Initialize jitter buffer delay with half of its size

Also add a function to reset jitter buffer

src/libjitter/jitter.c

@@ -30,16 +30,26 @@
 int jitter_create(jitter_t *jitter, int length)
 {
 	memset(jitter, 0, sizeof(*jitter));
-	jitter->spl = calloc(length * sizeof(sample_t), 1);
+	jitter->spl = malloc(length * sizeof(sample_t));
 	if (!jitter->spl) {
 		PDEBUG(DDSP, DEBUG_ERROR, "No memory for jitter buffer.\n");
 		return -ENOMEM;
 	}
 	jitter->len = length;
 
+	jitter_reset(jitter);
+
 	return 0;
 }
 
+void jitter_reset(jitter_t *jitter)
+{
+	memset(jitter->spl, 0, jitter->len * sizeof(sample_t));
+
+	/* put write pointer ahead by half of the buffer length */
+	jitter->inptr = jitter->len / 2;
+}
+
 void jitter_destroy(jitter_t *jitter)
 {
 	if (jitter->spl) {

src/libjitter/jitter.h

@@ -6,6 +6,7 @@ typedef struct jitter {
 } jitter_t;
 
 int jitter_create(jitter_t *jitter, int length);
+void jitter_reset(jitter_t *jitter);
 void jitter_destroy(jitter_t *jitter);
 void jitter_save(jitter_t *jb, sample_t *samples, int length);
 void jitter_load(jitter_t *jb, sample_t *samples, int length);