New SyncMedia draft online - please comment

Hi all,

I have put together a new draft and would like to ask for your feedback. An overview of the new documents can be found here:
https://raw.githack.com/w3c/sync-media-pub/wip/docs/new/index.html <https://raw.githack.com/w3c/sync-media-pub/wip/docs/new/index.html>

And the spec itself is here:
https://raw.githack.com/w3c/sync-media-pub/wip/docs/new/sync-media.html <https://raw.githack.com/w3c/sync-media-pub/wip/docs/new/sync-media.html>


The purpose of this ground-up rewrite is:

* To maintain continuity with EPUB Media Overlays by building on SMIL
* To expand what is possible with synchronized media: include more media types and rendering parameters
* Increase accessibility by introducing the idea of “tracks”, which represent roles in a presentation (think of “background music track”, “text transcript track”, “video track”, “sound effects track”, “images track”, etc). Tracks can be enabled/disabled, and have global parameters that can be adjusted.

To get an idea of what could be possible in this space now, here are a few types of examples we hope to create:

- SVG comic with audio narration
- EPUB with separate side-loaded audio overlay
- Audio-only presentation (with structuring beyond what is possible in the Audiobooks spec)
- Background music
- Video and text transcript


Regarding the existing Synchronized Narration documents:

To me, it did not feel like a good path, because it did not follow in the footsteps of EPUB Media Overlays closely enough, and it had issues that were preventing it from moving forward. 

That said, a possible JSON serialization of this new rewritten syntax, referenced above, could look not too different from the Synchronized Narration examples that have been floating around. 

Our landing page has been updated and while it still references Synchronized Narration, it also mentions that we are working on something new and that changes are to be anticipated:
https://w3c.github.io/sync-media-pub/#status <https://w3c.github.io/sync-media-pub/#status>

Also worth mentioning, the Audiobooks spec has been updated to be less specific in its references to our work, to give us some room. You can see the latest here:
https://www.w3.org/TR/audiobooks/#audio-accessibility <https://www.w3.org/TR/audiobooks/#audio-accessibility>

That said, Audiobooks will reach CR soon (November), so if we could stabilize our documents by then, it would be really great.

And finally, the new spec is called SyncMedia, as “Synchronized Narration” was a mouthful that no one could remember. In conversation, everyone was just saying “Sync Media” to me anyway. So why fight it? Open to suggestions here if anyone feels strongly.

Thanks to Lars Wallin for collaborating with me and really digging in to this work. I’m looking forward to hearing everyone’s thoughts and also working on some examples.

Thanks
Marisa