Lame APS nukes MPC 5 on Amnesia.wav, What the #@? Options

[Pio2001]

EDIT 02.27.2004 - Here is the sample : http://www.hydrogenaudio.org/forums/index....ST&f=35&t=19099

Hello,
First let me say that I'm a complete newbie in MPC (didn't encode anything until 2 days ago).
The common opinion in here is that MPC is way better than MP3 at high quality encoding, so I thought I would use --quality 5.

Since I prefer testing than trusting, I took a bunch of tests samples : Amnesia, short, vilbel, spahm, ravebase, and a sample of Rebecca Pidgeon- Granmother (an audiophile recording, not difficult for encoding).

And... big disappointment : amnesia sound UGLY ! Much worse than Lame APS : it rings.

ABX 16/16 at quality 5, 16/16 at quality 6, 8/8 at quality 7.

It still rings at quality 6, but the problem is gone in quality 7, there is just some unimportant noise left (still worse than Lame APS IMHO, but as Lame adds more noise, it becomes a matter of taste)

If we discard Short, that is an artificial sample, I find one big failure for Lame 3.90.2 APS (Badvilbel), and one big failure for Mppenc 1.14 beta --quality 5 (Amnesia) (decoded by Winamp plugin 0.97f).

Note that amnesia is a partly artificial sample, since it was normalized. The original peaked around -6 or -8 db AFAIR. On the other hand, it is a vinyl copy, so if it had been mastered on CD, it might have peaked higher anyway.

Amnesia is available is the test sample page. What do you think of it ?

I also searched for tests about MPC quality. I found Guruboolez one, that concluded that MPC 1.06 added a coloration to the sound of his sample in standard and extreme, but performed way better than Ogg and AAC. http://forum.hardware.fr/forum2.php3?post=...&trash=&subcat=

[nwn]

I'm not able to elaborate a serious discussion upon this purpose but ..

I'm coming very suspicious on real "auditive" quality of mpc encoding file ...
I'd many times a bad audio feeling on High freq (like saturation, glitches, lack of dynamic, choked, crushed ??)

i'm not confortable to explain that in english

I test a Mpc and Ape coding and notice that these issues doesn't append with Ape .. With Ape sound is clear on hig Freq without saturation and correct dynamicity

I'm sure that it's difficult to criticize Mpc that appears be adopted by expert community, so i think this post before .. and if i am not able to prove but that i can demonstrate and reproduce for myself, i'm sure of my feelings

[Pio2001]

Mhh, do you mean Ape "Monkey's audio", or Ape "Alt Preset Extreme" ?

Sorry to tell this since you are on my side, but we need blind tests, only blind tests ! When you get the feeling, decode the file to wav, cut it into a short sample, and run PC ABX.

[JohnV]

I'm coming very suspicious on real "auditive" quality of mpc encoding file ...
I'd many times a bad audio feeling on High freq (like saturation, glitches, lack of dynamic, choked, crushed ??)

EDIT: Jump over this message, the below is not the problem in question:


I wouldn't draw more conclusions about ringing that what there really is..

Amnesia is a sample which has high frequency "ringing" with MPC standard even with higher quality levels depending on hearing. High frequency ringing is a specfic problem, which is quite common for all codecs in some cases, but which is not unambiguous.

Here's a small image of MPC standard amnesia:

You can see that there are small spikes there, response is not totally smooth, like it is with Dibrom's APS. So, you may ask, does this apply for other cases as well, meaning that if the response is not always totally smooth, it will always "ring". The answer is no. It's very common with all codecs that there are high frequency spikes for example with hihat. The issue here, why people with good high frequency hearing may hear ringing artifacts in this case, is probably, because the sound is otherwise quite homogenic, but the small spikes break this reasonably homogenic sound. Of course, if there was a hihat hit there creating a big high frequency spike, nobody would notice this type of artifacting. But as I said, ringing is not unambiguous, and really depends on the case.

Is high frequency ringing generally a problem for MPC? In my opinion not a very big problem. But sure, it should perform better with this clip. I think one problem here was, that amnesia is a very good sample to illustrate this problem (and it was also used by Dibrom when tweaking APS), but it's a 48kHz sample, and MP+/mpc didn't support 48kHz until sometime after Klemm took over iirc (and of course people are too lazy to downsample), so I think it has kinda been forgotten in mpc testing, maybe. I agree that this issue should be further examined.

Can you make conclusions, that because there's riniging with amnesia, there's "saturation, other glitches, lack of dynamic, choked crushed high freqs". No, you can't. You better provide some proofs for these claims.

This post has been edited by JohnV: Feb 25 2003, 14:41

[Pio2001]

I doubt that peaks above 18 kHz, has any effect on what I hear : I can't hear anything past 16 kHz !

But I forgot that it was a 48 kHz sample, I'll downsample and retest, then I'll go hunting for similar samples... (say "bzz" !)

EDIT : Uh ? No, it is 44.1 kHz....
EDIT : oops : I'm working on a downsampled version from the begining

[guruboolez]

I haven't launched ABC/HR yet. But the sound of this amnesia sample seems to be close to the Jump sample (the short one) I provide some weeks ago. But the artifact was something like a smeared sound.

There is maybe a good way to know if the adapatative lowpass of mpc responsible of a audible degradation is : encode amnesia with the old mppenc (< 1.01j) at --insane, which never lowpassed anything.

[guruboolez]

CODE

ABC/HR Version 0.9b, 30 August 2002
Testname: amnesia mpc

1R = D:\temp\amnesia\amnesia.mpc5.wav
2L = D:\temp\amnesia\amnesia.mp3std.wav

---------------------------------------
General Comments:

---------------------------------------
1R File: D:\temp\amnesia\amnesia.mpc5.wav
1R Rating: 3.5
1R Comment: décrochage sonore vers 0.5'
---------------------------------------
2L File: D:\temp\amnesia\amnesia.mp3std.wav
2L Rating: 2.9
2L Comment: détails sont écrasés, flous
---------------------------------------

I haven't abx it. I focuse on seconds 00.000 - 01.500. Just noticed two kind of obvious flaws.
* mp3 blur the sound : smeared details on the whole passage
* mpc is sharp enough, but I hear something wrong at ~0:500, like an excessive contrast.

I opened the mpc file in CoolEdit ; here are the results :

mpc representation
original représentation

I suppose that the big empty spaces are directly responsible of the « contrast » I heard in ABC/HR. I checked other parts of the mpc file : generally, the visual degradation is not as pronounced as I saw it in this 0.500 area. However, some passages I didn't test (above the first second) are badly degraded too, and I suppose that they are ABXable too.
Maybe the explanation of the disappointment or surprise of Pio2001.

[guruboolez]

I understand (and share) the feeling of Pio2001. The last seconds are buggy, like colorated by an small electric noise (I suppose that the technical word for this is « HF ringing »). This is exactly the same feeling I had for the Jump sample, maybe stronger for amnesia. I began to heard it when I tested the standard preset with the old 1.01j codec : the whole file, from the beginning to the end, is audibly different. The 1.14 codec is a real progress : ringing seems (for me) to be reduced, and really annoying at the second part of the file.


part of amnesia : 4.3-5.9
mpc version : 1.14 --standard --xlevel
mp3 version : lame 3.90.2 --alt-preset standard

CODE

ABC/HR Version 0.9b, 30 August 2002
Testname: amnesia mpc

1L = D:\temp\amnesia\amnesia.mpc5.wav
2L = D:\temp\amnesia\amnesia.mp3std.wav

---------------------------------------
General Comments:

---------------------------------------
1L File: D:\temp\amnesia\amnesia.mpc5.wav
1L Rating: 3.9
1L Comment: mpc
---------------------------------------
2L File: D:\temp\amnesia\amnesia.mp3std.wav
2L Rating: 3.4
2L Comment: mp3
---------------------------------------
ABX Results:
Original vs D:\temp\amnesia\amnesia.mpc5.wav
   14 out of 16, pval = 0.002
Original vs D:\temp\amnesia\amnesia.mp3std.wav
   14 out of 16, pval = 0.002

This post has been edited by guruboolez: Feb 16 2003, 16:48

[JohnV]

Yeah, no excuse for me (except too little time) . The main problem is not that what I was presenting, rather the problem here is obviously dropouts, like guruboolez pointed out.
What surprised me is that even with old mp+ encoder and using VBRmode2 and minSMR 1-3 didn't still give as solid spectra as APS with this clip. Very weird.

[Pio2001]

Here's my Amnesi5.mpc file (you'll maybe have to right click and save target as).

Could you check that it has no more problem than yours ? And upload yours for me to check ?

In the meantime, I checked 26 tracks featuring transients from my CDs without finding any flaw in MPC encoding yet. The hunting goes on...

EDIT : did you notice that Lame APS gives 317 kbps ?

[guruboolez]

CODE

ABC/HR Version 0.9b, 30 August 2002
Testname:

1L = D:\temp\amnesia\amnesia.mpc5.wav
2L = D:\temp\amnesia\PIO_AMNESI5.wav

---------------------------------------
General Comments:

---------------------------------------
2L File: D:\temp\amnesia\PIO_AMNESI5.wav
2L Rating: 2.5
2L Comment:
---------------------------------------
ABX Results:

Didn't ABX it.
I just quickly played A-B A-B, and only one file was obviously and immediatly different : yours ! What did you make ?


EDIT : my encoding is here (right click/save target)
EDIT2 : link fixed

This post has been edited by guruboolez: Feb 16 2003, 22:00

[Gecko]

ABX 8/8

Sounds like hearing the spinning blades of a helicopter. I was using the 48kHz version directly without downsampling and mppenc 1.14 with no additional switches. Those sure are some serious dropouts, something I haven't witnessed before with mpc.

There are some samples which make mpc trip up bad, but those are mostly isolated cases. Mpc doesn't seem to have a specific type of sound it can't handle though, like transients for example.

edit: Pio, I just listened to your sample and I think it sounds different than what comes out of "my" mppenc. I believe it has some more noise in the stereo image. Stand by for abx

edit 2: There is some noisy garble which, when listened to with headphones, seems more "outside" than the rest of the sound at ca 0.4 secs. abx 8/8.

edit 3: wtf?! I just listend to your sample, guru, and it also sounds different, than Pio's and mine. I think it sounds worse. What's happening?!

This post has been edited by Gecko: Feb 16 2003, 22:07

[Secret Chief]

I can ABX 0.0-1.5 every time; the MPC file sounds 'garbled,' or also as if the distorted lead didn't have any reverb on it in the MPC version but did have it on the source file. I haven't compared it to APS yet.

I have to say that's a very, very particular situation. If the sound wasn't as repetitive, I'd probably only be able to catch the difference half of the time. I'm also using speakers instead of headphones, so I'm not sure what kind of a difference that makes.

I know of a similar situation on one of my CDs, and am going to dig it up now to see if it exhibits the same problem.

EDIT: "every time" meaning 15/15

This post has been edited by Secret Chief: Feb 16 2003, 21:57

[Pio2001]

Sounds like hearing the spinning blades of a helicopter.

Yes, exaxctly !

Guru, here's my original : Right click and save target as

I think your MPC file sounds basically the same as mine...

[guruboolez]

I think your MPC file sounds basically the same as mine...

I tested it, and I'm not totally agree. The degradation, at the end of the file, is the most awfull I never heard with a musepack encoding, at --standard. The amnesia sample I downloaded some month ago on HA server is not so critical for mpc.

Here are ABC/HR results (quick test) :

CODE

ABC/HR Version 0.9b, 30 August 2002
Testname: Amnesia new sample

1L = D:\temp\amnesia\[NEW] amnesia [PIO2001].mpc5.wav
2R = D:\temp\amnesia\[NEW] amnesia [PIO2001].mp3STD.wav

---------------------------------------
General Comments:
Passage de test : 0.0 - 1.5
mppenc 1.14beta --standard
lame 3.90.2 --alt-preset standard
---------------------------------------
1L File: D:\temp\amnesia\[NEW] amnesia [PIO2001].mpc5.wav
1L Rating: 4.5
1L Comment: toujours ce décrochage sonore, au même endroit,  qui trahit le mpc dans cet échantillon
---------------------------------------
2R File: D:\temp\amnesia\[NEW] amnesia [PIO2001].mp3STD.wav
2R Rating: 3.5
2R Comment: pertes de détails; certainement mp3
---------------------------------------
ABX Results:
Original vs D:\temp\amnesia\[NEW] amnesia [PIO2001].mpc5.wav
   11 out of 12, pval = 0.003
Original vs D:\temp\amnesia\[NEW] amnesia [PIO2001].mp3STD.wav
   12 out of 16, pval = 0.038

CODE

---------------------------------------
General Comments:
Passage de test : 4.1 - 5.6
mppenc 1.14beta --standard
lame 3.90.2 --alt-preset standard
---------------------------------------
1R File: D:\temp\amnesia\[NEW] amnesia [PIO2001].mpc5.wav
1R Rating: 1.5
1R Comment: absolument dégradé !
---------------------------------------
2R File: D:\temp\amnesia\[NEW] amnesia [PIO2001].mp3STD.wav
2R Rating: 3.5
2R Comment: pertes de détails coutumière.
---------------------------------------
ABX Results:
Original vs D:\temp\amnesia\[NEW] amnesia [PIO2001].mpc5.wav
   12 out of 12, pval < 0.001
Original vs D:\temp\amnesia\[NEW] amnesia [PIO2001].mp3STD.wav
   12 out of 16, pval = 0.038

I rated 1.5/5 the mpc sounding, at the last second. According to my imagination, sound is not like an helicopter, but more trivially like the oil bubbling on a electric fryer :-þ

This post has been edited by guruboolez: Feb 16 2003, 23:13

[nwn]

I would like to refer to this same link ... from gURuBoOleZZ
http://forum.hardware.fr/forum2.php3?post=...&trash=&subcat=

that i read after my last post

and found a similar evaluation referenced as "Piou piou .." for AAc psytel encoder (i have'nt test it) but also for "Musepack SV7 (mppenc 1.06) --standard (ou --quality 5)"

I'm sure of my hears feeling ..
but need .. of course to ... produce some proof .. and determine wich freq, instrument, or typical and repetitive sound curves produce this type of bad noises ...

I identify the "PIIIii" of piou as a saturation and distorsion defined as « HF ringing »
and the "IOUUUU" like an rapid audio decompression ..... that i think is a perceptive mechanism of brain treatment
"HF" is a bad usage of course .... it's probably not 16khz ...


My opinion is that "noises" are, for me, very difficult to support and produce, because i identify this as a repetitive situation with Mpc audio file, a suscipicious for that codec ...
Maybe, i hope, there is some solution to maybe fix or probably prevent that !!

I have also a real problem with QCD ... Audio player .. .. mpc file are insufferable to hear ... do you know this issue ??

I know some comparative tools and sites like ... PcABX and well-know the "blind-test" process coming from Pharmaceutical process of usa gov agreement .... and the different "sound test series" like Fatboy, Castanet, MpegData, Xiph and some good site like FF123, mp3.radified, Buschmann & Klemm, rareties etc ... others ..???

Or And will be a good first process to test .. audio devices and environement before ...
- ourself hear evaluation (ok include in PcAbx site..)
- some special audio situation .. http://www.dogstar.dantimax.dk/testwavs/ & http://www.dogstar.dantimax.dk/testwavs/
- Devices (for me Audigy I - ATP5 - )
- Softs for me ...... Win XP Pro - Foobar ...

So, is up to me to do the tests ... i never do that ...so

where can i Found the good procees method - tools and audio reference files
Here is maybe the good process steps??
1) evaluate your ears
2) test & verify your material & software
3) find a good reference set of audio file for testing (including freq, audio signal config, voice and music, etc ..)
4) find the correct blind-test soft and scope & visualization of audio signal ... with an acceptable protocol
5) make the test ... verify condition ...
6) publish (wich form ..?)

Is there anybody produce a such protocol & process description?

This post has been edited by nwn: Feb 17 2003, 01:23

[Frank Klemm]

Hi,

I moved some changes in the SV8 tree back to SV7, hopefully this will reduce some of the problems.
I can't move all SV8 changes to SV7, the format do not support some of the new features.

Bitrate is increased by typically 3.1% compared with 1.14. Most of this bitrate increase is related to
some modificitions in the tonality estimation model (which was introduced with 1.15g).

There are also some other changes which have nothing to do with quality (some counters are now
64 bit to overcome problems with very long movie sound tracks), and these must be tested very carefully.

mppenc 1.15q for Linux will be uploaded in the next minutes. Windows version will take a little bit longer.

[Garf]

amensia encoded with Frank's new encoder:

http://sjeng.org/ftp/vorbis/amnesia.std.mpc
http://sjeng.org/ftp/vorbis/amnesia.xtr.mpc

[guruboolez]

I'm an idiot : I used 1.95i codec, and not 1.15q

Thank you, Garf.

I tried to compare 1.14 and this new 1.15q, at --standard.
Sound is really close, without real improvement at the beginning (dropout at ~0.500), and seems to be identical at the end (helicopter sounding).

CODE

1R = D:\temp\amnesia\amnesia.mpc195std.wav
2L = D:\temp\amnesia\amnesia.mpc5.wav

---------------------------------------
General Comments:
0.0-1.5

Le fichier N.1 me semble un peu plus mauvais, notamment au début. Différence assez difficile à cerner entre les deux encodages.
---------------------------------------
1R File: D:\temp\amnesia\amnesia.mpc195std.wav
1R Rating: 3.0
1R Comment: décrochage sonore + sonorité aigrelette et déplaisante ensuite.
---------------------------------------
2L File: D:\temp\amnesia\amnesia.mpc5.wav
2L Rating: 3.5
2L Comment: mêmes remarques.
---------------------------------------
ABX Results:
Original vs D:\temp\amnesia\amnesia.mpc195std.wav
   8 out of 8, pval = 0.004
Original vs D:\temp\amnesia\amnesia.mpc5.wav
   8 out of 8, pval = 0.004

CODE

1R = D:\temp\amnesia\amnesia.mpc5.wav
2L = D:\temp\amnesia\amnesia.mpc195std.wav

---------------------------------------
General Comments:

---------------------------------------
1R File: D:\temp\amnesia\amnesia.mpc5.wav
1R Rating: 1.5
1R Comment: toujours ce bruit de friture, très aigre, métallique, huileux.
---------------------------------------
2L File: D:\temp\amnesia\amnesia.mpc195std.wav
2L Rating: 1.5
2L Comment:
---------------------------------------
ABX Results:
Original vs D:\temp\amnesia\amnesia.mpc5.wav
   7 out of 8, pval = 0.035
Original vs D:\temp\amnesia\amnesia.mpc195std.wav
   8 out of 8, pval = 0.004

With some doubts, I found 1.15q a bit worse at the beginning as 1.14. Before the dropout, the sound of 1.15q seems to be sour ; I hear it on 1.14 only after dropout.

This post has been edited by guruboolez: Feb 17 2003, 15:31

[guruboolez]

I'm an idiot : I used 1.95i codec, and not 1.15q

I compared directly 1.14 & 1.15q with an ABX test, at the beginning of the file (0.0-0.5).
One file was corruped by a sour, metallic and unpleasant coloration (the same I can hear, amplified, at the end of the file). I had some difficulties to perform a concluant ABX session. After three trials, the last one, with concentration :

CODE

1L = D:\temp\amnesia\amnesia.mpc195std.wav
2L = D:\temp\amnesia\amnesia.mpc5.wav

---------------------------------------
General Comments:
0.0-0.5

Le fichier No.2 présente cette aigreur qui me déplait tant, et qu'on retrouvera de façon croissante sur la suite du morceau.
Le fichier No.1 me semble préférable, car même s'il demeure éloigné de l'original (comme si les micro-contrastes étaient accentués façon sharpening graphique - l'original étant plus doux), il n'en demeure pas moins plus naturel.
Question de goût peut-être...
---------------------------------------
ABX Results:
D:\temp\amnesia\amnesia.mpc195std.wav vs D:\temp\amnesia\amnesia.mpc5.wav
   13 out of 16, pval = 0.011

13/16, in favour of... 1.15q, more natural, without this special coloration at the beginning.

This post has been edited by guruboolez: Feb 17 2003, 15:31

[guruboolez]

Just notice an epistemologic problem
My amnesia.flac (downloaded on HA server some weeks ago) is 44100 Hz
Pio2001 amnesia sample is 44100 Hz
Garf amnesia is 48000 Hz.

Now, I opposed a 44100 Hz encoding (my 1.14 one) to a 48000 Hz one (provided by Garf).

[Garf]

The original I used is at:

http://sjeng.org/ftp/vorbis/amnesia.flac

[guruboolez]

I'm stupid : I used 1.95i codec, and not 1.15q

Sorry...

[guruboolez]

Perform again the test, after a big, black coffee.
First comment : the degradation is, with the original sample provided by garf, less annoying, with both codec. Consequently, there are more difficult to hear, especially at the beginning. The end of the file is really better now


BEGINNING :

1.14 : small coloration (saur sound), and the dropout at the same place
1.15q : small dropout, no coloration

CODE

---------------------------------------
1R File: D:\temp\amnesia.15\amnesia.std114.wav
1R Rating: 4.0

---------------------------------------
2R File: D:\temp\amnesia.15\amnesia.std115q.wav
2R Rating: 4.5

---------------------------------------
ABX Results:
Original vs D:\temp\amnesia.15\amnesia.std114.wav
   8 out of 8, pval = 0.004
Original vs D:\temp\amnesia.15\amnesia.std115q.wav
   7 out of 8, pval = 0.035
D:\temp\amnesia.15\amnesia.std114.wav vs D:\temp\amnesia.15\amnesia.std115q.wav
   13 out of 16, pval = 0.011

ENDING :

1.14 : coloration but not pronouced. Unstable (trembling) signal
1.15 : nothing wrong : I wasn't able to distinguish the mpc file before the ABX test.

CODE

---------------------------------------
1R File: D:\temp\amnesia.15\amnesia.std114.wav
1R Rating: 4.0

---------------------------------------
ABX Results:
Original vs D:\temp\amnesia.15\amnesia.std114.wav
   9 out of 10, pval = 0.011
Original vs D:\temp\amnesia.15\amnesia.std115q.wav
   8 out of 16, pval = 0.598
D:\temp\amnesia.15\amnesia.std114.wav vs D:\temp\amnesia.15\amnesia.std115q.wav
   14 out of 20, pval = 0.058

Quality is in progress ; bitrate too :

1.14 : 225 kbps // 260 kbps
1.15q : 270 kbps // 311 kbps

[Gecko]

For the record, the sample I've been using is the same as the one Garf provided (only mine is a tad longer but otherwise bit identical). I double checked, I really am using 1.14 beta at quality 5.

Garf's 1.15q std sample is still ABXable vs Garf's original (8/8).
I can't abx my 1.14beta std encode vs Garf's 1.15q std encode.
I can however abx Pio's 1.14 std encode vs Garf's 1.15q std encode.

edit: damn, when you hit tab and then space, your post is submitted...

This post has been edited by Gecko: Feb 17 2003, 16:17