wangjinquan / ciglet

Lightweight signal processing library for audio and speech applications

ciglet

Ciglet is a lightweight C library for digital signal processing, in particular audio and speech processing.

Language: C99

License: BSD

Background

In the past few years I've been writing and maintaining quite a few C-written speech processing projects (e.g. libllsm, libpyin, moresampler), some of which were partially translated from Matlab/Octave-based prototypes. Gradually I ended up having lots of frequent rewrites of C version of Matlab routines such as sum, fir1, conv, interp1, etc. In August 2016 I finally made the move to extract all these repeating patterns and group them into one independent library. Since it would be referred by quite a few projects, the new library is meant to be lightweight, easy to link, and fast, which is why it's named ciglet, an acronym of "C-written sIGnal codeLETs".

Function index

Scalar operations

• random number generation: randu, randn
• miscellaneous: max, min, linterp, fastatan2
• complex arithmetics: c_cplx, c_conj, c_add, c_sub, c_mul, c_div, c_exp, c_abs, c_arg

Vector operations and statistics

• vectorized arithmetics: sumfp, sumsqrfp, maxfp, minfp
• descriptive statistics: meanfp, varfp, medianfp, xcorr, corr, cov
• sorting: selectnth, sort
• peak picking: find_peak, find_valley, find_maxima, find_minima

Numerical routines

fzero, polyval, roots

Basic linear algebra

• products: matmul, mvecmul, dot
• solving a linear system: lu, lusolve
• pivoting: ppivot, permm, permv

Memory (de)allocation

• enumeration: linspace, iota
• 2d array operations: malloc2d, free2d, copy2d, flatten, reshape, transpose

Audio I/O

wavread, wavwrite

General DSP routines

• windows: boxcar, hanning, hamming, mltsine, blackman_harris, nuttall98, blackman
• Fourier transform: fft, ifft, czt, iczt, idft, dct, fftshift
• phase manipulation: wrap, unwrap, phase_diff
• complex number conversion: abscplx, argcplx, polar2real, polar2imag, complete_symm, complete_asymm
• cepstral analysis: rceps, irceps, minphase
• filtering: fir1, conv, filter, filtfilt, moving_avg, moving_rms, medfilt1, kalmanf1d, kalmans1d
• linear prediction: levinson, lpc, flpc, lpgain, lpspec, lpresf
• interpolation: interp1, interp1u, sincinterp1u, interp_in_blank, rresample
• operations on sinusoids: gensin, gensins, safe_aliased_sinc, safe_aliased_dsinc
• miscellaneous: fetch_frame, diff, cumsum, flip ,white_noise, itakura_saito

Audio/speech processing routines

• psychoacoustics: mel2freq, freq2mel, freq2bark, bark2freq, eqloud, melspace
• frequency estimation: ifdetector_estimate, correlogram, invcrgm
• spectrogram and STFT: stft, istft, qifft, spgm2cegm, cegm2spgm
• filterbank analysis: filterbank_spgm, filterbank_spec, be2cc, be2ccgm
• spectral envelope estimation: spec2env
• glottal model: lfmodel_from_rd, lfmodel_spectrum, lfmodel_period

Plotting utilities (Gnuplot interface, unavailable on Windows)

plotopen, plot, imagesc, plotclose