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lame: lowpass filter disabled for -V0 but enabled for -b 320 -- why?
banan
post Mar 3 2013, 22:27
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Does anyone know the reason behind disabling the lowpass filter with -V0 but enabling it with -b 320? I mean, if -V0 can handle the high frequencies, then why -b 320 cannot? Hydrogenaudio recommends either -V0 or -b 320 for maximum quality, and so far I thought the major difference between them is the size of the file...
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saratoga
post Mar 4 2013, 00:17
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My random guess is that the low pass was disabled in v0 to encourage the encoder to use a higher bit rate, but that is just a guess.
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Kohlrabi
post Mar 4 2013, 06:10
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QUOTE (banan @ Mar 3 2013, 22:27) *
Hydrogenaudio recommends either -V0 or -b 320 for maximum quality, and so far I thought the major difference between them is the size of the file...
The major difference is that CBR is pointless to use in lossy encoding, for it defeats the main purpose of lossy encoding, and VBR isn't. If you are looking at very high bitrate solutions already, take a look at halb27's lame3100i encoder for improved VBR performance.


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Ceterum censeo Masterdiskem esse delendam.
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halb27
post Mar 4 2013, 09:31
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With current VBR sfb21 content (the stuff above 16 kHz) is encoded with lower accuracy compared to previous versions. I guess this allowed the Lame dev(s) to skip the lowpass altogether. It's a matter of taste what behavior to prefer, and it doesn't play a major role anyway.

This post has been edited by halb27: Mar 4 2013, 09:31


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lame3100m -V1 --insane-factor 0.75
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banan
post Mar 4 2013, 10:50
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Kohlrabi, saying that -b 320 is pointless and offering an improvement over -V0 in the same post is as confusing as removing the lowpass filter from one option an leaving it in another.

halb27, I guess what I'm trying to understand is what behavior Lame devs preferred. The inconsistency between the default settings leaves me a bit puzzled. What about lame3100i? Is the filter on or off by default?

This post has been edited by banan: Mar 4 2013, 10:52
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halb27
post Mar 4 2013, 11:44
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With 3100i I use a lowpass for any -Vn+ setting by default.

This post has been edited by halb27: Mar 4 2013, 11:45


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lame3100m -V1 --insane-factor 0.75
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banan
post Mar 4 2013, 12:42
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I see... So the choice you made for 3100i default settings implies that you recommend to explicitly enable the filter with --lowpass if -V0 option is used, unless personal taste dictates otherwise.
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db1989
post Mar 4 2013, 16:49
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Which, in itself, is just his personal taste.
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Kohlrabi
post Mar 4 2013, 17:00
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QUOTE (banan @ Mar 4 2013, 10:50) *
Kohlrabi, saying that -b 320 is pointless and offering an improvement over -V0 in the same post is as confusing as removing the lowpass filter from one option an leaving it in another.
My recommending -V0+ does not change the fact that CBR is pointless*.

*except with broken/old decoders or for very specific streaming situations where ABR does not work

This post has been edited by Kohlrabi: Mar 4 2013, 17:01


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