compress: Adjust forumla for clipping

Use (3 * old + min) / 4 instead of (old + min) / 2 as the new gain
if clipping occures.

diff --git a/compress.c b/compress.c
index b4e4c40a7a1663c95b38cdbada69715c519da5dc..3e605d0e091a2bf4ffcfb99f21adf19550188036 100644 (file)
--- a/compress.c
+++ b/compress.c
@@ -67,8 +67,8 @@ static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
                                >> gain_shift;
                        if (unlikely(adjusted_sample > 32767)) {
                                adjusted_sample = 32767;
                                >> gain_shift;
                        if (unlikely(adjusted_sample > 32767)) {
                                adjusted_sample = 32767;

-                               pcd->current_gain = (pcd->current_gain +
-                                       (1 << pcd->conf->inertia_arg)) / 2;
+                               pcd->current_gain = (3 * pcd->current_gain +
+                                       (1 << pcd->conf->inertia_arg)) / 4;

                                pcd->peak = 0;
                        } else
                                if (adjusted_sample > pcd->peak)
                                pcd->peak = 0;
                        } else
                                if (adjusted_sample > pcd->peak)


@@ -78,8 +78,8 @@ static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
                                >> gain_shift);
                        if (unlikely(adjusted_sample < -32768)) {
                                adjusted_sample = -32768;
                                >> gain_shift);
                        if (unlikely(adjusted_sample < -32768)) {
                                adjusted_sample = -32768;

-                               pcd->current_gain = (pcd->current_gain +
-                                       (1 << pcd->conf->inertia_arg)) / 2;
+                               pcd->current_gain = (3 * pcd->current_gain +
+                                       (1 << pcd->conf->inertia_arg)) / 4;

                                pcd->peak = 0;
                        } else
                                if (-adjusted_sample > pcd->peak)
                                pcd->peak = 0;
                        } else
                                if (-adjusted_sample > pcd->peak)