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Posted by fred-bloggs on 10/16/50 11:37
Wes Groleau <groleau+news@freeshell.org> wrote in news:2hkzf.9138$US3.844
@trnddc04:
>
>
> fred-bloggs wrote:
>
>> -s refers to the source sampling frequency,
>> -resample sets the *output* sampling frequency.
>>
>> -a downmixes stereo to mono.
>>
>> So try
>> -b 32 -a --resample 11.025 --highpass 5
>>
>> (the highpass frequency should always be less than half the sampling
>> frequency or you will get aliasing noise)
>
> Ah, thanks. I didn't see resample in the LOONG man page.
> But it did allege that --comp N would cause it to pick
> reasonable parameters to achieve the requested ratio.
> Apparently not.
--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.
>
> I will give those numbers a try.
>
> I thought that in MP3 the output bit rate was not
> directly tied to the size because some kinds of sounds
> could be compressed more than others.
> ??
The *definition* of bit rate is
bitrate = 8 x Size / time
You may be thinking of variable bitrate encoding (VBR) where Lame encoder
reduces the bitrate when encoding silence or simple tones.
--
fred
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