- if (x < -32768) {
- return x;
- } else if (x > 32767) {
- return 32767;
- } else {
- return short(x);
- }
-}
-
-static float a1, a2, b0, b1, b2;
-static float d0, d1;
-
-static void filter_init(float cutoff_radians)
-{
- float resonance = 1.0f / sqrt(2.0f);
- float sn, cs;
- sincosf(cutoff_radians, &sn, &cs);
-
- float alpha = float(sn / (2 * resonance));
-
- // coefficients for lowpass filter
- float a0 = 1 + alpha;
- b0 = (1 - cs) * 0.5f;
- b1 = 1 - cs;
- b2 = b0;
- a1 = -2 * cs;
- a2 = 1 - alpha;
-
- float invA0 = 1.0f / a0;
- b0 *= invA0;
- b1 *= invA0;
- b2 *= invA0;
- a1 *= invA0;
- a2 *= invA0;
-
- // reset filter delays
- d0 = d1 = 0.0f;
-}
-
-static float filter_update(float in)
-{
- float out = b0*in + d0;
- d0 = b1 * in - a1 * out + d1;
- d1 = b2 * in - a2 * out;
- return out;
-}
-
-int main(int argc, char **argv)
-{
- std::vector<short> pcm;
-
- while (!feof(stdin)) {
- short buf[BUFSIZE];
- ssize_t ret = fread(buf, sizeof(short), BUFSIZE, stdin);
- if (ret >= 0) {
- pcm.insert(pcm.end(), buf, buf + ret);
- }
- }
-