256kbps vs FLAC

[Arainach]

Quote:

Originally Posted by FrederikS|TPU /img/forum/go_quote.gif From a compression algorithmic point of view the different FLAC compression levels have a significant impact on the bit per bit output. In an ideal world FLAC should sound the same no matter what compression rate (0-8), but since most of the hardware used for decoding uses a different logic depending on compression the decoded result can sound different. If you examine a decoded FLAC file compression level 8 to say a level 1 there will be no difference bit wise. In theory the only things that differs is the artifacts that the hardware decoder produces at different compression levels. I'm with Quaddy on this one it's all just a matter of finding out which compression level that gives the best result on your hardware.

Wrong on all levels. To the best of my knowledge there is no hardware FLAC decoder in existence. FLAC is decoded in software to PCM, and any compression level decodes to the exact same PCM. That's why it's called LOSSLESS. It's just like a ZIP file (which ALSO has different levels of compression, and somehow decodes to the exact same binary files), and I'm not sure why you have such a hard time grasping that.

 

[Aman]

Quote:

Originally Posted by ataraxia /img/forum/go_quote.gif This only tells half the story. I would not doubt that many of the mp3s obtained from the internet have been made through mediocre compression methods. There is a world of difference between mp3s compressed through LAME and those that have not. This is not a statement "gong completely against the scientific facts behind audio compression", as not all compression executable files are created equal. There are those that compress efficiently, and those that do it less so. To say that it is impossible to tell the difference between compressed lossy files and compressed lossless files is incorrect.

In this post you're introducing a new variable which had nothing to do with my argument. I didn't say the theoretical MP3s would be gathered through online means, whereas the FLAC files would be gathered through a more pure source. This is a useless defense; of course I thought it would be implied that the two files would come from the same reliable source.

And, OF COURSE it's incorrect to say that there's no difference between lossy and lossless files. I didn't say this, however. You ought to read my original post on the matter before you make yourself look even more foolish.

 

[Aman]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif ^^ sorry febs. ipod + bithead isn't exactly the most ideal setup for determining if there are audible differences between wav and mp3. get back to me when you get something better.

???

Some common sense could also be used to determine the audible differences between WAV and MP3. Until 192k compression and lower, MP3s will provide absolutely no audible difference in sound quality because the compression algorithm is intended to remove frequencies from the audio file that the human ear is completely insensitive to at all dynamic levels. You, too, should read my original post on the matter.

 

[krmathis]

...and the discussion goes on.

MP3 vs. FLAC is a fair discussion. But talking about an audible difference between different FLAC compression levels is just insane, imo.

 

[FrederikS|TPU]

The only thing I was trying to say is that when you decode something you use a chip that uses some form of software to take FLAC from being bits to sound. Depending on how the hardware step works and what software it uses you will get different results. And Arainach I didn't say (well I did, but half a sleep) anything about it not being lossless, I just said that depending on how you convert it music quality can suffer because your hardware and software can introduce artifacts to it like jittering or lag. I was half a sleep yesterday while writing I can see that now, sorry I managed to screw up half of the sentences GG. Cleaned it up a bit now.

 

[EnOYiN]

Quote:

Originally Posted by FrederikS|TPU /img/forum/go_quote.gif The only thing I was trying to say is that when you decode something you use a chip that uses some form of software to take FLAC from being bits to sound. Depending on how the hardware step works and what software it uses you will get different results. And Arainach I didn't say (well I did, but half a sleep) anything about it not being lossless, I just said that depending on how you convert it music quality can suffer because your hardware and software can introduce artifacts to it like jittering or lag. I was half a sleep yesterday while writing I can see that now, sorry I managed to screw up half of the sentences GG. Cleaned it up a bit now.

This has nothing to do with FLAC decoding. I think you are talking about a DAC. (but I could be wrong about it) Before audio content in the form of FLAC will go there is isn't FLAC any more but the same as any lossless file.

 

[FrederikS|TPU]

Alright I just thought that FLAC needed processing before being converted to an analogue signal. Anyway that is just how I read it of some random site a while ago. It could be really cool with an in depth wiki on the subject.

 

[Febs]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif ^^ sorry febs. ipod + bithead isn't exactly the most ideal setup for determining if there are audible differences between wav and mp3. get back to me when you get something better.

Yawn. How typical of you to try to insult me instead of addressing the merits of what I have to say. Is your capacity for an intellectual discussion really so limited that you have to resort to base insults anytime someone disagrees with you? Apparently so.

You are making a broad-brush statement about the quality of all MP3s based on some files of dubious origin that you downloaded from the internet. Are you so focused on insulting my gear that you can't see the flaws in that analysis?

Regardless, an iPod and BitHead is in fact the most ideal setup for me to determine if there are audible differences between .wav and MP3 for portable use since that is exactly what I use for portable listening. But I have listened to MP3s and done ABX testing on a wide variety of other gear, and I use FLAC (or WavPackO) for home listening and archiving.

 

[carlineng]

The thought that different compression levels of FLAC sound different completely baffles me. AB/X results, anyone?

 

[krmathis]

Quote:

Originally Posted by carlineng /img/forum/go_quote.gif The thought that different compression levels of FLAC sound different completely baffles me. AB/X results, anyone?

Most (all?) AB/X applications decode all audio streams to PCM (WAV or AIFF) before the listening session starts. Hence you won't be able to AB/X lossless encoded audio, just uncompressed PCM data.

 

[milkweg]

I don't know about flac but I've done ABX testing on myself and a freind using .wav and .mp3@256kb/s and neither of us could tell the difference. Sure, we guessed right sometimes but "guess" is the key word. I don't believe most people who claim they can hear a difference either because most of those people have not done proper ABX testing.

 

[majkel]

Quote:

Originally Posted by Febs /img/forum/go_quote.gif As EnOYiN pointed out, considering how many people here assert that they can hear a difference between MP3 and the uncompressed original, and considering how easy it is to prove that assertion, there is a surprising dearth of substantiated claims. Frankly, I don't understand this. After doing some ABX testing myself, I found that on my portable players, LAME -V5 is completely transparent to me, which allowed me to put substantially more music on my portable players without sacrificing any (subjective) quality at all. I archive all of my music in FLAC anyway, so if I ever find a track that has audible artifacts, I can simply reencode it at a higher setting. But for portable purposes, I don't see any reason to waste limited storage space with encodings that don't offer any audible improvement over MP3.

So, try another portable or desktop source because most mp3 players unfortunately don't play more than highest mp3 VBR bitrates might provide. In the portable world the bottleneck is the hardware. And of course, your threshold of hearing might be different as well.
If you're interested, one fellow prepared for me the same Papa Roach track in ogg Vorbis Q5, Q6, Q7, Q8 converted to wav files, and my task was to order them according to growing bitrate. Q8 and Q5 were the easiest - Q8 had full midrange (like mp3 320kb/s and no lower), Q5 was significantly colder. I had a problem in positioning Q6 and Q7 but here the main role played the nuances. So, I succeeded and it wasn't a guess, I could described the differences I realised. It was on my Connexant AC97 driven laptop. :| On iRiver clix2 it's much easier to hear how the quality grows with the Q factor. Actually, Q7 is acceptable, Q6 gray and uninvolving, Q5 poor and cold, Q8 - full satisfaction. Unfortunately, clix2 corrupts ogg Vorbis playback a bit.
Coming back to the mp3 quality topic - from my experience of iRivers, let's leave other players: T10 does not allow to distinguish 256kb/s mp3 from 320kb/s mp3, in other words - its abilities are no higher than these of the mp3 format in the 256kb/s bitrate. iRiver ifp-799 allows you hear "clearly" the superiority of the 320kb/s bitrate over anything lower CBR/VBR. Actually, this is where the world of pleasant midrange begins. So that's why I often argue about some people's opinions when they say a certain player plays fantastic, while its actual capabilities end at the level of medium quality mp3's.

 

[Febs]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif Most (all?) AB/X applications decode all audio streams to PCM (WAV or AIFF) before the listening session starts. Hence you won't be able to AB/X lossless encoded audio, just uncompressed PCM data.

Of course, all audio applications decode all audio streams to PCM before sending them to the DAC as well, so as long as the decoder is functioning properly, there should be no difference in the playback of different lossless formats/compression levels.

 

[bigshot]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif ^^ sorry febs. ipod + bithead isn't exactly the most ideal setup for determining if there are audible differences between wav and mp3. get back to me when you get something better.

I've done direct A/B level matched comparisons between my home CD player and my iPod playing the same CD/AIFF rip. There was absolutely no difference between the two. The iPod is a perfectly good source. If it isn't possible to hear some aspect of sound on an iPod amped from the line out, the thing you're listening for must be tiny enough to be considered totally insignificant.

Your last sentence is very condescending and doesn't make you look very good, by the way.

See ya
Steve

 

[bigshot]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif So, try another portable or desktop source because most mp3 players unfortunately don't play more than highest mp3 VBR bitrates might provide.

That may be true of some mp3 players, but it isn't the case with the iPod. The Wolfson DAC in the iPod is as good or better as the one in most home CD players. It's capable of playing uncompressed audio as well as it does compressed.

See ya
Steve