Version 3.9:
 * support full covariance for 'gmmp' command.
 * add -B, -c1 and -c2 option to 'gmmp' command to specify block size and structure of covariance matrix.
 * change temporary file path for csh.
 * bug fixes.

Version 3.8:
 * add 'c2ndps' command for transform from cepstrum to negative derivative of phrase spectrum.
 * add 'mgclsp2sp' command for transform from LSP to spectrum.
 * add 'ndps2c' command for transform from negative derivative of phrase spectrum to cepstrum.
 * add 'wavjoin' command to save stereo wav file.
 * add 'wavsplit' command to load stereo wav file.
 * add -V option to 'dtw' command for loading DTW results.
 * add -e option to calculate inverse matrix stably for 'delta' and 'vc' commands.
 * support MAP estimation in 'gmm' command.
 * replace -i option to -q option for 'lsp2lpc,' 'lspcheck,' and 'mgclsp2mgc' commands.
 * change -c option of 'mlsacheck' command.
 * update swipe and hts_engine API.
 * bug fixes.

Version 3.7:
 * add 'vc' command to perform GMM-based voice conversion.
 * add 'lsp2sp' command to transform LSP coefficients to spectrum.
 * add -R option to 'mlsacheck' command to specify threshold value.
 * add -f option to 'gmmp' command to specify full covariance matrix.
 * add -M, -c1 and -c2 option to 'gmm' command to specify block size and structure of covariance matrix.
 * add -n option to 'delta' command to specify order of regression polynomial.
 * add -magic and -MAGIC option to 'rmse' command to delete and substitute magic number.
 * add -n and -t option to 'rmse' command to specify order and number of vector, respectively.
 * add -POWX, -LOGX option, and new constant (semitone) to 'sopr' command.
 * add -l option to 'decimate' and 'interpolate' command to specify length of vector.
 * add -g and -G option to 'lspcheck' command to check value of gain.
 * add -L option to 'lspcheck' command to specify log gain.
 * add -n option to 'mgc2mgclsp' command to specify split number of unit circle.
 * add -p and -d to 'mgc2mgclsp' command to specify maximum number and end condition of interpolation.
 * add -x 16, 22, 24 and 48 option of 'glogsp' and 'grlogsp' command to specify more x-axis scales.
 * add filter coefficients for 7:4 down-sampling, 3:5 and 7:8 up-sampling.
 * unify option to specify log gain into -L option.
 * fix -c option of 'mlsacheck' command to specify the type of modification of filter coefficients.
 * bug fixes.

Version 3.6:
 * add -o option to 'minmax' command to output maximum, minimum or both values.
 * add -o 4 option to 'vstat' command to output medians.
 * add options to 'vopr' command to deal with relational operators, arithmetic/geometric mean, and ceiling/flooring.
 * add -T option to 'smcep' command to specifiy emphasized frequency.
 * add -E option to 'gcep', 'mcep', 'mgcep', 'spec', 'smcep' and 'uels' command to specify floor in dB.
 * add -F option to 'gmm' command to read initial GMM parameter file.
 * add -L and -R option to 'wav2raw' command to deal with stereo wav file.
 * add 'gseries', 'ifftr', 'mlsacheck', 'symmetrize' and 'transpose' command.
 * change -f option of 'lbg' command into -F option.
 * unify option to specify sampling frequency into -s option.
 * fix 'x2x', 'dmp' and 'fd' command to read format string without space in front of '%'.
 * bug fixes.

Version 3.5:
 * add 'dtw' command.
 * add 'mfcc' command.
 * add 'mgc2mgclsp' and 'mgclsp2mgc' command.
 * add two pitch extraction algorithm, 'RAPT' and 'SWIPE' to 'pitch' command.
 * add -R and -M option to 'delta' command, to skip the magic number during the calculation.
 * unify data type for sampling frequency into float in kHz.
 * fix options of 'psgr' and 'grlogsp' command to draw more large graph.
 * fix 'wav2raw' to deal with IEEE float format.
 * bug fixes.

Version 3.4.1:
 * add 'idct' command.
 * remove all input/output data type except float from 'frame', 'snr', 'us16', and 'uscd' command.
 * add input/output data type to many commands.
 * show number of byte for all input/output data type in 'x2x' command.
 * rename 'pcap' command to 'pcas' command.
 * add new constant (octave and cent) to 'sopr' command.
 * bug fixes.

Version 3.4:
 * add magic and MAGIC option to delete and substitute magic number to 'sopr' command.
 * add flooring and clipping option to 'sopr' command.
 * add clipping switch to 'x2x' command.
 * add i3, I3, le, LE, and de option to 'x2x' command.
 * add new paper size (A0, A1, A2, B0, B1, B2, B3) to 'psgr' command.
 * add option for scaling factor to 'fig', 'fdrw', 'glogsp', 'grlogsp', and 'gwave' command.
 * add option to select type of exception procedure to 'lbg' command.
 * add option to specify random seed for centroid update to 'lbg' command.
 * add option to specify minimum number of training vectors for each cell to 'lbg' command.
 * add option to specify maximum number of iteration for centroid update to 'lbg' command.
 * add output format for confidence interval via t-dist. to 'vstat' command.
 * add output format for squared format to 'spec' and 'mgc2sp' command.
 * add floating-point support of frame period to 'train' command.
 * add option to 'gmm' command, to specify random seed for initialization of GMM using LBG algorithm.
 * add full convariance switch to 'gmm' command. 
 * add i and i3 (int and 3 byte int) option to 'swab' command.
 * add 'wav2raw' command.
 * bug fixes.

Version 3.3:
 * add 'pca', 'pcap', and 'raw2wav' commands.
 * add FFT switch to 'dct' command.
 * add transpose filter to 'glsadf' command.
 * add inverse filter to 'glsadf', 'lmsadf', and 'mglsadf' commands.
 * add flooring value for GMM weight to 'gmm' command.
 * add LOG2 and POW2 option to 'sopr' command.
 * add option to extend the distance between two consecutive LSPs to 'lspcheck' command.
 * remove 'iglsadf' and 'imglsadf' commands.
 * bug fixes.

Version 3.2:
 * released under the New and Simplified BSD license.
 * add 'gmm', 'delta', and 'dct' commands.
 * Command options are rearranged for improving consistency among related commands, e.g., mgcep, mglsa, etc.
 * support Windows (except 'xgr').
 * bug fixes.

Version 3.1:
 * change from K&R to ANSI C.
 * add several commands
 * release a Reference Manual written in English, and abandon Japanese manuals and web pages
 * bug fixes.
