Sound Mega-commit. Expect further cleanup until code freeze.

For a slightly thorough explaination, please refer to
	[1] http://people.freebsd.org/~ariff/SOUND_4.TXT.html .

Summary of changes includes:

1 Volume Per-Channel (vpc).  Provides private / standalone volume control
  unique per-stream pcm channel without touching master volume / pcm.
  Applications can directly use SNDCTL_DSP_[GET|SET][PLAY|REC]VOL, or for
  backwards compatibility, SOUND_MIXER_PCM through the opened dsp device
  instead of /dev/mixer.  Special "bypass" mode is enabled through
  /dev/mixer which will automatically detect if the adjustment is made
  through /dev/mixer and forward its request to this private volume
  controller.  Changes to this volume object will not interfere with
  other channels.

  Requirements:
    - SNDCTL_DSP_[GET|SET][PLAY|REC]_VOL are newer ioctls (OSSv4) which
      require specific application modifications (preferred).
    - No modifications required for using bypass mode, so applications
      like mplayer or xmms should work out of the box.

  Kernel hints:
    - hint.pcm.%d.vpc (0 = disable vpc).

  Kernel sysctls:
    - hw.snd.vpc_mixer_bypass (default: 1).  Enable or disable /dev/mixer
      bypass mode.
    - hw.snd.vpc_autoreset (default: 1).  By default, closing/opening
      /dev/dsp will reset the volume back to 0 db gain/attenuation.
      Setting this to 0 will preserve its settings across device
      closing/opening.
    - hw.snd.vpc_reset (default: 0).  Panic/reset button to reset all
      volume settings back to 0 db.
    - hw.snd.vpc_0db (default: 45).  0 db relative to linear mixer value.

2 High quality fixed-point Bandlimited SINC sampling rate converter,
  based on Julius O'Smith's Digital Audio Resampling -
  http://ccrma.stanford.edu/~jos/resample/.  It includes a filter design
  script written in awk (the clumsiest joke I've ever written)
    - 100% 32bit fixed-point, 64bit accumulator.
    - Possibly among the fastest (if not fastest) of its kind.
    - Resampling quality is tunable, either runtime or during kernel
      compilation (FEEDER_RATE_PRESETS).
    - Quality can be further customized during kernel compilation by
      defining FEEDER_RATE_PRESETS in /etc/make.conf.

  Kernel sysctls:
    - hw.snd.feeder_rate_quality.
      0 - Zero-order Hold (ZOH).  Fastest, bad quality.
      1 - Linear Interpolation (LINEAR).  Slightly slower than ZOH,
          better quality but still does not eliminate aliasing.
      2 - (and above) - Sinc Interpolation(SINC).  Best quality.  SINC
          quality always start from 2 and above.

  Rough quality comparisons:
    - http://people.freebsd.org/~ariff/z_comparison/

3 Bit-perfect mode.  Bypasses all feeder/dsp effects.  Pure sound will be
  directly fed into the hardware.

4 Parametric (compile time) Software Equalizer (Bass/Treble mixer). Can
  be customized by defining FEEDER_EQ_PRESETS in /etc/make.conf.

5 Transparent/Adaptive Virtual Channel. Now you don't have to disable
  vchans in order to make digital format pass through.  It also makes
  vchans more dynamic by choosing a better format/rate among all the
  concurrent streams, which means that dev.pcm.X.play.vchanformat/rate
  becomes sort of optional.

6 Exclusive Stream, with special open() mode O_EXCL.  This will "mute"
  other concurrent vchan streams and only allow a single channel with
  O_EXCL set to keep producing sound.

Other Changes:
    * most feeder_* stuffs are compilable in userland. Let's not
      speculate whether we should go all out for it (save that for
      FreeBSD 16.0-RELEASE).
    * kobj signature fixups, thanks to Andriy Gapon <avg@freebsd.org>
    * pull out channel mixing logic out of vchan.c and create its own
      feeder_mixer for world justice.
    * various refactoring here and there, for good or bad.
    * activation of few more OSSv4 ioctls() (see [1] above).
    * opt_snd.h for possible compile time configuration:
      (mostly for debugging purposes, don't try these at home)
        SND_DEBUG
        SND_DIAGNOSTIC
        SND_FEEDER_MULTIFORMAT
        SND_FEEDER_FULL_MULTIFORMAT
        SND_FEEDER_RATE_HP
        SND_PCM_64
        SND_OLDSTEREO

Manual page updates are on the way.

Tested by:	joel, Olivier SMEDTS <olivier at gid0 d org>, too many
          	unsung / unnamed heroes.

1 files changed, 142 insertions, 0 deletions

diff --git a/sys/tools/snd_fxdiv_gen.awk b/sys/tools/snd_fxdiv_gen.awk
new file mode 100644
index 0000000..5828062
--- /dev/null
+++ b/sys/tools/snd_fxdiv_gen.awk
@@ -0,0 +1,142 @@
+#!/usr/bin/awk -f
+#
+# Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# $FreeBSD$
+#
+
+function floor(x, r)
+{
+	r = int(x);
+	if (r > x)
+		r--;
+	return (r + 0);
+}
+
+function shl(x, y)
+{
+	while (y > 0) {
+		x *= 2;
+		y--;
+	}
+	return (x);
+}
+
+function shr(x, y)
+{
+	while (y > 0 && x != 0) {
+		x = floor(x / 2);
+		y--;
+	}
+	return (x);
+}
+
+function calcdiv(r, x, y, z)
+{
+	y = floor(FXONE / x);
+	z = FXSHIFT;
+
+	while (shr((y * x), z) < 1)
+		y++;
+
+	while ((y % 2) == 0 && z > 0) {
+		y = floor(y / 2);
+		z--;
+	}
+
+	r["mul"] = y;
+	r["shift"] = z;
+}
+
+BEGIN {
+	FXSHIFT = 16;
+	FXONE   = shl(1, FXSHIFT);
+
+	SND_CHN_MAX = 18;
+
+	PCM_8_BPS  = 1;
+	PCM_16_BPS = 2;
+	PCM_24_BPS = 3;
+	PCM_32_BPS = 4;
+
+	SND_MAX_ALIGN = SND_CHN_MAX * PCM_32_BPS;
+
+	for (i = 1; i <= SND_CHN_MAX; i++) {
+		aligns[PCM_8_BPS * i]  = 1;
+		aligns[PCM_16_BPS * i] = 1;
+		aligns[PCM_24_BPS * i] = 1;
+		aligns[PCM_32_BPS * i] = 1;
+	}
+
+	printf("#ifndef _SND_FXDIV_GEN_H_\n");
+	printf("#define _SND_FXDIV_GEN_H_\n\n");
+
+	printf("/*\n");
+	printf(" * Generated using snd_fxdiv_gen.awk, heaven, wind and awesome.\n");
+	printf(" *\n");
+	printf(" * DO NOT EDIT!\n");
+	printf(" */\n\n");
+	printf("#ifdef SND_USE_FXDIV\n\n");
+
+	printf("/*\n");
+	printf(" * Fast unsigned 32bit integer division and rounding, accurate for\n");
+	printf(" * x = 1 - %d. This table should be enough to handle possible\n", FXONE);
+	printf(" * division for 1 - 72 (more can be generated though..).\n");
+	printf(" *\n");
+	printf(" * 72 = SND_CHN_MAX * PCM_32_BPS, which is why....\n");
+	printf(" */\n\n");
+
+	printf("static const uint32_t snd_fxdiv_table[][2] = {\n");
+
+	for (i = 1; i <= SND_MAX_ALIGN; i++) {
+		if (aligns[i] != 1)
+			continue;
+		calcdiv(r, i);
+		printf("\t[0x%02x] = { 0x%04x, 0x%02x },",		\
+		    i, r["mul"], r["shift"]);
+		printf("\t/* x / %-2d = (x * %-5d) >> %-2d */\n",	\
+		    i, r["mul"], r["shift"]);
+	}
+
+	printf("};\n\n");
+
+	printf("#define SND_FXDIV_MAX\t\t0x%08x\n", FXONE);
+	printf("#define SND_FXDIV(x, y)\t\t(((uint32_t)(x) *\t\t\t\\\n");
+	printf("\t\t\t\t    snd_fxdiv_table[y][0]) >>\t\t\\\n");
+	printf("\t\t\t\t    snd_fxdiv_table[y][1])\n");
+	printf("#define SND_FXROUND(x, y)\t(SND_FXDIV(x, y) * (y))\n");
+	printf("#define SND_FXMOD(x, y)\t\t((x) - SND_FXROUND(x, y))\n\n");
+
+	printf("#else\t/* !SND_USE_FXDIV */\n\n");
+
+	printf("#define SND_FXDIV_MAX\t\t0x%08x\n", 131072);
+	printf("#define SND_FXDIV(x, y)\t\t((x) / (y))\n");
+	printf("#define SND_FXROUND(x, y)\t((x) - ((x) %% (y)))\n");
+	printf("#define SND_FXMOD(x, y)\t\t((x) %% (y))\n\n");
+
+	printf("#endif\t/* SND_USE_FXDIV */\n\n");
+
+	printf("#endif\t/* !_SND_FXDIV_GEN_H_ */\n");
+}