- From: Philipp Hancke via GitHub <sysbot+gh@w3.org>
- Date: Tue, 04 Mar 2025 18:45:55 +0000
- To: public-webrtc-logs@w3.org
fippo has just created a new issue for https://github.com/w3c/webrtc-stats: == which qp range is used for AV1? == AV1 apparently has two common definitions of qp, 0-63 and 0-255. Webcodecs uses 0-63 [here](https://www.w3.org/TR/webcodecs-av1-codec-registration/#av1-encode-options) for *input* (h/t @Djuffin) I observed that Chromiums getStats shows calculated values which are way above 63. It turned out that the libaom encoder in Chromium/webrtc is using AOME_GET_LAST_QUANTIZER which returns 0-255 (see [here](https://source.chromium.org/chromium/chromium/src/+/main:third_party/libaom/source/libaom/aom/aomcx.h;l=256;drc=e08c8c1d9caefd98e6b2c7b13d562137c7ee877a;bpv=1;bpt=1)), not AOME_GET_LAST_QUANTIZER_64 (below) which returns 0-63. The dav1d decoder returns the same range which is good but this might get confusing when hardware is involved. Please view or discuss this issue at https://github.com/w3c/webrtc-stats/issues/799 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 4 March 2025 18:45:56 UTC