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Added rms, maxpp and avgpp methods.

This commit is contained in:
Jack Jansen 1992-08-24 14:36:31 +00:00
parent 8eace20f68
commit e1b4d7ce14
1 changed files with 146 additions and 0 deletions
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146
Modules/audioop.c
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@ -28,6 +28,8 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#define signed
#endif
#include <math.h>
#include "allobjects.h"
#include "modsupport.h"
@ -239,6 +241,147 @@ audioop_avg(self, args)
return newintobject(val);
}
static object *
audioop_rms(self, args)
object *self;
object *args;
{
signed char *cp;
int len, size, val;
int i;
float sum_squares = 0.0;
if ( !getargs(args, "(s#i)", &cp, &len, &size) )
return 0;
if ( size != 1 && size != 2 && size != 4 ) {
err_setstr(AudioopError, "Size should be 1, 2 or 4");
return 0;
}
for ( i=0; i<len; i+= size) {
if ( size == 1 ) val = (int)*CHARP(cp, i);
else if ( size == 2 ) val = (int)*SHORTP(cp, i);
else if ( size == 4 ) val = (int)*LONGP(cp, i);
sum_squares += (float)val*(float)val;
}
if ( len == 0 )
val = 0;
else
val = (int)sqrt(sum_squares / (float)(len/size));
return newintobject(val);
}
static object *
audioop_avgpp(self, args)
object *self;
object *args;
{
signed char *cp;
int len, size, val, prevval, prevextremevalid = 0, prevextreme;
int i;
float avg = 0.0;
int diff, prevdiff, extremediff, nextreme = 0;
if ( !getargs(args, "(s#i)", &cp, &len, &size) )
return 0;
if ( size != 1 && size != 2 && size != 4 ) {
err_setstr(AudioopError, "Size should be 1, 2 or 4");
return 0;
}
/* Compute first delta value ahead. Also automatically makes us
** skip the first extreme value
*/
if ( size == 1 ) prevval = (int)*CHARP(cp, 0);
else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0);
else if ( size == 4 ) prevval = (int)*LONGP(cp, 0);
if ( size == 1 ) val = (int)*CHARP(cp, size);
else if ( size == 2 ) val = (int)*SHORTP(cp, size);
else if ( size == 4 ) val = (int)*LONGP(cp, size);
prevdiff = val - prevval;
for ( i=size; i<len; i+= size) {
if ( size == 1 ) val = (int)*CHARP(cp, i);
else if ( size == 2 ) val = (int)*SHORTP(cp, i);
else if ( size == 4 ) val = (int)*LONGP(cp, i);
diff = val - prevval;
if ( diff*prevdiff < 0 ) {
/* Derivative changed sign. Compute difference to last extreme
** value and remember.
*/
if ( prevextremevalid ) {
extremediff = prevval - prevextreme;
if ( extremediff < 0 )
extremediff = -extremediff;
avg += extremediff;
nextreme++;
}
prevextremevalid = 1;
prevextreme = prevval;
}
prevval = val;
if ( diff != 0 )
prevdiff = diff;
}
if ( nextreme == 0 )
val = 0;
else
val = (int)(avg / (float)nextreme);
return newintobject(val);
}
static object *
audioop_maxpp(self, args)
object *self;
object *args;
{
signed char *cp;
int len, size, val, prevval, prevextremevalid = 0, prevextreme;
int i;
int max = 0;
int diff, prevdiff, extremediff;
if ( !getargs(args, "(s#i)", &cp, &len, &size) )
return 0;
if ( size != 1 && size != 2 && size != 4 ) {
err_setstr(AudioopError, "Size should be 1, 2 or 4");
return 0;
}
/* Compute first delta value ahead. Also automatically makes us
** skip the first extreme value
*/
if ( size == 1 ) prevval = (int)*CHARP(cp, 0);
else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0);
else if ( size == 4 ) prevval = (int)*LONGP(cp, 0);
if ( size == 1 ) val = (int)*CHARP(cp, size);
else if ( size == 2 ) val = (int)*SHORTP(cp, size);
else if ( size == 4 ) val = (int)*LONGP(cp, size);
prevdiff = val - prevval;
for ( i=size; i<len; i+= size) {
if ( size == 1 ) val = (int)*CHARP(cp, i);
else if ( size == 2 ) val = (int)*SHORTP(cp, i);
else if ( size == 4 ) val = (int)*LONGP(cp, i);
diff = val - prevval;
if ( diff*prevdiff < 0 ) {
/* Derivative changed sign. Compute difference to last extreme
** value and remember.
*/
if ( prevextremevalid ) {
extremediff = prevval - prevextreme;
if ( extremediff < 0 )
extremediff = -extremediff;
if ( extremediff > max )
max = extremediff;
}
prevextremevalid = 1;
prevextreme = prevval;
}
prevval = val;
if ( diff != 0 )
prevdiff = diff;
}
return newintobject(max);
}
static object *
audioop_cross(self, args)
object *self;
@ -869,6 +1012,9 @@ audioop_adpcm2lin(self, args)
static struct methodlist audioop_methods[] = {
{ "max", audioop_max },
{ "avg", audioop_avg },
{ "maxpp", audioop_maxpp },
{ "avgpp", audioop_avgpp },
{ "rms", audioop_rms },
{ "cross", audioop_cross },
{ "mul", audioop_mul },
{ "add", audioop_add },