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How Do Lossless Formats Compare when played back?

I'm a newby here.
Seems like much studies have been made on the CPU performance and conversion accuracy of different lossless formats, but haven't heard much on the sound quality when they are played back. Bottom line, so what if one format has better CPU performance and conversion accuracy, if it doesn't duplicate the original CD sound.  I believe that the theory behind lossless is decoding the file back to the original WAV/AIFF file.  Hence, it should sound identical to CD.  I say that this not the case in the real world.

I have compared Apple lossless with their counterpart AIFF using iTunes and CDs played directly through a cheap Technique CD player.  Apple lossless doesn't sound as good as AIFF/CD. I couldn't distinguish between AIFF and CD, but Apple lossless suffers slight loss of bass and clarity at the low end. To me, it produces a muddier lows and mid-lows, producing boxier sound. BTW, the testing was done with decent equipment: M-Audio Firewire 410 interfaced to Mac G4 Dual and Crown amp output to Polk SDA speakers (old, but still good). The louder I played, more noticeable the differences become.  This is not just my opinion.  Others have said the same.

Have people compared different formats played through quality Hi-Fi equipment?  And what's the verdict?  Do I have supersensitve ears or lossless formats in fact produce tainted sound?

How Do Lossless Formats Compare when played back?

Reply #1
Hello, and welcome to Hydrogenaudio.

You are reading this because you violated forum rule number 8. Don't worry - you probably didn't know about it, or didn't understand the implications, and we understand that. The Hydrogenaudio Terms Of Service are here:

http://www.hydrogenaudio.org/forums/index.php?showtopic=3974

The gist of rule #8 is that if you make a claim, you must have proper supporting evidence for it. This rule is the very core of Hydrogenaudio, so it is very important that you follow it.

This is a generic post, and not all what follows may be applicable to this situation. Read through it nevertheless, it contains essential information and will help you understand what to do (or not to do).

Why should I bother with all of this, I just want to report a problem?

For audio quality matters, 'proper supporting evidence' is a blind listening test result demonstrating that you can hear a difference, together with a test sample. Graphs, non-blind tests, subtracting two files and so on are definetely not!

A proper blind test serves several purposes: it shows that you are serious towards our community, it proves to yourself that you can indeed hear a difference, it provides an indication of the seriousness of the issue at hand, and it helps pinpointing the problem for differnent listeners.

The easiest and most common way to do a blind test is an ABX test. There are several free utilities to do one:

http://www.pcabx.com/
http://ff123.net/abchr/abchr.html
http://www.rarewares.org/files/others/abchr-java.zip
http://www.kikeg.arrakis.es/winabx/winabx.zip
http://www.beryllium.net/~remco/linabx/

An ABX test requires you do identify an unknown (X) sample as either the original (A) or the processed (B) sample. With some statistics it can be figured out how likely it is that you were actually hearing a difference instead of just guessing which was which. Hydrogenaudio uses as a general guideline that < 5% change of guessing is considered 'proof' that you are hearing a difference. If you try the ABX test multiple tests, add up all attempts. You can use http://www.ff123.net/abx/abx.html to calculate the p-value ( < 5% = < 0.05), though most ABX programs have it built in.

If you managed to get a significant score, congratulations, it seems that the problem is real.

If applicable, you'll need to upload the test clip you used so other people can verify it and developers can tinker with it.

Uploading copyrighted music is generally illegal, but fair use laws generally permit short clips (< 30 secs) to be used for purposes such as this. Compress it with a lossless encoder (e.g. FLAC http://flac.sf.net) and upload it to either your own webspace or Hydrogenaudio's Uploads Section.

If you finally make your post to Hydrogenaudio, try to include as much information as is relevant, and be sure to explain exactly what and where (important but often forgotten) you hear the problem best.

Audio is to a large extent a subjective matter, and as such, quality matters are prone to a few problems. The first is listener preferences. Something that applies to you may not apply to the majority of people. Maybe the clip is an exception or problem case and not representative of general performance. This is why being able to verify a result is imporant, as well as giving the developers something concrete to work with.

The second is the mind. The human mind is powerfull, but has some weaknesses. It is very vulnerable to suggestion and subconscious influences, even for people experienced in these tests. No matter how how 'sure' you are  that a problem exists, verify that it's not your mind playing tricks on you first, it'll save embarassement later.

'Simply' reporting a problem generally doesn't tell us anything, isn't indicative of anything, can be impossible to reproduce, confuses people, and most importantly, wastes precious developer time determining if the problem is real and serious or not.

You may have saved yourself 5 minutes, but you've cost other people an hour. That's not very nice.

A more detailed introduction to ABX tests has been written by Pio2001 here
"To understand me, you'll have to swallow a world." Or maybe your words.

How Do Lossless Formats Compare when played back?

Reply #2
Mea culpa.
Rule 8 seems pretty complex and time consuming.  So I won't be able to do this.  But let me rephrase my earlier forum without making any "claim".  By previous comments were merely my opinion.

Seems like much studies have been made on the CPU performance and conversion accuracy of different lossless formats, but haven't heard much on the sound quality when they are played back.  The theory behind lossless is decoding the file back to the original WAV/AIFF file, right?  Hence, it theoretically should sound identical to CD.  But how is it in the real world?

Have people compared different formats played through quality Hi-Fi equipment? And what's your opinion?  I'm not asking for your proof or verification, just your opinion based on your observation. 

And what do you recommend for lossless format?  I prefer Mac OS.

How Do Lossless Formats Compare when played back?

Reply #3
Which part of "lossless" word you do not understand ?

How Do Lossless Formats Compare when played back?

Reply #4
It is pretty simple.
If you cannot decode back to the same exact* file it is not lossless.
There is no need for listening tests to figure out if something is lossless. You can just compare the files bit by bit.


*The whole file might not be bit identical due to difference in the headers but the audio data itself will be. Use something like EAC's or foobar's "compare" tool that only compares the audio data itself.

How Do Lossless Formats Compare when played back?

Reply #5
Quote
Mea culpa.
Rule 8 seems pretty complex and time consuming.  So I won't be able to do this.[{POST_SNAPBACK}][/a]

Perhaps [a href="http://www.hydrogenaudio.org/forums/index.php?showtopic=16295&]this thread[/url] will help.
Quote
Have people compared different formats played through quality Hi-Fi equipment? And what's your opinion?  I'm not asking for your proof or verification, just your opinion based on your observation.[a href="index.php?act=findpost&pid=253453"][{POST_SNAPBACK}][/a]

So you would rather have opinions instead of facts
Quote
And what do you recommend for lossless format?  I prefer Mac OS.
[a href="index.php?act=findpost&pid=253453"][{POST_SNAPBACK}][/a]

You would do well to search. Many people prefer FLAC and it is one of the most supported lossless codecs.
"Facts do not cease to exist just because they are ignored."
—Aldous Huxley

How Do Lossless Formats Compare when played back?

Reply #6
Quote
You would do well to search. Many people prefer FLAC and it is one of the most supported lossless codecs.
[a href="index.php?act=findpost&pid=253467"][{POST_SNAPBACK}][/a]

But on Mac OS, Apple Lossless is much better supported.

How Do Lossless Formats Compare when played back?

Reply #7
Quote
The gist of rule #8 is that if you make a claim, you must have proper supporting evidence for it. This rule is the very core of Hydrogenaudio, so it is very important that you follow it.
  ......
For audio quality matters, 'proper supporting evidence' is a blind listening test result demonstrating that you can hear a difference, together with a test sample. Graphs, non-blind tests, subtracting two files and so on are definetely not!


Sort of a mixed situation.  Rule 8 specifically applies to subjective claims.  Comparing lossless compressions can be done objectively by the means prohibited in the above clip, but he *did* make a subjective judgement..

How Do Lossless Formats Compare when played back?

Reply #8
Code: [Select]
D:\>fsum -jnc track01.wav

SlavaSoft Optimizing Checksum Utility - fsum 2.51
Implemented using SlavaSoft QuickHash Library <www.slavasoft.com>
Copyright (C) SlavaSoft Inc. 1999-2004. All rights reserved.

c6427dcb856794b0179893165084796a *track01.wav

D:\>flac track01.wav

flac 1.1.1, Copyright (C) 2000,2001,2002,2003,2004 Josh Coalson
flac comes with ABSOLUTELY NO WARRANTY.  This is free software, and you are
welcome to redistribute it under certain conditions.  Type `flac' for details.

options: -P 4096 -b 4608 -m -l 8 -q 0 -r 3,3
track01.wav: wrote 6464449 bytes, ratio=0,461

D:\>flac -d track01.flac -o track01_decode.wav

flac 1.1.1, Copyright (C) 2000,2001,2002,2003,2004 Josh Coalson
flac comes with ABSOLUTELY NO WARRANTY.  This is free software, and you are
welcome to redistribute it under certain conditions.  Type `flac' for details.

track01.flac: done

D:\>fsum -jnc track01_decode.wav

SlavaSoft Optimizing Checksum Utility - fsum 2.51
Implemented using SlavaSoft QuickHash Library <www.slavasoft.com>
Copyright (C) SlavaSoft Inc. 1999-2004. All rights reserved.

c6427dcb856794b0179893165084796a *track01_decode.wav

D:\>

Quote
c6427dcb856794b0179893165084796a *track01.wav
c6427dcb856794b0179893165084796a *track01_decode.wav

The input and output files are identical. The process is lossless.

Quote
lossless

<algorithm, compression> A term describing a data compression algorithm which retains all the information in the data, allowing it to be recovered perfectly by decompression.

Unix compress and GNU gzip perform lossless compression.

Opposite: lossy.

How Do Lossless Formats Compare when played back?

Reply #9
If the lossless formats decoder was crap I imagine it could introduce some artifacts.  Although that would make it no longer lossless.  I dislike TOS#8 since I got a warning level because of it for something that I have yet to get a response about, although the rule is necassary.  Avoid any topics around #8.  So in this case, lossless formats will all sound exactly the same.

How Do Lossless Formats Compare when played back?

Reply #10
Quote
Which part of "lossless" word you do not understand ?
[a href="index.php?act=findpost&pid=253457"][{POST_SNAPBACK}][/a]

Have you played backed different "lossless" formats and you believe they all sound the same or are  you just going by what's advertised as "lossless"?

How Do Lossless Formats Compare when played back?

Reply #11
I wouldn't challenge 7z if I were you, he has a great deal of knowledge...

How Do Lossless Formats Compare when played back?

Reply #12
Go away and quit wasting our time with newbie questions. Lossless is lossless, end of story.

How Do Lossless Formats Compare when played back?

Reply #13
Maybe iTunes screws up playback of Apple Lossless.

How Do Lossless Formats Compare when played back?

Reply #14
Quote
I'm a newby here.
Seems like much studies have been made on the CPU performance and conversion accuracy of different lossless formats, but haven't heard much on the sound quality when they are played back. Bottom line, so what if one format has better CPU performance and conversion accuracy, if it doesn't duplicate the original CD sound.  I believe that the theory behind lossless is decoding the file back to the original WAV/AIFF file.  Hence, it should sound identical to CD.  I say that this not the case in the real world.

I have compared Apple lossless with their counterpart AIFF using iTunes and CDs played directly through a cheap Technique CD player.  Apple lossless doesn't sound as good as AIFF/CD. I couldn't distinguish between AIFF and CD, but Apple lossless suffers slight loss of bass and clarity at the low end. To me, it produces a muddier lows and mid-lows, producing boxier sound. BTW, the testing was done with decent equipment: M-Audio Firewire 410 interfaced to Mac G4 Dual and Crown amp output to Polk SDA speakers (old, but still good). The louder I played, more noticeable the differences become.  This is not just my opinion.  Others have said the same.

Have people compared different formats played through quality Hi-Fi equipment?  And what's the verdict?  Do I have supersensitve ears or lossless formats in fact produce tainted sound?

[a href="index.php?act=findpost&pid=253443"][{POST_SNAPBACK}][/a]
The audio data in lossless files is exactly the same as in the original file : it's exactly like a .zip or .rar file... Imagine that you zip a text file, and then uncompress it, would it suffer from "slight loss of bass"? That's nonesens.

The only thing that varies is in fact hardware : lossless files need more CPU power... but they need less hard drive access... And HD are much louder than CPU... Therefore lossless files sound even better than original ones when playedback

How Do Lossless Formats Compare when played back?

Reply #15
Strange idea that one file that is contains binarily exactly the same information as the other one could sound differently...

The zipped text file is a good example
Life is Real...
(But not in audio :) )

How Do Lossless Formats Compare when played back?

Reply #16
Well, I see you decided to continue trolling rather than bothering to read and understand very informative replies you've got; or even to comply with forum rules. One more useless post / TOS #8 violation and you are out.

How Do Lossless Formats Compare when played back?

Reply #17
Quote
Maybe iTunes screws up playback of Apple Lossless.
[a href="index.php?act=findpost&pid=253515"][{POST_SNAPBACK}][/a]

Playback of corrupted lossless files generally sounds much less pleasant than "slight loss of bass and clarity at the low end" he describes. Until he provides blind test results, he's most likely yet another victim of placebo effect, or a troll.

How Do Lossless Formats Compare when played back?

Reply #18
Wow.  Tough crowd.  Sorry to have wasted your precious time with my newbie comment/question.
So you all pretty much take the position that  all lossless files, when decoded, are binarically identical to AIFF/WAV files originating from CDs.

You all have good life.

How Do Lossless Formats Compare when played back?

Reply #19
@oogywawa. No, the output AIFF/WAV from a decoded lossless file dont need to be identical to the source.
But the PCM stream inside it needs to be identical!

Ok, bye! 

How Do Lossless Formats Compare when played back?

Reply #20
Quote
So you all pretty much take the position that  all lossless files, when decoded, are binarically identical to AIFF/WAV files originating from CDs.
[a href="index.php?act=findpost&pid=253608"][{POST_SNAPBACK}][/a]

Yes we do... that's because - stay with me here... it is

[span style='font-size:30pt;line-height:100%']LOSSLESS[/span]

How Do Lossless Formats Compare when played back?

Reply #21
As in... without loss and maybe this would be a good reading for you http://en.wikipedia.org/wiki/Lossless
Two things are infinite: the universe and human stupidity; and I'm not sure about the universe

How Do Lossless Formats Compare when played back?

Reply #22
I don't know about you, but I don't "take the position" that the earth is round, I know it...

How Do Lossless Formats Compare when played back?

Reply #23
Quote
I have compared Apple lossless with their counterpart AIFF using iTunes and CDs played directly through a cheap Technique CD player.  Apple lossless doesn't sound as good as AIFF/CD. [...] BTW, the testing was done with decent equipment: M-Audio Firewire 410 interfaced to Mac G4 Dual and Crown amp output to Polk SDA speakers (old, but still good).

Have people compared different formats played through quality Hi-Fi equipment?  And what's the verdict?  Do I have supersensitve ears or lossless formats in fact produce tainted sound?


Mmm-kay. A lossless codec compresses audio in such a way that it reproduces the original audio bit for bit. That means, the compressed file and the original are absolutely IDENTICAL, audio-wise. There is ABSOLUTELY no doubt about that. A codec is 100% lossless, or it's not. Period.

Your problem here is that you're comparing the sound quality of your computer and your standalone CD player. This has nothing to do with that. You're not even comparing apples and oranges here, you're comparing apples to apple-pie. An apple is always an apple, even though it can be cooked by more or less talented cooks. The exact same sound file may sound very differently on different hardware.

I'm having a very hard time trying to explain this to you, but I can't see what it is that you don't understand. Your comparison is equivalent to playing the exact same CD on both the computer and your CD player.

How Do Lossless Formats Compare when played back?

Reply #24
Good analogy about the apple/apple-pie, I'll have to remember that one =]

 
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