Re: MediaStreams and canPlayType

For example, MediaRecorder has a canRecordMimeType method to allow applications to know if an output type is available.  

Jim Barnett
Genesys

> On Oct 17, 2014, at 6:14 AM, Harald Alvestrand <harald@alvestrand.no> wrote:
> 
> A MediaStream is a control surface for what the browser does with media.
> 
> The concept of a "type" is totally foreign to the concept of a MediaStream; if the MediaStream(track) can be created, the browser can play it - it was created by the very same browser!
> 
> Wherever the MediaStream converts into something that can be passed over the network, types are of relevance: MediaStreamRecorder, <video> tag rendering to canvas, WebAudio rendering to audio buffers, PeerConnections rendering to RTP - and at the corresponding interfaces for incoming, the media type is also of relevance.
> 
> But this needs to be functions that belong on that interface, not on the MediaStream.
> 
> MediaStreams are abstractions that live in the browser. The browser can always do it.
> 
>> On 10/17/2014 10:48 AM, Stefan Håkansson LK wrote:
>> I recently came across a WebRTC site that used video.canPlayType to
>> check up front if the endpoint was compatible with their service or not.
>> 
>> Our document says nothing about this, and I think it should (but I'm not
>> sure what it should say).
>> 
>> Off the top of my head there are a couple of paths we could follow:
>> 
>> #1: state that canPlayType is unsuitable to check compatibility with
>> MediaStreams of a certain format and that it can be assumed that
>> anything the PeerConnection can negotiate can be played (as well as of
>> course any strictly locally generated media). The follow up question is
>> of course how you check if the PeerConnection will be able to decode
>> your network streams without doing a call set up with negotiation, I
>> guess there the answer would be to use createOffer and parse the SDP.
>> 
>> #2: Define strings (mime-types?) that can be used with canPlayType to
>> see if the video element can play the MediaStream format in question.
>> 
>> Should we do something about this, and if so, #1, #2 or something else?
>> 
>> Stefan
>> 
> 
>

Received on Friday, 17 October 2014 20:26:24 UTC