LPANAL

[GENERIC-FUNCTION]


om4csound
Function Reference
ARGUMENTS:
  - sound a sound  
  - outfile name of the output file [default = "mazinga"]
&optional
 
  - alternate_storage asks lpanal to write a file with filter poles values rather than the usual filter coefficient files  
  - sample_rate sampling rate of the audio input file. This will over-ride the srate of the soundfile header, which otherwise applies  
  - channel channel number sought. The default is 1  
  - begin beginning time (in seconds) of the audio segment to be analyzed  
  - duration duration (in seconds) of the audio segment to be analyzed  
  - npoles number of poles for analysis. The default is 34, the maximum 50  
  - hopsize hop size (in samples) between frames of analysis  
  - string text for the comments field of the lpfile header  
  - mincps lowest frequency (in Hz) of pitch tracking  
  - maxcps highest frequency (in Hz) of pitch tracking  

Description:

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.



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