aubuf: allow zero as min_sz/wish_sz

The aubuf collects data until wish size is reached before returning real data
when the read function is called. A wish size of zero means, that data is
returned as soon there was pushed some.

On first read old data is dropped in order to reduce the latency. This is done
only if min_sz (wish_sz internally) was set to a positive value.

src/aubuf/ajb.c

@@ -244,7 +244,9 @@ void ajb_calc(struct ajb *ajb, const struct auframe *af, size_t cur_sz)
 
 	ptime = (uint32_t) (af->sampc * AUDIO_TIMEBASE / (af->srate * af->ch));
 	bufmin = MAX(bufmin, ptime * 2 / 3);
-	bufmin = MAX(bufmin, bufwish - ptime / 3);
+	if (bufwish >= ptime)
+		bufmin = MAX(bufmin, bufwish - ptime / 3);
+
 	bufmax = MAX(bufmax, bufmin + 7 * ptime / 6);
 
 	/* reset time base if a frame is missing */

src/aubuf/aubuf.c

@@ -23,7 +23,7 @@ struct aubuf {
 	size_t cur_sz;
 	size_t max_sz;
 	size_t fill_sz;         /**< To fill size                            */
-	size_t pkt_sz;        /**< Packet size                             */
+	size_t pkt_sz;          /**< Packet size                             */
 	bool started;
 	uint64_t ts;
 
@@ -118,7 +118,7 @@ int aubuf_alloc(struct aubuf **abp, size_t min_sz, size_t max_sz)
 	struct aubuf *ab;
 	int err;
 
-	if (!abp || !min_sz)
+	if (!abp)
 		return EINVAL;
 
 	ab = mem_zalloc(sizeof(*ab), aubuf_destructor);
@@ -178,7 +178,7 @@ void aubuf_set_silence(struct aubuf *ab, double silence)
  */
 int aubuf_resize(struct aubuf *ab, size_t min_sz, size_t max_sz)
 {
-	if (!ab || !min_sz)
+	if (!ab)
 		return EINVAL;
 
 	mtx_lock(ab->lock);
@@ -240,11 +240,9 @@ int aubuf_append_auframe(struct aubuf *ab, struct mbuf *mb,
 
 	if (ab->max_sz && ab->cur_sz > ab->max_sz) {
 #if AUBUF_DEBUG
-		if (ab->started) {
-			++ab->stats.or;
-			(void)re_printf("aubuf: %p overrun (cur=%zu/%zu)\n",
-					ab, ab->cur_sz, ab->max_sz);
-		}
+		++ab->stats.or;
+		(void)re_printf("aubuf: %p overrun (cur=%zu/%zu)\n",
+				ab, ab->cur_sz, ab->max_sz);
 #endif
 		f = list_ledata(ab->afl.head);
 		if (f) {