Re: how to render chapters (was Re: A new proposal for how to deal with text track cues)

On 6/23/13 11:21 AM, Silvia Pfeiffer wrote:
> Hi all,
>
> I'd like to focus the discussion on the chapter issue for the moment.
>
> I'm really wondering how to write the "cues in isolation" section:
> http://dev.w3.org/html5/webvtt/#cues-in-isolation .
>
> Since the HTML spec refers to it for rendering chapters:
> "Note: For WebVTT, the rules for rendering the cue in isolation are
> the rules for interpreting WebVTT cue text. [WEBVTT]"
> it's bit of a dangling pointer that I want to close.
>
> I've wondered about these approaches:
>
>> The chapters could be represented through dots
>> on the timeline and a mouseover could render the thumbnails. Or the
>> chapters could be represented in a menu on the controls with the
>> thumbnail as an icon.
> There are more examples at
> http://wiki.whatwg.org/wiki/Use_cases_for_API-level_access_to_timed_tracks#Chapter_Markers
>
> So, chapters could be in a special menu dropping down from the top of
> the video or a list that is rendered off the video viewport, but
> navigates the video.
>
> Should the section say anything about rendering or just say that
> browser should somehow expose chapters in the video controls?
> What do people prefer?
I think chapter selection falls into the user interface bucket where we 
generally have no spec requirements whatsoever (having UI requirements 
in specs either leads to the spec being ignored or implementations sucking).
> Another related issues is that about thumbnails. You will have noticed
> that many chapter rendering approaches have an image thumbnail in
> them.
>
> I can think of two ways to add an image thumbnail to chapter cues:
>
> 1. as markup inside the cue text
> e.g.
> <img data-url-encoded-image>
>
> 2. as a cue setting
> e.g.
> thumb:data-url-encoded-image
3. The UA seeks to the start time of each chapter and uses that frame 
from the video as the chapter thumbnail. (This might not have good 
enough results, I don't know.)

4. We leave this use case to custom controls to solve (for now).
> The first approach has the side effect that we can then also represent
> images in caption or subtitle cues.
>
> The second approach has the side effect that we can then also
> represent caption or subtitle cues with an image thumbnail.
Are there use cases for these?
> What is the preference here - and: are browsers interested to support
> thumbnails?
>
> Silvia.
>
>


-- 
Simon Pieters
Opera Software

Received on Monday, 24 June 2013 06:36:46 UTC