[SOLVED] What does libwebrtc's DegradationPreference:: Balanced do?

What does libwebrtc's DegradationPreference:: Balanced do?

I am integrating a opensource libwebrtc from https://opensource.apple.com/source/WebCore/WebCore-7604.5.6/Modules/mediastream/libwebrtc/LibWebRTCMediaEndpoint.cpp.auto.html.

In the code I see

switch (rtcParameters.degradation_preference) {
    case webrtc::DegradationPreference::MAINTAIN_FRAMERATE:
        parameters.degradationPreference = RTCRtpParameters::DegradationPreference::MaintainFramerate;
        break;
    case webrtc::DegradationPreference::MAINTAIN_RESOLUTION:
        parameters.degradationPreference = RTCRtpParameters::DegradationPreference::MaintainResolution;
        break;
    case webrtc::DegradationPreference::BALANCED:
        parameters.degradationPreference = RTCRtpParameters::DegradationPreference::Balanced;
        break;
    };

What is the internal behavior when the BALANCED option is selected?

I have looked through the opensource documentation and searched the web, but I have not found relevant information. I'd appreciate if anyone can point me to the right place.

Solution

Using Chromiums codesearch which includes the original sources is way more helpful than Apple's copy: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/api/rtp_parameters.h;l=88;drc=d31d2d07343b6515b61bb4b7f7c4ce32bd7e38d4 it is a mix between the two options, maintaining framerate or resolution.

The concrete implementation can be found here