FFT-based EQ.
in RTcmix/insts/jg/SPECTACLE2
SPECTEQ2(outsk, insk, dur, AMP, fftsize, windowsize, WINDOWTABLE, overlap, EQTABLE[, MINFREQ, MAXFREQ, BYPASS, inputchan, PAN])
CAPITALIZED parameters are pfield-enabled for table or dynamic control (see the maketable or makeconnection scorefile commands). Parameters after the [bracket] are optional and default to 0 unless otherwise noted.
| Param Field | Parameter | Units | Dynamic | Optional | Notes |
|---|---|---|---|---|---|
| p0 | output start time | seconds | no | no | |
| p1 | input start time | seconds | no | no | |
| p2 | duration | seconds | no | no | |
| p3 | amplitude multiplier | relative multiplier of input signal | yes | no | |
| p4 | FFT length | samples, power of 2, | no | no | usually 1024 |
| p5 | window length | samples, power of 2 | no | no | usually FFT length * 2 |
| p6 | window table | reference to pfield table-handle | yes | no | use zero for internally generated Hamming window |
| p7 | overlap (FFT window overlap) | positive power of 2: 1: no overlap, 2: hopsize=FFTlen/2, 4: hopsize=FFTlen/4, etc. | no | no | 2 or 4 is usually fine; 1 is fluttery; higher overlaps use more CPU |
| p8 | EQ table (i.e., amplitude scaling of each band) | dB (use reference to pfield table-handle) | yes | no | 0 dB means no change, +dB boost, -dB cut |
| p9 | minimum frequency | Hz | yes | yes | default: 0 Hz |
| p10 | maximum frequency | Hz | yes | yes | default: Nyquist |
| p11 | bypass | 0: bypass off, 1: bypass on | yes | yes | default: 0 |
| p12 | input channel | - | no | yes | default: 0 |
| p13 | pan | 0-1 stereo; 0.5 is middle | yes | yes | default: 0 |
Parameters labled as Dynamic can receive dynamic updates from a table or real-time control source.
Author: John Gibson, 6/12/05
SPECTEQ2 is an evolution of the earlier SPECTEQ instrument. It can do very specific filtering jobs, operating directly on the FFT analysis of a signal spectrum.
SPECTEQ2 is very similar in design to the SPECTACLE2 instrument. You may wish to consult the SPECTACLE2 Usage Notes for additional information.
As in SPECTACLE2, it is possible to update the EQ table (p8, “EQTABLE”) dynamically using the modtable(table, “draw”, …) scorefile command.
Output begins after a brief period of time during which internal buffers are filling. This time is the duration corresponding to the following number of sample frames: window length - (fft length / overlap).
Parameters p9 (“MINFREQ”) and p10 (“MAXFREQ”) operate in a similar way to the range parameters in SPECTACLE2.
SPECTEQ2 can produce either mono or stereo output.
There are no sample scorefiles.
CONVOLVE1, LPCPLAY, PVOC, SPECTACLE, SPECTACLE2, SPECTEQ, TVSPECTACLE, VOCODE2, VOCODE3, VOCODESYNTH