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Old 6th October 2007, 10:34   #1  |  Link
Cyber Akuma
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Will this LAME command produce optimal sounding mp3s?

After reading over the commands in lame produced by "- ?" switch, here is the command I eventually constructed that I typically use when converting the source audio to MP3 in LAME:

lame -t -V 0 -b 128 -F source.wav destination.mp3

I have been using this command for a while, and I value audio quality over filesize but I don't want to produce 15meg mp3s for a typical 5 minute song (not that this does, but i'm just giving an example). I have a few questions to ask about this:

1. the -b 128 command (keep in mind I am also using the -V command), is there any point is limiting the lowest setting of a VBR to 128? Will this produce any higher quality audio then if I set the minimum to 96 or didnt set a lowest limit at all? Do any players have problems with mp3s below 128 or 96khz?

2. The -V 0 command, how much larger a file would this produce than using the default (which would be the equivelent of -V 4), and is the quality difference noticable? What setting would you recommend?

3. The - F command, why does it need to force it to obey the - b 128 command? I noticed it encodes below 128 anyway unless this command is used. Whats the point of having a command to set minimum VBR bitrate if it will not listen to you unless you force it?


What set of switches would you recommend I use in lame to produce the best sounding files? (I understand that there are other higher quality audio formats like OGM, AT3, etc but mp3 is the most compatible (and has the least CPU impact) to date out of these formats)

Thanks
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Old 6th October 2007, 17:20   #2  |  Link
LANjackal
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First off, read this, the official LAME wiki.

1 -No point in using the -b command with a -V switch. And 96 and 128 are kbps, NOT kHz. It's a bitrate, not a frequency. There's a HUGE difference.

2 - Actually, there is NO default LAME switch, unless you're referring to an equivalent for -alt preset standard, which is -V 2, NOT -V 4. Quality varies from listener to listener. Do an ABX test for yourself. According to the Wiki, though, it's nearly impossible to tell the difference between the -V 2, 1 and 0 switches

3 - AFAIK that's because the -V switch overrides all other encoding commands.

MP3 maxes out at -b 320. It doesn't get any better than that. Period.

HOWEVER

That doesn't mean you can't get an equivalent sounding file at a lower bitrate. You see, you're looking at things from the wrong perspective. Unless you're really strapped for space, the real thing to worry about is quality, not bitrate. Quality is what the -V switches are all about. Just select which one works for you and forget about bitrate. The encoder will do the rest.
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Old 6th October 2007, 21:10   #3  |  Link
Cyber Akuma
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1. Sorry, I meant to say 128 and 96kbps, not khz, my mistake. I am aware of the differences between bitrate and frequency. So I am just doing a neesless task by limiting the minimum bitrate to 128 in a VBR mp3? There will not be any difference in quality?

2. Well, LAME itself said "-V n quality setting for VBR. default n=4". And I have to admit, I have no idea what an ABX test is.

Yes, I know MP3 maxes out at 320.

So according to what you said, I should just use this and it will sound the same as my previous command?

lame -t -V 0 source.wav destination.mp3

What about what lame said about some players having a problem with very low bitrates? How low exactly would this be?

And I know, I said I am going for quality over disk space, I wanted to ask if I was just needlessly increasing bitrate limits or if there are any other switches one would recommend to produce a good sounding MP3.
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Old 9th October 2007, 16:51   #4  |  Link
skromnibog
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Here is an explanation of ABX test: http://wiki.hydrogenaudio.org/index.php?title=ABX
You can participate in coming mp3 test at hydrogenaudio and determine yourself if maybe even bitrate around 128kbps is enough for you (for many people it is).
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Old 9th October 2007, 17:05   #5  |  Link
Fishman0919
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http://www.hydrogenaudio.org/forums/...indpost&p=1595

Code:
The settings, presets are listed beginning with highest possible quality (-b 320) stepping down to lower qualities:

CODE
switch           equals preset        target kbit/s   bitrate range kbit/s

-b 320           = --preset insane          320         320 CBR
-V 0 --vbr-new   = --preset fast extreme    245       220260
-V 0             = --preset extreme         245       220260
-V 1 --vbr-new                              225       200250
-V 1                                        225       200250
-V 2 --vbr-new   = --preset fast standard   190       170210
-V 2             = --preset standard        190       170210
-V 3 --vbr-new                              175       155195
-V 3                                        175       155195
-V 4 --vbr-new   = --preset fast medium     165       145185
-V 4             = --preset medium          165       145185
-V 5 --vbr-new                              130       110150
-V 5                                        130       110150
-V 6 --vbr-new                              115        95135
-V 6                                        115        95135
-V 7 --vbr-new                              100        80120
-V 7                                        100        80120
-V 8 --vbr-new                               85        65105
-V 8                                         85        65105
-V 9 --vbr-new                               65        4585
-V 9                                         65        4585
--abr 56 -mm     = --preset voice            56          56 ABR
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