move mix/sub underrun/overrun handling code and data in the

generic abuf structure, so it can reused. Required for an audio
server. No behaviour change.

ok jakemsr

3 files changed, 72 insertions, 59 deletions

diff --git a/usr.bin/aucat/abuf.c b/usr.bin/aucat/abuf.c
index a3143d9ac18..a6f2ebc1bc9 100644
--- a/usr.bin/aucat/abuf.c
+++ b/usr.bin/aucat/abuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: abuf.c,v 1.3 2008/08/14 09:39:16 ratchov Exp $	*/
+/*	$OpenBSD: abuf.c,v 1.4 2008/08/14 09:44:15 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -36,6 +36,7 @@
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "conf.h"
 #include "aproc.h"
@@ -60,6 +61,8 @@ abuf_new(unsigned nfr, unsigned bpf)
 	buf->len = len;
 	buf->used = 0;
 	buf->start = 0;
+	buf->silence = 0;
+	buf->drop = 0;
 	buf->rproc = NULL;
 	buf->wproc = NULL;
 	buf->data = (unsigned char *)buf + sizeof(*buf);
@@ -151,23 +154,73 @@ abuf_wgetblk(struct abuf *buf, unsigned *rsize, unsigned ofs)
 }
 
 /*
+ * flush buffer either by dropping samples or by calling the aproc
+ * call-back to consume data. Return 0 if blocked, 1 otherwise
+ */
+int
+abuf_flush_do(struct abuf *buf)
+{
+	struct aproc *p;
+	unsigned count;
+
+	if (buf->drop > 0) {
+		count = buf->drop;
+		if (count > buf->used)
+			count = buf->used;
+		abuf_rdiscard(buf, count);
+		buf->drop -= count;
+		DPRINTF("abuf_flush_do: drop = %u\n", buf->drop);
+	} else {
+		p = buf->rproc;
+		if (p == NULL || !p->ops->in(p, buf))
+			return 0;
+	}
+	return 1;
+}
+
+/*
  * Notify the read end of the buffer that there is input available
  * and that data can be processed again.
  */
 void
 abuf_flush(struct abuf *buf)
 {
-	struct aproc *p = buf->rproc;
-
 	for (;;) {
 		if (!ABUF_ROK(buf))
 			break;
-		if (p == NULL || !p->ops->in(p, buf))
+		if (!abuf_flush_do(buf))
 			break;
 	}
 }
 
 /*
+ * fill the buffer either by generating silence or by calling the aproc
+ * call-back to provide data. Return 0 if blocked, 1 otherwise
+ */
+int
+abuf_fill_do(struct abuf *buf)
+{
+	struct aproc *p;
+	unsigned char *data;
+	unsigned count;
+
+	if (buf->silence > 0) {
+		data = abuf_wgetblk(buf, &count, 0);
+		if (count >= buf->silence)
+			count = buf->silence;
+		memset(data, 0, count);
+		abuf_wcommit(buf, count);
+		buf->silence -= count;
+		DPRINTF("abuf_fill_do: silence = %u\n", buf->silence);
+	} else {
+		p = buf->wproc;
+		if (p == NULL || !p->ops->out(p, buf))
+			return 0;
+	}
+	return 1;
+}
+
+/*
  * Notify the write end of the buffer that there is room and data can be
  * written again. This routine can only be called from the out()
  * call-back of the reader.
@@ -178,12 +231,10 @@ abuf_flush(struct abuf *buf)
 void
 abuf_fill(struct abuf *buf)
 {
-	struct aproc *p = buf->wproc;
-
 	for (;;) {
 		if (!ABUF_WOK(buf))
 			break;
-		if (p == NULL || !p->ops->out(p, buf))
+		if (!abuf_fill_do(buf))
 			break;
 	}
 }
@@ -211,12 +262,10 @@ abuf_run(struct abuf *buf)
 			abuf_del(buf);
 			return;
 		}
-		if (ABUF_WOK(buf) && canfill && buf->wproc) {
-			p = buf->wproc;
-			canfill = p->ops->out(p, buf);
+		if (ABUF_WOK(buf) && canfill) {
+			canfill = abuf_fill_do(buf);
 		} else if (ABUF_ROK(buf) && canflush) {
-			p = buf->rproc;
-			canflush = p->ops->in(p, buf);
+			canflush = abuf_flush_do(buf);
 		} else
 			break; /* can neither read nor write */
 	}
diff --git a/usr.bin/aucat/abuf.h b/usr.bin/aucat/abuf.h
index d7345e0dcd5..860a6c5be6b 100644
--- a/usr.bin/aucat/abuf.h
+++ b/usr.bin/aucat/abuf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: abuf.h,v 1.5 2008/08/14 09:39:16 ratchov Exp $	*/
+/*	$OpenBSD: abuf.h,v 1.6 2008/08/14 09:44:15 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -34,9 +34,7 @@ struct abuf {
 	int mixvol;		/* input gain */
 	unsigned mixdone;	/* input of mixer */
 	unsigned mixtodo;	/* output of mixer */
-	unsigned mixdrop;	/* frames mix_in() will discard */
 	unsigned subdone;	/* output if sub */
-	unsigned subdrop;	/* silence frames sub_out() will insert */ 
 #define XRUN_IGNORE	0	/* on xrun silently insert/discard samples */
 #define XRUN_SYNC	1	/* catchup to sync to the mix/sub */
 #define XRUN_ERROR	2	/* xruns are errors, eof/hup buffer */
@@ -51,9 +49,11 @@ struct abuf {
 	unsigned start;		/* offset where data starts */
 	unsigned used;		/* valid data */
 	unsigned len;		/* size of the ring */
+	unsigned silence;	/* silence to insert on next write */
+	unsigned drop;		/* frames to drop on next read */
 	struct aproc *rproc;	/* reader */
 	struct aproc *wproc;	/* writer */
-	unsigned char *data;	/* pointer to actual data (immediately following) */
+	unsigned char *data;	/* actual data (immediately following) */
 };
 
 /*
diff --git a/usr.bin/aucat/aproc.c b/usr.bin/aucat/aproc.c
index b938bb6907d..b98959069b8 100644
--- a/usr.bin/aucat/aproc.c
+++ b/usr.bin/aucat/aproc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aproc.c,v 1.6 2008/08/14 09:39:16 ratchov Exp $	*/
+/*	$OpenBSD: aproc.c,v 1.7 2008/08/14 09:44:15 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -320,25 +320,10 @@ int
 mix_in(struct aproc *p, struct abuf *ibuf)
 {
 	struct abuf *i, *inext, *obuf = LIST_FIRST(&p->obuflist);
-	unsigned icount, ocount;
+	unsigned ocount;
 
-	DPRINTFN(4, "mix_in: used = %u, done = %u, zero = %u\n",
+	DPRINTFN(4, "mix_in: used = %u, done = %u, todo = %u\n",
 	    ibuf->used, ibuf->mixdone, obuf->mixtodo);
-
-	/* 
-	 * discard data already sent as silence
-	 */
-	if (ibuf->mixdrop > 0) {
-		icount = ibuf->mixdrop;
-		if (icount > ibuf->used)
-			icount = ibuf->used;
-		ibuf->used -= icount;
-		ibuf->start += icount;
-		if (ibuf->start >= ibuf->len)
-			ibuf->start -= ibuf->len;
-		ibuf->mixdrop -= icount;
-		DPRINTF("mix_in: catched xruns, drop = %u\n", ibuf->mixdrop);
-	}
 		
 	if (ibuf->mixdone >= obuf->mixtodo)
 		return 0;
@@ -394,9 +379,8 @@ mix_out(struct aproc *p, struct abuf *obuf)
 				drop = obuf->mixtodo;
 				i->mixdone += drop;
 				if (i->xrun == XRUN_SYNC)
-					i->mixdrop += drop;
-				DPRINTF("mix_out: xrun, drop = %u\n", 
-				    i->mixdrop);
+					i->drop += drop;
+				DPRINTF("mix_out: drop = %u\n", i->drop);
 			}
 		} else
 			mix_badd(i, obuf);
@@ -458,7 +442,6 @@ void
 mix_newin(struct aproc *p, struct abuf *ibuf)
 {
 	ibuf->mixdone = 0;
-	ibuf->mixdrop = 0;
 	ibuf->mixvol = ADATA_UNIT;
 	ibuf->xrun = XRUN_IGNORE;
 }
@@ -539,10 +522,9 @@ sub_in(struct aproc *p, struct abuf *ibuf)
 				}
 				drop = ibuf->used;
 				if (i->xrun == XRUN_SYNC)
-					i->subdrop += drop;
+					i->silence += drop;
 				i->subdone += drop;
-				DPRINTF("sub_in: xrun, drop =  %u\n",
-				    i->subdrop);
+				DPRINTF("sub_in: silence =  %u\n", i->silence);
 			}
 		} else {
 			sub_bcopy(ibuf, i);
@@ -565,25 +547,8 @@ sub_out(struct aproc *p, struct abuf *obuf)
 {
 	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);
 	struct abuf *i, *inext;
-	unsigned char *odata;
-	unsigned ocount;
 	unsigned done;
 
-	/*
-	 * generate silence for dropped samples
-	 */
-	while (obuf->subdrop > 0) {
-		odata = abuf_wgetblk(obuf, &ocount, 0);
-		if (ocount >= obuf->subdrop)
-			ocount = obuf->subdrop;
-		if (ocount == 0)
-			break;
-		memset(odata, 0, ocount);
-		obuf->used += ocount;
-		obuf->subdrop -= ocount;
-		DPRINTF("sub_out: catch, drop = %u\n", obuf->subdrop);
-	}
-
 	if (obuf->subdone >= ibuf->used)
 		return 0;
 
@@ -653,7 +618,6 @@ void
 sub_newout(struct aproc *p, struct abuf *obuf)
 {
 	obuf->subdone = 0;
-	obuf->subdrop = 0;
 	obuf->xrun = XRUN_IGNORE;
 }