A discussion on file sharing led to this on iRiver's forums;

http://www.iriver.com/community/discussion...=&p_name=&word=

uncool cat's posts intrigued me. Does he have a point? He's by far the most competent person on that board IMO, so I don't want to deem him wrong right off the back. Anyone here have something to say?

This person is either trolling or doesn't really have a clue what 'lossless audio compression' means.

Buoooy, this is even better.
I smell "audiophile science" about "differences" between bit-identical streams.

He is the most competent person on iriver board??? Umm.. ok..

Heh, I thought so. Thanks. B)

Read around a bit, he is one of the smarter apples in the bunch...

It sounds more as though uncool cat is trying (albeit not with the highest degree of successful literary transparency) to explain that any digital sampling process invariably introduces stepping, and thus interpolation between the steps. In that sense, something has been "lost": the actual, continuous non-interpolated waveform as it originally existed between those steps. But to argue that that implies a "lossy" method of archival is to ignore the implied acceptance of the digitized waveform as the reference by which loss is measured.

- M.

Still, "crippled" digitized signal is all he can get out of CDs. And I fail to see what this has to do with lossy/lossless formats, he should flame the way audio CDs work instead.

Agreed, but you know as well as I do that there will always be some element of the population bent on flaunting their "knowledge," whether or not it's truly the most appropriate application.

- M.

Déjà vu...

Actually, he seems to be saying that if you encode to a lossless format, then convert back to WAV, your file doesn't exactly match the original - it's just a "facsimile."

...

He also states the following, which is just as ridiculous:

What it sounds like is saying is the losslessly encoded file is decoded it is not the original file. I suppose that is true in the sense that a master tape is the only "original" recording.

Other than that abstract POV it sounds like he is dead wrong.

What a character, contradicting himself within the same sentence.

Thanks for all the compliments, I also use the iRiver forums.
If I am not mistaken certain persons were happy to frequent there when they were looking for info on buying an MP3 CD Player.

Must people take the higher ground/ holier than thow attitude, it's great to be able to judge people from behind a computer but stuff like that does this forum no favours.

While I agree there are some "silly" posts, (mostly from anons) it's only meant to be a forum for people to discuss their iRiver players. Give them a break !!

Tom Kat does his best to help people out or contribute to the forum, but his posts can get overlong and complicated to follow. In my case, I usually end up not reading them fully as he sometimes assumes a technical knowledge on behalf of the other posters, which some don't have (or need/ want).

I wouldn't get too caught up in analysing his posts

Jesus Christ ... how can it be that such a person can be called knowledgeable ?

For me, it seems that he 1. is not able to articulate his thoughts on the matter (which could be possible, if english isn't his mother language) or that 2. he does not know at all what digital storing of music is all about ...

I own 2 MD recorders and consider ATRAC 4 as being a transparent way of compressing "raw" PCM data (although I miss VBR in ATRAC ) .... MD bitrate is roughly at 300 kbps and thus comparable to software encoders (which work far more efficient at the present time).

Hmm ... I wonder if that guy could ABX between FLAC/APE and WAV ... or does he really state that a facsimile is an identical copy of the original ?

I'd like to give him the benefit of the doubt and think that maybe he's somehow come to understand that lossless only means totally transparent, and that compression throws out bits (which it does...otherwise there would be no compression) that don't come back when you decompress (which, of course, they do...that's the whole point of lossless algorithms). He also mentioned something about program-specific propriatary lossless formats, which also make me think he's accidentally come to use the word lossless in the incorrect context.

This really isn't a big deal, and certainly nothing worth bashing anybody about, but sometimes we all need to step back and realize that it takes a little patience to educate the public about audio encoding, and there are a lot of ways for a person to become misinformed. I'm guessing this guy will figure it out eventually, just like the rest of us did...

That guy is flat, dead-wrong, and has no idea of what he's talking about, period.

If that guy is one of the most knowledgeable, how can be the non-knowledgeable ones?? Instead, I guess that he is among the ones that *look* most knowledgeable, which is not same thing as being really knowledgeable, because obviously he's not. This happens sometimes with esoteric "audiophile" equipment owners, whose rethoric can shine but has nothing relevant behind.

There is quite some difference between trolls and uneducated people (eg. trolls know that they're writing BS). This one's posts even look similarly styled to those written by some other popular trolls.

Am I the only one who thinks that he is meaning "there's a loss" as in bytes? I picked up that he means because the compressed file is byte-wise smaller, it's somehow not the same audio data.

If you compress any random file with eg. ZIP, it's (usually) smaller, isn't it ? And decompression results are exactly same as source file. Perhaps some people don't realize that.

I didn't read that thread. But from the quotes above, I think that he doesn't know the existence of lossless codecs (Flac, Lpac, etc), and only talk about lossy audio, using the word lossless completely out of context.

I think, IMHO, that he is taking issue with the name lossless. His post does not seem to be relevant to anything else.

As far as he is concerned the de-compressed lossless file is not the same as the original, for whatever reason, and shouldn't be called lossless in the first place.

Actually this is typical of his posts, a minor comment from another poster results in a huge response. Eg explaining why he does not think Lossless should be called lossless. He does not say what he thinks is lost in the re-forming of the source, so it is pointless.

Opinions are like ar**h**** everybody has one.

...and most of them stink.

----------------------
Quote by Tom Kat...
I really dont care if the backward decode of lossless files is digitally considered authentic (i.e. the hashes etc), as it is still less of (in absolute terms) of what was there in the original - hence it is a mere facsimilie.
----------------------
From yourDictionary.com...
fac·sim·i·le - n. - An exact copy or reproduction, as of a document. See fax. - adj. - Of or used to produce exact reproductions, as of documents. Exactly reproduced; duplicate.
----------------------

Maybe he's assuming a loose application of the word 'exact'? Seems like a pretty boolean term to me, and a very easy word to define and use.

It's a mere exact copy? That would be merely good enough for me, and I'm a pretty anal person.

As for his statement that "...it is still less of (in absolute terms) of what was there in the original..." :buzzer sounds: Sorry sir, you are incorrect. Raw PCM > FLAC > Raw PCM? Checksum don't lie, brother! Or is he complaining that the resulting "exact copy" WAV that comes from WAV > FLAC > WAV isn't lossless because it's not the same file? I mean the exact same file...taking up the same space in the universe? Uh...well, even his 'perfect', never-been-compressed files don't even meet that criteria.

Bottom line...IMO, it sounds like he's vying for attention and trying to impress DAE newbies. I'm a newbie. I'm not impressed. The debate I had with Pio2001 and David (2Bdecided), on the other hand, impressed me (and educated me).

I'd only agree with Tom Kat to the point of, as I've argued before, "standing vigil in front of the word lossless", as it is practically a holy term in digitial audio. But even as a newbie, I know that FLAC, LA, Monkey's, and the like are indeed truly "lossless" when compared to the source PCM WAV they are encoded from.

And just for sport, I'd *really* love to have him sit down and do an ABC/HR comparison between PCM WAV, FLAC and some of my Vorbis -q 4.25 encodings. I think he'd be surprised and amazed at the results. Just before the denials and rationalizations started anyway...

Edit: Formatting errors...

Give up. This is the exact kind of guy that says DBTs are worthless.

Doesn't one of the lossless codecs use Joint Stereo if the user so desires? In that unique case, then, lossless wouldn't be quite lossless, not would it? Or would the Joint Stereo work differently that Lame-MP3's mid-side/left-right joint stereo does?

Yes, it would be just as lossless. What makes you think that joint stereo is "lossy" because it's used in lossy compression?

Yes, a lot of lossless codecs use some kind of joint stereo. The simplest form is indeed just Mid/Side stereo. But this does not make them a bit lossy.

-Eugene

The difference between "pure stereo" lossless and "joint stereo" lossless is similar to the difference between compressing two WAVs in RAR non-solid mode and compressing the same two files in RAR solid mode. (this is a much simplified explaination though, lossless audio encoders are far more optimized to utilize corelation between channels).
I really don't understand where some of you get those ideas about "lossless not being lossless". If one of those codecs was actually altering the sound data at that big bitrate, it would become absolutely useless, because lossy codecs can achieve transparency at 2x-3x lower bitrates. Lossless codecs are meant to store (archive) original unaltered sound data, rather than cut file size while preserving the way it sounds.

lossless = no loss = identical to the original!

"Just An UnCool Cat" = no knowledge = worth it for the entertainment value and pure exasperation!

Cheers,
David.

P.S. let's just put another link to that thread:
Are CDs lossless? including a nice definition of lossless.

CRC32 tests show that the originals remain exactly the the same when compressed and then uncompressed. Full stop.

CRC add unnecessary uncertainty. A 32-bit CRC can match on different files once out of about 4 billion (4e9) times. Actually, that's probably wrong, but my CRC knowledge isn't that great. You have the original, the encoded version and a decoded version. You can compare the files byte for byte for 100% certainty (or within the error rates of your hardware at least).

But yes, lossless == no loss == the guy is an idiot.

I was thinking that this must be the case. After all if CRCs were absolutely perfect you should be able to play back the file from just the CRC.

HUH?!

Meh ?
CRC32 can't store entire information from some file (after all its ONLY 4 bytes), it's just a number that it always the same for two identical files but extremely unlikely to be the same for two different files.
Probability of finding two different files having same CRC32 is low enough to use it for comparing files in real life.
You can't restore original data from CRC32, just like you can't guess numbers if you only know their sum.

IMO this is correct: Absolutely perfect means there are no 2 files of a given length that result in the same checksum. This is only possible if the checksum is of the same size as the original file, e.g. the "checksum" would be a copy of the file.

Which wouldn't serve its main purpose anymore.

The other very funny thing in that thread (which I'll post now since this thread came back up) is that he explains how he heard differences between the original and lossless files.



The idea of this guy switching between two identical files, and thinking to himself "ooo, yup, I can hear a difference there" is so funny!


And the serious point is that in confirms the placebo effect yet again: he heard a difference because he expected to hear a difference. Even though he was just listening to the same thing.


blind testing people - it's essential.

Unless you're a pure subjectivist, when you'll say that he must have heard a real difference, therefore it was down to the slightly different HDD velocity when reading different sectors of the disc, giving rise to small but perceptable changes in the current drawn from the PSU, which affected the sound card output in some way.

Cheers,
David.

It might not be a big deal, but it's certainly something you'd want to stop while in the making. If you have a group of people thinking he is 'the knowledgable one', they will go around thinking that lossless is just a facsimile and could end up hard to convince otherwise because they were told this from a 'knowledgable' source. Misinformation is damaging I guess I'm saying?

Differenciam, I am hurt by your implications of the caliber of posters at that board. I post at those forums on an occasional basis. I'm not implying I'm some highly knowledgeable entity but neither do I pretend to be on every topic that surfaces on said board.

Uncool Kat has posted here several times and I believe he is no longer posting on the Iriver forums due to the anonymous user harassment. He seems to just be unconvinced about the validity of lossless mainly due to his experience with lossy formats and their inherent nature of destroying bits which DO affect sound quality.

While we on lossless discussion again, I'd like to ask a tangible question:

Of course all of the people who ever looked at WMP 9 noticed that lossless option in the Music Copy tab, adds the word Mathematicaly to it. Now a thread on another board I visit (thread now deleted due to extensive trolling) there was a person claiming that the reason for word Mathematicaly to be there is that if someone decided to sue MS by saying just like the guy in the thread above, that Lossless has lost something dispite advertised "loss-less-ness", MS present a Mathematical proof that their lossless is in fact lossless. They didn't release this proof 'couse that would disclose the way the compression algorithm works, and whatever public opinion about business practices of MS is, they do have good mathematicians working for them (some with Field Medals), is that true.

Plus if you check out Flac docs, you'll see that a lot (if not all) of lossless compression is based on some works by several guys, which could imply that MS using those works also to some extent. Now if MS got a mathematical proof, woldn't it suggest that if done correctly other compressors would also fall under same proff (with adjustments) since they all derive from the same source?

This is possible but, to be honest, I think (from reading the whole thread) that he is just trolling. He is not even *considering* the fact that he *might* be wrong, even after a bunch of people tried to tell him that the files were bit identical. Plus, as Pio2000 pointed out, why would anyone use lossless, and put up with the huge files if it wasn't actually lossless? It just doesn't make any sense.

I do agree with your point in general, but you going over board with that last one. There are Millions of people smoking, eating fatty foods, and taking drugs, if it's bad why do they do it? It just doesn't make any sense.

That just sounds like speculation.

The more mundane answer is probably that a lossy codec is "perceptually lossless" (at least to marketing people!) if it (supposedly) doesn't audibly alter the sound.

Saying something is "mathematically lossless" simply removes this possible confusion - the numbers you get out are the same as the numbers you put it.


Anyway, after saying that 128kbps is CD quality, these interfaces were always going to struggle to explain something that was better! "really, genuinely sounding even more like the original CD than the actual CD does - er...." etc. To cut through the cynicism this hype has caused, just add the word "mathematically", and everyone knows that there's no argument about this one!

Well, that's my guess anyway.

Cheers,
David.

The proof would be pretty trivial. All lossless audio codecs I know of work essentially like this:

encode:
- take input f(t)
- magically conjure up g(t)
- store g and the difference(error) which is f(t)-g(t)

decode:
- compute g(t)
- add the error

Proof that it's lossless:

g(t) + [f(t) - g(t)] = f(t) + g(t) - g(t) = f(t)

QED

Notice it doesn't matter even what g(t) is, unless of course you care about the compression ratio

Maybe then someone would challenge the losslessness of the error-coding stage; for most of those, proofs are already available.

Josh

Arrrgh.... Using the term lossless in a sentence discussing a subjective concept (transparency).

Just kidding!

I know we've been through the debate about multiple concepts of "lossless", and we obviously agreed that the term has to be qualified for proper use...meaning
"Lossless compared to what source?"

I guess I'm just sensitive to seeing the word lossless used in any way but the absolute. [Forgive me...I'm standing at the gates again. ] I'd use the term tranparent to mean what you say with the phrase perceptually lossless, though I know (assume?) you mean the same thing.

Sorry...just being neurotic. I know you know far more than I do about this kind of thing...I just get very philosophical about the sanctity of absolute concepts (and terms). Once we start saying "perceptually lossless", and JoeAverageMusicFan hears this, how long before the word "perceptually" is dropped among the less informed, and people start going around saying, "Yeah, my MP3s are lossless."

Edit: And I know that it's the fault of marketing organizations misusing these terms, but all the more reason for us (and everyone) to permeate them with the word transparency. I'd much rather hear them say "128kbps is transparent" than even "320kbps is lossless", though even the former is not true for a lot of people.


Edit: Clarification...

umm... I don't understand how 128kbps and transparency came up. I always thought that Lossless means it can be decoded to original WAV, or played back in the encoded form as if it was original WAV (on the fly decoding I presume). And I thought that the MS lossless was just another kind of compression, with different compression ration, playback speed. So I don't understand the point you make about transaperency, how can it not be transparent, we aren't about WMA std 128kbps we talking lossless, arent' we?