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- #ifndef POLYPHASE_RESAMPLER_H
- #define POLYPHASE_RESAMPLER_H
-
- #include <vector>
-
-
- using uint = unsigned int;
-
- /* This is a polyphase sinc-filtered resampler. It is built for very high
- * quality results, rather than real-time performance.
- *
- * Upsample Downsample
- *
- * p/q = 3/2 p/q = 3/5
- *
- * M-+-+-+-> M-+-+-+->
- * -------------------+ ---------------------+
- * p s * f f f f|f| | p s * f f f f f |
- * | 0 * 0 0 0|0|0 | | 0 * 0 0 0 0|0| |
- * v 0 * 0 0|0|0 0 | v 0 * 0 0 0|0|0 |
- * s * f|f|f f f | s * f f|f|f f |
- * 0 * |0|0 0 0 0 | 0 * 0|0|0 0 0 |
- * --------+=+--------+ 0 * |0|0 0 0 0 |
- * d . d .|d|. d . d ----------+=+--------+
- * d . . . .|d|. . . .
- * q->
- * q-+-+-+->
- *
- * P_f(i,j) = q i mod p + pj
- * P_s(i,j) = floor(q i / p) - j
- * d[i=0..N-1] = sum_{j=0}^{floor((M - 1) / p)} {
- * { f[P_f(i,j)] s[P_s(i,j)], P_f(i,j) < M
- * { 0, P_f(i,j) >= M. }
- */
-
- struct PPhaseResampler {
- void init(const uint srcRate, const uint dstRate);
- void process(const uint inN, const double *in, const uint outN, double *out);
-
- private:
- uint mP, mQ, mM, mL;
- std::vector<double> mF;
- };
-
- #endif /* POLYPHASE_RESAMPLER_H */
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