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       lpanal - Performs both linear predictive and pitch-tracking analysis on
       a soundfile. .


       Linear predictive analysis for the Csound Linear Predictive Coding
       (LPC) Resynthesis opcodes.


           csound -U lpanal [flags] infilename outfilename

           lpanal [flags] infilename outfilename


       lpanal performs both lpc and pitch-tracking analysis on a soundfile to
       produce a time-ordered sequence of frames of control information
       suitable for Csound resynthesis. Analysis is conditioned by the control
       flags below. A space is optional between the flag and its value.

       -a -- [alternate storage] asks lpanal to write a file with filter poles
       values rather than the usual filter coefficient files. When lpread /
       lpreson are used with pole files, automatic stabilization is performed
       and the filter should not get wild. (This is the default in the Windows
       GUI) - Changed by Marc Resibois.

       -s srate -- sampling rate of the audio input file. This will over-ride
       the srate of the soundfile header, which otherwise applies. If neither
       is present, the default is 10000.

       -c channel -- channel number sought. The default is 1.

       -b begin -- beginning time (in seconds) of the audio segment to be
       analyzed. The default is 0.0

       -d duration -- duration (in seconds) of the audio segment to be
       analyzed. The default of 0.0 means to the end of the file.

       -p npoles -- number of poles for analysis. The default is 34, the
       maximum 50.

       -h hopsize -- hop size (in samples) between frames of analysis. This
       determines the number of frames per second (srate / hopsize) in the
       output control file. The analysis framesize is hopsize * 2 samples. The
       default is 200, the maximum 500.

       -C string -- text for the comments field of the lpfile header. The
       default is the null string.

       -P mincps -- lowest frequency (in Hz) of pitch tracking. -P0 means no
       pitch tracking.

       -Q maxcps -- highest frequency (in Hz) of pitch tracking. The narrower
       the pitch range, the more accurate the pitch estimate. The defaults are
       -P70, -Q200.

       -v verbosity -- level of terminal information during analysis.

       ·   0 = none

       ·   1 = verbose

       ·   2 = debug

       The default is 0.


           lpanal -a -p26 -d2.5 -P100 -Q400 audiofile.test lpfil22

       will analyze the first 2.5 seconds of file "audiofile.test", producing
       srate/200 frames per second, each containing 26-pole filter
       coefficients and a pitch estimate between 100 and 400 Hertz. Stabilized
       (-a) output will be placed in "lpfil22" in the current directory.

   File Format
       Output is a file comprised of an identifiable header plus a set of
       frames of floating point analysis data. Each frame contains four values
       of pitch and gain information, followed by npoles filter coefficients.
       The file is readable by Csound´s lpread.

       lpanal is an extensive modification of Paul Lanksy´s lpc analysis


       Barry Vercoe
       MIT Media Lab


       Dan Ellis
       MIT Media Lab,