> could 1080p playback from an mkv file (let's leave aside the BR thing) be > possible with the fastest G4 cards?
It depends very much on the video encoding that is used (MKV being just the container format). If we're talking about H264 encoding, then I'd say no, it's not possible on a 1.8 GHz G4 (or even 2.0 GHz G4, which exists for PowerMac, but haven't seen so far in use with MorphOS). Additionally, bitrate and nominal FPS have some weight in the outcome (the lower, the easier to play in realtime).
> In my 1.25Ghz G4, 1080p is not so slow... [...] I'd say I got around 18fps, and > around whole 25fps with low-bitrate parts (very darks scenes, and all that).
