add a writable ``appbufsz'' field to the sa_par structure, containing

the program-part of the buffer size, ie the part that is subject to
underruns. Useful for apps like cdio(1) that don't have their own
rings, or to apps that have a minimum ring size constraint. Setting
the ``bufsz'' parameter becomes deprecated.
ok jakemsr

6 files changed, 66 insertions, 47 deletions

diff --git a/lib/libsndio/aucat.c b/lib/libsndio/aucat.c
index d3add816a06..2f373c8815f 100644
--- a/lib/libsndio/aucat.c
+++ b/lib/libsndio/aucat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aucat.c,v 1.4 2008/11/17 07:04:13 ratchov Exp $	*/
+/*	$OpenBSD: aucat.c,v 1.5 2008/12/17 07:19:27 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -326,7 +326,7 @@ aucat_setpar(struct sio_hdl *sh, struct sio_par *par)
 	hdl->wmsg.u.par.le = par->le;
 	hdl->wmsg.u.par.msb = par->msb;
 	hdl->wmsg.u.par.rate = par->rate;
-	hdl->wmsg.u.par.bufsz = par->bufsz;
+	hdl->wmsg.u.par.appbufsz = par->appbufsz;
 	hdl->wmsg.u.par.xrun = par->xrun;
 	hdl->wmsg.u.par.mode = hdl->sa.mode;
 	if (hdl->sa.mode & SIO_REC)
@@ -364,6 +364,7 @@ aucat_getpar(struct sio_hdl *sh, struct sio_par *par)
 	par->msb = hdl->rmsg.u.par.msb;
 	par->rate = hdl->rmsg.u.par.rate;
 	par->bufsz = hdl->rmsg.u.par.bufsz;
+	par->appbufsz = hdl->rmsg.u.par.appbufsz;
 	par->xrun = hdl->rmsg.u.par.xrun;
 	par->round = hdl->rmsg.u.par.round;
 	if (hdl->sa.mode & SIO_PLAY)
diff --git a/lib/libsndio/shlib_version b/lib/libsndio/shlib_version
index 3f0196ebf4a..83a67c373cc 100644
--- a/lib/libsndio/shlib_version
+++ b/lib/libsndio/shlib_version
@@ -1,2 +1,2 @@
 major=3
-minor=1
+minor=2
diff --git a/lib/libsndio/sio_open.3 b/lib/libsndio/sio_open.3
index c194efa58d6..df0c0edf603 100644
--- a/lib/libsndio/sio_open.3
+++ b/lib/libsndio/sio_open.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: sio_open.3,v 1.8 2008/11/17 07:49:48 jmc Exp $
+.\" $OpenBSD: sio_open.3,v 1.9 2008/12/17 07:19:27 ratchov Exp $
 .\"
 .\" Copyright (c) 2007 Alexandre Ratchov <alex@caoua.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 17 2008 $
+.Dd $Mdocdate: December 17 2008 $
 .Dt SIO_OPEN 3
 .Os
 .Sh NAME
@@ -149,27 +149,28 @@ handle.
 Audio streams always use linear interleaved encoding.
 The set of parameters of the stream that can be controlled
 is given by the following structure:
-.Bd -literal -offset -indent
+.Bd -literal
 struct sio_par {
-	unsigned bits;	/* bits per sample */
-	unsigned bps;	/* bytes per sample */
-	unsigned sig;	/* 1 = signed, 0 = unsigned */
-	unsigned le;	/* 1 = LE, 0 = BE byte order */
-	unsigned msb;	/* 1 = MSB, 0 = LSB aligned */
-	unsigned rchan;	/* number channels for recording */
-	unsigned pchan;	/* number channels for playback */
-	unsigned rate;	/* frames per second */
-	unsigned bufsz;	/* frames in the stream buffer */
-	unsigned round;	/* optimal buffer size divisor */
+	unsigned bits;		/* bits per sample */
+	unsigned bps;		/* bytes per sample */
+	unsigned sig;		/* 1 = signed, 0 = unsigned */
+	unsigned le;		/* 1 = LE, 0 = BE byte order */
+	unsigned msb;		/* 1 = MSB, 0 = LSB aligned */
+	unsigned rchan;		/* number channels for recording */
+	unsigned pchan;		/* number channels for playback */
+	unsigned rate;		/* frames per second */
+	unsigned appbufsz;	/* minimum buffer size without xruns */
+	unsigned bufsz;		/* end-to-end buffer size (read-only) */
+	unsigned round;		/* optimal buffer size divisor */
 #define SIO_IGNORE	0	/* pause during xrun */
-#define SIO_SYNC		1	/* resync after xrun */
+#define SIO_SYNC	1	/* resync after xrun */
 #define SIO_ERROR	2	/* terminate on xrun */
-	unsigned xrun;	/* what to do on overrun/underrun */
+	unsigned xrun;		/* what to do on overrun/underrun */
 };
 .Ed
 .Pp
 The parameters are as follows:
-.Bl -tag -width "round"
+.Bl -tag -width "appbufsz"
 .It Va bits
 Number of bits per sample: must be between 1 and 32.
 .It Va bps
@@ -202,8 +203,19 @@ mode was selected.
 .It Va rate
 The sampling frequency in Hz.
 .It Va bufsz
-The number of frames that will be buffered for both
-play and record directions.
+The maximum number of frames that may be buffered.
+This parameter takes into accout any buffers, and
+can be used for latency calculations.
+This parameter is read-only.
+.It Va appbufsz
+Size of the buffer in frames the application must maintain non empty
+(on the play end) or non full (on the record end) by calling
+.Fn sio_write
+or
+.Fn sio_read
+fast enough to avoid overrun or underrun conditions.
+The audio subsystem may use additionnal buffering, thus this
+parameter cannot be used for latency calculations
 .It Va round
 Optimal number of frames that the application buffers
 should be a multiple of, to get best performance.
@@ -578,7 +590,7 @@ for this.
 .Ss Handling buffer overruns and underruns
 When the application cannot accept recorded data fast enough,
 the record buffer (of size
-.Va bufsz )
+.Va appbufsz )
 might overrun; in this case recorded data is lost.
 Similarly if the application cannot provide data to play
 fast enough, the play buffer underruns and silence is played
diff --git a/lib/libsndio/sndio.c b/lib/libsndio/sndio.c
index cccc38905ee..a849f4bf7d0 100644
--- a/lib/libsndio/sndio.c
+++ b/lib/libsndio/sndio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndio.c,v 1.7 2008/11/20 16:31:26 ratchov Exp $	*/
+/*	$OpenBSD: sndio.c,v 1.8 2008/12/17 07:19:27 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -266,8 +266,12 @@ sio_setpar(struct sio_hdl *hdl, struct sio_par *par)
 		hdl->eof = 1;
 		return 0;
 	}
-	if (par->rate != (unsigned)~0 && par->bufsz == (unsigned)~0)
-		par->bufsz = par->rate * 200 / 1000;
+	if (par->bufsz != (unsigned)~0) {
+		fprintf(stderr, "sio_setpar: setting bufsz is deprecated\n");
+		par->appbufsz = par->bufsz;
+	}
+	if (par->rate != (unsigned)~0 && par->appbufsz == (unsigned)~0)
+		par->appbufsz = par->rate * 200 / 1000;
 	return hdl->ops->setpar(hdl, par);
 }
 
diff --git a/lib/libsndio/sndio.h b/lib/libsndio/sndio.h
index ec0afaa468d..1b3dddbb4b6 100644
--- a/lib/libsndio/sndio.h
+++ b/lib/libsndio/sndio.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndio.h,v 1.3 2008/11/11 19:39:35 ratchov Exp $	*/
+/*	$OpenBSD: sndio.h,v 1.4 2008/12/17 07:19:27 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -28,29 +28,30 @@ struct sio_hdl;
  * parameters of a full-duplex stream
  */
 struct sio_par {
-	unsigned bits;	/* bits per sample */
-	unsigned bps;	/* bytes per sample */
-	unsigned sig;	/* 1 = signed, 0 = unsigned */
-	unsigned le;	/* 1 = LE, 0 = BE byte order */
-	unsigned msb;	/* 1 = MSB, 0 = LSB aligned */
-	unsigned rchan;	/* number channels for recording direction */
-	unsigned pchan;	/* number channels for playback direction */
-	unsigned rate;	/* frames per second */
-	unsigned bufsz;	/* minimum buffer size */
+	unsigned bits;		/* bits per sample */
+	unsigned bps;		/* bytes per sample */
+	unsigned sig;		/* 1 = signed, 0 = unsigned */
+	unsigned le;		/* 1 = LE, 0 = BE byte order */
+	unsigned msb;		/* 1 = MSB, 0 = LSB aligned */
+	unsigned rchan;		/* number channels for recording direction */
+	unsigned pchan;		/* number channels for playback direction */
+	unsigned rate;		/* frames per second */
+	unsigned bufsz;		/* end-to-end buffer size */
 #define SIO_IGNORE	0	/* pause during xrun */
-#define SIO_SYNC		1	/* resync after xrun */
+#define SIO_SYNC	1	/* resync after xrun */
 #define SIO_ERROR	2	/* terminate on xrun */
-	unsigned xrun;	/* what to do on overruns/underruns */
-	unsigned round;	/* optimal bufsz divisor */
-	int __pad[4];	/* for future use */
-	int __magic;	/* for internal/debug purposes only */
+	unsigned xrun;		/* what to do on overruns/underruns */
+	unsigned round;		/* optimal bufsz divisor */
+	unsigned appbufsz;	/* minimum buffer size */
+	int __pad[3];		/* for future use */
+	int __magic;		/* for internal/debug purposes only */
 };
 
 /*
  * capabilities of a stream
  */
 struct sio_cap {
-#define SIO_NENC		8
+#define SIO_NENC	8
 #define SIO_NCHAN	8
 #define SIO_NRATE	16
 #define SIO_NCONF	4
@@ -79,8 +80,8 @@ struct sio_cap {
 /*
  * mode bitmap
  */
-#define SIO_PLAY 1
-#define SIO_REC	2
+#define SIO_PLAY	1
+#define SIO_REC		2
 
 /*
  * maximum size of the encording string (the longest possible
diff --git a/lib/libsndio/sun.c b/lib/libsndio/sun.c
index 5b4db13842b..14dbbe14400 100644
--- a/lib/libsndio/sun.c
+++ b/lib/libsndio/sun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sun.c,v 1.7 2008/11/20 16:31:26 ratchov Exp $	*/
+/*	$OpenBSD: sun.c,v 1.8 2008/12/17 07:19:27 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -494,7 +494,7 @@ sio_open_sun(char *path, unsigned mode, int nbio)
 	par.rate = 48000;
 	par.sig = 1;
 	par.bits = 16;
-	par.bufsz = 1200;
+	par.appbufsz = 1200;
 	if (!sio_setpar(&hdl->sa, &par))
 		goto bad_close;
 	return (struct sio_hdl *)hdl;
@@ -639,7 +639,7 @@ sun_setpar(struct sio_hdl *sh, struct sio_par *par)
 	 * if block size and buffer size are not both set then
 	 * set the blocksize to half the buffer size
 	 */ 
-	bufsz = par->bufsz;
+	bufsz = par->appbufsz;
 	round = par->round;
 	if (bufsz != (unsigned)~0) {
 		if (round == (unsigned)~0)
@@ -751,7 +751,8 @@ sun_getpar(struct sio_hdl *sh, struct sio_par *par)
 	par->round = (hdl->sa.mode & SIO_REC) ?
 	    aui.record.block_size / (par->bps * par->rchan) :
 	    aui.play.block_size / (par->bps * par->pchan);
-	par->bufsz = aui.hiwat * par->round;
+	par->appbufsz = aui.hiwat * par->round;
+	par->bufsz = par->appbufsz;
 	return 1;
 }