HydrogenAudio

Lossy Audio Compression => MP3 => MP3 - General => Topic started by: crodgers on 2012-06-22 04:45:01

Title: quality of amazon and itunes mp3s
Post by: crodgers on 2012-06-22 04:45:01
Does anyone know what the quality of mp3s is from Amazon mp3? 

What about the quality of mp3s from iTunes (the store, not ripping on pc)?

How are either of these qualities compared to buying a CD and ripping it myself with EAC and lame?
Title: quality of amazon and itunes mp3s
Post by: eahm on 2012-06-22 04:54:02
Amazon = MP3 (LAME) (.mp3) VBR V0

iTunes (Music Store) = AAC / MP4 (.m4a) ABR 256

iTunes (iTunes Match) = AAC / MP4 (.m4a) VBR 256

Google Play Music = MP3 (FHG or LAME) (.mp3) CBR 320

Quality is less than a physical CD since they only sell lossy but the same of the one you make with EAC and whatever lossy encoder.
Title: quality of amazon and itunes mp3s
Post by: RobertoDomenico on 2012-06-22 06:14:06
At those bit-rates under abx tests it would be extremely difficult to impossible to hear the difference from the original CD.
Title: quality of amazon and itunes mp3s
Post by: slks on 2012-06-22 09:46:19
I've never used Amazon MP3 myself, but I recall a thread here where people analyzed MP3s they'd bought at Amazon, and they were not all LAME -V0 encodes. They seemed to come from a variety of encoders and settings, although many were VBR from one LAME version or another. Unless they've made an effort to standardize recently, I imagine this is still the case.
Title: quality of amazon and itunes mp3s
Post by: kornchild2002 on 2012-06-22 10:29:07
They do vary depending on what was provided to them.  So far, these are the ones I have come across:

-V 0 Lame 3.98 joint-stereo
-V 0 Lame 3.97 joint-stereo
256kbps CBR Lame 3.96 stereo
256kbps CBR Lame 3.91 stereo
256kbps CBR FhG stereo

I downloaded a new song a couple of weeks ago and it was 256kbps CBR FhG stereo as well so I don't think Amazon has tried to do anything to even out their offerings.  That is one of the reasons why I stopped buying from them.  Although the chances of me actually ABXing anything are slim to none, I don't like the idea of not knowing what I will get and I like my lossy library to be uniform.
Title: quality of amazon and itunes mp3s
Post by: Engelsstaub on 2012-06-22 11:58:50
...iTunes (Music Store) = AAC / MP4 (.m4a) ABR 256

iTunes (iTunes Match) = AAC / MP4 (.m4a) VBR 256...


Are you saying that matched songs downloaded from iTunes differ from the files one purchases -or- that your (ALAC, for example) uploads are transcoded to VBR 256?

If you're stating the former could you please elaborate and/or refer me to some documentation?
Title: quality of amazon and itunes mp3s
Post by: crodgers on 2012-06-22 12:11:11
They do vary depending on what was provided to them.  So far, these are the ones I have come across:

-V 0 Lame 3.98 joint-stereo
-V 0 Lame 3.97 joint-stereo
256kbps CBR Lame 3.96 stereo
256kbps CBR Lame 3.91 stereo
256kbps CBR FhG stereo

I downloaded a new song a couple of weeks ago and it was 256kbps CBR FhG stereo as well so I don't think Amazon has tried to do anything to even out their offerings.  That is one of the reasons why I stopped buying from them.  Although the chances of me actually ABXing anything are slim to none, I don't like the idea of not knowing what I will get and I like my lossy library to be uniform.


So, do you think they do the actual rip?  Or do they all get it from the cd provider and state a minimum quality standard and the folks that provide the CDs to the stores also make the mp3s for distribution?

I am kinda torn.  I have downloaded some things from iTunes and Amazon and the quality sounds good, but then again, I do not have the CD to compare it to.  I saw a box set that goes for $200 in CD format, but they are offering the whole thing in mp3 format for $36.  And quite often a new CD may still be at $12-15 while the mp3 version is $10 or less. The physical CD is also a good form of backup... and I get the album art that I do not see offered with most mp3 downloads.
Title: quality of amazon and itunes mp3s
Post by: Porcus on 2012-06-22 12:16:26
I wouldn't worry that much about possibly audible differences between 256 CBR LAME-MP3 and 256 ABR AAC per se. Rather I would worry over (I) the possibility that a "256" file is transcoded from a lossy, and (II) the chance of someone sneaking in an audible watermark (http://www.mattmontag.com/music/universals-audible-watermark), putting you at risk of purchasing an audibly inferior product regardless of file format.

There is not much we can say about exactly who makes an Amazon/iTunes file or how though. But, as much as I think the 'Mastered for iTunes' thing smells of mumbo-jumbo, the idea that iTunes specifies to the production chain 'we want precisely THIS!' appears to me as a safeguard against at least some kinds of mindlessness (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=94716&view=findpost&p=794029).

Edit: crodgers beat me at at least part of the point.
Title: quality of amazon and itunes mp3s
Post by: crodgers on 2012-06-22 15:14:01
For my own ripping and encoding, I use EAC and let it launch RazorLame.  My current (EAC) settings for RazorLame are:

path: G:\Program Files\Exact Audio Copy\lame.3.97.b2.exe
Additional command-line options:  -V2 --vbr-new

Bit rate:  224 kBit/s
[X]  Delete WAV after compression
[  ]  Use CRC check
[X]  Add ID 3 tag
[X]  Check for external programs return code

(*) High quality
(  ) Low quality

Looking at the properties of an mp3 in foobar2000, it shows encoding settings as:
lame.3.97.b2.exe -h -b 224-V2 --vbr-new

Does that seem reasonable?  How does that compare to what amazon and itunes are releasing?
Title: quality of amazon and itunes mp3s
Post by: eahm on 2012-06-22 16:20:41
crodgers, don't worry about the quality in terms of what you will hear. They will sound the same to you and probably to everyone else. I just told you what is mathematically different.

I don't use MP3s but this is what my foobar2000 mp3 encoder looks like:
-S --noreplaygain -V 2 - %d

I use the latest foobar2000 (1.1.13) with the latest LAME encoder (3.99.5 x86)
Title: quality of amazon and itunes mp3s
Post by: kornchild2002 on 2012-06-22 19:41:19
So, do you think they do the actual rip?  Or do they all get it from the cd provider and state a minimum quality standard and the folks that provide the CDs to the stores also make the mp3s for distribution?


I'm not sure how Amazon's mp3 store works.  If I had to make an educated guess, I would say that they specify some minimum encoding while offering other suggestions.  That may explain why there are so many discrepancies and song encoders/settings appear to be rather random.  I do have some knowledge as to how the iTunes Store operates though as those are either supplied by the record company/band/artist as-is or are encoded by Apple.  The music source (band, artist, record company, etc.) has the option of taking their master and encoding it to ALAC and then having Apple transcode that to 256kbps AAC VBR_constrained for an iTunes Store upload, outputting a 256kbps AAC VBR_constrained from their master, or they can actually  have an engineer/producer follow the procedure to make an album with the "Made for iTunes" label.  Either way, files downloaded from the iTunes Store will always (at least at the moment) be mpeg-4 LC-AAC and most are encoded at 256kbps VBR_constrained.  I say most as I do remember some older files (~2005) that were encoded using 256kbps CBR AAC.  That was around the time when they first started offering DRM-free 256kbps AAC files and they were definitely CBR, not VBR_constrained as they are now.  Even then I think the modern settings are a little different than just VBR_constrained.  If I remember correctly, the standard encoding settings in iTunes use the "medium" quality setting while the iTunes Plus option (i.e. what is offered on the iTunes Store) uses the "high" quality setting.  I could be wrong but songs downloaded from the iTunes Store/encoded using the iTunes Plus setting are a little bit bigger (maybe 0.2MB for a 4 minute song) than songs encoded using 256kbps VBR_constrained in iTunes.

In all honesty, I don't really think it matters which service you use.  I used to buy from the least expensive one but I didn't like not knowing what I would get from Amazon so i just stick with the iTunes Store now.
Title: quality of amazon and itunes mp3s
Post by: Jedi82 on 2012-06-22 20:58:25
Why is so difficult for these company say to us what they use and how the make their mp3! Really, so frustrating :-(
Title: quality of amazon and itunes mp3s
Post by: HamilcarBarca on 2012-06-22 22:26:51
Amazon = MP3 (LAME) (.mp3) VBR V0


Some Amazon MP3 files I have are 256kbps (and, IIRC, 320kbps) CBR.
I purchased them in late 2010 and early 2011 before switching back to CD's.

I've only bought one album in many months; foobar2000 identifies its tracks
as "MP3 VBR V0".
Title: quality of amazon and itunes mp3s
Post by: kornchild2002 on 2012-06-23 00:51:57
Why is so difficult for these company say to us what they use and how the make their mp3! Really, so frustrating :-(


Well, Apple is somewhat up front as every song in the iTunes Store is essentially going to be the same unless it is marked as being made for iTunes (even then it is encoded with the same standards as other material).  So buying one song, or even downloading a free song, will let you know the settings, container, and format they use.  I can't find the page but Amazon does specify that all of their songs are encoded at a minimum of 256kbps CBR.  They also state that other songs may be encoded differently and that there isn't a uniform setting or encoder.  It takes a little navigating to find that page though.  Neither are that outright about it though.  Apple lists the general encoding settings in the iTunes Store FAQs (which can be found through a 2 second Google search) while Amazon seems a little more cryptic as I haven't been able to find their webpage detailing their encoding settings yet (though I have read it in the past).
Title: quality of amazon and itunes mp3s
Post by: Aleron Ives on 2012-06-23 06:26:48
Amazon does indeed bury that page, but it does exist:

http://www.amazon.com/gp/help/customer/dis...odeId=200389400 (http://www.amazon.com/gp/help/customer/display.html/ref=hp_rel_topic?ie=UTF8&nodeId=200389400)

Title: quality of amazon and itunes mp3s
Post by: Porcus on 2012-06-23 07:03:26
Amazon does indeed bury that page, but it does exist:

http://www.amazon.com/gp/help/customer/dis...odeId=200389400 (http://www.amazon.com/gp/help/customer/display.html/ref=hp_rel_topic?ie=UTF8&nodeId=200389400)




Ah!


... “Note: Amazon Cloud Player does not currently support Lossless AAC files.

?!? Do they mean lossless-in-m4a?
Title: quality of amazon and itunes mp3s
Post by: kornchild2002 on 2012-06-23 13:00:48
Thanks Aleron for providing that link.  I gave up my search after I was unable to net any results within a ~90 second period.

They probably mean ALAC as that is more widespread than lossless mpeg-4.  I wouldn't expect Amazon's cloud player service to work with ALAC files anyway.  Even iTunes Match doesn't offer ALAC hosting as any lossless files in an iTunes library are either matched with 256kbps iTunes Store variants or are transcoded (using the iTunes Plus setting) and then uploaded.
Title: quality of amazon and itunes mp3s
Post by: Jedi82 on 2012-06-24 12:28:33
also the AAC files download via iTunes match are THE SAME as the iTunes store AAC files right? I always think that the first ones 8ITMarch songs) are worst than the ITS files :-(
Title: quality of amazon and itunes mp3s
Post by: db1989 on 2012-06-24 12:35:26
You could search. One example for the query iTunes Match same (http://www.hydrogenaudio.org/forums/index.php?showtopic=94996)

Edit: Oh look – that thread was started by you. Did you not read it the first time around, or something?
Title: quality of amazon and itunes mp3s
Post by: slks on 2012-07-04 19:35:49
For my own ripping and encoding, I use EAC and let it launch RazorLame.  My current (EAC) settings for RazorLame are:

path: G:\Program Files\Exact Audio Copy\lame.3.97.b2.exe
Additional command-line options:  -V2 --vbr-new

Bit rate:  224 kBit/s
[X]  Delete WAV after compression
[  ]  Use CRC check
[X]  Add ID 3 tag
[X]  Check for external programs return code

(*) High quality
(  ) Low quality

Looking at the properties of an mp3 in foobar2000, it shows encoding settings as:
lame.3.97.b2.exe -h -b 224-V2 --vbr-new

Does that seem reasonable?  How does that compare to what amazon and itunes are releasing?


The "-b 224" forces a minimum bit rate of 224 kb/s, which is going to inflate the file size and makes your files not "true" VBR. EAC is adding the "-b 224" to the command line because you've selected that bit rate in the drop-down menu. I never liked this behavior of EAC, since it only makes sense if you're encoding CBR. It's been a while since I used EAC, but there should be a drop-down menu somewhere that lets you select your format (which is currently going to be "MP3" or "LAME" or something) - What you need to do is change it to "User-defined encoder" or "Custom encoder" or equivalent. If you have it set to custom encoder, EAC isn't going to add any extra command line arguments besides what you manually type in.
Title: quality of amazon and itunes mp3s
Post by: Blutarsky on 2012-10-21 15:29:14
While attempting to abandon Apple for my rare & spot music shopping (aiming to convert my whole library to FLAC) I thought of giving a try with Amazon however I was curious about the formats being used by the online stores. I bought the same track from Amazon and iTunes just to make a comparison, and.... big disappointment:

iTunes
(http://s9.postimage.org/aoxpfjyqz/m4a.jpg) (http://postimage.org/image/aoxpfjyqz/)

Amazon
(http://s16.postimage.org/525maro4h/mp3.jpg) (http://postimage.org/image/525maro4h/)

Apart from any ABX consideration, this is quite a new track, how can it be that Amazon used such a lower quality setting?
Title: quality of amazon and itunes mp3s
Post by: lvqcl on 2012-10-21 15:48:28
and.... big disappointment:

TOS #8.

how can it be that Amazon used such a lower quality setting?

It's not 'iTunes vs. Amazon', it's 'AAC vs. MP3' comparison.
Title: quality of amazon and itunes mp3s
Post by: Blutarsky on 2012-10-21 16:28:52
how can it be that Amazon used such a lower quality setting?

It's not 'iTunes vs. Amazon', it's 'AAC vs. MP3' comparison.


This thread title: "quality of amazon and itunes mp3s"

and.... big disappointment:

TOS #8.


"I was disappointed" doesn't mean "everyone should be disappointed"   

I some admin believes my post breaking the rules, feel free to delete
Title: quality of amazon and itunes mp3s
Post by: lvqcl on 2012-10-21 16:40:38
I just wanted to say that you compare AAC (M4A file from iTunes) and MP3 (from Amazon). And yes, AAC spectrograms usually look better.
Title: quality of amazon and itunes mp3s
Post by: Blutarsky on 2012-10-21 16:43:03
I just wanted to say that you compare AAC (M4A file from iTunes) and MP3 (from Amazon). And yes, AAC spectrograms usually look better.


Some MP3 V0 spectrograms are better than AAC 256...
Title: quality of amazon and itunes mp3s
Post by: Kohlrabi on 2012-10-21 17:54:54
I just wanted to say that you compare AAC (M4A file from iTunes) and MP3 (from Amazon). And yes, AAC spectrograms usually look better.


Some MP3 V0 spectrograms are better than AAC 256...
And some girls are bigger than others. And some girls' mothers are bigger than other girls' mothers.

Joking aside, spectrograms convey no information whatsoever about the quality of a lossy encoder. As long as the bought files are artifact free, I really don't see why any user needs or should care about the encoder settings used by an online shop. I doubt that shops care about users who want to transcode files, and I'd say users wishing to do so should buy lossless media in the first place.
Title: quality of amazon and itunes mp3s
Post by: [JAZ] on 2012-10-21 19:04:56
@Blutarsky: From your post and replies to what others told you, it is clear that you don't know several things about MP3, (and several others about iTunes Store).

First, that MP4/AAC (which is what iTunes Store has always used) is not the same as MP3. (Second post in this thread already explains it).
Second, that you don't know how to judge quality in terms of lossy codecs.
And third, you don't know the limitations of the MP3 codec, and how LAME has been tweaked these last years to increase in sound quality, while not caring about "visual" quality.


See your posted graph:
- The differences in background from 16Khz above are at -95dBFS and below.
- The filter in MP3 is at 19Khz and in AAC at 21Khz. Said that, filtered sounds are around -70dbFS and below.
- Peaks on that sound are at -30dbFS or so.


LAME:
- MP3 has a limitation at 16Khz and above that can cause to use many bits to keep precision, reducing the amount free for the rest of the sound (which is not desiderable). As such, LAME limits the precision in these bands. That's why you see the clear 16Khz background cut.
- Also, higher frequencies are always more difficult to encode, because they are not tonal (easy to describe), but noise-like (difficult to describe).
Using the filter around 20Khz (which most CD audio players were supposed to do anyway) is just another way to reduce the bits spent on frequencies that the human ear doesn't hear (most of the time), to spend them on the rest of the bands.


As such, from those spectograms, one cannot say that the MP3 one is of less quality in terms of lossy codecs. One can only say that they use a different strategy, which in the case of AAC/MP4 can do so because it does not have those MP3 limitations.
Title: quality of amazon and itunes mp3s
Post by: Porcus on 2012-10-22 00:28:49
It strikes me that perceptual noise substitution is A Good Thing In That It Keeps Users From Judging Sound With Their Eyes.