Re: [rtcweb] Mute implementations (Re: More Comments on draft-ietf-rtcweb-use-cases-and-requirements-07)

[Harald Alvestrand <[e-mail]>]

On 06/15/2012 11:18 PM, Randell Jesup wrote:
> On 6/15/2012 4:49 PM, Martin Thomson wrote:
>> On 15 June 2012 13:42, Randell Jesup<[e-mail]>  wrote:
>>> I would also suggest that for video-mute that instead of stopping 
>>> video or
>>> sending black, the application should send a "mute image".
>>
>> The question I have is whether there is: a) a fixed image/video that
>> is serialized to RTP b) video "comfort noise", or c) local mute
>> image/video playback.  If it can't be c, then you might need to
>> explain yourself.
>
> Either we build it into the system (which I dislike - SetMuteImage() 
> or whathaveyou, though we could), or we put it in the application 
> domain and suggest or assist implementation.
>
> The simple way to handle Mute is to revector the input to a "mute" or 
> "hold" source, and they may not be the same (hold would have "Please 
> Hold" and music, perhaps; mute would have silence and "Muted" or a 
> camera with a circle/slash, etc).  You can also signal that out of 
> band to let the other end take smart action (remove muted video image, 
> display "muted" next to a name, etc).  This can be done via 
> DataChannels, for example.  You may then reinvite for Hold to make it 
> one-way, but that's mostly optional.
The resulting requirements seem to me to be:

1) To be able to use a still image as source for a video stream
2) To be able to change the source of a video stream after its creation

Both are requirements on the GetUserMedia API. Can we link these to a 
specific use case, or do we need to modify the use case document so that 
the requirements are clear?

              Harald