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Re: maxHeight and maxWidth

From: Peter Thatcher <pthatcher@google.com>
Date: Wed, 17 Feb 2016 09:36:55 -0800
Message-ID: <CAJrXDUGet0ztUe9pTbVowiQgRfzo6mBAZhwR=Z5ViFO4JBywBQ@mail.gmail.com>
To: Jan-Ivar Bruaroey <jib@mozilla.com>
Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>
The original thread was about both screencasts and rotating cameras, and
I've mostly been focusing on the screencasting case (trying to figure that
out before moving on to rotation).

But, actually, I have a question for you about getUserMedia:

If I specify an exact height of 90 pixels (min and max are 90) and the
camera can't open that small, what will an implementation of getUserMedia
be expected to do?  Will it scale the camera's input in order to get that
exact height, or will it just say "nope"?  Or is it implementation
dependent?


On Wed, Feb 17, 2016 at 9:07 AM, Jan-Ivar Bruaroey <jib@mozilla.com> wrote:

> How is this discussion limited to screencasts? Didn't you say "camera" a
> couple messages ago?
>
> .: Jan-Ivar :.
>
>
> On 2/16/16 10:00 PM, Peter Thatcher wrote:
>
> This was brought up specifically in the context of screencasts.  I assume
> a screencast track implementation could easily meet arbitrary min/max
> resolution constraints (by scaling).
>
> On Tue, Feb 16, 2016 at 3:26 PM, Jan-Ivar Bruaroey < <jib@mozilla.com>
> jib@mozilla.com> wrote:
>
>> On 2/13/16 11:50 PM, Peter Thatcher wrote:
>>
>> ‚ÄčI hope we can all remember that we are only considering
>> scaleResolutionDownToHeight/Width for the encoding parameters *for
>> simulcast scenarios*.  If simulcast isn't part of the scenario, then
>> there's no need for these (or maxFramerate, or scaleResolutionDownBy,
>> etc).  And most app developers never deal with simulcast.   Anything we add
>> for simulcast is already well in the realm of an advanced use case.
>>
>>
>> Given the years the Media Capture and Streams WG spent defining an overly
>> complex constraints language, I find the repeated assumption in this thread
>> that a track can be constrained to any arbitrary size and frame rate,
>> amusing.
>>
>> If it were true, it would offer amazing simplifications to that spec,
>> like:
>>
>>   function fitnessDistance() { return 0 }; // = Whatever you want.
>>
>>   typedef  MediaTrackSettings MediaConstraintsSet; // no
>> min|max|exact|ideal
>>   typedef MediaConstraintsSet MediaTrackConstraints; // bye-bye advanced!
>>
>> Despite having sunk effort into implementing this already, I would
>> personally welcome it. Just make up your collective minds.
>>
>> If that's not happening, then I find scaleResolutionDownBy and
>> maxFramerate useful outside of simulcast.
>>
>> .: Jan-Ivar :.
>>
>>
>
>
> --
> .: Jan-Ivar :.
>
Received on Wednesday, 17 February 2016 17:38:04 UTC

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