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Re: Mute and MediaStream repointing

From: Randell Jesup <randell-ietf@jesup.org>
Date: Mon, 13 Feb 2012 10:05:46 -0500
Message-ID: <4F3926CA.2080107@jesup.org>
To: public-webrtc@w3.org
On 2/13/2012 9:49 AM, Stefan Hakansson LK wrote:
> On 02/13/2012 03:23 PM, Randell Jesup wrote:
>> We've discussed it once or twice - muted tracks should generate
>> *something* until/unless signaling allows them to be turned off. We
>> found in our videophone company that 'black' was a bad choice for video,
>> as it confuses users ("is something broken?")
>
> My thinking was not that the black video would ever be shown, but rather
> that the application receiving it would detect that is was black and
> replace it with some image (detecting a certain color is quite simple
> with a canvas element). Not that I am saying black is a good choice. I
> guess transparency can be detected as well - so it could even be
> transparent.

You can't guarantee what a destination will do with 'black' (even 
assuming it goes through unmolested), and if gatewayed to other 
equipment/networks ("legacy"), you're right out of luck.

We (WorldGate) originally had a closed network, and just used 
side-signaling over RTCP APP and 'black' for mute.  When we started 
interoperating with other devices, we had to replace black with a mute 
image to avoid confusion.

Also, 'black' means you ust run a "is frame black" test on every 
frame...  Just to support a mute image.  Ugh. :-)

-- 
Randell Jesup
randell-ietf@jesup.org
Received on Monday, 13 February 2012 15:07:17 GMT

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