[webrtc-pc] scaleResolutionDownBy's odd-resolution requirement trips up HW encoders (#2802)

Drekabi has just created a new issue for https://github.com/w3c/webrtc-pc:

== scaleResolutionDownBy's odd-resolution requirement trips up HW encoders ==
Some hardware encoders require specific alignment values that need to be taken into consideration when requesting specific resolutions.

https://w3c.github.io/webrtc-pc/#dfn-rtp-media-api  says:
"When video is rescaled, for example for certain combinations of width or height and [scaleResolutionDownBy](https://w3c.github.io/webrtc-pc/#dom-rtcrtpencodingparameters-scaleresolutiondownby) values, situations when the resulting width or height is not an integer may occur. In such situations the user agent MUST use [the integer part of the result](https://tc39.github.io/ecma262/#eqn-floor)."

I would like to propose that this text be amended to support selecting a resolution supported by the encoder greater than the calculated scaled resolution. It appears the [Chrome implementation](https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/video/config/encoder_stream_factory.cc;l=452;drc=2df668b7cbf6c1d0766b6ee0ae8147adc8830f2e) may already be doing this.

Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/2802 using your GitHub account

Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Thursday, 1 December 2022 17:16:34 UTC