Any listening test Stereo vs Joint stereo in mp3? Options

[crazyman]

Hi all,

in many discussions I read about mp3 via Lame encoder the result is that the best solution is joint stereo. I believe in that as the developers who I highly esteem say so. But is this statement supported also by more independent listening tests? Especially I would be interested in comparison between --preset standard (joint stereo) and dtto with stereo mode.

Can the result in general depend also on the Lame version? From the tests I could read usually still the old good Lame 3.90.3 comes out as the winner.

Cheers,

Crazyman

[beto]

This makes no sense, since joint stereo is just a way to encode stereo losslessly.

There should be no audible difference between them AFAIK....

[mithrandir]

This makes no sense, since joint stereo is just a way to encode stereo losslessly.

There should be no audible difference between them AFAIK....

No, joint stereo is lossy. That's what directed the Scene to use full stereo mode (not that they really know what they are doing). But joint stereo can be objectively transparent if implemented properly...and it can save you a lot of bits. There is generally no need to use full stereo in LAME.

[SirGrey]

>>No, joint stereo is lossy.
Wrong.
joint-stereo is lossless, intensity stereo is lossy.

The only thing about it, that is testable is switching algorhytm - i.e. what representation saving more bits.
EDIT:

beto: This makes no sense,

Agree

This post has been edited by SirGrey: Jan 14 2005, 16:51

[Otto42]

No, joint stereo is lossy.

Depends on what you're talking about. As I understood it, there's two ways to do Joint Stereo. Mid/Side Stereo is lossless. Intensity Stereo is lossy. But intensity stereo is only used at low bitrates (96k and less) and so Joint Stereo is lossless at normal bitrates used for audio anyway.

So in other words, Joint Stereo can only improve quality by offering another possible data set to compress and giving a possible higher quality. Using Stereo Only makes no sense because that's just eliminating the possibility of using M/S encoding.

This post has been edited by Otto42: Jan 14 2005, 16:53

[SirGrey]

Addenium:
Lots of the confusion goes from Fhg.
They usually call ms stereo as joint stereo and intensity stereo as ms-is stereo.

[Gray_Wolf]

This is incredible

Many people in present moment believe that Lame CBR 192kbps - Stereo mode is the best solution

This post has been edited by Gray_Wolf: Jan 14 2005, 18:33

[Jojo]

The bottom line is that Joint-Stereo used in LAME is lossless. Therefore, it will either improve quality or reduce filesize. So, Joint-Stereo + LAME is a must! The Stereo mode in LAME should be removed since there is no use for this anymore...

This post has been edited by Jojo: Jan 14 2005, 17:54

[dev0]

No, joint stereo is lossy. That's what directed the Scene to use full stereo mode (not that they really know what they are doing). But joint stereo can be objectively transparent if implemented properly...and it can save you a lot of bits. There is generally no need to use full stereo in LAME.

No, Joint Stereo is lossless concerning stereo information. Some scene groups are using 'full stereo' VBR, because using a Dolby Pro Logic or similliar surround DSP will unmask JS artifacts, which are masked under normal (=stereo) playback conditions.
For more information see this thread:
http://www.hydrogenaudio.org/forums/index....showtopic=12004

[Mark7]

No, joint stereo is lossy. That's what directed the Scene to use full stereo mode (not that they really know what they are doing). But joint stereo can be objectively transparent if implemented properly...and it can save you a lot of bits. There is generally no need to use full stereo in LAME.

No, Joint Stereo is lossless concerning stereo information. Some scene groups are using 'full stereo' VBR, because using a Dolby Pro Logic or similliar surround DSP will unmask JS artifacts, which are masked under normal (=stereo) playback conditions.
For more information see this thread:
http://www.hydrogenaudio.org/forums/index....showtopic=12004

Won't stereo mode destroy the centre channel of DPL suround? Both channels are encoded seperately so there will be a bigger chance that sounds that should the same on each channel are actually be slightly different on each channel and won't go to the centre channel where they belong. (just a theory)

And doesn't DPL more or less play the side channel through the surround speakers? How come there will be artifacts?

This post has been edited by Mark7: Jan 14 2005, 19:04

[mithrandir]

No, joint stereo is lossy. That's what directed the Scene to use full stereo mode (not that they really know what they are doing). But joint stereo can be objectively transparent if implemented properly...and it can save you a lot of bits. There is generally no need to use full stereo in LAME.

No, Joint Stereo is lossless concerning stereo information. Some scene groups are using 'full stereo' VBR, because using a Dolby Pro Logic or similliar surround DSP will unmask JS artifacts, which are masked under normal (=stereo) playback conditions.
For more information see this thread:
http://www.hydrogenaudio.org/forums/index....showtopic=12004

I think there is some confusion here...and perhaps it is me. This is what I mean:

If you encode with VBR -V 5, which uses joint stereo not full, it is possible to positively ABX between WAV and MP3 from a stereo perspective (i.e. -V 5 has a smaller soundstage than original thanks to more aggressive use of mid-side frames instead of LR). The variable here is --nsmsfix. Set it low enough (closer to 0) and it would probably be impossible to ABX between MP3 and WAV in terms of stereo performance.

If joint stereo were in fact lossless then why does LAME have to decide between LR and MS frame allocation? It's going lossy in many cases to save bitrate.

[Jojo]

If joint stereo were in fact lossless then why does LAME have to decide between LR and MS frame allocation? It's going lossy in many cases to save bitrate.

even if that was the case...Joint-Stereo would be still better than 'Stereo'...I mean, mp3 is a lossy format afterall...however, I don't think that Joint-Stereo used in --preset standard is lossy...

[Busemann]

If joint stereo were in fact lossless then why does LAME have to decide between LR and MS frame allocation? It's going lossy in many cases to save bitrate.

even if that was the case...Joint-Stereo would be still better than 'Stereo'...I mean, mp3 is a lossy format afterall...

Huh!?

Doing things that could be messing up the stereo separation is the last thing I'd like to see at high bit-rates

This post has been edited by Busemann: Jan 15 2005, 01:55

[Jojo]

If joint stereo were in fact lossless then why does LAME have to decide between LR and MS frame allocation? It's going lossy in many cases to save bitrate.

even if that was the case...Joint-Stereo would be still better than 'Stereo'...I mean, mp3 is a lossy format afterall...

Huh!?

Doing things that could be messing up the stereo separation is the last thing I'd like to see at high bit-rates

he was talking about -V5, which targets for 130kbps

[2Bdecided]

The stereo to joint stereo (i.e. L+R>M+S) transform is lossless and perfectly reversible. However, the channels are then lossily coded.

If you force an encoder to (a) stay in L+R mode (i.e. "discrete" or "true" stereo), and then (b) force it into a bitrate area where it will add audible distortion, the stereo image will be preserved but you'll have audible quantisation noise. If anything, the addition of poorly-correlated noise to both channels may make the stereo sound stage sound wider - artificially and quite nastily of course. The centre image could be damaged.

If you force an encoder to (a) stay in M+S mode (i.e. one of the options available in "joint" stereo), and then (b) force it into a bitrate area where it will add audible distortion, the stereo image will start to collapse and you may have audible quantisation noise, but it will be less obvious.

The point of VBR is to use as many bits are as necessary for a transparent result, and the point of joint stereo is to give the option of encoding M+S (or L+R!). You're only going to hear a difference between discrete and joint stereo if something goes wrong. Which it rarely does with lame 3.90.3 aps. What's more, of all the thousands of tracks that must have been encoded with aps, and the handful of tracks which are not transparent, no one has suggested that any of these are improved by forcing discrete stereo.

I'd encourage people to look at that thread...
http://www.hydrogenaudio.org/forums/index....showtopic=12004
...to see that forcing stereo may not be the answer - even when using a DPL or DPLII decoder.

Was this issue ever resolved?

Cheers,
David.

This post has been edited by 2Bdecided: Jan 17 2005, 16:38

[crazyman]

The stereo to joint stereo (i.e. L+R>M+S) transform is lossless and perfectly reversible. However, the channels are then lossily coded.

If you force an encoder to (a) stay in L+R mode (i.e. "discrete" or "true" stereo), and then (b) force it into a bitrate area where it will add audible distortion, the stereo image will be preserved but you'll have audible quantisation noise. If anything, the addition of poorly-correlated noise to both channels may make the stereo sound stage sound wider - artificially and quite nastily of course. The centre image could be damaged.

If you force an encoder to (a) stay in M+S mode (i.e. one of the options available in "joint" stereo), and then (b) force it into a bitrate area where it will add audible distortion, the stereo image will start to collapse and you may have audible quantisation noise, but it will be less obvious.

The point of VBR is to use as many bits are as necessary for a transparent result, and the point of joint stereo is to give the option of encoding M+S (or L+R!). You're only going to hear a difference between discrete and joint stereo if something goes wrong. Which it rarely does with lame 3.90.3 aps. What's more, of all the thousands of tracks that must have been encoded with aps, and the handful of tracks which are not transparent, no one has suggested that any of these are improved by forcing discrete stereo.

I'd encourage people to look at that thread...
http://www.hydrogenaudio.org/forums/index....showtopic=12004
...to see that forcing stereo may not be the answer - even when using a DPL or DPLII decoder.

Was this issue ever resolved?

Cheers,
David.

David,

many thanks. BTW, mp3 gain is also one of necessary tools for me.
Rgds,

Crzmn

[crazyman]

This is incredible 

Many people in present moment believe that Lame CBR 192kbps - Stereo mode is the best solution   

Quite agree. Even some good rippers (f.i. CDEx) in help file say that for internal encoder, stereo is the recommended option ...

Rgds,

Crzmn

[Busemann]

Quite agree. Even some good rippers (f.i. CDEx) in help file say that for internal encoder, stereo is the recommended option ...

Rgds,

Crzmn

If it isn't referring to LAME, that isn't necessarily wrong though

[mithrandir]

The stereo to joint stereo (i.e. L+R>M+S) transform is lossless and perfectly reversible. However, the channels are then lossily coded.

Thanks for the clarification...this was the source of my confusion.

[MugFunky]

guh, why has this myth never been dispelled?

it should be mentioned in the TOS or something.

[edit] something like "MS joint-stereo is not lossy! it's simply a way to decorellate data so it can be stored more efficiently". also mention that the lossy IS stereo mode is not implemented in LAME, and probably never will be.

for a start, just because DPL might bork your stereo image is no reason to pre-bork your mp3s. dolby pro-logic is not relevant for music that is mixed and mastered as stereo. and if it were mixed and mastered for DPL, i highly doubt (but cannot prove without an actual DPL decoder) that a preset-standard mp3's transparency will break on it. so pro-logic is no reason to encode in LR stereo. DPLII is much more sophisticated than DPL, but again, you'd be stupid to use it on stuff that wasn't meant for it (though apparently it's brilliant on SQ quad records though, having been heavily based on a quad decoder itself).

besides, MS can't be lossy if you're able to put an equals sign between it and LR - maths doesn't work that way. it's best to leave the decision of where to go LR and where to go MS to lame itself, rather than forcing it. after all, by forcing LR, you are disabling a feature of the encoder, rather than improving it.

This post has been edited by MugFunky: Jan 20 2005, 06:32

[DreamTactix291]

guh, why has this myth never been dispelled?

No idea. Even when I was a newbie after I'd read about the L/R to M/S process I understood it once. Just two ways to express the same data and letting the encoder pick which one is more efficient is what LAME does in its joint stereo mode.

I agree that somewhere this should be posted where it is obvious that using M/S stereo is not lossy. If it was certain lossless encoders couldn't use it (I know one does but I can't remember which one)

[Gabriel]

The M/S stereo transform itself is lossless.
However, in the context of a lossy encoder, anything leading to some variations in the bits might affect the final loss.
It means that in the context of mp3 encoding, M/S stereo is as lossy as the Huffman coding.

[crazyman]

Quite agree. Even some good rippers (f.i. CDEx) in help file say that for internal encoder, stereo is the recommended option ...

Rgds,

Crzmn

If it isn't referring to LAME, that isn't necessarily wrong though

The problem is that it is referring to lame. Also, I used to be a bit confused that is seetings of encoder there were logical lines: Mono, Forced stereo, Joint stereo, Stereo.

[2Bdecided]

Talk about things coming back to bite you...

I'm on a UK media forum, talking about how joint stereo on DAB digital radio is bad (because it's MPEG-1 layer II, which only implements intensity stereo, which is 7-point panned mono above 3, 6, 9, or 12kHz) and someone points me to Hydrogen Audio to learn about why joint stereo isn't really bad at all!

Cheers,
David.

[Gabriel]

Well, in your case intensity stereo is a good thing compared to l/r stereo, considering that UK DAB is something like 128kbps Layer II.