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Clarification of MPEG 4, AAC and Apple

Two thoughts:

1. For those who have plenty of space and want maximum quality, you can *already* rip your CD's using the lossless AIFF format in iTunes.

2. Listening improves through education (this is my job). Those who don't hear a difference between two songs encoded differently may well learn to reliably hear a difference if shown how to listen and what to listen for. This can be proven using double-blind tests. If you *don't* hear a difference, it doesn't necessarily mean that a difference isn't audible to others.

Nice thread.

elo
 
DEaf from play it to loud...NOT

This is all fine and dandy . . . But I will treat all compression techniques and a digital version of cassette.

I am NOt a musician. or have perfect pitch trained ears yet I can tell:

1: all forms of compression
2: all fox channels on dish and Directv are badly compressed
3: the difference between a one bit and a sixteen bit cd player
4: standard and HDCD encoded cd's

I guess this explains why I do most of my listening on SACD or DVD Audio. (by the way the rerelease of Pink Floyd's dark side of the moon is wicked)

For me to tell the diff' from all these formats was in 5 minutes in a high end audio shop. NOT BEST BUY(mostly low end stuff)

As a MAC user, I demand a higher level of quality, not quantity, in all of my purchases.

Yes most look at the price tag and understandably so, but I'll go without if the market provides a junk only option

'nuff said
 
Re: recmpress ect

Originally posted by ennerseed
just some personal thoughts...

I would keep you mp3s as they are.

i would re-rip your cds to aac... this time make sure it sounds good to you!

I have thousands ( 4221 ) of mp3s, I could re-rip but they are from vinyl and are a pain in the a** to record, much less tag properly. I have totally stoped recording my records till I find out what the final deal is with aac, iTunes, iPod.

As time went on I went from 128k to 320k and really wish this stuff came, would be coming, about faster.

Thanks for the info Arn
Click to expand...

Ah! So I'm not the only one who is converting an older music collection to a newer format. Here's a piece of advice: You can keep on recording. Just record to AIFF, burn a CD, then convert to MP3 (or MP4). If, later, you want to re-rip the music, you have a copy on CD that iTunes will remember the tags for, and it was recorded from the lossless AIFF format (i.e. best quality possible). Of course, the down side of this is you have to buy lots of CD-Rs...

:D
 
Re: DEaf from play it to loud...NOT

Originally posted by docpsycho
3: the difference between a one bit and a sixteen bit cd player
Click to expand...

What does this sound like to you? (Honestly curious). For those who can't hear the difference between mp3s done at things like 128-196, etc... try the following:

Get the source CD. Pick out a specific percussion instrument or the strongest portion of the bass line. Listen to it. Now play the mp3 specifically listening for that portion only. You should notice a definite difference in crispness, strength and clarity. You can also do this with strong voice performances, try a piece of opera. But the best overall way I've found to demonstrate the difference between mp3 bit rates is classical music. mp3 at lower bit rates absolutely murders the full-bodied sound of an orchestra.

As to encodings everything I do or have done for the last bit has been lame+alt preset. The size growth is definitely worth the difference in quality. Another thing I rarely see people talk about is how mp3s sound coming from different hardware. Luckily the iPod is one of the better sounding portable mp3 players (although to my ears the pjb100 still sounds more full despite less output power).
 
Re: DEaf from play it to loud...NOT

Originally posted by docpsycho
This is all fine and dandy . . . But I will treat all compression techniques and a digital version of cassette.

I am NOt a musician. or have perfect pitch trained ears yet I can tell:

1: all forms of compression
2: all fox channels on dish and Directv are badly compressed
Click to expand...
It seems to me like you are confusing BITRATE compression and DYNAMIC compression. The former does nothing of the latter as long as we're not talking about the kind of bitrate compression used in cellular phones. I apologize if your point in saying this was only to emphasize that you have good ears.
3: the difference between a one bit and a sixteen bit cd player
Click to expand...
I believe you are referring to SACD vs. Red Book AudioCD. To clarify the issue: SACD uses a 1 bit PAM signal with 64 x oversampling to overcome the shortcomings of a 16 bit PCM signal (i.e Audio CD). The result is, presumably, alot better, but the SACD Sony/Phillips standard is not compatible with most of today's audio equipment.

On the other hand, if your point was to emphasize that you hear the difference in ENOBs (Effective Number Of Bits), then please answer the following: If you were to hear a stereo DVD Audio recording (24 bit) and a CD recording (16 bit) through THE SAME SIGNAL CHAIN, would you hear any difference? Chances are you would not. Why? If you were to buy the world's most expensive AD/DA converter, it would still only give you 17 ENOBs.

My third interpretation of your statement is that you are confusing quantize levels (bits) with throughput (bps, bits PER SECOND). They are in no way related especially since mp3 uses variable quantize levels (don't confuse with variable bit rate!), so any such comparison becomes irrellevant.

What's my reason for saying all this? Mainly that there is about as much confusion with bits in the audio world as with bits in the processor world - and we've all seen the big discussions on the 32 vs. 64 bit processor issue, right?
 
Not that I'm against a new format. but this story is a load of crap. Anyomne with even half an ear, can hear a vast difference between an MP3 at 256kb, and original CD file. cd's sound bad enough, Mp3, or Mp4, sounds bad. 256kb p/s doesnt help with MP3's harsh, mid-heavy crappy sound. An MP3 is like listening to a pro-mastered CD through a pair of 1 1/2 inch speakers. It loses most of the dynamics. most of the range, and all of the original mix. .AIFF is compressed and squashed enough, anything less is a demo, not a good sounding mix.

MP3 is convenient, but sounds like a steaming turd.
 
Re: recmpress ect

Originally posted by ennerseed

I have thousands ( 4221 ) of mp3s, I could re-rip but they are from vinyl and are a pain in the a** to record, much less tag properly.
Click to expand...

Amen. However, you should *always* keep uncompressed digital copies of your vinyl-transferred audio. Even if you keep it on cheap CDRs, it would allow you to go back to an AIFF, WAV in order to rip using another codec.

I have thousands of vinyl records and after calculating how long it would take me just to digitize them as AIFFs, I just walked away shaking my head.

Now if someone could come up with some sort of *scanner* that would allow me to digitize my vinyl much like reading bar codes... oh boy... they would have my wallet!

Imagine walking past a stack of records *waaawwnngggg* AIFFs. Even if it made one huge AIFF that I had to disect, no problem.
 
Originally posted by Steak
Not that I'm against a new format. but this story is a load of crap. Anyomne with even half an ear, can hear a vast difference between an MP3 at 256kb, and original CD file. cd's sound bad enough, Mp3, or Mp4, sounds bad. 256kb p/s doesnt help with MP3's harsh, mid-heavy crappy sound. An MP3 is like listening to a pro-mastered CD through a pair of 1 1/2 inch speakers. It loses most of the dynamics. most of the range, and all of the original mix. .AIFF is compressed and squashed enough, anything less is a demo, not a good sounding mix.

MP3 is convenient, but sounds like a steaming turd.
Click to expand...
Then, unless you are storing everything in uncompressed format, what's your point? MP3 and MP4 are good enough for the masses and that's where the money is.
 
Originally posted by Abstract


Is this AAC going to be better than "almost lossless", because I sure can't see anything compressed as being completely lossless.
Click to expand...

It all depends on your listening habits and on the equipment you use. The music also plays an important role. I for instance listen mostly to the original CDs or even the LP, when it is available. MP3s are only good on the road or in the iPod.

I wonder just how much of the "AAC is indistiguishable from CD at 225bps" is marketing, and how much is truth.
 
Re: Re: recmpress ect

Originally posted by deepkid
Now if someone could come up with some sort of *scanner* that would allow me to digitize my vinyl much like reading bar codes... oh boy... they would have my wallet!

Imagine walking past a stack of records *waaawwnngggg* AIFFs. Even if it made one huge AIFF that I had to disect, no problem.
Click to expand...
Your wish is my command! Check this out: http://www.cs.huji.ac.il/~springer/

(Doubt it's the quality you're looking for though!)
 
Re: Re: Re: recmpress ect

Originally posted by eric_n_dfw
Your wish is my command! Check this out: http://www.cs.huji.ac.il/~springer/

(Doubt it's the quality you're looking for though!)
Click to expand...

I remember reading about laser turntables a decade or so ago... I wonder how much progress has been made? But then again, the goal would be to avoid real-time conversion.

I'd like to see the scanner referenced above.. wonder what progress has been made there.

Thanks.
 
I'll do some tests

Originally posted by impierced
The "--r3mix" has been superseded by the "archive quality" "--alt-preset standard" for lame encoding.

--r3mix will be a bit smaller at good quality, but the --alt-preset standard will sound much better.

Do a blind test on your hi-fi system and I think you'll agree.
Click to expand...

Indeed I will, thank you for pointing it out. Just as a point of reference this is a list of the equipment I will be using to compare the LAME switches:

- B&W 602DM Speakers
- Transparent "The Link 100" Bi-wired Speaker Cable
- Rotel RB976 Six Channel Amplifier (Running 4 channels for Bi-Amped mode)
- Creek OHB-12 Passive Pre-Amp
- Musical Fidelity X-10D Buffered Tube Stage
- Musical Fidelity X-ACT 18-bit 48kHz DAC
- 2 Monarchy Audio DIP's (Anti Jitter)
- Kimber Kable Digital X 75-ohm digital cables
- Kimber Kable Silver Streak interconnect cables (RCA unbalanced)
- MOTU 2408 (Digital SPDIF out from my computer)

As soon as I get a chance I'll encode some of my best cd's (best quality recordings) and do some tests. Of course sound is highly objective so whatever my findings are just an opinion.
 
re: Re: recmpress ect

hmmmm uncompressed copy, on cd... or dvd.... ..... .. . ****.

- a tear slowly falls through the air, then crashes on his desk with a sound of thunder (at 192-kHz) -
 
Originally posted by Steak
Not that I'm against a new format. but this story is a load of crap. Anyomne with even half an ear, can hear a vast difference between an MP3 at 256kb, and original CD file. cd's sound bad enough, Mp3, or Mp4, sounds bad. 256kb p/s doesnt help with MP3's harsh, mid-heavy crappy sound. An MP3 is like listening to a pro-mastered CD through a pair of 1 1/2 inch speakers. It loses most of the dynamics. most of the range, and all of the original mix. .AIFF is compressed and squashed enough, anything less is a demo, not a good sounding mix.

MP3 is convenient, but sounds like a steaming turd.
Click to expand...

TEHO, I guess.

I have all my iPod music compressed at 160kbps and it seems okay. At home I run 7.1 and I've got a factory Monsoon in the car and for all I'm worth I don't notice much of a difference if any.

I guess the question becomes one of usability. What good is *perfect* sound if I have to listen to it on studio master tapes and equipment? A CD might not sound perfect, but it's convenient and usable; MP3 even moreso. I can easily carry and access over 1100 songs on my 5GB scollwheel iPod.

I'd rather put up with imperfect music and have 100 CDs worth of music crammed into the size of a cigarette pack. How many pounds of vinyl or studio master tape would that equal?
 
Just for fun, I just did my own MP3-MP4 taste test. It's not remotely scientific, so if you folks wanna argue about my methodology, that's fine, but don't get all worked up about it.

For my subject matter I picked the track "Beautiful Day" from the U2 album "All That You Can't Leave Behind." I chose this track for two reasons: first, because I happened to have the CD sitting here on my desk, and second because I noticed some weeks ago that a 128 kbps MP3 of this song ripped with iTunes sounds like chisled spam, and even a 160 kbps MP3 ain't all that great.

I opened the AIFF file in QuickTime Player and exported it as a 128 kbps MP4 at 128 kbps using a sample rate of 48 kHz and "High" encoding quality.

The results astounded me. I loaded both the AIFF and the MP4 up in QuickTime Player, then used the "Play All Movies" feature. I toggled back and forth between the two, and yes, by God, they were indistinguishable to me. I am no audiophile, but 128 kbps MP3's generally make me cringe, so I guess you'd call my ear "semi-educated," for what that's worth.

I then did the same test with the 128 kbps MP4 and a 192 kbps MP3 ripped through iTunes. The MP4 sounded a bit better. In particular, in the first minute of the song, listen to the high hat. The MP3 muddies it, though it's not shredded like it is at 128 kbps. The MP4 preserves it. I'll say it again: a 128 kbps MP4 sounds slightly better, and certainly no worse, than a 192 kbps MP3.

I'm amazed. A 3.8 MB file sounds better than a 5.6 MB file, and very nearly as good as a 42 MB AIFF.

I'm hooked! Sign me up! Where's that iPod firmware update enabling .mp4 playback?
 
I hear people complaining of no bass in their MP3s...if you are using iTunes to encode then you do know that there is a low-frequency filter than you can turn off, of course it says the cut-off is 10Hz, but I always turn it off anyway. Another problem could be the *el-cheapo* sound systems beaing used to play them. I don't care which brand of "computer systems" you buy, none of them are high-end stuff. Granted, the source CDs will always sound fuller, but I see no major depreciation in the low frequencies on my MP3s.

I'm surprised no one has mentioned MiniDiscs. Sony's minidisc systems compress as well, and they seem to sound half way decent.

Oh well, since I've invested in some "real" audio gear for my home setup, I've decided that if I "really" want to listen to some music, I will just put the CD in. :D

-mark
 
Originally posted by avkills


I'm surprised no one has mentioned MiniDiscs. Sony's minidisc systems compress as well, and they seem to sound half way decent.


-mark
Click to expand...

Sony uses ATRAC or something like MP3 but with DRM stuff, right?
 
Re: recmpress ect

Originally posted by ennerseed
just some personal thoughts...

I would keep you mp3s as they are.

i would re-rip your cds to aac... this time make sure it sounds good to you!

I have thousands ( 4221 ) of mp3s, I could re-rip but they are from vinyl and are a pain in the a** to record, much less tag properly. I have totally stoped recording my records till I find out what the final deal is with aac, iTunes, iPod.

As time went on I went from 128k to 320k and really wish this stuff came, would be coming, about faster.

Thanks for the info Arn
Click to expand...

_______________________________

One of these days I need to copy a bunch of vinyl to digital. Maybe the new compression standard will be out by then. Are you using anything in particular to clean up the pop/scratch noises from the vinyl? I have Toast Titanium that has some sort of program that is supposed to do that, but I have not tried it as yet. Are there others? Better ones?

Thanks!
 
Re: Re: recmpress ect

Originally posted by RBR2
_______________________________

One of these days I need to copy a bunch of vinyl to digital. Maybe the new compression standard will be out by then. Are you using anything in particular to clean up the pop/scratch noises from the vinyl? I have Toast Titanium that has some sort of program that is supposed to do that, but I have not tried it as yet. Are there others? Better ones?

Thanks!
Click to expand...

Stienberg makes a vst plugin called declicker, as to its quality, I don't know.

I tried running some other filters over some tracks and messed up the range too much.

Added - http://pub41.ezboard.com/fr3mixfrm1.showMessage?topicID=564.topic
 
Originally posted by Jeff Harrell
I opened the AIFF file in QuickTime Player and exported it as a 128 kbps MP4 at 128 kbps using a sample rate of 48 kHz and "High" encoding quality.
Click to expand...

Actually, using a sample rate of 48khz on a CD-Audio file will probably decrease the quality since QT will have to upsample the audio (from 44.1->48) which is not a good conversion to do. If you are going to rip from QT, use the 'Recommended' sample rate setting - it will use the current sample rate of the song.
 
Is mp4, AAC?

Stupid question but ot hought that AAC and MP4 were two copletely different formats. I guess thats not true is it? I also thought that Panasonic made AAC, is that npot true either?
 
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