|
Author
|
Topic: Joint Stereo vs. Stereo - (Read 26 times)
|
Jeeves
Junior Member  From:
Registered: Apr 2001
Posts: 7
|
Hey all,Whats the different between joint stereo and just the "stereo" in the mp3 settings? I mean as in does the regular stereo do less compression, (thus more diskspace used,) while the joint stereo does more compression? Which is better in quality?
-J
|
markov
Member From:Newcastle, Aus
Registered: Oct 2000
Posts: 234
|
the AG help file says:
· Joint Stereo: Joint Stereo shares certain bits between high frequency left and right channels. This improves compression efficiency at a slight loss of stereo separation. Lower frequencies are treated as normal stereo. Use Joint Stereo to obtain the best overall quality at mid-to-lower bit rates. < 224 Kbit.· Stereo: Stereo includes two independent channels. The total bit rate remains constant, but the split between the channels can vary. The Encoder uses this flexibility to improve quality by allocating more bits to the channel with the more dynamic signal. Use the Stereo setting for best quality stereo audio at higher bit rates. while the lame usage file says:
jstereo means the encoder can use (on a frame by frame bases) either regular stereo (just encode left and right channels independently) or mid/side stereo. In mid/side stereo, the mid (L+R) and side (L-R)
channels are encoded, and more bits are allocated to the mid channel than the side channel. This will effectively increase the bandwidth if the signal does not have too much stereo separation.
Mid/side stereo is basically a trick to increase bandwidth. At 128 kbps,
it is clearly worth while. At higher bitrates it is less useful.
Using mid/side stereo inappropriately can result in audible compression artifacts. To much switching between mid/side and regular
stereo can also sound bad. To determine when to switch to mid/side stereo, LAME uses a much more sophisticated algorithm than that
described in the ISO documentation. both modes use the same amount of disk space to store a track. i always just use joint stereo, i cant notice any difference (although may people may). just try using both modes and see if you can notice a difference, if you cant i would suggest jstereo.
|
Spaceknarf
Member  From:International Space Station
Registered: Sep 2000
Posts: 1128
|
Joint Stereo *does* save space if you're using VBR, then it saves about 20kbps! www.r3mix.net says you should use it. If you're using CBR then the space freed by combining some stereo information will be used to achieve higher quality in the same bitrate. If you're an audiophile: Joint Stereo means you will lose a little stereo information, but it's up to you.[This message has been edited by Spaceknarf on 01 May 2001 @ 13:20]
|
+···+
Junior Member From:
Registered: May 2001
Posts: 8
|
I followed r3mix.net's advice, and ended up with some rather horrible-sounding MP3s. I think the problem is exactly what everything ELSE I've read has told me: That the (potentially constant) mode shifting that can occur between frames when you use jstereo can cause more harm than good. In my case, it was obvious--the sound was terrible, even at 192 Kbps. I switched to stereo (the LAME default at >128 anyway), and my files sounded great. So much for the "gurus".[This message has been edited by +···+ on 27 May 2001 @ 12:18]
|
bubkaii
Junior Member From:
Registered: Apr 2001
Posts: 5
|
Joint sterio encodes faster too
|
tladuca
Junior Member From:Florida, USA
Registered: Jun 2001
Posts: 8
|
quote:
Originally posted by +···+:
I followed r3mix.net's advice, and ended up with some rather horrible-sounding MP3s. I think the problem is exactly what everything ELSE I've read has told me: That the (potentially constant) mode shifting that can occur between frames when you use jstereo can cause more harm than good. In my case, it was obvious--the sound was terrible, even at 192 Kbps. I switched to stereo (the LAME default at >128 anyway), and my files sounded great. So much for the "gurus".</font>
What version of LAME do you use? I am using JS and VBR too as per I think r3mix's advice. Also, what VBR compresstion rate I use "2" and haven't noticed any problems <i>so far</i>.
[This message has been edited by tladuca on 03 June 2001 @ 19:34]
|
Dragline
Junior Member From:
Registered: Jun 2001
Posts: 5
|
read other posts for specific reasons.. js sucks - avoid it like the plague
|
Spaceknarf
Member From:International Space Station
Registered: Sep 2000
Posts: 1128
|
This will be an endless discussion, and I hate these...
Only real audiophiles can hear the difference, ok?
It saves 20kbps when using JStereo, I'd say that's a good enough reason to use it...
|
Drawshot
Member From:Silver Spring, Md
Registered: Sep 2000
Posts: 49
|
Yeah... The stereo vs. joint stereo argument will never be settled. The same goes for the cbr vs. vbr debate. There is a lot of false information floating around about these topics, and people repeating hearsay and nonsense.As for me... I have pretty good hearing, and I have some decent audio equipment. I use js and vbr, and I'm happy with the results. Show me an audiophile, and I'll show you someone who paid too much for his audio equipment.
|
Sputnik
Member From:Stratosfear
Registered: Jun 2001
Posts: 309
|
I think I'm not a great audiophile, and my equipment is not an expensive one. But I can show everybody some empiric arguments to say that Joint Stereo is a bad method to encode.
Just try to encode from some different source than cda. Vinyls, p.e.
When you try to digitalize a vinyl, lots of undesired frequencies are coming, and then you will need to clean your wav files with some special software, like Cool Edit or Sound Forge.
When your wav files seems to be clear and clean, then you will try to encode them to mp3. But you will find that mp3 emphasizes lots of background noises that remained "masked" in your original wav files.
This problem increases if you employ jstereo, because the "unmasked" frequencies will be shown equally in both channels of the stereo. If you employ a natural stereo mode and a very high bitrate, the most probably is that background noises will remain "masked", because your mp3 file will be as similar as possible to its original wav file.
Perhaps the problem of Drawshot maybe that his equipment is excessively good, and it make sound everything nice, even when it sounds horrible :-)
|
bugblatter
Junior Member From:
Registered: Jun 2001
Posts: 3
|
Well I'm not an audiophile but when I tried the two methods I could tell the difference. The one with js seemed less expansive, less spatial. It's something you'd really only notice if you were listening for it (and then only through headphones), but that's true of most of this kind of setting.If I was to encode mp3s at 128kbps I'd definitely use js though, any higher and I wouldn't.
|
Chris_GA
Member From:Chattanooga, TN, USA
Registered: Apr 2001
Posts: 221
|
I encode at VBR q=2, simple stereo. I tried js for some time, and I found that what bugblatter says is true. The sound is still basically the same quality in all mp3s I've made (although I haven't tried out any vinyl remasterings), but the stereo mp3s have a broader sound. Since many of my mp3s end up back on CD anyway as compilations, I like to keep the sound as original as I can. I also burn all my mp3s to CDs, so space isn't an issue anymore  If it were, I'd probably encode at 160 cbr, with js, to preserve the general sound quality at a moderate bitrate.
|
Anthony S
Member From:
Registered: May 2001
Posts: 70
|
I agree that for those uncaring about file size, go with the stereo setting. I tried joint stereo on a few songs that had a lot going on across the audio range and I noticed the stereo files captured the original sound better. The -mj setting seemed to narrow and also resulted a swishy/spacey type of sound. I've gotten a little anal about settings lately since I'm archiving all my CD's to MP3 for my mp3 car player and use @ work. The best command-line I've found after God knows how many hours of testing @ different times of the days is:
%s %d -V0 -ms -q0 --vbr-new -b192 -F -B320 --lowpass 20For some, the lowpass 20 setting might be a waste if you can't hear a difference from the lowpass 19.5 or 19 setting.
|
UBBFriend: Email This Page to Someone! 
Click here to bookmark this thread!
Audiograbber Forums
posted 29 April 2001 14:43 
posted 29 April 2001 17:31 
posted 01 May 2001 13:20 
posted 27 May 2001 00:18 
posted 03 June 2001 19:30 
posted 03 June 2001 20:54 
posted 04 June 2001 04:17