IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
iTunes vs. LAME: A little spot test, Can you hear a difference (mp3 inside)?
mute.
post Jul 30 2005, 17:45
Post #1





Group: Members
Posts: 3
Joined: 30-July 05
Member No.: 23607



Hi folks

Today I stumbled across this forum (great place!), browsed a few topics and was quite taken aback to learn that by encoding all my MP3 files with iTunes/192kbps/Stereo I'd quality-wise not be "on the safe side" like I always thought. Then I took a look at LAME and reencoded a few songs but couldn't hear a clear difference (though my hifi stereo is currently not available).

Now I'm curious how better trained ears would judge the following sample. I tried to remove all obvious traces to the encoder but please be honest and use a player that doesn't show you any mp3 frame information (i.e. bitrate).

Clipping A
Clipping B

1. Which audio file do you think sounds better (if you can hear a difference)?
2. How do you rate the sound quality overall, i.e. would it be good enough for your personal preference?
3. Is the difference worth not just choosing the simplest encoding solution?

I'm going to post "the solution" and technical details when a few opinions have come in... cool.gif
Go to the top of the page
+Quote Post
guruboolez
post Jul 30 2005, 17:53
Post #2





Group: Members (Donating)
Posts: 3474
Joined: 7-November 01
From: Strasbourg (France)
Member No.: 420



5,4 MB per file in MP3 format? Did you encode the full track?
Go to the top of the page
+Quote Post
mp3chan
post Jul 30 2005, 18:00
Post #3





Group: Members (Donating)
Posts: 164
Joined: 19-June 02
From: Netherlands
Member No.: 2343



How would you know which sounds better without comparing to the original sample?
Go to the top of the page
+Quote Post
guruboolez
post Jul 30 2005, 18:04
Post #4





Group: Members (Donating)
Posts: 3474
Joined: 7-November 01
From: Strasbourg (France)
Member No.: 420



QUOTE (mp3chan @ Jul 30 2005, 06:00 PM)
How would you know which sounds better without comparing to the original sample?
*

If you can detect usual distortions introduced by lossy encoding (pre-echo, ringing...) the reference is most often not a need.
Go to the top of the page
+Quote Post
mute.
post Jul 31 2005, 15:03
Post #5





Group: Members
Posts: 3
Joined: 30-July 05
Member No.: 23607



QUOTE (guruboolez @ Jul 30 2005, 06:04 PM)
QUOTE (mp3chan @ Jul 30 2005, 06:00 PM)
How would you know which sounds better without comparing to the original sample?
*

If you can detect usual distortions introduced by lossy encoding (pre-echo, ringing...) the reference is most often not a need.
*


Exactly. If it's not possible to distinguish the two samples without a reference, the discussion about which encoder to use gets quite superfluous.
Go to the top of the page
+Quote Post
smok3
post Jul 31 2005, 15:28
Post #6


A/V Moderator


Group: Moderator
Posts: 1737
Joined: 30-April 02
From: Slovenia
Member No.: 1922



unless preecho and ringing are part of the reference (artistic expression maybe? wink.gif)


--------------------
PANIC: CPU 1: Cache Error (unrecoverable - dcache data) Eframe = 0x90000000208cf3b8
NOTICE - cpu 0 didn't dump TLB, may be hung
Go to the top of the page
+Quote Post
kindofblue
post Aug 2 2005, 08:53
Post #7





Group: Members
Posts: 175
Joined: 16-January 03
Member No.: 4600



@mute: cmiiw, itunes uses the Fraunhofer encoder for mp3 encoding, and 192kbps CBR should give decent quality. of course, you miss out on the benefits of VBR, which LAME offers.

On the other hand, I tried ABXing the two clips you posted and was hard-pressed to tell which was which. It might be hard to make conclusions based on just one sample, but you're probably fine with your 192 CBR encodes, especially for portable listening.

just my two cents.


--------------------
WavPack 4.31 / LAME 3.98 alpha 3 -V9 -vbr-new
Go to the top of the page
+Quote Post
Gabriel
post Aug 2 2005, 09:05
Post #8


LAME developer


Group: Developer
Posts: 2950
Joined: 1-October 01
From: Nanterre, France
Member No.: 138



QUOTE
@mute: cmiiw, itunes uses the Fraunhofer encoder for mp3 encoding

No, it uses a custom encoder, which is an evolution of the SoundJam one.
Go to the top of the page
+Quote Post
Defsac
post Aug 2 2005, 09:45
Post #9





Group: Members
Posts: 347
Joined: 17-May 05
Member No.: 22107



Gabriel is correct. When Apple bought SoundJam MP (now iTunes) they improved the encoding engine.

This post has been edited by Defsac: Aug 2 2005, 09:50
Go to the top of the page
+Quote Post
kindofblue
post Aug 2 2005, 10:05
Post #10





Group: Members
Posts: 175
Joined: 16-January 03
Member No.: 4600



Whoops. I stand corrected then.


--------------------
WavPack 4.31 / LAME 3.98 alpha 3 -V9 -vbr-new
Go to the top of the page
+Quote Post
mute.
post Aug 2 2005, 21:35
Post #11





Group: Members
Posts: 3
Joined: 30-July 05
Member No.: 23607



QUOTE (kindofblue @ Aug 2 2005, 08:53 AM)
@mute: cmiiw, itunes uses the Fraunhofer encoder for mp3 encoding, and 192kbps CBR should give decent quality. of course, you miss out on the benefits of VBR, which LAME offers.

On the other hand, I tried ABXing the two clips you posted and was hard-pressed to tell which was which. It might be hard to make conclusions based on just one sample, but you're probably fine with your 192 CBR encodes, especially for portable listening.

just my two cents.
*

kindofblue, thanks a lot for your comments. The standard LAME encoding (v3.96.1 (--alt-preset standard), 192 kbps VBR, Joint Stereo) certainly has - while being 4 times slower - a theoretical quality advantage over my standard iTunes encoding (v4.9(17), 192 kbps, Stereo, "Smart Encoding Adjustments", "Filter Frequencies Below 10 Hz") that is obviously not easy to perceive. Then how big could the differece be when the iTunes encoding was also done at VBR (except iTunes does VBR and Joint Stereo terribly bad)? Has anyone actually ever conducted serious encoder tests at bitrates of 192 kbps or higher? Anyway, it's still not clear to me what makes iTunes "the worst MP3 encoder still in widespread use".

Btw, in iTunes it says "MPEG Layer-3 audio coding technology licensed from Fraunhofer IIS and Thomson multimedia".
Go to the top of the page
+Quote Post
Gabriel
post Aug 2 2005, 21:46
Post #12


LAME developer


Group: Developer
Posts: 2950
Joined: 1-October 01
From: Nanterre, France
Member No.: 138



QUOTE
Btw, in iTunes it says "MPEG Layer-3 audio coding technology licensed from Fraunhofer IIS and Thomson multimedia".

This means that they licenced the patent pool from FhG/Thomson, but does not mean that they licensed the encoder implementation.
Winamp 5 is displaying a similar message, while it is using Lame.
Go to the top of the page
+Quote Post
guruboolez
post Aug 2 2005, 23:50
Post #13





Group: Members (Donating)
Posts: 3474
Joined: 7-November 01
From: Strasbourg (France)
Member No.: 420



QUOTE (mute. @ Aug 2 2005, 09:35 PM)
v3.96.1 (--alt-preset standard), 192 kbps VBR, Joint Stereo certainly has (...) a theoretical quality advantage over my standard iTunes (...) that is obviously not easy to perceive.

For you and probably a lot of people, it's probably true. But you're not exploiting the real (and not theoretical) advantage of LAME. You are obviously comparing two encodings profiles which are purely transparent for you. Try with lower settings. You can probably obtain the same degree of quality than iTunes with a lower VBR profile (as -V5/-V4/-V3) and also increase encoding speed by using --vbr-new (also providing a better quality than regular VBR mode with latest 3.97 alphas).
Go to the top of the page
+Quote Post
kindofblue
post Aug 3 2005, 09:59
Post #14





Group: Members
Posts: 175
Joined: 16-January 03
Member No.: 4600



@mute: your sample seems like a nice one for abx tests. any chance you could upload a wav/lossless version? thx


--------------------
WavPack 4.31 / LAME 3.98 alpha 3 -V9 -vbr-new
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 24th October 2014 - 10:34