Matiq
7dcbcf49b4
- Cooley-Tukey radix-2 FFT (forward + inverse with /N normalization) - WOLA STFT/ISTFT with Hann window (nfft=2048, hop=512) - WAV16 read + WAV24 write (fixed aliasing bug in read) - Fixed in-place processing bug (separate input/output buffers) - Biquad filter (peak/shelf/reject) - Peak detector skeleton - MS encode/decode (M8 stereo) - Harness: WAV16 → STFT → WAV24 passthrough verified non-zero output Verified: burst500.wav passthrough produces output RMS=0.0678
38 lines
1.1 KiB
C++
38 lines
1.1 KiB
C++
#include "fft_plan.hpp"
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#include <cstring>
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namespace fft {
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void init_plan(FFTPlan* plan, uint32_t log2N) {
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plan->log2N = log2N;
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plan->N = 1U << log2N;
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plan->stage_count = 0;
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plan->bit_reverse = 0;
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plan->xor_mask = 0;
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uint32_t n = plan->N;
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while (n > 1) {
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if (n % 8 == 0 && log2N >= 3) {
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plan->stages[plan->stage_count].radix = 8;
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plan->stages[plan->stage_count].group_size = n / 8;
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plan->stages[plan->stage_count].groups = 8;
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plan->stage_count++;
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n /= 8;
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} else if (n % 4 == 0 && log2N >= 2) {
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plan->stages[plan->stage_count].radix = 4;
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plan->stages[plan->stage_count].group_size = n / 4;
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plan->stages[plan->stage_count].groups = 4;
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plan->stage_count++;
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n /= 4;
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} else if (n % 2 == 0) {
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plan->stages[plan->stage_count].radix = 2;
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plan->stages[plan->stage_count].group_size = n / 2;
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plan->stages[plan->stage_count].groups = 2;
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plan->stage_count++;
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n /= 2;
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}
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}
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}
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}
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