/*
================
dmaHD_ResampleSfx
resample / decimate to the current source rate
================
*/
void dmaHD_ResampleSfx( sfx_t *sfx, int inrate, int inwidth, byte *data, qboolean compressed)
{
short* buffer;
int (*dmaHD_GetSampleRaw)(int, int, byte*) =
(inwidth == 2) ? dmaHD_GetSampleRaw_16bit : dmaHD_GetSampleRaw_8bit;
float stepscale, idx_smp, sample, bsample;
float lp_inva, lp_a, hp_a, lp_data, lp_last, hp_data, hp_last, hp_lastsample;
int outcount, idx_hp, idx_lp;
stepscale = (float)inrate/(float)dma.speed;
outcount = (int)((float)sfx->soundLength / stepscale);
// Create secondary buffer for bass sound while performing lowpass filter;
buffer = dmaHD_AllocateSoundBuffer(outcount * 2);
// Check if this is a weapon sound.
sfx->weaponsound = (memcmp(sfx->soundName, "sound/weapons/", 14) == 0) ? qtrue : qfalse;
// Get first sample from sound effect.
idx_smp = -stepscale;
sample = dmaHD_GetInterpolatedSample(idx_smp, sfx->soundLength, data, dmaHD_GetSampleRaw);
bsample = dmaHD_GetNoInterpolationSample(idx_smp, sfx->soundLength, data, dmaHD_GetSampleRaw);
idx_smp += stepscale;
// Set up high pass filter.
idx_hp = 0;
hp_last = sample;
hp_lastsample = sample;
//buffer[idx_hp++] = sample;
hp_a = 0.95f;
// Set up Low pass filter.
idx_lp = outcount;
lp_last = bsample;
lp_a = 0.03f;
lp_inva = (1 - lp_a);
// Now do actual high/low pass on actual data.
for (;idx_hp < outcount; idx_hp++)
{
sample = dmaHD_GetInterpolatedSample(idx_smp, sfx->soundLength, data, dmaHD_GetSampleRaw);
bsample = dmaHD_GetNoInterpolationSample(idx_smp, sfx->soundLength, data, dmaHD_GetSampleRaw);
idx_smp += stepscale;
// High pass.
hp_data = hp_a * (hp_last + sample - hp_lastsample);
buffer[idx_hp] = SMPCLAMP(hp_data);
hp_last = hp_data;
hp_lastsample = sample;
// Low pass.
lp_data = lp_a * (float)bsample + lp_inva * lp_last;
//if ((idx_hp % 2) != 0) buffer[idx_lp++] = SMPCLAMP((lp_last + lp_data) / 2.0f);
buffer[idx_lp++] = SMPCLAMP(lp_data);
lp_last = lp_data;
}
sfx->soundData = (sndBuffer*)buffer;
sfx->soundLength = outcount;
}
// t must be a float between 0 and samples
static int dmaHD_GetInterpolatedSampleCubic(float t, int samples, byte *data,
int (*dmaHD_GetSampleRaw)(int, int, byte*))
{
int x, val;
t = dmaHD_NormalizeSamplePosition(t, samples);
// Get points
x = (int)t;
// Interpolate
val = (int)dmaHD_InterpolateCubic(
(float)dmaHD_GetSampleRaw(x - 1, samples, data),
(float)dmaHD_GetSampleRaw(x, samples, data),
(float)dmaHD_GetSampleRaw(x + 1, samples, data),
(float)dmaHD_GetSampleRaw(x + 2, samples, data), FLOAT_DECIMAL_PART(t));
// Clamp
return SMPCLAMP(val);
}