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In the specification of the <track> element, we now have a @default attribute, which is great. The spec says: "The default attribute, if specified, indicates that the track is to be enabled if the user's preferences do not indicate that another track would be more appropriate. There must not be more than one track element with the same parent node with the default attribute specified." I think that last sentence should say: "There must not be more than one track element for all tracks of the same @kind with the same parent node with the default attribute specified." Note the change "for all tracks of the same @kind". The idea is that you can activate a track as default per @kind, not just a single track for all of the tracks of a video.
What's the use case for having two subtitle tracks and an audio description track all enabled by default at the same time?
(In reply to comment #1) > What's the use case for having two subtitle tracks and an audio description > track all enabled by default at the same time? I am not talking about two subtitle tracks. Note how I added "of the same @kind"? So, the idea is to allow having subtitles and chapters and possibly text descriptions active at the same time. But no more than one subtitle track, one chapter track and one text description.
One of each kind would allow one "subtitle" track and one "caption" track, which is what I meant in comment 1. For "chapters", one chapter track is always enabled regardless of the "default" attribute, so adding this doesn't seem useful. For "descriptions", having an audio description track and a subtitle track enabled at the same time seems highly unlikely to be a common use case, since they are targetting basically mutually exclusive groups of people. For "metadata", the only use case requires script, so you can just enable it from script. EDITOR'S RESPONSE: This is an Editor's Response to your comment. If you are satisfied with this response, please change the state of this bug to CLOSED. If you have additional information and would like the editor to reconsider, please reopen this bug. If you would like to escalate the issue to the full HTML Working Group, please add the TrackerRequest keyword to this bug, and suggest title and text for the tracker issue; or you may create a tracker issue yourself, if you are able to do so. For more details, see this document: http://dev.w3.org/html5/decision-policy/decision-policy.html Status: Rejected Change Description: no spec change Rationale: I don't understand the use case here.
(In reply to comment #3) > One of each kind would allow one "subtitle" track and one "caption" track, > which is what I meant in comment 1. So the "default" attribute is really only to decide which of the visible tracks will be active during playback. OK. > For "chapters", one chapter track is always enabled regardless of the "default" > attribute, so adding this doesn't seem useful. If there are several chapter tracks, which of them is the one that is enabled? Also, I don't think it's clearly stated that a chapter track is always enabled - at least I wasn't aware of this. Can we make this more explicit? > For "descriptions", having an audio description track and a subtitle track > enabled at the same time seems highly unlikely to be a common use case, since > they are targetting basically mutually exclusive groups of people. Could be for useful deaf-blind users, but I guess you are right and the Web page publisher has to decide whether they prefer to target deaf or blind people preferentially with their markup. OK. > For "metadata", the only use case requires script, so you can just enable it > from script. OK.
(In reply to comment #4) > (In reply to comment #3) > > One of each kind would allow one "subtitle" track and one "caption" track, > > which is what I meant in comment 1. > > So the "default" attribute is really only to decide which of the visible tracks > will be active during playback. OK. > > > > For "chapters", one chapter track is always enabled regardless of the "default" > > attribute, so adding this doesn't seem useful. > > If there are several chapter tracks, which of them is the one that is enabled? > > Also, I don't think it's clearly stated that a chapter track is always enabled > - at least I wasn't aware of this. Can we make this more explicit? After discussing it through with Hixie on irc, it's clear now: http://www.w3.org/TR/html5/the-iframe-element.html#sourcing-out-of-band-text-tracks bascially says that the first chapter track of the appropriate language will be active. So, OK.
mass-moved component to LC1