Source: smplayer Followup-For: Bug #1034867 Using smplayer 23.6.0+ds0-1 with mplayer does now play video under Wayland as expected; thank you!
The separate issue of mplayer breakage when using an invalid wid parameter in combination with the nokeepaspect option still seems replicable to me using mplayer at version 1.5+svn38423-2+b1 -- a version that _should_ include the potential fix from r38428 I think.. but I'll look into that separately (and it would have been better for me to file a separate Debian bug for that instead of mentioning it here.. that is/was indeed confusing).