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Any listening test Stereo vs Joint stereo in mp3?
crazyman
post Jan 14 2005, 14:46
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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
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2Bdecided
post Jan 17 2005, 16:34
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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
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crazyman
post Jan 19 2005, 09:25
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QUOTE (2Bdecided @ Jan 17 2005, 07:34 AM)
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
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Posts in this topic
- crazyman   Any listening test Stereo vs Joint stereo in mp3?   Jan 14 2005, 14:46
- - beto   This makes no sense, since joint stereo is just a ...   Jan 14 2005, 14:51
|- - mithrandir   QUOTE (beto @ Jan 14 2005, 08:51 AM)This make...   Jan 14 2005, 16:38
|- - Otto42   QUOTE (mithrandir @ Jan 14 2005, 09:38 AM)No,...   Jan 14 2005, 16:50
|- - dev0   QUOTE (mithrandir @ Jan 14 2005, 04:38 PM)No,...   Jan 14 2005, 18:42
|- - Mark7   QUOTE (dev0 @ Jan 14 2005, 09:42 AM)QUOTE (mi...   Jan 14 2005, 19:04
|- - mithrandir   QUOTE (dev0 @ Jan 14 2005, 12:42 PM)QUOTE (mi...   Jan 14 2005, 22:44
|- - Jojo   QUOTE (mithrandir @ Jan 14 2005, 01:44 PM)If ...   Jan 15 2005, 01:49
|- - Busemann   QUOTE (Jojo @ Jan 14 2005, 04:49 PM)QUOTE (mi...   Jan 15 2005, 01:55
|- - Jojo   QUOTE (Busemann @ Jan 14 2005, 04:55 PM)QUOTE...   Jan 15 2005, 02:03
- - SirGrey   >>No, joint stereo is lossy. Wrong. joint-st...   Jan 14 2005, 16:48
- - SirGrey   Addenium: Lots of the confusion goes from Fhg. The...   Jan 14 2005, 16:53
- - Gray_Wolf   This is incredible Many people in present mome...   Jan 14 2005, 17:10
|- - crazyman   QUOTE (Gray_Wolf @ Jan 14 2005, 08:10 AM)This...   Jan 19 2005, 09:30
|- - Busemann   QUOTE (crazyman @ Jan 19 2005, 12:30 AM)Quite...   Jan 19 2005, 11:44
|- - crazyman   QUOTE (Busemann @ Jan 19 2005, 02:44 AM)QUOTE...   Jan 20 2005, 11:29
- - Jojo   The bottom line is that Joint-Stereo used in LAME ...   Jan 14 2005, 17:53
- - 2Bdecided   The stereo to joint stereo (i.e. L+R>M+S) trans...   Jan 17 2005, 16:34
|- - crazyman   QUOTE (2Bdecided @ Jan 17 2005, 07:34 AM)The ...   Jan 19 2005, 09:25
|- - mithrandir   QUOTE (2Bdecided @ Jan 17 2005, 10:34 AM)The ...   Jan 20 2005, 05:52
- - MugFunky   guh, why has this myth never been dispelled? it s...   Jan 20 2005, 06:29
|- - DreamTactix291   QUOTE (MugFunky @ Jan 19 2005, 11:29 PM)guh, ...   Jan 20 2005, 06:56
- - Gabriel   The M/S stereo transform itself is lossless. Howev...   Jan 20 2005, 09:13
- - 2Bdecided   Talk about things coming back to bite you... I...   Jan 21 2005, 12:10
- - Gabriel   Well, in your case intensity stereo is a good thin...   Jan 21 2005, 13:55
|- - Bogalvator   QUOTE (Gabriel @ Jan 21 2005, 04:55 AM)Well, ...   Jan 22 2005, 04:49
|- - 2Bdecided   QUOTE (Gabriel @ Jan 21 2005, 12:55 PM)Well, ...   Jan 24 2005, 17:00
- - Gabriel   QUOTE but the broadcasters have reportedly asked f...   Jan 24 2005, 20:41
- - Ossie   Hi, I just want to check if the following staement...   May 21 2005, 10:57
- - Pio2001   It all depends if the psychoacoustic model can han...   May 21 2005, 13:01
- - Pio2001   Oh, that's not all, you'll have to force m...   May 21 2005, 13:07
- - mjkng2   hey this is an old article against Joint Stereo: ...   Aug 4 2006, 19:20
|- - Garf   QUOTE (mjkng2 @ Aug 4 2006, 20:20) hey t...   Aug 5 2006, 09:44
- - stephanV   It's not against JS... it just says that an al...   Aug 4 2006, 20:16
- - Pio2001   I've performed two joint stereo listening test...   Aug 4 2006, 22:52
- - haregoo   This sample is ABXable(16/16) even with -V 0 becau...   Aug 5 2006, 03:57
- - Gabriel   QUOTE (haregoo @ Aug 5 2006, 04:57) This ...   Aug 5 2006, 08:48
- - haregoo   QUOTE (Gabriel @ Aug 5 2006, 16:48) Regar...   Aug 5 2006, 14:14


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