Re: draft proposal : active multiple devices for getUserMedia

On 2012-04-12 04:53, William Lin wrote:
> Hi,
>
> in these days, Constraints and Capabilities API for getUserMedia were
> discussed while i found one scenario doesn't be covered:
> "users may want to initiate capture from multiple devices at one time in
> multiple media streams" (refer to
> http://www.w3.org/TR/capture-scenarios/#multiple-active-devices).
> is it possible adding the options to set the number of active devices?
> and the callback function needs to change:
>
>
>         2.1.3 NavigatorUserMediaSuccessCallback
>
> [Callback=FunctionOnly, NoInterfaceObject]
> interfaceNavigatorUserMediaSuccessCallback  {
>      void  handleEvent (LocalMediaStream  stream);
> };
>
> -->
>
> [Callback=FunctionOnly, NoInterfaceObject]
> interfaceNavigatorUserMediaSuccessCallback  {
>      void  handleEvent (LocalMediaStream[]  streams);
> };

It't true that it's not possible to specify how many devices the app 
wants to get access to. However, the API does support the case where the 
user selects several devices of the same type. The result is one 
LocalMediaStream object with several tracks of each type. The developer 
can then split the single LocalMediaStream by constructing new 
MediaStream objects from the tracks of the LocalMediaStream.

/Adam

Received on Friday, 13 April 2012 14:59:01 UTC