ref: c972f90f8d7f2e4ff8d2c865ef7b2f897a408de7
dir: /FEATURES.in/
The current release handles the following audio file formats: (:table border=0:) (:cellnr:) * Raw files in various binary formats * Raw textual data * Amiga 8svx files * Apple/SGI AIFF files * SUN .au files ** PCM, u-law, A-law ** G7xx ADPCM files (read only) ** mutant DEC .au files ** NeXT .snd files * AVR files * CDDA (Compact Disc Digital Audio format) * CVS and VMS files (continuous variable slope) * Grandstream ring-tone files * GSM files * HTK files * LPC-10 files * Macintosh HCOM files * Amiga MAUD files * AMR-WB & AMR-NB (with optional libamrwb & libamrnb libraries) * MP2/MP3 (with optional libmad, libtwolame and libmp3lame libraries) * Opus files (read only; with optional Opus libraries) (:cell:) * Ogg Vorbis files (with optional Ogg Vorbis libraries) * FLAC files (with optional libFLAC) * IRCAM SoundFile files * NIST SPHERE files * Turtle beach SampleVision files * Sounder & Soundtool (DOS) files * Yamaha TX-16W sampler files * SoundBlaster .VOC files * Dialogic/OKI ADPCM files (.VOX) * Microsoft .WAV files ** PCM, floating point ** u-law, A-law, MS ADPCM, IMA (DMI) ADPCM ** GSM ** RIFX (big endian) * WavPack files (with optional libwavpack library) * Psion (palmtop) A-law WVE files and Record voice notes * Maxis XA Audio files ** EA ADPCM (read support only, for now) * Pseudo formats that allow direct playing/recording from most audio devices * The "null" pseudo-file that reads and writes from/to nowhere (:tableend:) The audio effects/tools included in this release are as follows: * Tone/filter effects ** allpass: RBJ all-pass biquad IIR filter ** bandpass: RBJ band-pass biquad IIR filter ** bandreject: RBJ band-reject biquad IIR filter ** band: SPKit resonator band-pass IIR filter ** bass: Tone control: RBJ shelving biquad IIR filter ** equalizer: RBJ peaking equalisation biquad IIR filter ** firfit+: FFT convolution FIR filter using given freq. response (W.I.P.) ** highpass: High-pass filter: Single pole or RBJ biquad IIR ** hilbert: Hilbert transform filter (90 degrees phase shift) ** lowpass: Low-pass filter: single pole or RBJ biquad IIR ** sinc: Sinc-windowed low/high-pass/band-pass/reject FIR ** treble: Tone control: RBJ shelving biquad IIR filter * Production effects ** chorus: Make a single instrument sound like many ** delay: Delay one or more channels ** echo: Add an echo ** echos: Add a sequence of echos ** flanger: Stereo flanger ** overdrive: Non-linear distortion ** phaser: Phase shifter ** repeat: Loop the audio a number of times ** reverb: Add reverberation ** reverse: Reverse the audio (to search for Satanic messages ;-) ** tremolo: Sinusoidal volume modulation * Volume/level effects ** compand: Signal level compression/expansion/limiting ** contrast: Phase contrast volume enhancement ** dcshift: Apply or remove DC offset ** fade: Apply a fade-in and/or fade-out to the audio ** gain: Apply gain or attenuation; normalise/equalise/balance/headroom ** loudness: Gain control with ISO 226 loudness compensation ** mcompand: Multi-band compression/expansion/limiting ** norm: Normalise to 0dB (or other) ** vol: Adjust audio volume * Editing effects ** pad: Pad (usually) the ends of the audio with silence ** silence: Remove portions of silence from the audio ** splice: Perform the equivalent of a cross-faded tape splice ** trim: Cuts portions out of the audio ** vad: Voice activity detector * Mixing effects ** channels: Auto mix or duplicate to change number of channels ** divide+: Divide sample values by those in the 1st channel (W.I.P.) ** remix: Produce arbitrarily mixed output channels ** swap: Swap pairs of channels * Pitch/tempo effects ** bend: Bend pitch at given times without changing tempo ** pitch: Adjust pitch (= key) without changing tempo ** speed: Adjust pitch & tempo together ** stretch: Adjust tempo without changing pitch (simple alg.) ** tempo: Adjust tempo without changing pitch (WSOLA alg.) * Mastering effects ** dither: Add dither noise to increase quantisation SNR ** rate: Change audio sampling rate * Specialised filters/mixers ** deemph: ISO 908 CD de-emphasis (shelving) IIR filter ** earwax: Process CD audio to best effect for headphone use ** noisered: Filter out noise from the audio ** oops: Out Of Phase Stereo (or `Karaoke') effect ** riaa: RIAA vinyl playback equalisation * Analysis `effects' ** noiseprof: Produce a DFT profile of the audio (use with noisered) ** spectrogram: graph signal level vs. frequency & time (needs `libpng') ** stat: Enumerate audio peak & RMS levels, approx. freq., etc. ** stats: Multichannel aware `stat' * Miscellaneous effects ** ladspa: Apply LADSPA plug-in effects e.g. CMT (Computer Music Toolkit) ** synth: Synthesise/modulate audio tones or noise signals ** newfile: Create a new output file when an effects chain ends. ** restart: Restart 1st effects chain when multiple chains exist. * Low-level signal processing effects ** biquad: 2nd-order IIR filter using externally provided coefficients ** downsample: Reduce sample rate by discarding samples ** fir: FFT convolution FIR filter using externally provided coefficients ** upsample: Increase sample rate by zero stuffing + Experimental or incomplete effect; may change in future. Multiple audio files can be combined (and then further processed with effects) using any one of the following combiner methods: * concatenate * mix * merge: E.g. two mono files to one stereo file * sequence: For playing multiple audio files/streams