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Apply deltas to last phase as well.

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Themaister 2012-02-25 16:33:33 +01:00
parent 7c15f5a537
commit bdc8cd1cb1
1 changed files with 15 additions and 4 deletions
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19
audio/sinc.c
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@ -103,7 +103,7 @@ static void init_sinc_table(ssnes_resampler_t *resamp)
// Sinc phases: [..., p + 3, p + 2, p + 1, p + 0, p - 1, p - 2, p - 3, p - 4, ...]
for (int i = 0; i < PHASES; i++)
{
for (int j = 0; j < 2 * SIDELOBES; j++)
for (int j = 0; j < TAPS; j++)
{
double p = (double)i / PHASES;
double sinc_phase = M_PI * (p + (SIDELOBES - 1 - j));
@ -114,12 +114,23 @@ static void init_sinc_table(ssnes_resampler_t *resamp)
// Optimize linear interpolation.
for (int i = 0; i < PHASES - 1; i++)
{
for (int j = 0; j < 2 * SIDELOBES; j++)
for (int j = 0; j < TAPS; j++)
{
resamp->phase_table[i][DELTA_INDEX][j] =
(resamp->phase_table[i + 1][PHASE_INDEX][j] - resamp->phase_table[i][PHASE_INDEX][j]) / SUBPHASES;
}
}
// Interpolation between [PHASES - 1] => [PHASES]
for (int j = 0; j < TAPS; j++)
{
double p = 1.0;
double sinc_phase = M_PI * (p + (SIDELOBES - 1 - j));
double phase = sinc(sinc_phase) * blackman(sinc_phase / SIDELOBES);
float result = (phase - resamp->phase_table[PHASES - 1][PHASE_INDEX][j]) / SUBPHASES;
resamp->phase_table[PHASES - 1][DELTA_INDEX][j] = result;
}
}
ssnes_resampler_t *resampler_new(void)
@ -186,8 +197,8 @@ static void process_sinc(ssnes_resampler_t *resamp, float *out_buffer)
[1] = { .v = sum_r },
};
out_buffer[0] = u[0].f[0] + u[0].f[1] + u[0].f[2] + u[0].f[3];
out_buffer[1] = u[1].f[0] + u[1].f[1] + u[1].f[2] + u[1].f[3];
out_buffer[0] = (u[0].f[0] + u[0].f[1]) + (u[0].f[2] + u[0].f[3]);
out_buffer[1] = (u[1].f[0] + u[1].f[1]) + (u[1].f[2] + u[1].f[3]);
#endif
}
#else // Plain ol' C99