.TH RESAMPLE 1 "5 Jan 2006" "CCRMA".SH NAMEresample \- resample a 16-bit mono or stereo sound file by an arbitrary factor.SH SYNOPSIS\fBresample\fR [-by factor][-to newSrate][-f filterFile][-n][-l][-trace][-version]inputFile[outputFile].SH DESCRIPTIONThe \fBresample\fR program takes a 16-bit mono or stereo sound fileand performs bandlimited interpolation to produce an output sound filehave a desired new sampling rate.  The output file is in the sameformat as the input..SH OPTIONS.IP \fB\-toSrate\fRThis option or "-byFactor" is required.  Specify new sampling rate insamples per second.  The conversion factor is implied and will be setto the new sampling rate divided by the sampling rate of the inputsoundfile..IP \fB\-byFactor\fRSpecify conversion factor.  This option or "-toSrate" is required.The conversion factor is the amount by which the sampling rate ischanged.  If the sampling rate of the input signal is Srate1, then thesampling rate of the output is factor*Srate1.  For example, a factorof 2.0 increases the sampling rate by a factor of 2, giving twice asmany samples in the output signal as in the input.  The fractionalpart of the conversion factor is accurate to 15 bits.  This issufficiently accurate that humans should not be able to hear any errorwhatsoever in the pitch of resampled sounds..IP \fB\-filterFile\fRChange the resampling filter from its default.  Such a filter file canbe designed by the \fBwindowfilter (1)\fR program (included with the\fBresample\fR distribution).  The preloaded filter file requires anoversampling factor of at least 20% to avoid aliasing (in other words,its "transition band" as a lowpass filter is at least 20% of theuseable frequency range in the sampled signal); the stop-bandattenuation is approximately 80 dB..IP \fB\-noFilterInterp\fRBy default, the resampling filter table is linearly interpolated toprovide high audio quality at arbitrary sampling-rate conversionfactors.  This option turns off filter interpolation, thus cutting thenumber of multiply-adds in half in the inner loop (for most conversionfactors)..IP \fB\-linearInterpolation\fRSelect plain linear interpolation for resampling (which meansresampling filter table is not used at all). This option is very fast,but the output quality is poor unless the signal is already heavilyoversampled.  Do not confuse linear interpolation of the signal withlinear interpolation of the resampling-filter-table which iscontrolled by the "noFilterInterp" option..IP \fB\-terse\fRDisable informational printout..IP \fB\-version\fRPrint program version..SH EXAMPLETo convert the sampling rate from 48 kHz (used by DAT machines) to44.1 kHz (the standard sampling rate for Compact Discs), the commandline would look something like	resample -to 44100 dat.snd cd.sndor	resample -by 0.91875 dat.snd cd.sndAny reasonable sampling rate can be converted to any other.  (Notethat, in this example, if you have obtained a direct-digital transferfrom DAT or CD, you probably have some pre-emphasis filtering whichshould be canceled using a digital filter. See README.deemph in the\fBresample\fR release for further information).SH REFERENCESSource code and further documentation may be found at the DigitalAudio Resampling Home Page (DARHP) located at	http://ccrma.stanford.edu/~jos/resample/.SH HISTORYThe first version of this software was written by Julius O. Smith III<jos /at/ ccrma /dot/ stanford /dot/ edu> at CCRMA<http://ccrma.stanford.edu> in 1981.  It was called SRCONV and waswritten in SAIL for PDP-10 compatible machines (see the DARHP for thatcode).  The algorithm was first published inSmith, Julius O. and Phil Gossett. ``A Flexible Sampling-RateConversion Method,'' Proceedings (2): 19.4.1-19.4.4, IEEE Conferenceon Acoustics, Speech, and Signal Processing, San Diego, March 1984.An expanded tutorial based on this paper is available at the DARHP.Circa 1988, the SRCONV program was translated from SAIL to C byChristopher Lee Fraley working with Roger Dannenberg at CMU.Since then, the C version has been maintained by jos.Sndlib support was added 6/99 by John Gibson <jgg9c@virginia.edu>.The \fBresample\fR program is free software distributed in accordancewith the Lesser GNU Public License (LGPL).  There is NO warranty; noteven for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.