QUOTE(SometimesWarrior @ Jan 19 2003 - 02:00 AM)
What are you talking about?
Musepack's psychoacoustics will know when to encode high frequencies and when to omit them. Just because the file is sampled at 48KHz doesn't mean you're all frequencies up to 24,000Hz are going to be encoded. Hell, you could take a 192KHz-samplerate wavefile and lowpass that at 6KHz, or whatever. My point is, your argument about not needing high frequencies has nothing to do with the samplerate in this case.
It's true that a file encoded from a 48KHz source will likely be a bit larger than one from a 44.1KHz source, but if you avoid converting, you will have a better quality result. The 48 -> 44.1 samplerate conversion is going to cause some quality loss, and it will probably have to do another 44.1 -> 48 when it goes through the soundcard during playback.
So why not just keep it at 48KHz?
Oh, and while I'm on the rampage... I'm not sure how the Valex AC3 plugin handles 5.1 -> 2.0 conversion, or how it does the normalizing, or what kind of compression/limiting it uses, but I would make sure that it's properly mixing LFE and center channels and make sure the other settings make sense. I would still use Azid (or BeSweet, or something of that nature) to do a 2-pass normalization. As I understand it, AC3 stores the amplitude as floating-point, so you have to go through the whole file and find the peak, and then scale the whole file when decoding to fixed-point WAV. Otherwise you're re-quantizing or something when you normalize(generally considered a bad thing). The effects of all these settings might be near-negligible, but then again we're encoding to Musepack --standard, not MP3Pro; we want the best possible quality, with fewest possible compromises!
I understand that you were just doing a test to see what kind of filesize Musepack would produce, but if you want to get nitty-gritty about its quality and its size, you should perform the test under optimal conditions and see if the bitrate differs from your original report.
But even after all my yelling, I still think it's great to see Musepack performing so well on a movie soundtrack. If the filters were available, I'd certainly use Musepack for the audio compression on my DVD-rips.
You have a problem of some sort with me?...
No shit.. of COURSE frequencies won't be up to 24,000hz (!)
My argument about not needed high frequencies does have something to do with the samplerate in this case. Since 48,000hz is NOT, again, NOT needed, i convert it to 44,100hz.
"but if you avoid converting, you will have a better quality result."
You are wrong. I lose absolutely no quality when i do a very high quality conversion from 48khz to 44.1khz. If you use cooledit, then convert using pre/post filter and quality 999 (which is of course not needed, ~600 is more than enough) and try to find a difference, you will never find a difference.
"and it will probably have to do another 44.1 -> 48 when it goes through the soundcard during playback."
That is, if you have a resampling soundcard...
"So why not just keep it at 48KHz?"
Because it's not necessary. And i don't like the idea of using unnecessary things. That's my opinion, since it's not yours that's fine, use 48khz.
The Valex AC3 plugin handles 5.1 ->2 conversion very well as far as i could hear, it's very accurate. And of course i DID make sure it mixes the LFE and center channels properly, and i always make the "other settings make sense"..
I was not just doing a test without making sure the quality is the best it can be. I'm just not that kind of person.