Bug confirmed. And confirmed it's only in "mpv --hwdec=vaapi". So another workaround is to use hwdec=no. But that's not as good as your workaround of using "ytdl-format" to retain hardware acceleration via H.264.
I have also verified that the VP9 video stream is good. You can verify this using hwdec=no or by downloading the video and playing it with something else like mplayer or totem. They all play the webm/VP9 video file perfectly.
Interestingly users of older CPUs probably won't hit this problem. Seems that MPV is smart enough to not even try to download VP9 for them and will automatically get the H.264 instead.
Sorry for the delay...
Bug confirmed. And confirmed it's only in "mpv --hwdec=vaapi". So another workaround is to use hwdec=no. But that's not as good as your workaround of using "ytdl-format" to retain hardware acceleration via H.264.
I have also verified that the VP9 video stream is good. You can verify this using hwdec=no or by downloading the video and playing it with something else like mplayer or totem. They all play the webm/VP9 video file perfectly.
Interestingly users of older CPUs probably won't hit this problem. Seems that MPV is smart enough to not even try to download VP9 for them and will automatically get the H.264 instead.
Please log the bug upstream: https:/ /github. com/mpv- player/ mpv/issues