Re: Proposal to add defaultDevice attribute to getMediaDevices.

Gili,

AFAIK app will not have any control on selecting another device, in case of
unavailability of the selected device.
For example., If 3 devices are available and App is showing 1 as default
(according to its previous selection), 2 is the device selected by user,
and 3 is the default device according to browser platform. In this case if
user selects device-2 and if it is not available, then browser will get the
access for device-3 and not device-1 as shown by app. App will fail in this
case.

Another scenario is, if the previously selected device is not available in
the list of devices (in case if that user moves from home to office where
he has used some external device etc .. ) App can not judge a default
device.

If App is really willing to show the default as that corresponding to
previously selected one, then it can choose it with default selection but
highlight the browser specified default device to indicate that the
highlighted device will be selected in case of unavailability of selected
device. (Since this specification does not have any control on app
implementations, this is just my suggestion as one way for implementing
App).



On Fri, Mar 14, 2014 at 11:50 AM, cowwoc <cowwoc@bbs.darktech.org> wrote:

>  The concept of a "default" device without a context seems like a losing
> proposition. As Harald mentioned, there is no objective "default" when
> choosing between front and back cameras on a phone. I suggest that the
> "default device" should really corresponds to the last selected device in
> some application-defined context. Meaning, applications will probably want
> to default to the last device used and expect different "defaults"
> depending on the context (e.g. microphone plugged in, or not).
>
> Gili
>
>
> On 14/03/2014 1:11 AM, Kiran Kumar wrote:
> >
> >
> >
> > On Fri, Mar 14, 2014 at 2:34 AM, Harald Alvestrand
> > <harald@alvestrand.no <mailto:harald@alvestrand.no><harald@alvestrand.no>>
> wrote:
> >
> > On 03/13/2014 01:32 PM, Kiran Kumar wrote:
> >> Dear Harald, Please find my comments inline.
> >>
> >>
> >> On Thu, Mar 13, 2014 at 2:48 PM, Harald Alvestrand
> >> <harald@alvestrand.no <mailto:harald@alvestrand.no><harald@alvestrand.no>>
> wrote:
> >>
> >> On 03/12/2014 12:32 PM, Kiran Kumar wrote:
> >>> Hi, I would like to add this to bug list. Please let me know if
> >>> you have any comments.
> >>
> >> I would like to not add it.
> >>
> >> As has been noted, there isn't always an obvious default device. So
> >> if the flag is added, the JS must be written to handle the
> >> condition where no default device is in the list. But since this
> >> may be a rare case, JS apps might choose to ignore this possibility
> >> - which is bad for app portability.
> >>
> >>
> >> [Kiran] It is not obvious to have a defaultDevice but most of the
> >> mobile devices have default devices like front camera or back
> >> camera... Any new thing will increase the processing, but I don't
> >> agree addition of this attribute will result in too much complexity
> >> for checking. Generally most of the devices have a single device.
> >
> > Actually you illustrate my point. Which of the front and back cameras
> > on my phone is the "default" camera?
> >
> > *[Kiran]* This attribute helps in determining that.
>
> >
> >
> > Also, the moment you plug a Bluetooth or USB headset into a device,
> > it has multiple audio devices. I think the theory that most devices
> > have a single device (of each type) is a weak one.
> >
> > *[Kiran]* Agreed.
>
> >
> >>
> >>
> >>
> >> If the JS wishes to get a device, and it doesn't care about which
> >> one, it could just getUserMedia(). Which one is returned may vary
> >> depending on configuration parameters, constraints, or whether some
> >> other program has opened the device (for OSes that do exclusive
> >> device access).
> >>
> >> [Kiran] This will be helpful to give the judgement to user,
> >> ofcourse getMediaDevices() itself is meant for that. But in some
> >> applications, we can have a use case like if the selected device is
> >> not available, then go for the default device, instead of resulting
> >> in error.
> >>
> >> [Kiran] For example, my laptop is having a built-in-camera, when I
> >> want to chat with my friend, I will attache a webcam that supports
> >> high definition/ with higher pixel number. I prefer to access the
> >> external webcam attached, but if I am not able to access that in
> >> any case, instead of resulting in failure it will select the
> >> default built-in-camera.
> >
> > That's how it's supposed to work if you give the ID of your attached
> > webcam as an optional constraint: If it's not available, you'll get
> > another one.
> >
> >
> > *[Kiran]* If the devices is enabled with 3 devices, as you specified
>
> > above like through Bluetooth or any other means, and if the device
> > selected by user is not available, then out of the 2 remaining
> > devices, how the user can come to know which one it will be selected
> > by default ?
> >
> >>
> >> The only use case I can see is to preselect the default device in a
> >> list of devices, so that the user can tell which device will be
> >> opened if he doesn't select one - and as seen above, this is not
> >> guaranteed to be the device that actually gets selected (some other
> >> program may have grabbed it before the user selects a device).
> >>
> >> [Kiran] I agree.
> >>
> >> I see increased complexity, without a corresponding size of
> >> benefit. So I'd like to not do this.
> >>
> >>
> >> [Kiran] I see more benefit as  I explained in the above example.
> >> What do you say ....
> >
> > *[Kiran] *I can say one more use case here, that instead of just
>
> > default selection. 1. An app can provide the default selection for
> > the high resolution camera or sophisticated mic and highlight the
> > default devices, so that if the selected device is not available,
> > then highlighted device will be selected. 2. If user selects a third
> > device instead of default selected device and the platform default
> > device, then in case of in-availability of selected device, it should
> > select the default device.
> >
> > I'd like more opinions...
> >
> >
> >>
> >>
> >>>
> >>>
> >>> On Mon, Mar 10, 2014 at 3:43 PM, Kiran Kumar
> >>> <g.kiranreddy4u@gmail.com <mailto:g.kiranreddy4u@gmail.com><g.kiranreddy4u@gmail.com>
> >
>
> >>> wrote:
> >>>
> >>> It is not universally true for all,
> >>>
> >>> When I connect an external webcam to my desktop PC, which has no
> >>> camera, Mozilla is displaying its names as YUV-xxx-camera.
> >>> Laptops are also not showing "default" prefix in the names.
> >>>
> >>> I am not sure which devices/SO's are showing the "default"
> >>> prefix.
> >>>
> >>> Thanks, Kiran.
> >>>
> >>>
> >>>
> >>> On Mon, Mar 10, 2014 at 3:19 PM, Iñaki Baz Castillo
> >>> <ibc@aliax.net <mailto:ibc@aliax.net> <ibc@aliax.net>> wrote:
> >>>
> >>> 2014-03-10 6:51 GMT+01:00 Kiran Kumar <g.kiranreddy4u@gmail.com
> >>> <mailto:g.kiranreddy4u@gmail.com> <g.kiranreddy4u@gmail.com>>:
>
> >>>> I would like to propose adding a defaultDevice attribute which
> >>>> indicates which device is the default device out of the list.
> >>>>
> >>>> dictionary MediaDeviceInfo { DOMString       deviceId;
> >>>> MediaDeviceKind kind; DOMString       label; DOMString
> >>>> groupId;
> >>>>
> >>>> bool            defaultDevice; };
> >>>>
> >>>> This will allow a default value checked while displaying the
> >>>> list of devices.
> >>>
> >>>
> >>> Correct me if I'm wrong, but AFAIK the multimedia subsystem in
> >>> some SO's report a "default sound card", "default mic" and
> >>> "default webcam".
> >>>
> >>>
> >>> -- Iñaki Baz Castillo <ibc@aliax.net <mailto:ibc@aliax.net><ibc@aliax.net>
> >
> >>>
> >>>
> >>>
> >>
> >>
> >
> >
>
>
>