020 15:59:16 +0000
To: public-web-and-tv@w3.org
Message-ID: <issue_comment.created-575684595-1579276754-sysbot+gh@w3.org>
PR #49 includes changes that I hope address the terminology issues mentioned here. Please comment there if further changes are needed.

The other topic discussed here is minimum cue duration required for a cue to appear in the `activeCues` list. This is affected by: how often _time marches on_ is run, the execution time of the JavaScript handler function.

> Is there a particular use case for wanting to see these cues in the active cue list at some particular playback time?

I think `emsg` events HbbTV would be one such case. Because this uses a native DASH player, the only mechanisms the web app has to receive the events are: use a `cuechange` handler, or poll `activeCues` from a rAF loop for higher timing precision. A rAF handler would be expensive particularly for TV devices.

The current specifed `cuechange` and `activeCues` behaviour seems correct to me. My hope is that we can develop a solution such that native DASH implementations can use cue `enter`/`exit` events rather than `cuechange` events.

-- 
GitHub Notification of comment by chrisn
Please view or discuss this issue at https://github.com/w3c/me-media-timed-events/issues/41#issuecomment-575684595 using your GitHub account
Received on Friday, 17 January 2020 15:59:17 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:57:46 UTC