Re: [Bug 23220] Add 'zoom' constraint to VideoStreamTrack

On Mon, Sep 30, 2013 at 8:17 AM, Harald Alvestrand <harald@alvestrand.no> wrote:
> On 09/29/2013 06:39 AM, Silvia Pfeiffer wrote:
>> FWIW, I'd like to have the capability to zoom into a specific part of
>> a screen share and only transport that part of the screen over to the
>> peer.
>>
>> I'm not fuzzed if it's provided in version 1.0 or later, but I'd
>> definitely like to see such functionality supported eventually.
>
> I think you can build that (out of strings and duct tape, kind of) by
> screencasting onto a canvas, and then re-screencasting a part of that
> canvas. I'm sure there's missing pieces in that pipeline, though - I
> don't think we have defined a way to create a MediaStreamTrack from a
> canvas yet.

Interesting idea.

It would be possible to pipe the canvas back into a video element, but
I'm not sure if we can as yet take video element content and add it to
a MediaStream.

> It takes more than a zoom constraint to do it, however; at minimum you
> need 2 coordinate pairs (for a rectangular viewport).

True. I also think we haven't standardised screensharing yet, even if
there is an implementation in Chrome.

Silvia.

Received on Sunday, 29 September 2013 23:59:57 UTC