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320K MP3 vs 256K WMA10, Observations
Glenn Gundlach
post Feb 4 2013, 08:19
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There has been quite a bit of MP3 S/N and negative comments about WMA files so I tried some experiments in Adobe Audition version 3.0.1 build 8347.0. I was interested in what kind of artifacts happen on boundaries so I created a series tone bursts starting with a 15 second sweep of 10 Hz to 22000 Hz at 44100. Then I inserted many 0.1 second silences with no 'fades' to smooth the boundaries so the file is now 24.7 seconds and saved as a WAV. Then I converted to 320 Kbit MP3 and a 256K WMA10 file and started looking at the residue at the start and stop of the bursts. WMA is significantly lower - about 10-15 dB on average. Well that's nice but what happens with actual music since that's what this is all about? I took Michael Buble's 'Everything' and lined up to the sample of the FLAC/WAV to the MP3 and WMA. Invert the phase of the FLAC and add to the MP3 and then add to the WMA and save those files. The difference is not subtle. I will no longer be using MP3s in my car. I'm of the opinion that the difference file is the 'distortion' and the lower the better. I do not know if there is a better MP3 encoder than in Audition but it's what I've been using for the last 7 years.

The WMA files tag in MP3Tag exactly like MP3 files and while I don't care about the space used, the WMA files are somewhat smaller.

I've been looking around to find out how to post files and screen shots but I'd be happy to share what I have so far.

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Seren
post Feb 4 2013, 09:50
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Does your car support AAC playback? If so you'll most likely enjoy it more than mp3 or wma. Otherwise try out the Lame encoder (and possibly even Halb27's variation of it).

This post has been edited by Seren: Feb 4 2013, 09:54
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DonP
post Feb 4 2013, 13:21
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QUOTE (Glenn Gundlach @ Feb 4 2013, 02:19) *
I took Michael Buble's 'Everything' and lined up to the sample of the FLAC/WAV to the MP3 and WMA. Invert the phase of the FLAC and add to the MP3 and then add to the WMA and save those files. The difference is not subtle. I will no longer be using MP3s in my car. I'm of the opinion that the difference file is the 'distortion' and the lower the better. I do not know if there is a better MP3 encoder than in Audition but it's what I've been using for the last 7 years.


You do know that these are lossy encoders? The whole idea is to change the wave form (to something represented in less bits) while keeping the sound as close as possible. So comparing before and after wave forms is a particularly bad way of judging quality.

There certainly *can* be bad differences that degrade the sound. That would be measured by how it sounds. Did you try that (the usual ABX testing)?

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Soap
post Feb 4 2013, 13:55
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Almost five years here and almost 300 posts and you somehow believe that the described tests are meaningful?


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db1989
post Feb 4 2013, 14:04
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Yes, and somehow do not have the foggiest idea about TOS #8. Do you have anything to say in defence of these pointless non-perceptual tests, or should we just bin this right away?
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Porcus
post Feb 4 2013, 14:52
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QUOTE (db1989 @ Feb 4 2013, 14:04) *
or should we just bin this right away?


Such threads do serve a purpose though.


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db1989
post Feb 4 2013, 15:39
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…which is not something that we wish to promote, contrary to the belief of some.

The purpose that might be served is that the OP would rethink the fatally flawed idea that difference signals, spectrograms, or any other visually or measurement-based metrics need have any correlation with perceptual quality, which obviously they do not. Logic aside, such means of measuring are clearly specified as being irrelevant in TOS #8, so this thread has no future if it does not yield a revised approach to the comparison in question. Again, the fact that this was posted not by a clueless new user but by someone who has been registered for years and posts reasonably frequently makes it all the less understandable.
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Nessuno
post Feb 4 2013, 16:04
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QUOTE (db1989 @ Feb 4 2013, 15:39) *
The purpose that might be served is that the OP would rethink the fatally flawed idea that difference signals, spectrograms, or any other visually or measurement-based metrics need have any correlation with perceptual quality, which obviously they do not.

Well, as an afterthought: they have, but the sense is quite the opposite: see how much we can throw away without actually noticing. So the more, the better! smile.gif


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bilbo
post Feb 4 2013, 16:06
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I don't think that the OP is serious and just making a joke. I think the key phrase is "I will no longer be using MP3s in my car." which is one of the worst places to distinguish a difference.


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dhromed
post Feb 4 2013, 16:22
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QUOTE (bilbo @ Feb 4 2013, 16:06) *
I don't think that the OP is serious and just making a joke.


Then his hyperbole is so subtle as to be indistinguishable from reality!
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greynol
post Feb 4 2013, 16:23
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QUOTE (Glenn Gundlach @ Feb 3 2013, 23:19) *
There has been quite a bit of MP3 S/N and negative comments about WMA files so...

...so with this post you've succeeded in raising the noise floor even further.

emot-toot.gif

This post has been edited by greynol: Feb 4 2013, 16:23


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Porcus
post Feb 4 2013, 17:15
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QUOTE (Nessuno @ Feb 4 2013, 16:04) *
Well, as an afterthought: they have, but the sense is quite the opposite: see how much we can throw away without actually noticing. So the more, the better! smile.gif


Are you referring to the binning of threads now?


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db1989
post Feb 4 2013, 17:33
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No, clearly the discarding of information by perceptual encoders. Which was a great point, Nessuno!
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greynol
post Feb 4 2013, 20:30
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http://www.hydrogenaudio.org/forums/index....st&p=818799


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