[blessingx]

And egglick, Febs is right on the money concerning joint stereo. If you're running 256 CBR kbps as stereo, you're effectively running dual 128 streams. Depending on stereo separation, complexity, etc. it's quite easy to imagine a lot of unnecessary duplicate data that would be easy to beat with an ABR or VBR joint stereo file at even ~192 kpbs. If it was a mono source recorded in stereo you may even be able to go down to 160 CBR JS and achieve statistically better results. Looked at in reverse, the bytes in a 256 joint stereo encoding has more information at its disposal.

I'm in the "if you're going to compromise quality for size... compromise quality for size." I don't understand those that encode at 320 kbps "'cause it's the best." No it's not. It's just the best setting for your particular lossly encoder. 320 kbps stereo makes even less sense to me. Might as well give up on perceptual encoding completely.

 

[mrarroyo]

Ok, I need help. I do not understand, so here is my questions: I normally record at 192 kbs vbr set at highest, and I am using iTunes. For sound quality would I be better served to use joint stereo or not? Thanks.

Miguel

 

[Ikon]

Quote:

Originally Posted by mrarroyo Ok, I need help. I do not understand, so here is my questions: I normally record at 192 kbs vbr set at highest, and I am using iTunes. For sound quality would I be better served to use joint stereo or not? Thanks.

Short answer: Use joint-stereo.

Long answer: Enabling joint-stereo doesn't mean the encoder will use joint-stereo in every frame, it just allows it to choose that stereo-mode if it decides that plain stereo is not needed. Note that MP3 as a format allows different stereo-modes for every frame in a file, so if the channel separation in a particular frame makes plain stereo necessary, the encoder will use plain stereo for this frame. LAME and the FhG codec (which iTunes AFAIK uses) have become very good at deciding where which stereo-mode should be used, so you can savely activate joint-stereo at any bitrate with these encoders. Just be sure not to activate the "forced joint-stereo" option as it well ... forces joint-stereo in every frame which is bad for the sound, naturally.

 

[blessingx]

mrarroyo if you're using iTunes branched FhG encoder, be aware that the setting is a minimum bitrate and not quite VBR or ABR as commonly discussed. If you're on a Mac you have the iTunes-LAME option too.

 

[upstateguy]

Quote:

Originally Posted by egglick I'm not familiar with the particular VBR switches you guys are discussing. As I said, it all depends on the quality of VBR you're using versus the quality of CBR. If you're using 256/320kbps CBR files, it's hard to argue that a VBR file even over the same ranges is going to sound "better". VBR may be more efficient in filesize, but you still run the risk of having too low a bitrate in a particular passage. Using a high bitrate CBR prevents this from happening, at the expense of often having too high a bitrate in many low quality passages (and thus having a larger overall file). Sound quality wise, the latter is perferable. You bring up a good point about the other aspects of lossy encoding, which is why I try to keep those things to a minimum by not introducing another variable. I also don't use joint stereo.

I don't use joint stereo either. It doesn't work well if your source has any kind of phase changes in it, such as those in Bob Dylan's "Time out of Mind," for example.

 

[Ikon]

Quote:

Originally Posted by upstateguy I don't use joint stereo either. It doesn't work well if your source has any kind of phase changes in it, such as those in Bob Dylan's "Time out of Mind," for example.

Unless you force joint-stereo on every frame, I seriously, seriously doubt that.
There are still some joint-stereo disbelievers out there and there have been a lot of replies from LAME developers saying that it is indeed VERY safe to use. In fact, I remember Dibrom (LAME dev and HydrogenAudio founder) specifically stating that LAME's alt-presets - which use joint-stereo - fully (read: 100%) preserve phase information.
It should be a clear sign that even --alt-preset-insane, which is as best as it gets quality-wise with MP3 uses joint-stereo.

Forcing plain stereo on every frame only wastes bitrate that could be used elsewhere to improve audio quality. It might be acceptable to use at very high bitrates (256/320kbps), but it won't gain anything except a slight decrease in overall sound quality.

 

[upstateguy]

Quote:

Originally Posted by Ikon Unless you force joint-stereo on every frame, I seriously, seriously doubt that. There are still some joint-stereo disbelievers out there and there have been a lot of replies from LAME developers saying that it is indeed VERY safe to use. In fact, I remember Dibrom (LAME dev and HydrogenAudio founder) specifically saying that LAME's alt-presets - which use joint-stereo - fully (read: 100%) preserve phase information. It should be a clear sign that even --alt-preset-insane, which is as best as it gets quality-wise with MP3 uses joint-stereo.

Hi Ikon,

That sure is what they say isn't it?....

But when I ripped the Dylan CD mentioned above, I could clearly hear the effect joint stereo had on that album....

Haven't used it since.

Check it out for yourself. Joint stereo sounds like he's singing into a tin can. Regular stereo sounds like the CD.

Used the newest Plextools for the rip (VBR 192-320), so the other option is that somehow Plextools is at fault.
Didn't try it with EAC.

I also don't use VBR any more, just 320 or flac. I can easily hear the difference, even on this:

Regards

USG

 

[Ikon]

The quality of the MP3 encoder is very important for the resulting audio quality of a file as the complexity of the encoding process varies quite much among the different encoders.
I have no idea what MP3 encoder the PlexTools use, but if it's so bad that even VBR sounds inferior to CBR, I also wouldn't trust it with joint stereo.
In fact, I wouldn't trust it with my music at all

-> You might want to try LAME and EAC some time, it may very well give you a whole new view on MP3 *shameless advertising*

 

[Febs]

Quote:

Originally Posted by upstateguy Used the newest Plextools for the rip (VBR 192-320), so the other option is that somehow Plextools is at fault.

According to the Plextools FAQ, Plextools does NOT ship with LAME: http://www.plextools.com/support/support.asp#question5

I couldn't find anything about what encoder it does use. You really should try LAME before you reach any conclusions about how joint stereo mode in LAME affects phase information.

 

[upstateguy]

Quote:

Originally Posted by Febs According to the Plextools FAQ, Plextools does NOT ship with LAME: http://www.plextools.com/support/support.asp#question5 I couldn't find anything about what encoder it does use. You really should try LAME before you reach any conclusions about how joint stereo mode in LAME affects phase information.

Hi Febs

Of course you are right, it doesn't ship with LAME.... You have to download the LAME version of your choice and drop it into the Plextools folder....

USG


Quote:

Originally Posted by Ikon The quality of the MP3 encoder is very important for the resulting audio quality of a file as the complexity of the encoding process varies quite much among the different encoders. I have no idea what MP3 encoder the PlexTools use, but if it's so bad that even VBR sounds inferior to CBR, I also wouldn't trust it with joint stereo. In fact, I wouldn't trust it with my music at all -> You might want to try LAME and EAC some time, it may very well give you a whole new view on MP3 *shameless advertising*

Hi Ikon

There are several threads regarding Plextools Vs EAC over at Hydrogen, that you might find interesting. For the record, I have and use both.

USG