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Quicktime pro resampler quality?
Reply #25
Well, it's interesting. Quickly tried now QT pro 7.7.1 for Win with a few configuration parameters, and I also couldn't get identical result between QT pro and qaac. Same for CVBR.
On the other hand, I could confirm iTunes plus is still bit-identical with qaac --cvbr 256 -q2, and iTunes custom  (CVBR) is identical with qaac --cvbr -q1;

qaac is now built directly upon CoreAudioToolbox, and is not using QuickTime API.
QT pro might be doing something different... I don't know for sure.


Hey, thanks for your response, I think I will just convert to alac and downsample using coreaudio now.One question though, on http://src.infinitewave.ca/ which core audio is present in the windows version?I see leopord and tiger, but I believe those are the mac versions.

  • nu774
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Quicktime pro resampler quality?
Reply #26
I think I will just convert to alac and downsample using coreaudio now.

My personal recommendation is just to use SoX. It's good enough and still very efficient (fast). You can run sox resampler from foobar2000 DSP, too.
I implemented --native-resampler on qaac to tweek around with CoreAudio SRC not because I want/recommend people to use it seriously.

One question though, on http://src.infinitewave.ca/ which core audio is present in the windows version?

Apparently CoreAudio has been updated after Leopard release. Leopard is two generation behind from the newest (Lion). However, I don't know if SRC has been updated. I'm not a Mac user anyway.
I just quickly tested with sweep wave conversion; From what I can see, --bats,127 gives me something looks similar with Leopard version on the site. However, I don't know if it is exactly the same.
  • Last Edit: 12 April, 2012, 09:32:31 PM by nu774

Quicktime pro resampler quality?
Reply #27
I think I will just convert to alac and downsample using coreaudio now.

My personal recommendation is just to use SoX. It's good enough and still very efficient (fast). You can run sox resampler from foobar2000 DSP, too.
I implemented --native-resampler on qaac to tweek around with CoreAudio SRC not because I want/recommend people to use it seriously.

One question though, on http://src.infinitewave.ca/ which core audio is present in the windows version?

Apparently CoreAudio has been updated after Leopard release. Leopard is two generation behind from the newest (Lion). However, I don't know if SRC has been updated. I'm not a Mac user anyway.
I just quickly tested with sweep wave conversion; From what I can see, --bats,127 gives me something looks similar with Leopard version on the site. However, I don't know if it is exactly the same.


Do you think it would be worth re-encoding all my needledrops to sox then and delete all the quicktime downsampled ones?
What I find puzzling is the fact that you say leopard two generations behind lion, but lion performs notably worse on the src scales in just about every fashion than leopard.

Also, I have uploaded samples of izotope 64 mbit dithered, original wav, and quicktime and sox comparisons now, so an actual listening test for the public can commence

quicktime
http://www.mediafire.com/?hgjv2mfu8b095w2

sox
http://www.mediafire.com/?xcdj0hj7yawio0g

izotope 64 src/mbit dithered
http://www.mediafire.com/?umnkxd63585rha5

original unsampled wav
http://www.mediafire.com/?pyc2o5ks74jebs2

QAAC bats native resampled
http://www.mediafire.com/?3421h4mz86dm8hi

*note, I forgot to rename some of the files all of them are in .mp4 and some might overwrite one another if saved in same place*

Anybody care to share their results?No serious abxing required, just to see if any differences can be spotted.

  • nu774
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Quicktime pro resampler quality?
Reply #28
Do you think it would be worth re-encoding all my needledrops to sox then and delete all the quicktime downsampled ones?

No, especially on AAC encoding.
If *you* cannot ABX it, it's worth nothing.

What I find puzzling is the fact that you say leopard two generations behind lion, but lion performs notably worse on the src scales in just about every fashion than leopard.

How did you know that? Maybe another source?

Quicktime pro resampler quality?
Reply #29
Do you think it would be worth re-encoding all my needledrops to sox then and delete all the quicktime downsampled ones?

No, especially on AAC encoding.
If *you* cannot ABX it, it's worth nothing.


What I find puzzling is the fact that you say leopard two generations behind lion, but lion performs notably worse on the src scales in just about every fashion than leopard.

How did you know that? Maybe another source?


Care to explain what you mean with aac encoding? This is not to sound like a jack a, i just want to know as much as possible about all of this, and music.

on the src website, i compared the two, namely on passband, transition, tiger falls off from the ideal filter for both, while leopord maintains near accuracy.On sweep, it has all this extra stuff that leopard doesn't have *and izotope 64 doesn't either, so I assume it to not be good*
  • Last Edit: 13 April, 2012, 12:41:44 AM by Mix3dmessagez

  • nu774
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Quicktime pro resampler quality?
Reply #30
Care to explain what you mean with aac encoding?

Sorry for my English if it's unclear; It's not my native tongue and I'm really not good at it.
I just thought you are encoding to AAC and that's all.

on the src website, i compared the two, namely on passband, transition, tiger falls off from the ideal filter for both,

Tiger ? Lion
Tiger is older than Leopard.

Quicktime pro resampler quality?
Reply #31
Care to explain what you mean with aac encoding?

Sorry for my English if it's unclear; It's not my native tongue and I'm really not good at it.
I just thought you are encoding to AAC and that's all.

on the src website, i compared the two, namely on passband, transition, tiger falls off from the ideal filter for both,

Tiger ? Lion
Tiger is older than Leopard.



Your english is extremely clear and correct, there's nothing wrong with it.What i meant was..

Do you think it would be worth re-encoding all my needledrops to sox then and delete all the quicktime downsampled ones?

No, especially on AAC encoding.
If *you* cannot ABX it, it's worth nothing.

Why is not worth deleting and resampling everything if I convert to aac, thats what i was asking

  • nu774
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Quicktime pro resampler quality?
Reply #32
Why is not worth deleting and resampling everything if I convert to aac, thats what i was asking

Okay, I was assuming that you won't be able to ABX them, so I said no. If you are encoding with perceptual coder like AAC and you cannot tell the audible difference, the difference is not important.
Of course it's a different story if you can.

Quicktime pro resampler quality?
Reply #33
Why is not worth deleting and resampling everything if I convert to aac, thats what i was asking

Okay, I was assuming that you won't be able to ABX them, so I said no. If you are encoding with perceptual coder like AAC and you cannot tell the audible difference, the difference is not important.
Of course it's a different story if you can.


From the samples I've provided could you abx it?I'd just like someone whose more knowledgeable and smarter on this with better ears to scale the differences between them.

  • Wombat
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Quicktime pro resampler quality?
Reply #34
Better ask on some audiophile forum for an abx of resamplers that all work very well, especially when you use some audiophile recommended settings like non-linear phase with sox.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

  • IgorC
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Quicktime pro resampler quality?
Reply #35
From the samples I've provided could you abx it?I'd just like someone whose more knowledgeable and smarter on this with better ears to scale the differences between them.

Both Apple (Leopard) and SoX VHQ have a noise lower than perceptible (-160 ... -170 dB). Anything below -120 dB is inaudible. 
And your files have nothing above 20 kHz so it's safe to resample to 44.1 kHz.

P.S. Even if the difference would be ABXable it's still hard to say what is better or worse. It could be just different.
  • Last Edit: 13 April, 2012, 11:52:32 AM by IgorC