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LAME's resampling leaves something to be desired
post Oct 15 2012, 20:16
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http://shibatch.sourceforge.net/ is a good resampler. It beats lame in quality every time. Here is an example:

Yes I retested Baba O'Reilly and it sounded noticibly better with ssrc.

I did

FLAC 88.2 > lame.exe -S --noreplaygain -b 32 --lowpass 10 --resample 24 - %d
FLAC 88.2 > WAV > ssrc.exe --rate 24000 --bits 16 > lame.exe -S --noreplaygain -b 32 --lowpass 10 - %d

in ABX and got 14/16 (0.2% prob of guessing). I was hearing a whole different type of artifact that I have either never heard before or just never listened for before. I was 5/2 up when I started listening to the bass drum and it just sounded fuller, warmer and louder in ssrc. It was then that I noticed that there was a shrill artifact at about 9 kHz at the same time as the drum beat in question. It was obvious in both files, but louder in the LAME version. Up until now the bass drum "masked" it, "masking" is seriously like an aural illusion, that bass drum sounded fine before I heard the shrill in one and then I heard it in the other, I was dumbfounded! After that I just listened for that beep and the louder one was LAME. LAME should really look into their resampler, a lot of people are downsamping high res FLACs these days!

I feel like I did the first time I discovered that I had a blind spot on my retina that I could "discover" at will with carefully engineered designs and some ordinated displacement of said designs. Discovering the nature of my aural blind spots first hand I can only describe myself as feeling enlightened!

Maybe that shrill noise is due to a crappy lpf in LAME?


ssrc is foss, maybe the LAME devs would like to copy some of it's code?
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post Oct 17 2012, 11:23
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Spectrogram aside (which is notable), I also preferred down-sampling using FB2K's SSRC prior to encoding low-bitrate MP3's (80kbps stereo and 48kbps mono).

My own ABX is not very conclusive either, so call it paranoia smile.gif . Yet, I think it is possible to locate where LAME's internal re-sampling falls short in certain lower bit-rate areas.

OP: My advice is: instead of directly shoveling the (assumed) WAV directly to LAME at bitrates lower than 96kbps, just continue to use SSRC pre-processing function inside FB2K like you have been doing. I see no harm in that. Is it overkill? Maybe... or not? smile.gif

"Something bothering you, Mister Spock?"
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