Created attachment 468290 [details] A screenshot of https://andadinosaur.com/hls-vp9/index.html as viewed on Safari on my macOS device. I'm experiencing an issue with Safari on macOS where it's unable to play HLS streams encoded in VP9. Here are the steps to reproduce the issue: 1. Open Safari on a macOS device. 2. Navigate to https://andadinosaur.com/hls-vp9/index.html 3. Attempt to play the HLS stream. When I follow these steps, the stream doesn't play. But when I try the same steps on iOS and iPadOS devices, the stream plays without any problems. I expected the stream to play on all platforms. The error property of the `<video>` element returns a MediaError with the code "3" and the message "Media failed to decode".
From initial discussion with Jean-Yves, this is likely below WebKit, importing for Apple engineers to take a look.
<rdar://problem/117358569>