I want to convert a CD to mp3 files with a good quality and a reasonable
file size. I played around with the VBR setting and found that using the
follwing switches (lame 3.60):
-h -k -lowpass 999 -b 32 -B 224 -v -V 3
results in mp3 files in stereo with a means bitrate of about 182 kbps. I
can imagin that this should give a higher quality then CBR at 192 kbps
because difficult parts gets 224 kbps.
But reading the file usage I found:
*NOTE* No psy-model is perfect, so there can often be distortion which
is audible even though the psy-model claims it is not! Thus using a
small minimum bitrate can result in some aggressive compression and
audible distortion even with -V 0. Thus using -V 0 does not sound
better than a fixed 256kbs encoding. For example: suppose in the 1kHz
frequency band the psy-model claims 20db of distortion will not be
detectable by the human ear, so LAME VBR-0 will compress that
frequency band as much as possible and introduce at most 20db of
distortion. Using a fixed 256kbit framesize, LAME could end up
introducing only 2db of distortion. If the psy-model was correct,
they will both sound the same. If the psy-model was wrong, the VBR-0
result can sound worse.
I read that as: Quality is unsure in VBR compared to CBR
Is it a better choice to encode the CD on CBR 192 kbps?
I know listening is a good probe but this takes a lot of time.
BTW I 've never seen a histogram in VBR mode, with the windows version,
without using the the --nohist option.
Marc
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