when an audio program connects to aucat, restore the volume it

had the last time. For instance, this fixes the problem of programs
reopenning the connection to aucat very often and thus resetting
the volume setting all the time.

1 files changed, 52 insertions, 9 deletions

diff --git a/usr.bin/aucat/midi.c b/usr.bin/aucat/midi.c
index 541d314de52..c930e9b73df 100644
--- a/usr.bin/aucat/midi.c
+++ b/usr.bin/aucat/midi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi.c,v 1.6 2009/08/26 08:28:21 ratchov Exp $	*/
+/*	$OpenBSD: midi.c,v 1.7 2009/08/27 06:31:13 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -17,10 +17,8 @@
 /*
  * TODO
  *
- * use abuf->duplex to implement bidirectionnal sockets
- * that don't receive what they send
- *
- * use shadow variables in the midi merger
+ * use shadow variables (to save NRPNs, LSB of controller) 
+ * in the midi merger
  *
  * make output and input identical when only one
  * input is used (fix running status)
@@ -71,6 +69,9 @@
 unsigned voice_len[] = { 3, 3, 3, 3, 2, 2, 3 };
 unsigned common_len[] = { 0, 2, 3, 2, 0, 0, 1, 1 };
 
+/*
+ * send the message stored in of ibuf->mdata to obuf
+ */
 void
 thru_flush(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
 {
@@ -100,6 +101,9 @@ thru_flush(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
 	p->u.thru.owner = ibuf;
 }
 
+/*
+ * send the real-time message (one byte) to obuf, similar to thrui_flush()
+ */
 void
 thru_rt(struct aproc *p, struct abuf *ibuf, struct abuf *obuf, unsigned c)
 {
@@ -118,7 +122,10 @@ thru_rt(struct aproc *p, struct abuf *ibuf, struct abuf *obuf, unsigned c)
 	abuf_wcommit(obuf, 1);
 }
 
-
+/*
+ * parse ibuf contents and store each message into obuf,
+ * use at most ``todo'' bytes (for throttling)
+ */
 void
 thru_bcopy(struct aproc *p, struct abuf *ibuf, struct abuf *obuf, unsigned todo)
 {
@@ -263,6 +270,11 @@ struct aproc_ops thru_ops = {
 	thru_done
 };
 
+/*
+ * call-back invoked periodically to implement throttling at each invocation
+ * gain more ``tickets'' for processing.  If one of the buffer was blocked by
+ * the throttelling mechanism, then run it
+ */
 void
 thru_cb(void *addr)
 {
@@ -293,6 +305,10 @@ thru_new(char *name)
 	return p;
 }
 
+/*
+ * broadcast a message to all output buffers on the behalf of ibuf.
+ * ie. don't sent back the message to the sender
+ */
 void
 ctl_sendmsg(struct aproc *p, struct abuf *ibuf, unsigned char *msg, unsigned len)
 {
@@ -324,6 +340,11 @@ ctl_sendmsg(struct aproc *p, struct abuf *ibuf, unsigned char *msg, unsigned len
 	}
 }
 
+/*
+ * allocate a new slot (ie midi channel), register the given call-back
+ * to be called volume is changed by MIDI. The call-back is invoked at
+ * initialization to restore the saved volume.
+ */
 int
 ctl_slotnew(struct aproc *p, char *who, void (*cb)(void *, unsigned), void *arg)
 {
@@ -373,9 +394,11 @@ ctl_slotnew(struct aproc *p, char *who, void (*cb)(void *, unsigned), void *arg)
 		if (slot->cb == NULL &&
 		    strcmp(slot->name, name) == 0 &&
 		    slot->unit == unit) {
+			DPRINTFN(1, "ctl_newslot: reusing %u\n", i);
 			slot->cb = cb;
 			slot->arg = arg;
-			DPRINTFN(1, "ctl_newslot: reusing %u\n", i);
+			slot->cb(slot->arg, slot->vol);
+			ctl_slotvol(p, i, slot->vol);
 			return i;
 		}
 	}
@@ -400,30 +423,45 @@ ctl_slotnew(struct aproc *p, char *who, void (*cb)(void *, unsigned), void *arg)
 	strlcpy(slot->name, name, CTL_NAMEMAX);
 	slot->serial = p->u.ctl.serial++;
 	slot->unit = unit;
+	slot->vol = MIDI_MAXCTL;
+	DPRINTFN(1, "ctl_newslot: %u overwritten)\n", bestidx);
 	slot->cb = cb;
 	slot->arg = arg;
-	DPRINTFN(1, "ctl_newslot: %u overwritten)\n", bestidx);
+	slot->cb(slot->arg, slot->vol);
+	ctl_slotvol(p, bestidx, slot->vol);
 	return bestidx;
 }
 
+/*
+ * release the given slot
+ */
 void
 ctl_slotdel(struct aproc *p, int index)
 {
 	p->u.ctl.slot[index].cb = NULL;
 }
 
+/*
+ * notifty the mixer that volume changed, called by whom allocad the slot using
+ * ctl_slotnew(). Note: it doesn't make sens to call this from within the
+ * call-back.
+ */
 void
 ctl_slotvol(struct aproc *p, int slot, unsigned vol)
 {
 	unsigned char msg[3];
 
 	DPRINTFN(1, "ctl_slotvol: [%u] -> %u\n", slot, vol);
+	p->u.ctl.slot[slot].vol = vol;
 	msg[0] = MIDI_CTL | slot;
 	msg[1] = MIDI_CTLVOL;
 	msg[2] = vol;
 	ctl_sendmsg(p, NULL, msg, 3);
 }
 
+/*
+ * handle a MIDI event received from ibuf
+ */
 void
 ctl_ev(struct aproc *p, struct abuf *ibuf)
 {
@@ -447,7 +485,8 @@ ctl_ev(struct aproc *p, struct abuf *ibuf)
 		slot = p->u.ctl.slot + chan;
 		if (slot->cb == NULL)
 			return;
-		slot->cb(slot->arg, ibuf->mdata[2]);
+		slot->vol = ibuf->mdata[2];
+		slot->cb(slot->arg, slot->vol);
 		ctl_sendmsg(p, ibuf, ibuf->mdata, ibuf->mlen);
 	}
 }
@@ -518,6 +557,9 @@ ctl_done(struct aproc *p)
 	struct ctl_slot *s;
 
 	for (i = 0, s = p->u.ctl.slot; i < CTL_NSLOT; i++, s++) {
+		/*
+		 * XXX: shouldn't we abord() here ?
+		 */
 		if (s->cb != NULL)
 			DPRINTF("ctl_done: %s%u in use\n", s->name, s->unit);
 	}
@@ -548,6 +590,7 @@ ctl_new(char *name)
 	for (i = 0, s = p->u.ctl.slot; i < CTL_NSLOT; i++, s++) {
 		p->u.ctl.slot[i].unit = i;
 		p->u.ctl.slot[i].cb = NULL;
+		p->u.ctl.slot[i].vol = MIDI_MAXCTL;
 		p->u.ctl.slot[i].serial = p->u.ctl.serial++;
 		strlcpy(p->u.ctl.slot[i].name, "unknown", CTL_NAMEMAX);
 	}