Hello, sorry you are having trouble,
There are so many variables when it comes to Video play back on a Mac..
Yea, 1.25 Ghz with 1 GB of Ram answers most questions, yea, it should play OK,
- Is the video on a CD or DVD ? well, these iMacs don't have a very fast optical drive.
- How much room do you have on your internal hard Drive, if it's too full ( more than 80% full ) then you will suffer read/write performance.
- Is the video on an external harddrive, is it a USB drive? the USB on the iMac G4 is USB 1.1, 11Mbit/sec, way too slow to play a big video smoothly.
- Just what is the size of the video, is it like that for all of them or just one, might it be a HD video with high frame rates?
- What version of the MacOS X do you have installed? If you installed Leopard 10.5 on the iMac G4, nothing will run smoothly,
- Are you playing this video over a network? forget it it's got to be on the internal or a FireWire external disk otherwise it will stagger...
Well, there you go, I know, it's so easy to say Hey man, just get a new Mac and everything will be fine... But that machine is going on 6 years old now, Video technology has not stood still.....