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       cvanal - Converts a soundfile into a single Fourier transform frame. .


       Impulse Response Fourier Analysis for convolve operator


           csound -U cvanal [flags] infilename outfilename

           cvanal [flags] infilename outfilename


       cvanal -- converts a soundfile into a single Fourier transform frame.
       The output file can be used by the convolve operator to perform Fast
       Convolution between an input signal and the original impulse response.
       Analysis is conditioned by the flags below. A space is optional between
       the flag and its argument.

       -s rate -- 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. If omitted, the default is to
       process all channels. If a value is given, only the selected channel
       will be processed.

       -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.


           cvanal asound cvfile

       will analyze the soundfile "asound" to produce the file "cvfile" for
       the use with convolve.

       To use data that is not already contained in a soundfile, a soundfile
       converter that accepts text files may be used to create a standard
       audio file, e.g., the .DAT format for SOX. This is useful for
       implementing FIR filters.

       The output file has a special convolve header, containing details of
       the source audio file. The analysis data is stored as “float”, in
       rectangular (real/imaginary) form.

           The analysis file is not system independent! Ensure that the
           original impulse recording/data is retained. If/when required, the
           analysis file can be recreated.


       Author: Greg Sullivan

       Based on algorithm given in Elements Of Computer Music, by F. Richard


       Barry Vercoe
       MIT Media Lab


       Dan Ellis
       MIT Media Lab,