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-V2 gives way too high bitrate!?!
masterridley
post Mar 29 2010, 16:48
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I use dbpoweramp and I encode flac tracks to LAME 3.98r -V2. Usually this results in ~170 to ~220 kbps files (close to 192kbps CBR quality)

Well, not so for 2 As I Lay Dying albums that I have (think REALLY LOUD metal). When I encode those I get 230-270 kbps and of course the resulting files are quite big.

My question is: is this a bug or completely natural?
Furthermore (if it's not a bug), isn't it just better to encode in 192kbps and get a smaller file, since that's the quality I was going for anyway?

Cheers
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Aleron Ives
post Mar 30 2010, 04:59
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I hate to continue discussion about -Y since it seems to be one of the least favourite LAME aspects to bring up, but there doesn't seem to be a definitive description of what it does. The best information I've seen is the topic from 2002 where Dibrom talks about its purpose, which I gathered is essentially to tell LAME not to encode frequencies > 16 Khz if doing so will significantly increase the bitrate. Aside from his statement that this means ~80% of 16 Khz or higher frequencies won't get encoded, I haven't found any more in-depth descriptions of exactly how much content gets cut. The topic also mentions that a person's frequency response in a test scenario like the egopont test page or the ff123 sweep test isn't necessarily the same as what that person can hear in music, i.e. just because you can hear the 17 Khz beep on the "test your hearing" page doesn't mean you will be able to ABX music with a lowpass of 16 or the Y switch. Consequently, is the only real answer to the -Y question to encode some files without -Y and also with -Y, then try to ABX them and if you can't hear a difference, you might as well use -Y to save space?

Also, the -Y description from --longhelp says that it ignores sfb21 noise like in CBR. Does this mean that in CBR mode, if you're encoding at a bitrate which uses a lowpass of > 16 Khz, LAME will discard 80% of the content at > 16 Khz so as to make the content < 16 Khz sound better? Presumably if this is the case, it's because since CBR mode is so restrictive, encoding frequencies at > 16 Khz would consume the majority of the available bitrate in CBR mode, and thus all the frequencies < 16 Khz would sound significantly worse. As a result, I assume CBR mode would ignore ~80% of the > 16 Khz content so that there would be sufficient bitrate to make the lower frequencies, which are usually more important, sound better.

I hope I'm not too far off track with this, haha.
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greynol
post Mar 30 2010, 05:20
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QUOTE (Aleron Ives @ Mar 29 2010, 20:59) *
Consequently, is the only real answer to the -Y question to encode some files without -Y and also with -Y, then try to ABX them and if you can't hear a difference, you might as well use -Y to save space?

Pretty much, yes, though you might want to include -V3 in your testing.


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Your eyes cannot hear.
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Aleron Ives
post Mar 30 2010, 05:48
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QUOTE (greynol @ Mar 29 2010, 20:20) *
QUOTE (Aleron Ives @ Mar 29 2010, 20:59) *
Consequently, is the only real answer to the -Y question to encode some files without -Y and also with -Y, then try to ABX them and if you can't hear a difference, you might as well use -Y to save space?

Pretty much, yes, though you might want to include -V3 in your testing.

Well, -V 3 would also cause a drop in bitrate as it relates to overall quality, whereas enabling -Y for -V 0 - 2 would still employ the respective qualities that those settings normally use at the frequencies below 16 kHz (and in the > 16 kHz frequencies that were still included), right?

I hope somebody can shed light on the CBR relationship that is mentioned in the -Y help.
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Posts in this topic
- masterridley   -V2 gives way too high bitrate!?!   Mar 29 2010, 16:48
- - dv1989   Natural. VBR targets quality, not bitrate. Loud me...   Mar 29 2010, 16:52
|- - dsimcha   QUOTE (dv1989 @ Mar 29 2010, 11:52) Natur...   Mar 29 2010, 16:56
- - [JAZ]   metal (being loud and "noisy"*) kicks on...   Mar 29 2010, 17:06
- - masterridley   Damn! That's what I suspected too (compres...   Mar 29 2010, 17:07
- - robert   You could update to LAME 3.98.4, as previous 3.98 ...   Mar 29 2010, 17:13
- - pdq   QUOTE (masterridley @ Mar 29 2010, 11:48)...   Mar 29 2010, 17:14
- - dv1989   QUOTE (pdq)If you really want the best quality whi...   Mar 29 2010, 17:24
- - masterridley   QUOTE (JAZ)Two ways to workaround (workaround not ...   Mar 29 2010, 17:26
- - greynol   -Y does not cut content above 16k; it is not a low...   Mar 29 2010, 17:43
- - lvqcl   QUOTE Regarding -Y, doesn't it kick in with -V...   Mar 29 2010, 18:06
- - Aleron Ives   I hate to continue discussion about -Y since it se...   Mar 30 2010, 04:59
|- - greynol   QUOTE (Aleron Ives @ Mar 29 2010, 20:59) ...   Mar 30 2010, 05:20
|- - Aleron Ives   QUOTE (greynol @ Mar 29 2010, 20:20) QUOT...   Mar 30 2010, 05:48
- - shadowking   I suggest not to fiddle with -Y . If you want a lo...   Mar 30 2010, 11:10
|- - Aleron Ives   QUOTE (shadowking @ Mar 30 2010, 02:10) I...   Mar 30 2010, 23:38
- - [JAZ]   I am preparing to put this on the wiki (but my use...   Mar 30 2010, 12:03
- - benski   very short version: -Y switch makes LAME not encod...   Mar 30 2010, 17:35
- - greynol   It was not too long and is well worth reading, ben...   Mar 30 2010, 17:42
|- - benski   QUOTE (greynol @ Mar 30 2010, 11:42) It w...   Mar 30 2010, 17:44
- - greynol   I hope you caught my edits above since I think you...   Mar 30 2010, 17:55
- - [JAZ]   I would like an answer from robert, or someone tha...   Mar 31 2010, 10:25
|- - Aleron Ives   QUOTE ([JAZ] @ Mar 31 2010, 02:25...   Mar 31 2010, 10:53
|- - robert   QUOTE ([JAZ] @ Mar 31 2010, 11:25...   Mar 31 2010, 12:33
- - shadowking   -Y is still 'experimental'. It was never ...   Mar 31 2010, 11:52
|- - Aleron Ives   I would like to thank robert for explaining the co...   Mar 31 2010, 23:58
- - [JAZ]   Thanks robert. I've used your explanations as ...   Mar 31 2010, 13:16
- - Ajax   The original poster "masterridley" (a ne...   Mar 31 2010, 14:16
- - robert   global gain: is the global quantization step size ...   Mar 31 2010, 14:25
- - pdq   @[JAZ] You might also point out that for older fo...   Mar 31 2010, 14:47
- - shadowking   We should not be recommending or documenting -Y un...   Mar 31 2010, 14:53
- - dv1989   QUOTE (Knowledgebase)LAME Y SWITH Surely I needn...   Mar 31 2010, 15:04
- - [JAZ]   DOH! I saw something strange in that, but i d...   Mar 31 2010, 20:45
- - dv1989   The spelling was one thing. Also, it may not matte...   Mar 31 2010, 21:09
- - shadowking   This is still going back to my point. Users don...   Apr 1 2010, 10:49
|- - Aleron Ives   QUOTE (shadowking @ Apr 1 2010, 02:49) Th...   Apr 1 2010, 11:18
|- - greynol   QUOTE (shadowking @ Apr 1 2010, 02:49) Us...   Apr 1 2010, 18:28
- - [JAZ]   Robert, can you comment on this line of the articl...   Apr 1 2010, 11:22
- - robert   QUOTE If global gain is zero, resolution will need...   Apr 1 2010, 11:37
- - [JAZ]   Talk about failing to read... I didn't ful...   Apr 1 2010, 13:39


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