From: ratchov <ratchov@openbsd.org>
Date: Mon, 7 Mar 2022 08:58:33 +0000 (+0000)
Subject: Switch internal sample representation to 24-bit fixed-point.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=19e766d9d1bd124bc7b69c7cfef4aa3d613cecc9;p=openbsd

Switch internal sample representation to 24-bit fixed-point.

The default device precision doesn't change (yet), i.e. we still
request the usual 16-bit mode, when available. Hardware supporting
24-bit samples only gets end-to-end 24-bit processing by default.

ok kettenis
---

diff --git a/usr.bin/sndiod/dsp.h b/usr.bin/sndiod/dsp.h
index 539889c7f2e..39e97c63f26 100644
--- a/usr.bin/sndiod/dsp.h
+++ b/usr.bin/sndiod/dsp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dsp.h,v 1.10 2021/05/25 08:06:12 ratchov Exp $	*/
+/*	$OpenBSD: dsp.h,v 1.11 2022/03/07 08:58:33 ratchov Exp $	*/
 /*
  * Copyright (c) 2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -25,29 +25,15 @@
  * boundary is excluded. We represent them as signed fixed point numbers
  * of ADATA_BITS. We also assume that 2^(ADATA_BITS - 1) fits in a int.
  */
-#ifndef ADATA_BITS
-#define ADATA_BITS			16
-#endif
+#define ADATA_BITS			24
 #define ADATA_LE			(BYTE_ORDER == LITTLE_ENDIAN)
 #define ADATA_UNIT			(1 << (ADATA_BITS - 1))
 
-#if ADATA_BITS == 16
-
-#define ADATA_MUL(x,y)		(((int)(x) * (int)(y)) >> (ADATA_BITS - 1))
-
-typedef short adata_t;
-
-#elif ADATA_BITS == 24
-
 #define ADATA_MUL(x,y)		\
 	((int)(((long long)(x) * (long long)(y)) >> (ADATA_BITS - 1)))
 
 typedef int adata_t;
 
-#else
-#error "only 16-bit and 24-bit precisions are supported"
-#endif
-
 /*
  * The FIR is sampled and stored in a table of fixed-point numbers
  * with 23 fractional bits. For convenience, we use the same fixed-point
diff --git a/usr.bin/sndiod/sndiod.8 b/usr.bin/sndiod/sndiod.8
index b7a1d86f404..0a161dd04a4 100644
--- a/usr.bin/sndiod/sndiod.8
+++ b/usr.bin/sndiod/sndiod.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: sndiod.8,v 1.15 2022/02/18 23:17:16 jsg Exp $
+.\"	$OpenBSD: sndiod.8,v 1.16 2022/03/07 08:58:33 ratchov Exp $
 .\"
 .\" Copyright (c) 2006-2012 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: February 18 2022 $
+.Dd $Mdocdate: March 7 2022 $
 .Dt SNDIOD 8
 .Os
 .Sh NAME
@@ -579,11 +579,6 @@ $ sndiod -r 48000 -b 480 -z 240
 Resampling is low quality; down-sampling especially should be avoided
 when recording.
 .Pp
-Processing is done using 16-bit arithmetic,
-thus samples with more than 16 bits are rounded.
-16 bits (i.e. 97dB dynamic) are largely enough for most applications though.
-Processing precision can be increased to 24-bit at compilation time though.
-.Pp
 If
 .Fl a Ar off
 is used,
diff --git a/usr.bin/sndiod/sndiod.c b/usr.bin/sndiod/sndiod.c
index 96088e33c04..b1719f1549d 100644
--- a/usr.bin/sndiod/sndiod.c
+++ b/usr.bin/sndiod/sndiod.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndiod.c,v 1.47 2021/11/01 14:43:25 ratchov Exp $	*/
+/*	$OpenBSD: sndiod.c,v 1.48 2022/03/07 08:58:33 ratchov Exp $	*/
 /*
  * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -85,6 +85,13 @@
 #define DEFAULT_BUFSZ	7680
 #endif
 
+/*
+ * default device precision
+ */
+#ifndef DEFAULT_BITS
+#define DEFAULT_BITS	16
+#endif
+
 void sigint(int);
 void sighup(int);
 void opt_ch(int *, int *);
@@ -486,7 +493,11 @@ main(int argc, char **argv)
 	pmax = 1;
 	rmin = 0;
 	rmax = 1;
-	aparams_init(&par);
+	par.bits = DEFAULT_BITS;
+	par.bps = APARAMS_BPS(par.bits);
+	par.le = ADATA_LE;
+	par.sig = 1;
+	par.msb = 0;
 	mode = MODE_PLAY | MODE_REC;
 	dev_first = dev_next = NULL;
 	port_first = port_next = NULL;