Skip to main content

Topic: Mp3 VBR Question (Read 11691 times) previous topic - next topic

0 Members and 1 Guest are viewing this topic.
  • Donunus
  • [*][*][*]
Mp3 VBR Question
How does vbr work in the cutting off of higher frequencies? Dont the different cbr bitrates cut off at different frequencies: ex 112 cutting off at around 14k while 320 cutting off data at around 20khz. Does vbr high frequency variably cut off when the bitrates fluctuate? Doesn't that theoretically change the character of the sound within one song?

  • Leo 69
  • [*][*][*]
Mp3 VBR Question
Reply #1
The lowpass is constant and is set according to VBR quality.

  • Alex B
  • [*][*][*][*][*]
Mp3 VBR Question
Reply #2
I made an updated version of the v. 3.95 table that can be found here: http://www.hydrogenaudio.org/forums/index....showtopic=18091.

LAME 3.97 beta 1
Code: [Select]
Switch		Equals			Target	Lowpass	Resample

-V 0 --preset extreme 210-270 19500
-V 0 --vbr-new --preset fast extreme 210-270 19500
-V 1 200-250 19000
-V 1 --vbr-new 200-250 19000
-V 2 --preset standard 170-230 18600
-V 2 --vbr-new --preset fast standard 170-230 18600
-V 3 140-210 18000
-V 3 --vbr-new 140-210 18000
-V 4 --preset medium 130-190 17500
-V 4 --vbr-new --preset fast medium 130-190 17500
-V 5 110-170 16000
-V 5 --vbr-new 110-170 16000
-V 6 100-150 15600
-V 6 --vbr-new 100-150 15600
-V 7 90-130 14900 32000
-V 7 --vbr-new 90-130 14900 32000
-V 8 70-110 12500 32000
-V 8 --vbr-new 70-110 12500 32000
-V 9 50-80 10000 24000
-V 9 --vbr-new 50-80 10000 24000
I used Encspot for checking the lowpass and resample values. The bitrate values are from my test here: http://www.hydrogenaudio.org/forums/index....ndpost&p=328558

[span style=\'font-size:7pt;line-height:100%\']Edit: typo[/span]
  • Last Edit: 18 October, 2005, 04:36:27 PM by Alex B

  • Donunus
  • [*][*][*]
Mp3 VBR Question
Reply #3
thanks for the info

  • beowulf7
  • [*][*]
Mp3 VBR Question
Reply #4
Quote
I made an updated version of the v. 3.95 table that can be found here: http://www.hydrogenaudio.org/forums/index....showtopic=18091.

LAME 3.97 beta 1
Code: [Select]
Switch  Equals  	Target	Lowpass	Resample

-V 0  --preset extreme 210-270 19500
-V 0 --vbr-new --preset fast extreme 210-270 19500
-V 1    200-250 19000
-V 1 --vbr-new    200-250 19000
-V 2  --preset standard 170-230 18600
-V 2 --vbr-new --preset fast standard 170-230 18600
-V 3    140-210 18000
-V 3 --vbr-new    140-210 18000
-V 4  --preset medium  130-190 17500
-V 4 --vbr-new --preset fast medium 130-190 17500
-V 5    110-170 16000
-V 5 --vbr-new    110-170 16000
-V 6    100-150 15600
-V 6 --vbr-new    100-150 15600
-V 7    90-130 14900 32000
-V 7 --vbr-new    90-130 14900 32000
-V 8    70-110 12500 32000
-V 8 --vbr-new    70-110 12500 32000
-V 9    50-80 10000 24000
-V 9 --vbr-new    50-80 10000 24000
I used Encspot for checking the lowpass and resample values. The bitrate values are from my test here: http://www.hydrogenaudio.org/forums/index....ndpost&p=328558

[span style=\'font-size:7pt;line-height:100%\']Edit: typo[/span]
[a href=\"index.php?act=findpost&pid=335491\"][{POST_SNAPBACK}][/a]
The --vbr-new and non --vbr-new versions appear to be identical (for a given -V n). 

  • saratoga
  • [*][*][*][*][*]
Mp3 VBR Question
Reply #5
Quote
How does vbr work in the cutting off of higher frequencies? Dont the different cbr bitrates cut off at different frequencies: ex 112 cutting off at around 14k while 320 cutting off data at around 20khz. Does vbr high frequency variably cut off when the bitrates fluctuate? Doesn't that theoretically change the character of the sound within one song?
[a href="index.php?act=findpost&pid=335453"][{POST_SNAPBACK}][/a]


Lowpass is fixed according to preset and/or switches.  In theory you can set a 64kbps file to have a 22kHz lowpass if you really want.  In practice, its best to just trust the developers on this one and not tweak the encoder.

  • Alex B
  • [*][*][*][*][*]
Mp3 VBR Question
Reply #6
Quote
The --vbr-new and non --vbr-new versions appear to be identical (for a given -V n).  [a href="index.php?act=findpost&pid=337762"][{POST_SNAPBACK}][/a]

Yes, the lowpass values written in the LAME tags are identical. In my test the bitrates were near, but not exactly the same. Because I rounded the resulting median values to the nearest ten no differences show up in the table.

  • beowulf7
  • [*][*]
Mp3 VBR Question
Reply #7
Quote
Quote
The --vbr-new and non --vbr-new versions appear to be identical (for a given -V n).  [a href="index.php?act=findpost&pid=337762"][{POST_SNAPBACK}][/a]

Yes, the lowpass values written in the LAME tags are identical. In my test the bitrates were near, but not exactly the same. Because I rounded the resulting median values to the nearest ten no differences show up in the table.
[a href="index.php?act=findpost&pid=337777"][{POST_SNAPBACK}][/a]

Thanks for the reply.  It sounds like it's a "you say 6, I say half a dozen" kind of difference.  In other words, there is no real difference.  When I ran "lame --preset help" for my LAME 3.96.1, the text said:

"fast" - Enables the new fast VBR for a particular profile. The disadvantage to the speed switch is that often times the bitrate will be slightly higher than with the normal mode and quality may be slightly lower also.

So if "fast" uses vbr-new, then it's not worth using vbr-new.  Maybe the word "new" in the above description is confusing me with the "new" in "vbr-new".

  • kotrtim
  • [*][*][*][*][*]
Mp3 VBR Question
Reply #8
Quote
So if "fast" uses vbr-new, then it's not worth using vbr-new.  Maybe the word "new" in the above description is confusing me with the "new" in "vbr-new".


Yes, its worth it! up to 1.5X faster than "OLD"
and the bitrate is not always bigger....if its bigger,  it won't be more than 10kbps, sometimes it's lesser (didn't test properly)
  • Last Edit: 29 October, 2005, 12:20:57 AM by Gambit

  • beowulf7
  • [*][*]
Mp3 VBR Question
Reply #9
Quote
Quote

So if "fast" uses vbr-new, then it's not worth using vbr-new.  Maybe the word "new" in the above description is confusing me with the "new" in "vbr-new".


Yes, its worth it! up to 1.5X faster than "OLD"
and the bitrate is not always bigger....if its bigger,  it won't be more than 10kbps, sometimes it's lesser (didn't test properly)
[a href="index.php?act=findpost&pid=337989"][{POST_SNAPBACK}][/a]

Yes, but what scared me is when LAME said, "quality may be slightly lower also", in reference to the "fast" option (vbr-new). 
  • Last Edit: 29 October, 2005, 12:21:35 AM by Gambit

  • DreamTactix291
  • [*][*][*][*][*]
  • Members (Donating)
Mp3 VBR Question
Reply #10
Quote
Yes, but what scared me is when LAME said, "quality may be slightly lower also", in reference to the "fast" option (vbr-new).  
[a href="index.php?act=findpost&pid=337995"][{POST_SNAPBACK}][/a]
I don't believe the "quality may be slightly lower also" holds true for --vbr-new any longer with regards to 3.97b.  I believe that was originally said for the 3.90 branch in relation to --alt-preset fast standard and --alt-preset fast extreme and was a somewhat general consensus for a long time.  guruboolez's test here though tend to favour --vbr-new over --vbr-old nowadays though.
  • Last Edit: 29 October, 2005, 12:12:11 AM by DreamTactix291
Nero AAC 1.5.1.0: -q0.45

  • beowulf7
  • [*][*]
Mp3 VBR Question
Reply #11
Quote
Quote
Yes, but what scared me is when LAME said, "quality may be slightly lower also", in reference to the "fast" option (vbr-new).  
[a href="index.php?act=findpost&pid=337995"][{POST_SNAPBACK}][/a]
I don't believe the "quality may be slightly lower also" holds true for --vbr-new any longer with regards to 3.97b.  I believe that was originally said for the 3.90 branch in relation to --alt-preset fast standard and --alt-preset fast extreme and was a somewhat general consensus for a long time.  guruboolez's test here though tend to favour --vbr-new over --vbr-old nowadays though.
[a href="index.php?act=findpost&pid=338000"][{POST_SNAPBACK}][/a]

Hmm, I see.  I wonder how applicable it would be for my LAME (3.96.1).  I guess vbr-new would be almost as fast as cbr, in terms of encoding time.

  • DreamTactix291
  • [*][*][*][*][*]
  • Members (Donating)
Mp3 VBR Question
Reply #12
I believe as of 3.97b the speed rankings are as follows.

--vbr-new is faster than CBR which is faster than ABR which is faster than --vbr-old.

I remember reading that posted by someone here, but I don't ever really encode CBR or ABR files to test it to be honest.
Nero AAC 1.5.1.0: -q0.45

  • audiomars
  • [*][*][*]
Mp3 VBR Question
Reply #13
Hmm, I see.  I wonder how applicable it would be for my LAME (3.96.1).  I guess vbr-new would be almost as fast as cbr, in terms of encoding time.


Any specific reason as to why you are using Lame 3.96.1? Lame 3.97b2 is the recommended version as per HA. The speed increase using --vbr new is worth it
Reason is immortal, all else mortal
- Pythagoras

Mp3 VBR Question
Reply #14

Hmm, I see.  I wonder how applicable it would be for my LAME (3.96.1).  I guess vbr-new would be almost as fast as cbr, in terms of encoding time.


Any specific reason as to why you are using Lame 3.96.1? Lame 3.97b2 is the recommended version as per HA. The speed increase using --vbr new is worth it



Given that beowulf7's post is over 8 months old, he might have moved up to 3.97b2 by now.

  • beowulf7
  • [*][*]
Mp3 VBR Question
Reply #15


Hmm, I see.  I wonder how applicable it would be for my LAME (3.96.1).  I guess vbr-new would be almost as fast as cbr, in terms of encoding time.


Any specific reason as to why you are using Lame 3.96.1? Lame 3.97b2 is the recommended version as per HA. The speed increase using --vbr new is worth it



Given that beowulf7's post is over 8 months old, he might have moved up to 3.97b2 by now.

LOL ... good call.  Yes, I upgraded to LAME 3.97b2 a few months ago. 

  • audiomars
  • [*][*][*]
Mp3 VBR Question
Reply #16
LOL ... good call.  Yes, I upgraded to LAME 3.97b2 a few months ago. 


Meh... I didn't notice the date of your earlier message
Reason is immortal, all else mortal
- Pythagoras