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Topic: Problems With Joint Stereo (LAME) (Read 15908 times) previous topic - next topic
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Problems With Joint Stereo (LAME)

Reply #25
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I just love the friendly supportive environment that is being nurtured here.  Welcome to the Jungle, Sonny!

It would be much more of a jungle if we would believe every claim without further examination and questioning and wouldn't follow any rules...
Juha Laaksonheimo

Problems With Joint Stereo (LAME)

Reply #26
Sonny,
Now you are focussing on mp3 @128kbps. Nobody on HA will ever claim or has ever that LAME or any other mp3 encoder will produce transparent results at that bitrate.

Problems With Joint Stereo (LAME)

Reply #27
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b. I trust my ears

This argument can not, and will not, be accepted.

Time and again, sighted evaluation of audio quality has been proved to be unreliable. This is the reason why in this community statements regrding sound quality have to be supported by blind test results.

Please follow the suggestions given above: use replaygain and do an ABX test if you want your claims to be considered as valid.

I trully understand that objective results are to be discussed to give reliable conclusions.
Still, I've started this topic with two 128kbps small samples that show a STRIKING difference between TS and JS. And I didn't get any reply about it.

OK now... Maybe the problem is coming from my computer. Maybe I make things up. Maybe I'm just dumb. I don't know. But I'm a musician, I play guitar, bass, I sing. And I know what I ear. Especially after something like 12-13 blind tests : on the samples I encoded, JS brings huge distortion, not TS.

So. I'm sorry for disturbing your great community with my pathetic problems. I won't bother again.
bye all

Problems With Joint Stereo (LAME)

Reply #28
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Sonny,
Now you are focussing on mp3 @128kbps. Nobody on HA will ever claim or has ever that LAME or any other mp3 encoder will produce transparent results at that bitrate.

I'm not talking about the overall transparency  just about that specific distortion

Problems With Joint Stereo (LAME)

Reply #29
gday...


@sonny..

Quote
JS is supposed to be better than True Stereo (TS). Theorically. Indeed, JS encodes 2 channels, middle (M) and side (S) instead of left (L) and right ( R). Demonstration :
If M=(L+R)/2 and S=(L-R)/2 , then it is easy to get the L and R channel back :
M+S=(L+R+L-R)/2 = 2L/2=L and M-S=(L+R-(L-R))/2=(L+R-L+R)/2=2R/2=R
The trick is : you encode M on one side, and on the other, the more L and R are similar, the less the S channel will need bits to be properly encoded (ex: if L=R (=Mono), the needed space for S channel is zero !)


my two cents..

MS stereo / Joint Stereo will unfortunately always have this affect on
disorted signals.. (mp3) as you say.. stick with TS..
in other words.. JS is the downside of audio compression.. (as i see it)

you also wanted possible 3rd. sulutions..
go for MPC format. of those codecs i have listened to..
mpc have the least problems with disortion..
(actually close to zero.)



Problems With Joint Stereo (LAME)

Reply #30
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So. I'm sorry for disturbing your great community with my pathetic problems. I won't bother again.
bye all

Please don't leave... 

I'm sure you're right when you say you're heard distortions.
but as you said, this has to be proven by short samples 

You're welcome. 

Problems With Joint Stereo (LAME)

Reply #31
Sonny: It could very well be that you hear problems with joint stereo. So, in order to point, that you truely can hear joint/stereo every time, could you download this package and tell which one/ones are joint stereo, and which ones are stereo.
The package is rather big: 17.3MB, and it includes 4 FLAC samples (decoded MP3s) and original (FLAC). The samples are mid/low bitrate.

http://www.hydrogenaudio.org/extra/js_test.zip

Although even guessing right isn't very hard, I think this issue would turn into much more serious discussion (instead of bickering) if you can pick the right ones up.

I hope you are up to the challenge.

PS. Don't leave now, just when I got my sample set made and uploaded..  It's just that people here want very good proof until they will believe something. There's just too many people making claims which turn out to be something else what was claimed...
Juha Laaksonheimo

Problems With Joint Stereo (LAME)

Reply #32
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1. I didn't do ONE blind test, I've spent DAYS blind testing and made something like 10 tests, with up to 14 FILES and I always hear the distortion.

This sounds like you have passed the test. If you blindly tested original vs. copy with correct results 10x in a row, the probability you were guessing is 0.5^10 = 0.1 %.

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Sometimes (for the 128kbps samples) I can hear it in less than 3 seconds.
2. tell you where is the distortion ? Did you actually listen to the 128kbps samples I've provided ? Surely not!! you wouldn't even ask. 

I don't regard this as polite. I spend time answering, trying to help you to find out if the problem is caused by playback conditions used etc. and you're not willing to give a simple answer to a simple question. Have you thought of this - maybe what I use for playback (good soundcard, player with replaygain enabled) makes the problem disappear for me? In fact I've listened to the 128kbps samples and with some concentration there are several positions where I can ABX (8/8) both from the original, but mostly because of things like pre-echo and watery sounding high pitched noisy sounds (cymbals etc.). I haven't noticed any position with particularly bad distortion. So again, could you please answer my question?

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Still, I've started this topic with two 128kbps small samples that show a STRIKING difference between TS and JS. And I didn't get any reply about it.

See above. I'd like to verify your findings and reply, but I need your reply for this.
Let's suppose that rain washes out a picnic. Who is feeling negative? The rain? Or YOU? What's causing the negative feeling? The rain or your reaction? - Anthony De Mello

Problems With Joint Stereo (LAME)

Reply #33
Sonny maybe you have to use the Winamp equalizer. generally you have distortion when the volume is too high.

Problems With Joint Stereo (LAME)

Reply #34
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gday...
my two cents..

MS stereo / Joint Stereo will unfortunately always have this affect on
disorted signals.. (mp3) as you say.. stick with TS..
in other words.. JS is the downside of audio compression.. (as i see it)

you also wanted possible 3rd. sulutions..
go for MPC format. of those codecs i have listened to..
mpc have the least problems with disortion..
(actually close to zero.)


thanks for your answer!
i've tried musepack and found it very good at high bitrate but strangely, also very poor near 128kbps 
given that i very often use high bitrates, musepack would be a good solution... if my mp3 player would support it !!
so for now, I stick with Lame in True Stereo. 

Problems With Joint Stereo (LAME)

Reply #35
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I don't regard this as polite. I spend time answering, trying to help you to find out if the problem is caused by playback conditions used etc. and you're not willing to give a simple answer to a simple question. Have you thought of this - maybe what I use for playback (good soundcard, player with replaygain enabled) makes the problem disappear for me? In fact I've listened to the 128kbps samples and with some concentration there are several positions where I can ABX (8/8) both from the original, but mostly because of things like pre-echo and watery sounding high pitched noisy sounds (cymbals etc.). I haven't noticed any position with particularly bad distortion. So again, could you please answer my question?


i hear the distortion particularly on the cymbals (in fact during blind test I focus on exclusivly on cymbals, makes it easier).
it's weird you didn't hear the difference. maybe it comes from my computer but then why TS would work fine ?
and i'm sorry if i was rude, it wasn't my intention. i just wanted to share some experience, in order to help things going on. i didn't PRETEND anything so i really didn't expect such answers. 
anyway, i've solve my problem (i stick with TS) and i don't want to argue (or be rude!) anymore
thanks for helping, really.
bye

Problems With Joint Stereo (LAME)

Reply #36
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Huh? Who's talked about 3.94betas - have I missed it?

Well, Gabriel (and, supposedly, other members of the LAME team) have spent some time reworking some of LAME 3.94's psychoacoustics (IIRC). The reworkings have yet to be tuned as extensively as other versions, but there could be a quality increase on some samples. I dunno. I was throwing something else out that could possibly assist our intrepid new member here in his studies.

This is MP3 @ 128, though guys... Do we honestly need to push ABX this hard when people hear artifacts with that?

Edit: As an (interesting?) sidenote, I had a CD player with a little "3D expander" button that would amplify the joint stereo loss by like ten times. It made some 160 and even some 192 kbps MP3s very audibly lossy. That was back before I played with -aps or ABX, but I knew I heard something very clearly. If I were to ABX with some DSP like this on for both samples, would that be legal?

Problems With Joint Stereo (LAME)

Reply #37
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anyway, i've solve my problem (i stick with TS) and i don't want to argue (or be rude!) anymore
thanks for helping, really.
bye

The thing is, people should help each other. It's a good thing

Therefore,  it would be nice if you could help the regulars and developers here figure out what problem you're hearing when using joint stereo, and why it goes away when using simple stereo. It would help you too, because the joint stereo mode has been tested much more than the simple stereo mode. Forcing simple stereo will probably just waste bits, but could break some of the tuning of the --alt-presets, and in any case can cause a decrease in quality for some samples.

So, are you willing to help?


Just to check: blind testing means you don't know what you're listening to. So, it could be the original, it could be the simple stereo version, or it could be the joint stereo version. From what you've said, you should be able to pick out the joint stereo version, but not the other two. Is this the case?

Now, the recommended version is lame 3.90.3, and the recommended command line is --alt-preset standard. The download link is in the FAQ. It's a very small download - give it a go. Do you still hear problems?

Please do not assume that people here are deaf, or that your musician ears are super sensitive and you're hearing something that no one else will. I've heard lots of people claim things like that. It's very rare in practice.


This is what I would try: people have said that the sample is clipping. First step: drop the gain on the original by 6dB (use any editor you like, or wavgain) so that this can't be an issue.

Now, encode the -6dB file using lame. --alt-preset standard, and --alt preset standard -m s. Decode both files using lame. (That's just lame --decode). Listen to the resulting .wav files back2back with the original. Blind. Do you still hear a difference?

If you're not sure (or even if you are!) try an ABX comparator. PC ABX, WinABX, and the one within ff123's ABC/HR are all suitable. Compare the original (-6dB) with the Joint stereo version, and compare the original (-6dB) with the Simple stereo version. Verify that the former pair sound different, and the latter pair sound the same.

Let us know how you get on. If you still get the same results, let us know. If you don't, check whether it's the lame version, or the -6dB gain which solves the problem, and let us know!

Cheers,
David.

Problems With Joint Stereo (LAME)

Reply #38
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Edit: As an (interesting?) sidenote, I had a CD player with a little "3D expander" button that would amplify the joint stereo loss by like ten times. It made some 160 and even some 192 kbps MP3s very audibly lossy. That was back before I played with -aps or ABX, but I knew I heard something very clearly. If I were to ABX with some DSP like this on for both samples, would that be legal?

Have you actually compared joint stereo vs. -m s with this device? I ask this because it's a known phenonemon with every lossy audio compression (exceptions might be codecs without psychoaccoustics like wavpack lossy), that you'll hear bad artifacts if you substract channels (like e.g Karaoke plugins do or your headphone if it's not plugged in correctly). The reason for the artifacts you hear could be somthing very similar.

Obvious: The more DSPs you use (and the more they change sound), the more likely you'll hear artifacts. If you plan to use DSPs with your encoded music you should do your own ABX test with the DSP chain you're planning to use of course to find good encoding settings for you (or apply DSPs before encoding if possible).
Let's suppose that rain washes out a picnic. Who is feeling negative? The rain? Or YOU? What's causing the negative feeling? The rain or your reaction? - Anthony De Mello

Problems With Joint Stereo (LAME)

Reply #39
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i've tried musepack and found it very good at high bitrate but strangely, also very poor near 128kbps 
given that i very often use high bitrates, musepack would be a good solution... if my mp3 player would support it !!
so for now, I stick with Lame in True Stereo. 

For low bitrates you should try AAC and Ogg Vorbis also. But i realy don't get it why do you use 128kbps bitrate if you hear artifacts in there?
Have you tested --alt-preset standard -y settings or --alt-preset 128? You can get close to 128kbps with those and better sound quality also.

Have you tryed other players? With for exaple with Winamp and with foobar2000 you can play Musepac, AAC and ogg vorbis.

Problems With Joint Stereo (LAME)

Reply #40
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thanks for your answer!
i've tried musepack and found it very good at high bitrate but strangely, also very poor near 128kbps 
given that i very often use high bitrates, musepack would be a good solution... if my mp3 player would support it !!
so for now, I stick with Lame in True Stereo. 

I'm curious about your opinion of Ogg Vorbis -q 6, and if you can hear the difference.

Problems With Joint Stereo (LAME)

Reply #41
Thanks for the info, Sonny.

I've done some testing:

All encoded files you uploaded clip on decoding, so this (together with a resampling soundcard) might be the reason for the problems you hear. I attatch test.zip containing 2 processed samples of your uploads (original and 128kbps JS mp3), with lowered volume + hq resampled to 48kHz. I'm interested if you still hear the bad distortions with these samples.

Another possibile reason for 128kbps Joint stereo performing worse than with -m s with your sample could be this (found out using spectral view):

The lowpass of the lame 128kbps setting you used is 17.5kHz. Using joint stereo, there are enough bits left for encoding much of the information between 16 and 17.5 kHz, but OTH there are dropouts in this frequency range (visible in frequency view - if you hear it is a completely different question). Using -m s additionally ("true stereo") There's hardly anything encoded between 16 and 17.5kHz, so there could be less dropout-related problems. To test if this is the case for you, you could add --lowpass 16 to your commandline.

Or - better - use this commandline from the recommended lame settings:
--abr 128 -h --nspsytune --athtype 2 --lowpass 16 --ns-bass -8 --scale 0.93
Using ABR should give better results than CBR in most cases. The only reason for using CBR is for encoding audio for .avi videos.
Let's suppose that rain washes out a picnic. Who is feeling negative? The rain? Or YOU? What's causing the negative feeling? The rain or your reaction? - Anthony De Mello

Problems With Joint Stereo (LAME)

Reply #42
Great a sample!  I look forward to testing it.

--

Ok encoded as APS w/ 3.90.3, replaygained using foobar.  I loaded both into foo_abx and could not pass the blind test.  I looped each and every spot with clear cymbols, however all sounded identical to my ears. 

Also, I'll need to check out some Kameloth, sounds interesting.

Edit:  Google says its actually Kamelot

Problems With Joint Stereo (LAME)

Reply #43
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Have you actually compared joint stereo vs. -m s with this device? I ask this because it's a known phenonemon with every lossy audio compression (exceptions might be codecs without psychoaccoustics like wavpack lossy), that you'll hear bad artifacts if you substract channels (like e.g Karaoke plugins do or your headphone if it's not plugged in correctly). The reason for the artifacts you hear could be somthing very similar.

I didn't make encodes with the two. I just noticed that all the tracks that had the problem were encoded as joint-stereo. There were some JS files that didn't potentiate the problem, but there were no non-JS files that caused the problem. Probably just some encoder that sucked at figuring out which frames to make JS or a poor encoder or something. I don't have the player, the audio CDs, or the source files anymore, so I can't double check any of it.

Thanks for the DSP enlightenment; figured it went something like that.

Problems With Joint Stereo (LAME)

Reply #44
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Thanks for the info, Sonny.

I've done some testing:

All encoded files you uploaded clip on decoding, so this (together with a resampling soundcard) might be the reason for the problems you hear. I attatch test.zip containing 2 processed samples of your uploads (original and 128kbps JS mp3), with lowered volume + hq resampled to 48kHz. I'm interested if you still hear the bad distortions with these samples.

yes a still clearly hear the distortion... i'm beggining to think this mess is coming from my computer, probably the sound board. i do not see any explanation

to be sure, i'll make a test on a friend's computer with a good sound board and let you know if i still hear the distortion.

Problems With Joint Stereo (LAME)

Reply #45
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Therefore,  it would be nice if you could help the regulars and developers here figure out what problem you're hearing when using joint stereo, and why it goes away when using simple stereo. It would help you too, because the joint stereo mode has been tested much more than the simple stereo mode. Forcing simple stereo will probably just waste bits, but could break some of the tuning of the --alt-presets, and in any case can cause a decrease in quality for some samples.

So, are you willing to help?


Just to check: blind testing means you don't know what you're listening to. So, it could be the original, it could be the simple stereo version, or it could be the joint stereo version. From what you've said, you should be able to pick out the joint stereo version, but not the other two. Is this the case?

Now, the recommended version is lame 3.90.3, and the recommended command line is --alt-preset standard. The download link is in the FAQ. It's a very small download - give it a go. Do you still hear problems?

Please do not assume that people here are deaf, or that your musician ears are super sensitive and you're hearing something that no one else will. I've heard lots of people claim things like that. It's very rare in practice.

This is what I would try: people have said that the sample is clipping. First step: drop the gain on the original by 6dB (use any editor you like, or wavgain) so that this can't be an issue.

Now, encode the -6dB file using lame. --alt-preset standard, and --alt preset standard -m s. Decode both files using lame. (That's just lame --decode). Listen to the resulting .wav files back2back with the original. Blind. Do you still hear a difference?

I'll try to help.

1. the distortion I hear is not a similar to the distortion you can hear from winamp when the equalizer/preamp is set too high. i call this, 'saturation' (i dunno if the term is good, this is not the point here). but lowering the gain won't change a thing in my case. coz the flaws i hear have nothing to see with this kind of distortion, it sounds like, i would say... a 'phaser' effect, only applied on cymbals. really weird and really LOUD    I can't describe it better than that.

2. yes, i know what is a blind test. and i ALWAYS pick up the JS sample when i've done the test with my samples, on my computer.

3. yes i've tried the 3.90.3 version along with the 3.93.1 and the 3.92. same (bad) results. 

4. hey hey hey, what's the hell, i didn't assume nor pretend anything! i've just said one thing, and i'll say it again : i hear this distortion, i do not invent it. it could well come from my computer, i just don't know, but again, i do not invent it. i don't care about having good ears, better ears or best ears, i really don't. all i want is to understand why do i have a terrible distortion ruining my Kamelot ripping !!!! 

5. i made the -6dB test, as you asked : 2 files, alt preset standard, one encoded in JS and one in TS. I did it 5 times, and 5 times picked up the JS samples, though i needed more time than with 128kbps samples. i also did the same test with the alt preset cbr 128 encoding line and passed the test much more easily.

Problems With Joint Stereo (LAME)

Reply #46
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Quote
thanks for your answer!
i've tried musepack and found it very good at high bitrate but strangely, also very poor near 128kbps 
given that i very often use high bitrates, musepack would be a good solution... if my mp3 player would support it !!
so for now, I stick with Lame in True Stereo. 

I'm curious about your opinion of Ogg Vorbis -q 6, and if you can hear the difference.

i've tested the ogg vorbis -q6 against a sample encoded lame with nearly the same bitrate.
ogg sample bitrate = 205kbps ; lame sample bitrate = 203kbps.
I used this command line for lame (3.93.1) : --alt-preset standard -V 3 -B 256 -m s

My impression is that the ogg sample is overall better than the lame. Particularly, it seems more dynamic to me, and cleaner on medium and high tunes.
But these are ONLY impressions (now don't tell me i've reach the conclusion that ogg is better or anything else !!)
Anyway, this was kinda obvious : given that the Lame sample is encoded in True Stereo, the ogg sample should sound better. if i solve my JS problem, i'll try a new comparison.
btw, the command line "--alt-preset standard -V 3 -B 256 -m s" is the best compromise i've found to get good sounding results without using JS. indeed, TS needs a LOT more bits to encode the same file with the same preset (for example, the same sample was encoded in 236kbps with the alt preset standard + TS, with lame 3.90.3), so i've lowered a bit the quality down to V3 and add a ceiling bitrate at 256 (i do not make the difference between 256 and 320). surely not great, but that's the best i've found out to keep the bitrate below 210-220.

Problems With Joint Stereo (LAME)

Reply #47
I forgot : if you're interested in some Kamelot, you sound try the last three albums : The Fourth Legacy (2000), Karma (2001) and Epica (2003). They're just great. Their previous work was a bit... immature to me.
and if you like Kamelot and/or Dream Theater, one should look after Symphony X : it's very hermetic at the beginning, but once you get to understand them, you'll be rewarded more than what you could imagine in your wildest dream. My favourite : V, The New Mythology Suite.

ok i stop bothering you with that 

Problems With Joint Stereo (LAME)

Reply #48
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i've tested the ogg vorbis -q6 against a sample encoded lame with nearly the same bitrate.
ogg sample bitrate = 205kbps ; lame sample bitrate = 203kbps.
I used this command line for lame (3.93.1) : --alt-preset standard -V 3 -B 256 -m s

My impression is that the ogg sample is overall better than the lame. Particularly, it seems more dynamic to me, and cleaner on medium and high tunes.
But these are ONLY impressions (now don't tell me i've reach the conclusion that ogg is better or anything else !!)
Anyway, this was kinda obvious : given that the Lame sample is encoded in True Stereo, the ogg sample should sound better. if i solve my JS problem, i'll try a new comparison.
btw, the command line "--alt-preset standard -V 3 -B 256 -m s" is the best compromise i've found to get good sounding results without using JS. indeed, TS needs a LOT more bits to encode the same file with the same preset (for example, the same sample was encoded in 236kbps with the alt preset standard + TS, with lame 3.90.3), so i've lowered a bit the quality down to V3 and add a ceiling bitrate at 256 (i do not make the difference between 256 and 320). surely not great, but that's the best i've found out to keep the bitrate below 210-220.

The only reason I asked is because Vorbis -q 6 uses lossless stereo coupling.  I want to make sure that this isn't in your head.

Problems With Joint Stereo (LAME)

Reply #49
Sonny: Have you tryed only "--alt-preset standard" setting wihtout any other settings of yours? How does it sounds against your own settings?