Re: 答复: Constraints and Capabilities API for getUserMedia: more detailed proposal

On 04/09/2012 06:22 PM, Li Li wrote:
> What if I want to use the video input on foo1 (a webcam with mic) and audio input on bar3 (a headset)?
that's why I suggested video-camera-identity rather than just
"identity"; a constraints set of "video-camera-identity: foo1,
audio-microphone-identity: bar3" would allow you to do this in one
getUserMedia call.

> If I say: 
> navigator.getUserMedia({audio:true, video:true}, {mandatory: [{identity:foo1}, {identity:bar3}]}, cb), then the UA doesn't know where the audio stream comes from: foo1 or bar3.
>
> It seems an object-oriented approach is needed for this case:
> foo1.getUserMedia({video:true}, cb);
> bar3.getUserMedia({audio:true}, cb);
>
> So it becomes a two-step drill-down process:
> 1) navigator.getCapabilitie() gets a list of qualified logical devices with stream capabilities;
> 2) {device}.getUserMedia() gets a stream from the selected device with the requested capability;
>
> Thanks.
> Li
>
> -----Original Message-----
> From: Harald Alvestrand [mailto:harald@alvestrand.no] 
> Sent: Monday, April 09, 2012 9:51 AM
> To: Li Li
> Cc: Soo-Hyun Choi; public-media-capture@w3.org
> Subject: Re: 答复: Constraints and Capabilities API for getUserMedia: more detailed proposal
>
> On 03/29/2012 03:55 AM, Li Li wrote:
>> Thanks for bringing this up. I hope application should be able to discover cameras and select which ones to use, as it is not uncommon for mobile devices to have two cameras these days.
>> If this ability is not supported, then there is also a gap between getCapabilities(), which return multiple cameras, and getUserMedia(), which can't select them.
> If we define a constraint named "video-camera-identity", with a string
> value, and define that getCapabilities() return a single, unique value
> of "video-camera-identity" for each camera, the problem is solved:
>
> getCapabilities() returns
> [ camera1 {
> 'video-camera-identity': 'foo1'
> },
> camera2 {
> 'video-camera-identity': 'bar3'
> }
> ]
>
> getUserMedia gets called as
>
> getUserMedia(....., [ mandatory: { 'video-camera-identity' : 'bar3' } ] )
>
> apologies for the braces and brackets of the wrong type; I hope the idea
> shines through.
> One issue: this constraint is not an enum, a max or a min - it's a
> fourth type of constraint.
>
> Does this need further definition?
>
>
>> Li
>>
>>
>> -----邮件原件-----
>> 发件人: Soo-Hyun Choi [mailto:s.choi@hackerslab.eu] 
>> 发送时间: 2012年3月29日 8:28
>> 收件人: Li Li
>> 抄送: public-media-capture@w3.org
>> 主题: Re: Constraints and Capabilities API for getUserMedia: more detailed proposal
>>
>> All,
>>
>> On Wed, Mar 28, 2012 at 11:32, Li Li <Li.NJ.Li@huawei.com> wrote:
>>> If the getCapabilities() returns multiple devices (e.g. camera001,
>>> camera002), I wonder how navigator.getUserMedia() is able to select which
>>> device to use. Do we have to say: camera001.getUserMedia(), or somehow
>>> designate the target device in the argument?
>>>
>> As I've raised the similar issue earlier regarding this
>> (http://lists.w3.org/Archives/Public/public-media-capture/2012Mar/0015.html),
>> this sort of choosing multiple cameras should better to be considered.
>>
>>
>> Best regards,
>> Soo-Hyun

Received on Monday, 9 April 2012 17:31:19 UTC