Re: Track kinds

On May 2, 2011, at 3:22 PM, David Singer wrote:

> 
> On May 2, 2011, at 10:57 , Mark Watson wrote:
> 
>>> 
>>> 2. A2 is labelled "main+description", not just "description", and B2 is labelled "alternate+description", not just "description"
>>> 
>> 
>> This is what I suggested below although I think B2 would be labeled just "description", because it is not an alternative to B1 - it is intended to be presented together with B1.
>> 
>> This would expose the "alternative vs additional" property to HTML.
>> 
>> The remaining question would be syntactically, is "main+description" two tags, with a global convention that any number of tags can be joined with a "+" character. Or is it a single tag defined separately from "main" and "description".
>> 
> 
> You are right, "alternative" (I was taught that alternating is what current does, switching back and forth, and a choice is an alternative) should be marked as meaning something other than the main content that nonetheless replaces it (e.g. a different camera angle, a different commentator).  My mistake.
> 
> By the way, an early version of this idea, which I am not sure ever hit this list, was to be explicit about what 'kind's affect what tracks, in this sense:  the components of the 'normal' presentation are initially enabled, and the other content disabled.  Instead of a plain label on each track, the label is explicitly prefixed with + (enable) or - (disable).
> 
> Then, a normally-enabled track could have a set of labels 
> -captions -highcontrast
> (disable this track if captions or highcontrast desires are on)
> and the captions track says
> +captions 
> (presumably burned-in captions)
> and the highcontrast track says
> +highcontrast
> 
> Basically, additive tracks have the +<whatever> on them; replacement tracks also put -<whatever> on the track they replace.
> 
> Not proposing it as such here, but providing in case it's helpful, and as background.

I think it's evidence that there is something to be solved.

I'd prefer a solution where adding a track to an existing presentation didn't require me to change the properties of existing tracks, though, since there is an error waiting to happen in that case.

...Mark

> 
> David Singer
> Multimedia and Software Standards, Apple Inc.
> 
>