[whatwg] Stream API Feedback

[Philip Jägenstedt]

On Thu, 17 Mar 2011 17:51:08 +0100, Olli Pettay <Olli.Pettay at helsinki.fi>  
wrote:

> On 03/17/2011 06:31 PM, Philip Jägenstedt wrote:
>> On Thu, 17 Mar 2011 16:48:40 +0100, Olli Pettay
>> <Olli.Pettay at helsinki.fi> wrote:
>>
>>> On 03/17/2011 03:11 PM, Lachlan Hunt wrote:
>>>> On 2011-03-16 19:29, Olli Pettay wrote:
>>>>> Perhaps navigator.getUserMedia("audio,video", success, error);
>>>>> could return an url to the device in the success callback, and that  
>>>>> url
>>>>> could be then set to video.src.
>>>>
>>>> The creation of a URL is unnecessary indirection. It's easier to avoid
>>>> creating special URLs entirely, and instead assign the the Stream  
>>>> object
>>>> directly to video.src.
>>>
>>>
>>> The type of .src is string.
>>> Assigning a different type of object to it
>>> is quite strange.
>>>
>>> Also, if getUserMedia would return just an URL, browser wouldn't need
>>> to create any stream object (unless someone then want to stream
>>> from <video> to PeerConnection).
>>
>> Sure, but instead one would have to mint URLs and keep a mapping between
>> those URLs and the streams that they actually represent. If people copy
>> those URLs around, how long are they supposed to work for? Consider this
>> scenario:
>>
>> function getStreamURL() {
>> var s;
>> // code that sets s to a new Stream object for the default camera or
>> something
>> return s.url;
>> }
>> var url = getStreamURL();
>> /* garbage collector? */
>> document.querySelector('video').src = url;
>
> I'd assume stream url would be handled like
> urls created using createObjectURL.
> It could be then revoked.

I wasn't aware of this API, it's in  
http://www.w3.org/TR/FileAPI/#dfn-createObjectURL for reference.

That API has an explicit revokeObjectURL to solve the lifetime issue, but  
there's no such thing for the Stream API.

-- 
Philip Jägenstedt
Core Developer
Opera Software