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Two stupid(?) questions about LAME
BFG
post Jul 22 2012, 00:22
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Hello all. As you can see, I'm new to the boards, but have perused them as a guest for some time.

I'm still trying to learn the ins and outs of audio archiving, and after doing considerable reading I've started archiving my CD collection with LAME, using the -V0 and -q0 (highest quality VBR) settings.


I have two (potentially stupid) questions for those more experienced than I:
(1) Do you see any point in recompressing my CDs using LAME 3.99.5? The vast majority of them are already compressed with 3.98.4. 3.99.5 seems to give a small file increase on the higher quality settings, but I'm really only concerned about the audio quality.


(2) I've noticed that LAME VBR always uses MPEG 1-Layer III bitrates (32, 40, 48 ... 320), presumably because CDs are always at a 44.1kHz sample rate. Would it be possible to combine MPEG 1 and MPEG 2/2.5 (8, 16, 24...144, 160) bitrates in the same file? If so, would those be readable by most players? And what about using freeformat options e.g. 288 or 640 kbps?
I'm thinking that allowing MPEG 1 and MPEG 2/2.5 in the same file, if that's possible, would allow VBR files to be a bit smaller with no quality loss - since silent sections, for example, could be encoded at 8 kbps instead of 32. And it'd be nice to have freeformat options above 320 kbps available since this is for archiving.
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Porcus
post Jul 22 2012, 17:35
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It is maybe fruitful to point out what is correct, and merely not what is wrong: VBR aims at maximizing quality at whatever the average bitrate output becomes (which is not the same as to say “a given predetermined average bitrate”), and for every given CBR file, there is a VBR file which does indeed achieve the same quality without increasing size.


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mjb2006
post Jul 23 2012, 07:41
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QUOTE (Porcus @ Jul 22 2012, 10:35) *
VBR aims at maximizing quality at whatever the average bitrate output becomes

I thought it aimed at achieving consistent quality.

QUOTE (halb27 @ Jul 22 2012, 15:22) *
somebody recently wrote that CBR and VBR mode share the same psychoacoustic model in 3.99, and IIRC he referred to the change log. I just looked up the change log but could not find a corresponding entry.

From the changelog:
QUOTE
LAME 3.99 beta 0 not officially released
[...]
All encoding modes use the PSY model from new VBR code


This post has been edited by mjb2006: Jul 23 2012, 07:45
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halb27
post Jul 23 2012, 11:21
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QUOTE (mjb2006 @ Jul 23 2012, 08:41) *
QUOTE (halb27 @ Jul 22 2012, 15:22) *
somebody recently wrote that CBR and VBR mode share the same psychoacoustic model in 3.99, and IIRC he referred to the change log. I just looked up the change log but could not find a corresponding entry.

From the changelog:
QUOTE
LAME 3.99 beta 0 not officially released
[...]
All encoding modes use the PSY model from new VBR code


OK, Thanks for the hint. The audio data created by the VBR and the CBR processes are significantly different nonetheless.


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Posts in this topic
- BFG   Two stupid(?) questions about LAME   Jul 22 2012, 00:22
- - Soap   Why in this day of cheap storage would you "a...   Jul 22 2012, 00:50
|- - BFG   QUOTE (Soap @ Jul 21 2012, 18:50) Why in ...   Jul 22 2012, 01:03
||- - Soap   QUOTE (BFG @ Jul 21 2012, 19:03) First, t...   Jul 22 2012, 01:08
|||- - BFG   QUOTE (Soap @ Jul 21 2012, 19:08) 1 - If ...   Jul 22 2012, 01:13
||- - Porcus   QUOTE (BFG @ Jul 22 2012, 02:03) frankly ...   Jul 22 2012, 14:32
|- - Glenn Gundlach   1: Last month I bought a 2TB Hitachi drive for ...   Jul 23 2012, 06:33
- - lvqcl   (0) http://wiki.hydrogenaudio.org/index.php?title=...   Jul 22 2012, 01:00
- - soundping   @ BFG Have you seen this page? CODEhttp://wik...   Jul 22 2012, 07:02
|- - kornchild2002   QUOTE (soundping @ Jul 22 2012, 00:02) CB...   Jul 22 2012, 12:59
|- - greynol   QUOTE (soundping @ Jul 21 2012, 23:02) CB...   Jul 22 2012, 17:09
- - JJZolx   QUOTE (BFG @ Jul 21 2012, 17:22) (1) Do y...   Jul 22 2012, 07:33
- - Porcus   It is maybe fruitful to point out what is correct,...   Jul 22 2012, 17:35
|- - halb27   QUOTE (Porcus @ Jul 22 2012, 18:35) ... f...   Jul 22 2012, 20:49
||- - Porcus   QUOTE (halb27 @ Jul 22 2012, 21:49) QUOTE...   Jul 22 2012, 22:13
|- - mjb2006   QUOTE (Porcus @ Jul 22 2012, 10:35) VBR a...   Jul 23 2012, 07:41
|- - halb27   QUOTE (mjb2006 @ Jul 23 2012, 08:41) QUOT...   Jul 23 2012, 11:21
- - greynol   I thought I read that the CBR and VBR modes now sh...   Jul 22 2012, 21:06
- - halb27   @greynol: Yes, somebody recently wrote that CBR an...   Jul 22 2012, 22:22
- - AliceWonder   If compatibility is what you are worried about the...   Jul 22 2012, 22:32
|- - kornchild2002   QUOTE (AliceWonder @ Jul 22 2012, 15:32) ...   Jul 23 2012, 00:31
- - Porcus   Are you really suggesting that Lame's VBR mode...   Jul 22 2012, 22:47
- - halb27   If you're addressing me: No, I don't, and ...   Jul 22 2012, 23:02
|- - Porcus   QUOTE (halb27 @ Jul 23 2012, 00:02) If yo...   Jul 22 2012, 23:36
- - AliceWonder   They are compatible with ALAC today, now, but AAC ...   Jul 23 2012, 02:53
|- - kornchild2002   QUOTE (AliceWonder @ Jul 22 2012, 19:53) ...   Jul 23 2012, 11:04
|- - Porcus   QUOTE (kornchild2002 @ Jul 23 2012, 12:04...   Jul 23 2012, 13:43
- - RobertoDomenico   Getting Flac to play in iTunes is a total pain, ev...   Jul 23 2012, 04:26
- - AliceWonder   You can still install the command line client and ...   Jul 23 2012, 04:36
- - BFG   QUOTE (halb27 @ Jul 22 2012, 17:02) Perso...   Jul 24 2012, 04:05
|- - halb27   QUOTE (BFG @ Jul 24 2012, 05:05) QUOTE (h...   Jul 24 2012, 08:59
|- - Porcus   QUOTE (BFG @ Jul 24 2012, 05:05) I'd ...   Jul 24 2012, 10:29
- - greynol   I suggest you bone up on the joint-stereo vs. forc...   Jul 24 2012, 05:46


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