moved delay to own files

decode.c

@@ -9,6 +9,7 @@
 #include "mmap_file.h"
 #include "pcm.h"
 #include "ddc.h"
+#include "delay.h"
 
 float lerp(float a, float b, float x)
 {
@@ -31,36 +32,6 @@ float limit(float min, float max, float x)
 	return tmp > max ? max : tmp;
 }
 
-typedef struct {
-	float *s;
-	int last;
-	int len;
-} delay_t;
-
-float do_delay(delay_t *d, float input)
-{
-	d->s[d->last] = input;
-	d->last = (d->last + 1) < d->len ? d->last + 1 : 0;
-	return d->s[d->last];
-}
-
-delay_t *alloc_delay(int samples)
-{
-	int len = samples + 1;
-	delay_t *d = malloc(sizeof(delay_t));
-	d->s = malloc(sizeof(float) * len);
-	d->last = 0;
-	d->len = len;
-	for (int i = 0; i < len; i++)
-		d->s[i] = 0.0;
-	return d;
-}
-void free_delay(delay_t *delay)
-{
-	free(delay->s);
-	free(delay);
-}
-
 typedef struct {
 	uint32_t ChunkID;
 	uint32_t ChunkSize;