fpnc said:
In any case, note the restrictions that I mentioned earlier with PowerPC-based Mac minis. You aren't going to be able to play HD content on a PowerPC Mac mini (if that is what you have).
Um ppc minis can play "most" HD content just fine. I don't know where you got that idea. My friends has one and it plays 720p mkvs just fine and even HD trailers from apples website.
Well, I have the fastest PowerPC-based Mac mini that Apple ever produced sitting right besides me and it literally pukes on any iTunes-ready 720p content that I try to play on it. This is the 1.5GHz G4 unit that Apple never formally announced (it was a "stealth" upgrade) that not only has the fastest CPU but also twice the video memory (64MB) of any other G4 Mac mini. I'm also testing this on a clean install of Mac OS 10.5.8 and the mini has been expanded to its maximum memory capacity (that's "only" 1GB, but it can't be taken any higher).
On this unit, when I try to play 720p content from either the iTunes Store or similar resolution HD trailers from the QuickTime website I average about 10 frames per second at
BEST. As for the trailers, since I have QuickTime Pro I can download these to the Mac mini so the playback problems aren't related to network issues. If you try these same videos on the VLC player the results are about the same with the VLC statistics panel showing over 10% frame loss and a frame rate of
zero (I think the latter is only a statistical anomaly since you do get several frames played each second). So, while this unit can "play" HD content it does so in a stuttering, near slide-show mode which is hardly worth watching.
Here's my rule of thumb on video playback, if the playback averages more than 60% or 70% of the available CPU cycles then it is likely to drop frames at some point in the playback (although the faults may be minor until you get near 80% utilization). When I try 720p playback on my PowerPC Mac mini the CPU is maxed out to 100% which means that it isn't even close to offering decent HD playback.
Now, you mention MKV files and I suppose that with a third-party codec bundle (Perian?) you could see better result than I'm getting with QuickTime and VLC. However, even if that were the case I wouldn't try to claim that PowerPC Mac minis can play "most HD content." Besides that, we were taking about using the iTunes player which without third-party extensions can't even use MKV files.
Lastly, here are Apple's own specification for playback of HD 720p video content:
1.8 GHz PowerMac G5 or 1.83 GHz Intel Core Duo or faster Macintosh computer
And here is the link to Apple's complete list of requirements for SD, enhanced SD, 720p, and 1080p:
http://www.apple.com/quicktime/player/specs.html
P.S. I just tried some 720p MKV files that I got off of the DivX website and they were even worse than the QuickTime files (although I'd admit that with this small sample -- two files -- I can't really say that this is representative of all HD MKV files). I used VLC to play them and not only did I see lots of frame stutter but there were many scenes that broken into random colored squares with hardly any recognizable image. However, these same files played just fine on my Mac Pro (where the playback uses only about 30% of one core).