Posted by Wes Groleau on 01/19/06 03:07
fred-bloggs wrote:
> --comp should work, but I suspect that Lame calculates a bitrate from the
> required compression ratio:
> b = 1411/comp (1411 is CD bitrate)
> and then chooses the *next* standard bitrate.
> You would have more control if you specify a standard bitrate directly.
Makes sense. But the documentation implied that you when get the
compression you specified or better. Not so.
> You may be thinking of variable bitrate encoding (VBR) where Lame encoder
> reduces the bitrate when encoding silence or simple tones.
Yes. The documentation also implied that VBR was used unless
explicitly set otherwise. Or maybe I interpreted it wrongly.
-b 32 --resample 11.025 --highpass 5
gave me the same size ratio as
--comp 21 and --comp 25
which was approximately 22.07 and would make the
whole book approximately 900 MB. (I'm aiming for
a single CD.) I left out the -a because I had already
used 'sox' to average the channels into mono.
(Also, for what it's worth, using -a and --comp
at the same time crashes this version of 'lame')
I am going to try -b 24 and -b 16.
I am also going to try other sampling rates.
Are you sure about highpass ? I would expect lowpass.
(If you can call 5Khz "low")
--
Wes Groleau
Nobody believes a theoretical analysis -- except the guy who did it.
Everybody believes an experimental analysis -- except the guy who
did it.
-- Unknown
[Back to original message]
|