Re: Proposal to add defaultDevice attribute to getMediaDevices.

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>> 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?

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.
>
>
>     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.

>
>     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 ....

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>> 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>> wrote:
>>
>>             2014-03-10 6:51 GMT+01:00 Kiran Kumar
>>             <g.kiranreddy4u@gmail.com <mailto: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>>
>>
>>
>>
>
>