:: >
:: > Question: When fs_in/fs_out is not representable by a:b with little a and b,
:: > what do you like best:
:: >
:: > [_] Lame rounds fs_in in a way, so fs_in/fs_out is representable by little a:b
:: > [_] Lame have a function to resample exactly any ratio
:: > [_] both, selectable
::
:: LAME is going to only work with integer samplerates. MP3 output must
:: always be an integer samplerate. If you want to encode
:: from non-integer samplerate source, resample first.
::
Input is a 57:10.00 WAV file with 34301.0 Hz sample frequency (470 MByte).
What should be IYHO the output?
a) Resample 9:7 and got a 57:10.10 MP3 file with 44.1 kHz with 30 ppm
pitch error
+ faster (factor of 2)
o little pitch error
- timing error
+ excellent side slope rejection is no problem
+ you need no fractional fs, because the precission is restricted
by the maximum possible a:b ratio (for instance a,b <= 441)
+ often rounds rounded values to the correct values (see below)
b) Resample 44100:34301 and got a 57:10.00 MP3 file with 44.1 kHz
with exact pitch
+ slower (nearly doubles the computation time)
+ no pitch error
+ no timing error
- for good side slope rejection (>90 dB) you need something between 128
and 256 tables
- this routine makes exactly what you are requesting:
fs_in = 33333, fs_out = 50000:
This method really resamples by 50000:33333 = 1.500015...:1, not 3:2.
c) Both should be possible.
I only need the input: a), b) or c).
--
Mit freundlichen Grüßen
Frank Klemm
eMail | [EMAIL PROTECTED] home: [EMAIL PROTECTED]
phone | +49 (3641) 64-2721 home: +49 (3641) 390545
sMail | R.-Breitscheid-Str. 43, 07747 Jena, Germany
--
MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
