[PKOneTwo]

I'm happy being to help ;-)

i was referring to this: if you use Ac3 and have an Av receiver connected with toslink (digital connection) to X-box, so the Ac3 stream (doesn't matter 2 or 6 channel) is pass throughed to the receiver. There is no intervention of the xbox, no CPU usage, nothing! You can use 100% CPU for video.

If you don't have an AC receiver, then the x-box have to decode the ac3 stream to analoge output => for 2 channels about 2-3%. (i dind't test the 6 channels AC3 to 2 channel analoge conversion, but may be about 7%).

Anyway: since we are all using DVD as a source: you can take the AC3 stream and there will be NO LOSS (nothing) of sound quality, and CPU can be used 100% for decoding.
Yes AC3 is little bigger than than AAC, but the difference is 100 -150 MB /at most). And don't firget one thing: you still can reencode the 6 Channel AC3 to a lower bitrate (say 224 Kbit). Is will become a difference of about 75MB then and the sound ist still almost perfect.

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PS: I think if you use Mp3 the x-box CPU is used again (doesn't matter if you have Av receiver or not) because the decoding is done by the cpu. But the CPU usage is low (about 5%).
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So finally: keeping AC3 stream ist the best thing you can do:
you can reencode it to a lower bitrate AND uses very LOW cpou usage for analoge output und NO CPU for pass through.

hope could answer ur questions.

I really like this post. You make a lot of good, valid points.

However, keep in mind that I always re-encode AC3 6 Channel audio to AAC 6 channel audio so the difference is size is a couple hundred MB. On 2 Channel audio the difference is minimal, like you said. I would like to go to MP3, but you cannot encode 6 channel MP3's.

On that other hand, you are actually onto something.... And it might be worth the extra couple hundred MB to use AC3 -- or the loss of fidelity and 5.1 in MP3. You see, in my tests with these new encodes I have been doing, videos encoded with deblocking had no problem playing back IF no audio track was muxed. But the addition of the audio track to the same exact video brought back the skipping. At first, I didn't equate this to the AAC codec using so much power, but now it makes a lot more sense...

So, in theory, you should be able to use the current settings posted in the wiki along with deblocking (remove the "-nf" option) as long as your audio is AC3 or MP3.

It would be interesting to know how much CPU 6-Channel AC3 uses and how much CPU 2-Channel MP3 uses. I'm assuming your "2-5%" figure is for 2-Channel AC3...

Can you guys give this a test and post your results? I would but I'm still having slight computer problems... I think my mobo is slowly dieing!!!