#ifdef IIR#define _ output += p->coefs[j] * p->previous_errors[p->pos + j] \                  - p->coefs[N + j] * p->previous_outputs[p->pos + j], ++j;#else#define _ d -= p->coefs[j] * p->previous_errors[p->pos + j], ++j;#endifstatic int NAME(sox_effect_t * effp, const sox_sample_t * ibuf,    sox_sample_t * obuf, size_t * isamp, size_t * osamp){  priv_t * p = (priv_t *)effp->priv;  size_t len = *isamp = *osamp = min(*isamp, *osamp);   while (len--) {    if (p->auto_detect) {      p->history = (p->history << 1) +          !!(*ibuf & (((unsigned)-1) >> p->prec));      if (p->history && p->dither_off) {        p->dither_off = sox_false;        lsx_debug("flow %" PRIuPTR ": on  @ %" PRIu64, effp->flow, p->num_output);      } else if (!p->history && !p->dither_off) {        p->dither_off = sox_true;        memset(p->previous_errors, 0, sizeof(p->previous_errors));        memset(p->previous_outputs, 0, sizeof(p->previous_outputs));        lsx_debug("flow %" PRIuPTR ": off @ %" PRIu64, effp->flow, p->num_output);      }    }     if (!p->dither_off) {      int32_t r1 = RANQD1 >> p->prec, r2 = RANQD1 >> p->prec; /* Defer add! */#ifdef IIR      double d1, d, output = 0;#else      double d1, d = *ibuf++;#endif       int i, j = 0;      CONVOLVE      assert(j == N);      p->pos = p->pos? p->pos - 1 : p->pos - 1 + N;#ifdef IIR      d = *ibuf++ - output;      p->previous_outputs[p->pos + N] = p->previous_outputs[p->pos] = output;#endif      d1 = (d + r1 + r2) / (1 << (32 - p->prec));      i = d1 < 0? d1 - .5 : d1 + .5;      p->previous_errors[p->pos + N] = p->previous_errors[p->pos] =          (double)i * (1 << (32 - p->prec)) - d;      if (i < (-1 << (p->prec-1)))        ++effp->clips, *obuf = SOX_SAMPLE_MIN;      else if (i > (int)SOX_INT_MAX(p->prec))        ++effp->clips, *obuf = SOX_INT_MAX(p->prec) << (32 - p->prec);      else *obuf = i << (32 - p->prec);      ++obuf;    }    else      *obuf++ = *ibuf++;    ++p->num_output;  }  return SOX_SUCCESS;}#undef CONVOLVE#undef _#undef NAME#undef N