Commit af29e778 authored by Stefan Sauer's avatar Stefan Sauer

monoscope: rework the scaling code

The running average was wrong and the resulting scaling factor was only held in
place using the CLAMP. In addtion we are now convering quickly to volume
changes.

FInally now with this change, we can change the resolution defines and
everythign adjusts.
parent 5e68873d
......@@ -99,7 +99,7 @@ monoscope_update (struct monoscope_state *stateptr, gint16 data[convolver_big])
int hh1 = hh - 1;
guint32 *loc;
int factor;
double factor;
int max = 1;
short *thisEq = stateptr->copyEq;
......@@ -108,21 +108,26 @@ monoscope_update (struct monoscope_state *stateptr, gint16 data[convolver_big])
memset (stateptr->display, 0, scope_width * scope_height * sizeof (guint32));
for (i = 0; i < convolver_small; i++) {
avg = thisEq[i] + (stateptr->avgEq[i] >> 1);
avg = (thisEq[i] + stateptr->avgEq[i]) >> 1;
stateptr->avgEq[i] = avg;
avg = abs (avg);
max = MAX (max, avg);
}
stateptr->avgMax += max - (stateptr->avgMax >> 8);
if (stateptr->avgMax < max)
stateptr->avgMax = max; /* Avoid overflow */
factor = 0x7fffffff / stateptr->avgMax;
/* Keep the scaling sensible. */
factor = CLAMP (factor, (1 << 8), (1 << 18));
/* running average, 4 values is enough to make it follow volume changes
* if this value is too large it will converge slowly
*/
stateptr->avgMax += (max / 4) - (stateptr->avgMax / 4);
/* input is +/- avgMax, output is +/- hh */
if (stateptr->avgMax) {
factor = (gdouble) hh / stateptr->avgMax;
} else {
factor = 1.0;
}
for (i = 0; i < scope_width; i++) {
/* scale 16bit signed audio values to scope_height */
foo = stateptr->avgEq[i] * factor;
foo >>= 18;
foo = CLAMP (foo, -hh1, hh1);
bar = (i + ((foo + hh) * scope_width));
if ((bar > 0) && (bar < (scope_width * scope_height))) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment