I have briefly tried the "--voice" mode and the "normal" mode when
encoding a purely voice signal (with background noise) at 8kbps, and
have been very impressed with the difference. I would like to compress
the signal more... but 8 is as low as it goes.
The "nomal" mode renders the voice absolutely unintelligible (I assume
the encoder tries too hard to preserve the background).
The "--voice" mode actually seems to reduce the background garbage
(noise) where there is no speech, and to also concentrate on the speech
when it is present.
I have looked at the spectrogram for each, and there is a BIG
difference.
My question (after all this guff) is "does LAME perform any smarts (like
looking for particular frequency domain patterns), and if so, what?"
I have read most of the past articles on "--voice" but they don't tell
me all I wish to know. I am also starting with a 11K/samples per sec
file (mono) and having to up-sample it to 44.1K before I can process it.
Has anyone considered allowing different input sample rates (ie: the
standard 16, 22.05, 24, 32, 48) as well as 44.1 ?
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