No conversion is needed now.

Google's official Chromium documentation mentions that H.265 support in WebRTC is currently in development. It has been released under 'Implemented behind flags' status: Chromium Feature.

This feature can be enabled using the following command:

For macOS:

open -a "Google Chrome" --args --enable-features=WebRtcAllowH265Send,WebRtcAllowH265Receive --force-fieldtrials=WebRTC-Video-H26xPacketBuffer/Enabled/

For Windows:

start chrome --enable-features=WebRtcAllowH265Send,WebRtcAllowH265Receive --force-fieldtrials=WebRTC-Video-H26xPacketBuffer/Enabled/

For Android: I used the WebView implementation to switch from Android System WebView (M134) to Android System WebView Dev (M136). It works perfectly, but the switch has to be done manually.

Chromium M136 stable release: Tue, Apr 29, 2025 Chromium.