ref: 3d08e8fa1aa19fd6c4c57be6da1459546cbedb14
parent: 57ec44a15f73b3bfc072469b84649b8a54eb1462
author: robs <robs>
date: Wed Oct 22 17:27:44 EDT 2008
doc/comment tweaks
--- a/src/rate.c
+++ b/src/rate.c
@@ -248,7 +248,7 @@
work = calloc(work_len, sizeof(*work));
for (i = 0; i < *len; ++i) work[i] = (*h)[i];
- lsx_safe_rdft(work_len, 1, work); /* Cepstrum: */
+ lsx_safe_rdft(work_len, 1, work); /* Cepstral: */
work[0] = log(fabs(work[0])), work[1] = log(fabs(work[1]));
for (i = 2; i < work_len; i += 2) {work[i] = log(sqrt(sqr(work[i]) + sqr(work[i + 1])));
@@ -261,8 +261,10 @@
work[i + work_len / 2] = 0;
}
lsx_safe_rdft(work_len, 1, work);
- /* Some filters require phase unwrapping here, but ours seem not to. */
+ /* Some filters require phase unwrapping at this point. Ours give dis-
+ * continuities only in the stop band, so no need to unwrap in this case. */
+
for (i = 2; i < work_len; i += 2) /* Interpolate between linear & min phase */
work[i + 1] = phase * M_PI * .5 * i + (1 - phase) * work[i + 1];
@@ -275,8 +277,8 @@
lsx_safe_rdft(work_len, -1, work);
for (i = 0; i < work_len; ++i) work[i] *= 2. / work_len;
- for (i = 1; i < work_len; ++i) if (work[i] > work[peak]) /* Find peak. */
- peak = i; /* N.B. peak > 0 */
+ for (i = 1; i < work_len; ++i) if (work[i] > work[peak]) /* Find peak pos. */
+ peak = i; /* N.B. peak val. > 0 */
if (phase == 0)
begin = 0;