Return to aproc.c CVS log

Up to [local] / src / usr.bin / aucat

While resampling, if input samples are available but output
is blocked don't start processing input. Similarly don't
produce output if input is blocked. This is to ensure that
to each output block corresponds exactly one input block.
This is necessary for full-duplex clients using block-based
i/o and very small buffers.

/*	$OpenBSD: aproc.c,v 1.48 2010/01/17 19:17:23 ratchov Exp $	*/
/*
 * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/*
 * aproc structures are simple audio processing units. They are
 * interconnected by abuf structures and form a kind of circuit. aproc
 * structure have call-backs that do the actual processing.
 *
 * This module implements the following processing units:
 *
 *  - rpipe: read end of an unix file (pipe, socket, device...)
 *
 *  - wpipe: write end of an unix file (pipe, socket, device...)
 *
 *  - mix: mix N inputs -> 1 output
 *
 *  - sub: from 1 input -> extract/copy N outputs
 *
 *  - conv: converts/resamples/remaps a single stream
 *
 *  - resamp: resample streams in native format
 *
 */
#include <err.h>
#include <stdlib.h>
#include <string.h>

#include "abuf.h"
#include "aparams.h"
#include "aproc.h"
#include "conf.h"
#include "file.h"
#include "midi.h"
#ifdef DEBUG
#include "dbg.h"
#endif

#ifdef DEBUG
void
aproc_dbg(struct aproc *p)
{
	dbg_puts(p->ops->name);
	dbg_puts("(");
	dbg_puts(p->name);
	dbg_puts(")");
}

int
zomb_in(struct aproc *p, struct abuf *ibuf)
{
	aproc_dbg(p);
	dbg_puts(": in: terminated\n");
	dbg_panic();
	return 0;
}


int
zomb_out(struct aproc *p, struct abuf *obuf)
{
	aproc_dbg(p);
	dbg_puts(": out: terminated\n");
	dbg_panic();
	return 0;
}

void
zomb_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_dbg(p);
	dbg_puts(": eof: terminated\n");
	dbg_panic();
}

void
zomb_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_dbg(p);
	dbg_puts(": hup: terminated\n");
	dbg_panic();
}

void
zomb_newin(struct aproc *p, struct abuf *ibuf)
{
	aproc_dbg(p);
	dbg_puts(": newin: terminated\n");
	dbg_panic();
}

void
zomb_newout(struct aproc *p, struct abuf *obuf)
{
	aproc_dbg(p);
	dbg_puts(": newout: terminated\n");
	dbg_panic();
}

void
zomb_ipos(struct aproc *p, struct abuf *ibuf, int delta)
{
	aproc_dbg(p);
	dbg_puts(": ipos: terminated\n");
	dbg_panic();
}

void
zomb_opos(struct aproc *p, struct abuf *obuf, int delta)
{
	aproc_dbg(p);
	dbg_puts(": opos: terminated\n");
	dbg_panic();
}

struct aproc_ops zomb_ops = {
	"zomb",
	zomb_in,
	zomb_out,
	zomb_eof,
	zomb_hup,
	zomb_newin,
	zomb_newout,
	zomb_ipos,
	zomb_opos,
	NULL
};
#endif

struct aproc *
aproc_new(struct aproc_ops *ops, char *name)
{
	struct aproc *p;

	p = malloc(sizeof(struct aproc));
	if (p == NULL)
		err(1, name);
	LIST_INIT(&p->ibuflist);
	LIST_INIT(&p->obuflist);
	p->name = name;
	p->ops = ops;
	p->refs = 0;
	p->flags = 0;
	return p;
}

void
aproc_del(struct aproc *p)
{
	struct abuf *i;

	if (!(p->flags & APROC_ZOMB)) {
#ifdef DEBUG
		if (debug_level >= 3) {
			aproc_dbg(p);
			dbg_puts(": terminating...\n");
		}
#endif
		if (p->ops->done) {
#ifdef DEBUG
			if (debug_level >= 3) {
				aproc_dbg(p);
				dbg_puts(": done\n");
			}
#endif
			p->ops->done(p);
		}
		while (!LIST_EMPTY(&p->ibuflist)) {
			i = LIST_FIRST(&p->ibuflist);
			abuf_hup(i);
		}
		while (!LIST_EMPTY(&p->obuflist)) {
			i = LIST_FIRST(&p->obuflist);
			abuf_eof(i);
		}
		p->flags |= APROC_ZOMB;
	}
	if (p->refs > 0) {
#ifdef DEBUG
		if (debug_level >= 3) {
			aproc_dbg(p);
			dbg_puts(": free delayed\n");
			p->ops = &zomb_ops;
		}
#endif
		return;
	}
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": freed\n");
	}
#endif
	free(p);
}

void
aproc_setin(struct aproc *p, struct abuf *ibuf)
{
	LIST_INSERT_HEAD(&p->ibuflist, ibuf, ient);
	ibuf->rproc = p;
	if (p->ops->newin)
		p->ops->newin(p, ibuf);
}

void
aproc_setout(struct aproc *p, struct abuf *obuf)
{
	LIST_INSERT_HEAD(&p->obuflist, obuf, oent);
	obuf->wproc = p;
	if (p->ops->newout)
		p->ops->newout(p, obuf);
}

void
aproc_ipos(struct aproc *p, struct abuf *ibuf, int delta)
{
	struct abuf *obuf;

	LIST_FOREACH(obuf, &p->obuflist, oent) {
		abuf_ipos(obuf, delta);
	}
}

void
aproc_opos(struct aproc *p, struct abuf *obuf, int delta)
{
	struct abuf *ibuf;

	LIST_FOREACH(ibuf, &p->ibuflist, ient) {
		abuf_opos(ibuf, delta);
	}
}

int
aproc_inuse(struct aproc *p)
{
	struct abuf *i;

	LIST_FOREACH(i, &p->ibuflist, ient) {
		if (i->inuse)
			return 1;
	}
	LIST_FOREACH(i, &p->obuflist, oent) {
		if (i->inuse)
			return 1;
	}
	return 0;
}

int
aproc_depend(struct aproc *p, struct aproc *dep)
{
	struct abuf *i;

	if (p == dep)
		return 1;
	LIST_FOREACH(i, &p->ibuflist, ient) {
		if (i->wproc && aproc_depend(i->wproc, dep))
			return 1;
	}
	return 0;
}

int
rfile_in(struct aproc *p, struct abuf *ibuf_dummy)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);
	struct file *f = p->u.io.file;
	unsigned char *data;
	unsigned count;

	if (ABUF_FULL(obuf) || !(f->state & FILE_ROK))
		return 0;
	data = abuf_wgetblk(obuf, &count, 0);
	count = file_read(f, data, count);
	if (count == 0)
		return 0;
	abuf_wcommit(obuf, count);
	if (!abuf_flush(obuf))
		return 0;
	return 1;
}

int
rfile_out(struct aproc *p, struct abuf *obuf)
{
	struct file *f = p->u.io.file;
	unsigned char *data;
	unsigned count;

	if (f->state & FILE_RINUSE)
		return 0;
	if (ABUF_FULL(obuf) || !(f->state & FILE_ROK))
		return 0;
	data = abuf_wgetblk(obuf, &count, 0);
	count = file_read(f, data, count);
	if (count == 0)
		return 0;
	abuf_wcommit(obuf, count);
	return 1;
}

void
rfile_done(struct aproc *p)
{
	struct file *f = p->u.io.file;
	struct abuf *obuf;

	if (f == NULL)
		return;
	/*
	 * all buffers must be detached before deleting f->wproc,
	 * because otherwise it could trigger this code again
	 */
	obuf = LIST_FIRST(&p->obuflist);
	if (obuf)
		abuf_eof(obuf);
	if (f->wproc) {
		f->rproc = NULL;
		aproc_del(f->wproc);
	} else
		file_del(f);
	p->u.io.file = NULL;
}

void
rfile_eof(struct aproc *p, struct abuf *ibuf_dummy)
{
	aproc_del(p);
}

void
rfile_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

struct aproc_ops rfile_ops = {
	"rfile",
	rfile_in,
	rfile_out,
	rfile_eof,
	rfile_hup,
	NULL, /* newin */
	NULL, /* newout */
	aproc_ipos,
	aproc_opos,
	rfile_done
};

struct aproc *
rfile_new(struct file *f)
{
	struct aproc *p;

	p = aproc_new(&rfile_ops, f->name);
	p->u.io.file = f;
	f->rproc = p;
	return p;
}

void
wfile_done(struct aproc *p)
{
	struct file *f = p->u.io.file;
	struct abuf *ibuf;

	if (f == NULL)
		return;
	/*
	 * all buffers must be detached before deleting f->rproc,
	 * because otherwise it could trigger this code again
	 */
	ibuf = LIST_FIRST(&p->ibuflist);
	if (ibuf)
		abuf_hup(ibuf);
	if (f->rproc) {
		f->wproc = NULL;
		aproc_del(f->rproc);
	} else
		file_del(f);
	p->u.io.file = NULL;
}

int
wfile_in(struct aproc *p, struct abuf *ibuf)
{
	struct file *f = p->u.io.file;
	unsigned char *data;
	unsigned count;

	if (f->state & FILE_WINUSE)
		return 0;
	if (ABUF_EMPTY(ibuf) || !(f->state & FILE_WOK))
		return 0;
	data = abuf_rgetblk(ibuf, &count, 0);
	count = file_write(f, data, count);
	if (count == 0)
		return 0;
	abuf_rdiscard(ibuf, count);
	return 1;
}

int
wfile_out(struct aproc *p, struct abuf *obuf_dummy)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);
	struct file *f = p->u.io.file;
	unsigned char *data;
	unsigned count;

	if (!abuf_fill(ibuf))
		return 0;
	if (ABUF_EMPTY(ibuf) || !(f->state & FILE_WOK))
		return 0;
	data = abuf_rgetblk(ibuf, &count, 0);
	if (count == 0) {
		/* XXX: this can't happen, right ? */
		return 0;
	}
	count = file_write(f, data, count);
	if (count == 0)
		return 0;
	abuf_rdiscard(ibuf, count);
	return 1;
}

void
wfile_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
wfile_hup(struct aproc *p, struct abuf *obuf_dummy)
{
	aproc_del(p);
}

struct aproc_ops wfile_ops = {
	"wfile",
	wfile_in,
	wfile_out,
	wfile_eof,
	wfile_hup,
	NULL, /* newin */
	NULL, /* newout */
	aproc_ipos,
	aproc_opos,
	wfile_done
};

struct aproc *
wfile_new(struct file *f)
{
	struct aproc *p;

	p = aproc_new(&wfile_ops, f->name);
	p->u.io.file = f;
	f->wproc = p;
	return p;
}

/*
 * Append the given amount of silence (or less if there's not enough
 * space), and crank mixitodo accordingly.
 */
void
mix_bzero(struct abuf *obuf, unsigned zcount)
{
	short *odata;
	unsigned ocount;

#ifdef DEBUG
	if (debug_level >= 4) {
		abuf_dbg(obuf);
		dbg_puts(": bzero(");
		dbg_putu(zcount);
		dbg_puts(")\n");
	}
#endif
	odata = (short *)abuf_wgetblk(obuf, &ocount, obuf->w.mix.todo);
	ocount -= ocount % obuf->bpf;
	if (ocount > zcount)
		ocount = zcount;
	memset(odata, 0, ocount);
	obuf->w.mix.todo += ocount;
}

/*
 * Mix an input block over an output block.
 */
void
mix_badd(struct abuf *ibuf, struct abuf *obuf)
{
	short *idata, *odata;
	unsigned i, j, icnt, onext, ostart;
	unsigned scount, icount, ocount, zcount;
	int vol;

#ifdef DEBUG
	if (debug_level >= 4) {
		abuf_dbg(ibuf);
		dbg_puts(": badd: done = ");
		dbg_putu(ibuf->r.mix.done);
		dbg_puts("/");
		dbg_putu(obuf->w.mix.todo);
		dbg_puts("\n");
	}
#endif
	/*
	 * Calculate the maximum we can read.
	 */
	idata = (short *)abuf_rgetblk(ibuf, &icount, 0);
	icount /= ibuf->bpf;
	if (icount == 0)
		return;

	/*
	 * Zero-fill if necessary.
	 */
	zcount = ibuf->r.mix.done + icount * obuf->bpf;
	if (zcount > obuf->w.mix.todo)
		mix_bzero(obuf, zcount - obuf->w.mix.todo);

	/*
	 * Calculate the maximum we can write.
	 */
	odata = (short *)abuf_wgetblk(obuf, &ocount, ibuf->r.mix.done);
	ocount /= obuf->bpf;
	if (ocount == 0)
		return;

	vol = (ibuf->r.mix.weight * ibuf->r.mix.vol) >> ADATA_SHIFT;
	ostart = ibuf->cmin - obuf->cmin;
	onext = obuf->cmax - ibuf->cmax + ostart;
	icnt = ibuf->cmax - ibuf->cmin + 1;
	odata += ostart;
	scount = (icount < ocount) ? icount : ocount;
	for (i = scount; i > 0; i--) {
		for (j = icnt; j > 0; j--) {
			*odata += (*idata * vol) >> ADATA_SHIFT;
			idata++;
			odata++;
		}
		odata += onext;
	}
	abuf_rdiscard(ibuf, scount * ibuf->bpf);
	ibuf->r.mix.done += scount * obuf->bpf;

#ifdef DEBUG
	if (debug_level >= 4) {
		abuf_dbg(ibuf);
		dbg_puts(": badd: done = ");
		dbg_putu(scount);
		dbg_puts(", todo = ");
		dbg_putu(ibuf->r.mix.done);
		dbg_puts("/");
		dbg_putu(obuf->w.mix.todo);
		dbg_puts("\n");
	}
#endif
}

/*
 * Handle buffer underrun, return 0 if stream died.
 */
int
mix_xrun(struct abuf *i, struct abuf *obuf)
{
	unsigned fdrop;

	if (i->r.mix.done > 0)
		return 1;
	if (i->r.mix.xrun == XRUN_ERROR) {
		abuf_hup(i);
		return 0;
	}
	mix_bzero(obuf, obuf->len);
	fdrop = obuf->w.mix.todo / obuf->bpf;
#ifdef DEBUG
	if (debug_level >= 3) {
		abuf_dbg(i);
		dbg_puts(": underrun, dropping ");
		dbg_putu(fdrop);
		dbg_puts(" + ");
		dbg_putu(i->drop / i->bpf);
		dbg_puts("\n");
	}
#endif
	i->r.mix.done += fdrop * obuf->bpf;
	if (i->r.mix.xrun == XRUN_SYNC)
		i->drop += fdrop * i->bpf;
	else {
		abuf_opos(i, -(int)fdrop);
		if (i->duplex) {
#ifdef DEBUG
			if (debug_level >= 3) {
				abuf_dbg(i->duplex);
				dbg_puts(": full-duplex resync\n");
			}
#endif
			i->duplex->drop += fdrop * i->duplex->bpf;
			abuf_ipos(i->duplex, -(int)fdrop);
		}
	}
	return 1;
}

int
mix_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *i, *inext, *obuf = LIST_FIRST(&p->obuflist);
	unsigned odone;

#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": used = ");
		dbg_putu(ibuf->used);
		dbg_puts("/");
		dbg_putu(ibuf->len);
		dbg_puts(", done = ");
		dbg_putu(ibuf->r.mix.done);
		dbg_puts("/");
		dbg_putu(obuf->w.mix.todo);
		dbg_puts("\n");
	}
#endif
	if (!ABUF_ROK(ibuf))
		return 0;
	odone = obuf->len;
	for (i = LIST_FIRST(&p->ibuflist); i != NULL; i = inext) {
		inext = LIST_NEXT(i, ient);
		if (!abuf_fill(i))
			continue; /* eof */
		mix_badd(i, obuf);
		if (odone > i->r.mix.done)
			odone = i->r.mix.done;
	}
	if (LIST_EMPTY(&p->ibuflist) || odone == 0)
		return 0;
	p->u.mix.lat += odone / obuf->bpf;
	LIST_FOREACH(i, &p->ibuflist, ient) {
		i->r.mix.done -= odone;
	}
	abuf_wcommit(obuf, odone);
	obuf->w.mix.todo -= odone;
	if (!abuf_flush(obuf))
		return 0; /* hup */
	return 1;
}

int
mix_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *i, *inext;
	unsigned odone;

#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": used = ");
		dbg_putu(obuf->used);
		dbg_puts("/");
		dbg_putu(obuf->len);
		dbg_puts(", todo = ");
		dbg_putu(obuf->w.mix.todo);
		dbg_puts("/");
		dbg_putu(obuf->len);
		dbg_puts("\n");
	}
#endif
	if (!ABUF_WOK(obuf))
		return 0;
	odone = obuf->len;
	for (i = LIST_FIRST(&p->ibuflist); i != NULL; i = inext) {
		inext = LIST_NEXT(i, ient);
		if (!abuf_fill(i))
			continue; /* eof */
		if (!ABUF_ROK(i)) {
			if (p->flags & APROC_DROP) {
				if (!mix_xrun(i, obuf))
					continue;
			}
		} else
			mix_badd(i, obuf);
		if (odone > i->r.mix.done)
			odone = i->r.mix.done;
	}
	if (LIST_EMPTY(&p->ibuflist)) {
		if (p->flags & APROC_QUIT) {
			aproc_del(p);
			return 0;
		}
		if (!(p->flags & APROC_DROP))
			return 0;
		mix_bzero(obuf, obuf->len);
		odone = obuf->w.mix.todo;
		p->u.mix.idle += odone / obuf->bpf;
	}
	if (odone == 0)
		return 0;
	p->u.mix.lat += odone / obuf->bpf;
	LIST_FOREACH(i, &p->ibuflist, ient) {
		i->r.mix.done -= odone;
	}
	abuf_wcommit(obuf, odone);
	obuf->w.mix.todo -= odone;
	return 1;
}

void
mix_eof(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *i, *obuf = LIST_FIRST(&p->obuflist);
	unsigned odone;

	mix_setmaster(p);

	if (!aproc_inuse(p)) {
#ifdef DEBUG
		if (debug_level >= 3) {
			aproc_dbg(p);
			dbg_puts(": running other streams\n");
		}
#endif
		/*
		 * Find a blocked input.
		 */
		odone = obuf->len;
		LIST_FOREACH(i, &p->ibuflist, ient) {
			if (ABUF_ROK(i) && i->r.mix.done < obuf->w.mix.todo) {
				abuf_run(i);
				return;
			}
			if (odone > i->r.mix.done)
				odone = i->r.mix.done;
		}
		/*
		 * No blocked inputs. Check if output is blocked.
		 */
		if (LIST_EMPTY(&p->ibuflist) || odone == obuf->w.mix.todo)
			abuf_run(obuf);
	}
}

void
mix_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

void
mix_newin(struct aproc *p, struct abuf *ibuf)
{
#ifdef DEBUG
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	if (!obuf || ibuf->cmin < obuf->cmin || ibuf->cmax > obuf->cmax) {
		dbg_puts("newin: channel ranges mismatch\n");
		dbg_panic();
	}
#endif
	p->u.mix.idle = 0;
	ibuf->r.mix.done = 0;
	ibuf->r.mix.vol = ADATA_UNIT;
	ibuf->r.mix.weight = ADATA_UNIT;
	ibuf->r.mix.maxweight = ADATA_UNIT;
	ibuf->r.mix.xrun = XRUN_IGNORE;
}

void
mix_newout(struct aproc *p, struct abuf *obuf)
{
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": newin, will use ");
		dbg_putu(obuf->len / obuf->bpf);
		dbg_puts(" fr\n");
	}
#endif
	obuf->w.mix.todo = 0;
}

void
mix_opos(struct aproc *p, struct abuf *obuf, int delta)
{
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": opos: lat = ");
		dbg_puti(p->u.mix.lat);
		dbg_puts("/");
		dbg_puti(p->u.mix.maxlat);
		dbg_puts(" fr\n");
	}
#endif
	p->u.mix.lat -= delta;
	if (p->u.mix.ctl)
		ctl_ontick(p->u.mix.ctl, delta);
	aproc_opos(p, obuf, delta);
}

struct aproc_ops mix_ops = {
	"mix",
	mix_in,
	mix_out,
	mix_eof,
	mix_hup,
	mix_newin,
	mix_newout,
	aproc_ipos,
	mix_opos,
	NULL
};

struct aproc *
mix_new(char *name, int maxlat, struct aproc *ctl)
{
	struct aproc *p;

	p = aproc_new(&mix_ops, name);
	p->u.mix.idle = 0;
	p->u.mix.lat = 0;
	p->u.mix.maxlat = maxlat;
	p->u.mix.ctl = ctl;
	return p;
}

/*
 * Normalize input levels.
 */
void
mix_setmaster(struct aproc *p)
{
	unsigned n;
	struct abuf *i, *j;
	int weight;

	/*
	 * count the number of inputs. If a set of inputs
	 * uses channels that have no intersection, they are 
	 * counted only once because they don't need to 
	 * share their volume
	 */
	n = 0;
	LIST_FOREACH(i, &p->ibuflist, ient) {
		j = LIST_NEXT(i, ient);
		for (;;) {
			if (j == NULL) {
				n++;
				break;
			}
			if (i->cmin > j->cmax || i->cmax < j->cmin)
				break;
			j = LIST_NEXT(j, ient);
		}
	}
	LIST_FOREACH(i, &p->ibuflist, ient) {
		weight = ADATA_UNIT / n;
		if (weight > i->r.mix.maxweight)
			weight = i->r.mix.maxweight;
		i->r.mix.weight = weight;
#ifdef DEBUG
		if (debug_level >= 3) {
			abuf_dbg(i);
			dbg_puts(": setmaster: ");
			dbg_puti(i->r.mix.weight);
			dbg_puts("/");
			dbg_puti(i->r.mix.maxweight);
			dbg_puts("\n");
		}
#endif
	}
}

void
mix_clear(struct aproc *p)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	p->u.mix.lat = 0;
	obuf->w.mix.todo = 0;
}

void
mix_prime(struct aproc *p)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);
	unsigned todo, count;

	for (;;) {
		if (!ABUF_WOK(obuf))
			break;
		todo = (p->u.mix.maxlat - p->u.mix.lat) * obuf->bpf;
		if (todo == 0)
			break;
		mix_bzero(obuf, obuf->len);
		count = obuf->w.mix.todo;
		if (count > todo)
			count = todo;
		obuf->w.mix.todo -= count;
		p->u.mix.lat += count / obuf->bpf;
		abuf_wcommit(obuf, count);
		abuf_flush(obuf);
	}
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": prime: lat/maxlat=");
		dbg_puti(p->u.mix.lat);
		dbg_puts("/");
		dbg_puti(p->u.mix.maxlat);
		dbg_puts("\n");
	}
#endif
}

/*
 * Copy data from ibuf to obuf.
 */
void
sub_bcopy(struct abuf *ibuf, struct abuf *obuf)
{
	short *idata, *odata;
	unsigned i, j, ocnt, inext, istart;
	unsigned icount, ocount, scount;

	idata = (short *)abuf_rgetblk(ibuf, &icount, obuf->w.sub.done);
	icount /= ibuf->bpf;
	if (icount == 0)
		return;
	odata = (short *)abuf_wgetblk(obuf, &ocount, 0);
	ocount /= obuf->bpf;
	if (ocount == 0)
		return;
	istart = obuf->cmin - ibuf->cmin;
	inext = ibuf->cmax - obuf->cmax + istart;
	ocnt = obuf->cmax - obuf->cmin + 1;
	scount = (icount < ocount) ? icount : ocount;
	idata += istart;
	for (i = scount; i > 0; i--) {
		for (j = ocnt; j > 0; j--) {
			*odata = *idata;
			odata++;
			idata++;
		}
		idata += inext;
	}
	abuf_wcommit(obuf, scount * obuf->bpf);
	obuf->w.sub.done += scount * ibuf->bpf;
#ifdef DEBUG
	if (debug_level >= 4) {
		abuf_dbg(obuf);
		dbg_puts(": bcopy ");
		dbg_putu(scount);
		dbg_puts(" fr\n");
	}
#endif
}

/*
 * Handle buffer overruns. Return 0 if the stream died.
 */
int
sub_xrun(struct abuf *ibuf, struct abuf *i)
{
	unsigned fdrop;

	if (i->w.sub.done > 0)
		return 1;
	if (i->w.sub.xrun == XRUN_ERROR) {
		abuf_eof(i);
		return 0;
	}
	fdrop = ibuf->used / ibuf->bpf;
#ifdef DEBUG
	if (debug_level >= 3) {
		abuf_dbg(i);
		dbg_puts(": overrun, silence ");
		dbg_putu(fdrop);
		dbg_puts(" + ");
		dbg_putu(i->silence / i->bpf);
		dbg_puts("\n");
	}
#endif
	if (i->w.sub.xrun == XRUN_SYNC)
		i->silence += fdrop * i->bpf;
	else {
		abuf_ipos(i, -(int)fdrop);
		if (i->duplex) {
#ifdef DEBUG
			if (debug_level >= 3) {
				abuf_dbg(i->duplex);
				dbg_puts(": full-duplex resync\n");
			}
#endif
			i->duplex->silence += fdrop * i->duplex->bpf;
			abuf_opos(i->duplex, -(int)fdrop);
		}
	}
	i->w.sub.done += fdrop * ibuf->bpf;
	return 1;
}

int
sub_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *i, *inext;
	unsigned idone;

	if (!ABUF_ROK(ibuf))
		return 0;
	idone = ibuf->len;
	for (i = LIST_FIRST(&p->obuflist); i != NULL; i = inext) {
		inext = LIST_NEXT(i, oent);
		if (!ABUF_WOK(i)) {
			if (p->flags & APROC_DROP) {
				if (!sub_xrun(ibuf, i))
					continue;
			}
		} else
			sub_bcopy(ibuf, i);
		if (idone > i->w.sub.done)
			idone = i->w.sub.done;
		if (!abuf_flush(i))
			continue;
	}
	if (LIST_EMPTY(&p->obuflist)) {
		if (p->flags & APROC_QUIT) {
			aproc_del(p);
			return 0;
		}
		if (!(p->flags & APROC_DROP))
			return 0;
		idone = ibuf->used;
		p->u.sub.idle += idone / ibuf->bpf;
	}
	if (idone == 0)
		return 0;
	LIST_FOREACH(i, &p->obuflist, oent) {
		i->w.sub.done -= idone;
	}
	abuf_rdiscard(ibuf, idone);
	p->u.sub.lat -= idone / ibuf->bpf;
	return 1;
}

int
sub_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);
	struct abuf *i, *inext;
	unsigned idone;

	if (!ABUF_WOK(obuf))
		return 0;
	if (!abuf_fill(ibuf))
		return 0; /* eof */
	idone = ibuf->len;
	for (i = LIST_FIRST(&p->obuflist); i != NULL; i = inext) {
		inext = LIST_NEXT(i, oent);
		sub_bcopy(ibuf, i);
		if (idone > i->w.sub.done)
			idone = i->w.sub.done;
		if (!abuf_flush(i))
			continue;
	}
	if (LIST_EMPTY(&p->obuflist) || idone == 0)
		return 0;
	LIST_FOREACH(i, &p->obuflist, oent) {
		i->w.sub.done -= idone;
	}
	abuf_rdiscard(ibuf, idone);
	p->u.sub.lat -= idone / ibuf->bpf;
	return 1;
}

void
sub_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
sub_hup(struct aproc *p, struct abuf *obuf)
{
	struct abuf *i, *ibuf = LIST_FIRST(&p->ibuflist);
	unsigned idone;

	if (!aproc_inuse(p)) {
#ifdef DEBUG
		if (debug_level >= 3) {
			aproc_dbg(p);
			dbg_puts(": running other streams\n");
		}
#endif
		/*
		 * Find a blocked output.
		 */
		idone = ibuf->len;
		LIST_FOREACH(i, &p->obuflist, oent) {
			if (ABUF_WOK(i) && i->w.sub.done < ibuf->used) {
				abuf_run(i);
				return;
			}
			if (idone > i->w.sub.done)
				idone = i->w.sub.done;
		}
		/*
		 * No blocked outputs. Check if input is blocked.
		 */
		if (LIST_EMPTY(&p->obuflist) || idone == ibuf->used)
			abuf_run(ibuf);
	}
}

void
sub_newout(struct aproc *p, struct abuf *obuf)
{
#ifdef DEBUG
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);

	if (!ibuf || obuf->cmin < ibuf->cmin || obuf->cmax > ibuf->cmax) {
		dbg_puts("newout: channel ranges mismatch\n");
		dbg_panic();
	}
#endif
	p->u.sub.idle = 0;
	obuf->w.sub.done = 0;
	obuf->w.sub.xrun = XRUN_IGNORE;
}

void
sub_ipos(struct aproc *p, struct abuf *ibuf, int delta)
{
	p->u.sub.lat += delta;
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": ipos: lat = ");
		dbg_puti(p->u.sub.lat);
		dbg_puts("/");
		dbg_puti(p->u.sub.maxlat);
		dbg_puts(" fr\n");
	}
#endif
	if (p->u.sub.ctl)
		ctl_ontick(p->u.sub.ctl, delta);
	aproc_ipos(p, ibuf, delta);
}

struct aproc_ops sub_ops = {
	"sub",
	sub_in,
	sub_out,
	sub_eof,
	sub_hup,
	NULL,
	sub_newout,
	sub_ipos,
	aproc_opos,
	NULL
};

struct aproc *
sub_new(char *name, int maxlat, struct aproc *ctl)
{
	struct aproc *p;

	p = aproc_new(&sub_ops, name);
	p->u.sub.idle = 0;
	p->u.sub.lat = 0;
	p->u.sub.maxlat = maxlat;
	p->u.sub.ctl = ctl;
	return p;
}

void
sub_clear(struct aproc *p)
{
	p->u.mix.lat = 0;
}

/*
 * Convert one block.
 */
void
resamp_bcopy(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
{
	unsigned inch;
	short *idata;
	unsigned oblksz;
	unsigned ifr;
	unsigned onch;
	int s1, s2, diff;
	short *odata;
	unsigned iblksz;
	unsigned ofr;
	unsigned c;
	short *ctxbuf, *ctx;
	unsigned ctx_start;
	unsigned icount, ocount;

	/*
	 * Calculate max frames readable at once from the input buffer.
	 */
	idata = (short *)abuf_rgetblk(ibuf, &icount, 0);
	ifr = icount / ibuf->bpf;
	icount = ifr * ibuf->bpf;

	odata = (short *)abuf_wgetblk(obuf, &ocount, 0);
	ofr = ocount / obuf->bpf;
	ocount = ofr * obuf->bpf;

	/*
	 * Partially copy structures into local variables, to avoid
	 * unnecessary indirections; this also allows the compiler to
	 * order local variables more "cache-friendly".
	 */
	diff = p->u.resamp.diff;
	inch = ibuf->cmax - ibuf->cmin + 1;
	iblksz = p->u.resamp.iblksz;
	onch = obuf->cmax - obuf->cmin + 1;
	oblksz = p->u.resamp.oblksz;
	ctxbuf = p->u.resamp.ctx;
	ctx_start = p->u.resamp.ctx_start;

	/*
	 * Start conversion.
	 */
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": resamp starting diff = ");
		dbg_puti(diff);
		dbg_puts(", ifr = ");
		dbg_putu(ifr);
		dbg_puts(", ofr = ");
		dbg_putu(ofr);
		dbg_puts(" fr\n");
	}
#endif
	for (;;) {
		if (diff < 0) {
			ctx_start ^= 1;
			ctx = ctxbuf + ctx_start;
			for (c = inch; c > 0; c--) {
				*ctx = *idata++;
				ctx += RESAMP_NCTX;
			}
			diff += oblksz;
			if (--ifr == 0)
				break;
		} else {
			ctx = ctxbuf;
			for (c = onch; c > 0; c--) {
				s1 = ctx[ctx_start];
				s2 = ctx[ctx_start ^ 1];
				ctx += RESAMP_NCTX;
				*odata++ = s1 + (s2 - s1) * diff / (int)oblksz;
			}
			diff -= iblksz;
			if (--ofr == 0)
				break;
		}
	}
	p->u.resamp.diff = diff;
	p->u.resamp.ctx_start = ctx_start;
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": resamp done delta = ");
		dbg_puti(diff);
		dbg_puts(", ifr = ");
		dbg_putu(ifr);
		dbg_puts(", ofr = ");
		dbg_putu(ofr);
		dbg_puts(" fr\n");
	}
#endif
	/*
	 * Update FIFO pointers.
	 */
	icount -= ifr * ibuf->bpf;
	ocount -= ofr * obuf->bpf;
	abuf_rdiscard(ibuf, icount);
	abuf_wcommit(obuf, ocount);
}

int
resamp_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	resamp_bcopy(p, ibuf, obuf);
	if (!abuf_flush(obuf))
		return 0;
	return 1;
}

int
resamp_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);

	if (!abuf_fill(ibuf))
		return 0;
	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	resamp_bcopy(p, ibuf, obuf);
	return 1;
}

void
resamp_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
resamp_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

void
resamp_ipos(struct aproc *p, struct abuf *ibuf, int delta)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);
	long long ipos;
	
	ipos = (long long)delta * p->u.resamp.oblksz + p->u.resamp.idelta;
	p->u.resamp.idelta = ipos % p->u.resamp.iblksz;
	abuf_ipos(obuf, ipos / (int)p->u.resamp.iblksz);
}

void
resamp_opos(struct aproc *p, struct abuf *obuf, int delta)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);
	long long opos;

	opos = (long long)delta * p->u.resamp.iblksz + p->u.resamp.odelta;
	p->u.resamp.odelta = opos % p->u.resamp.oblksz;
	abuf_opos(ibuf, opos / p->u.resamp.oblksz);
}

struct aproc_ops resamp_ops = {
	"resamp",
	resamp_in,
	resamp_out,
	resamp_eof,
	resamp_hup,
	NULL,
	NULL,
	resamp_ipos,
	resamp_opos,
	NULL
};

struct aproc *
resamp_new(char *name, unsigned iblksz, unsigned oblksz)
{
	struct aproc *p;
	unsigned i;

	p = aproc_new(&resamp_ops, name);
	p->u.resamp.iblksz = iblksz;
	p->u.resamp.oblksz = oblksz;
	p->u.resamp.diff = 0;
	p->u.resamp.idelta = 0;
	p->u.resamp.odelta = 0;
	p->u.resamp.ctx_start = 0;
	for (i = 0; i < NCHAN_MAX * RESAMP_NCTX; i++)
		p->u.resamp.ctx[i] = 0;
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": new ");
		dbg_putu(iblksz);
		dbg_puts("/");
		dbg_putu(oblksz);
		dbg_puts("\n");
	}
#endif
	return p;
}

/*
 * Convert one block.
 */
void
cmap_bcopy(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
{
	unsigned inch;
	short *idata;
	unsigned onch;
	short *odata;
	short *ctx, *ictx, *octx;
	unsigned c, f, scount, icount, ocount;

	/*
	 * Calculate max frames readable at once from the input buffer.
	 */
	idata = (short *)abuf_rgetblk(ibuf, &icount, 0);
	icount /= ibuf->bpf;
	if (icount == 0)
		return;
	odata = (short *)abuf_wgetblk(obuf, &ocount, 0);
	ocount /= obuf->bpf;
	if (ocount == 0)
		return;
	scount = icount < ocount ? icount : ocount;
	inch = ibuf->cmax - ibuf->cmin + 1;
	onch = obuf->cmax - obuf->cmin + 1;
	ictx = p->u.cmap.ctx + ibuf->cmin;
	octx = p->u.cmap.ctx + obuf->cmin;

	for (f = scount; f > 0; f--) {
		ctx = ictx;
		for (c = inch; c > 0; c--) {
			*ctx = *idata;
			idata++;
			ctx++;
		}
		ctx = octx;
		for (c = onch; c > 0; c--) {
			*odata = *ctx;
			odata++;
			ctx++;
		}
	}
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": bcopy ");
		dbg_putu(scount);
		dbg_puts(" fr\n");
	}
#endif
	abuf_rdiscard(ibuf, scount * ibuf->bpf);
	abuf_wcommit(obuf, scount * obuf->bpf);
}

int
cmap_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	cmap_bcopy(p, ibuf, obuf);
	if (!abuf_flush(obuf))
		return 0;
	return 1;
}

int
cmap_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);

	if (!abuf_fill(ibuf))
		return 0;
	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	cmap_bcopy(p, ibuf, obuf);
	return 1;
}

void
cmap_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
cmap_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

struct aproc_ops cmap_ops = {
	"cmap",
	cmap_in,
	cmap_out,
	cmap_eof,
	cmap_hup,
	NULL,
	NULL,
	aproc_ipos,
	aproc_opos,
	NULL
};

struct aproc *
cmap_new(char *name, struct aparams *ipar, struct aparams *opar)
{
	struct aproc *p;
	unsigned i;

	p = aproc_new(&cmap_ops, name);
	for (i = 0; i < NCHAN_MAX; i++)
		p->u.cmap.ctx[i] = 0;
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": new ");
		aparams_dbg(ipar);
		dbg_puts(" -> ");
		aparams_dbg(opar);
		dbg_puts("\n");
	}
#endif
	return p;
}

/*
 * Convert one block.
 */
void
enc_bcopy(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
{
	unsigned nch, scount, icount, ocount;
	unsigned f;
	short *idata;
	int s;
	unsigned oshift;
	int osigbit;
	unsigned obps;
	unsigned i;
	unsigned char *odata;
	int obnext;
	int osnext;

	/*
	 * Calculate max frames readable at once from the input buffer.
	 */
	idata = (short *)abuf_rgetblk(ibuf, &icount, 0);
	icount /= ibuf->bpf;
	if (icount == 0)
		return;
	odata = abuf_wgetblk(obuf, &ocount, 0);
	ocount /= obuf->bpf;
	if (ocount == 0)
		return;
	scount = (icount < ocount) ? icount : ocount;
	nch = ibuf->cmax - ibuf->cmin + 1;
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": bcopy ");
		dbg_putu(scount);
		dbg_puts(" fr * ");
		dbg_putu(nch);
		dbg_puts(" ch\n");
	}
#endif
	/*
	 * Partially copy structures into local variables, to avoid
	 * unnecessary indirections; this also allows the compiler to
	 * order local variables more "cache-friendly".
	 */
	oshift = p->u.conv.shift;
	osigbit = p->u.conv.sigbit;
	obps = p->u.conv.bps;
	obnext = p->u.conv.bnext;
	osnext = p->u.conv.snext;

	/*
	 * Start conversion.
	 */
	odata += p->u.conv.bfirst;
	for (f = scount * nch; f > 0; f--) {
		s = *idata++;
		s <<= 16;
		s >>= oshift;
		s ^= osigbit;
		for (i = obps; i > 0; i--) {
			*odata = (unsigned char)s;
			s >>= 8;
			odata += obnext;
		}
		odata += osnext;
	}

	/*
	 * Update FIFO pointers.
	 */
	abuf_rdiscard(ibuf, scount * ibuf->bpf);
	abuf_wcommit(obuf, scount * obuf->bpf);
}

int
enc_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	enc_bcopy(p, ibuf, obuf);
	if (!abuf_flush(obuf))
		return 0;
	return 1;
}

int
enc_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);

	if (!abuf_fill(ibuf))
		return 0;
	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	enc_bcopy(p, ibuf, obuf);
	return 1;
}

void
enc_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
enc_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

struct aproc_ops enc_ops = {
	"enc",
	enc_in,
	enc_out,
	enc_eof,
	enc_hup,
	NULL,
	NULL,
	aproc_ipos,
	aproc_opos,
	NULL
};

struct aproc *
enc_new(char *name, struct aparams *par)
{
	struct aproc *p;

	p = aproc_new(&enc_ops, name);
	p->u.conv.bps = par->bps;
	p->u.conv.sigbit = par->sig ? 0 : 1 << (par->bits - 1);
	if (par->msb) {
		p->u.conv.shift = 32 - par->bps * 8;
	} else {
		p->u.conv.shift = 32 - par->bits;
	}
	if (!par->le) {
		p->u.conv.bfirst = par->bps - 1;
		p->u.conv.bnext = -1;
		p->u.conv.snext = 2 * par->bps;
	} else {
		p->u.conv.bfirst = 0;
		p->u.conv.bnext = 1;
		p->u.conv.snext = 0;
	}
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": new ");
		aparams_dbg(par);
		dbg_puts("\n");
	}
#endif
	return p;
}

/*
 * Convert one block.
 */
void
dec_bcopy(struct aproc *p, struct abuf *ibuf, struct abuf *obuf)
{
	unsigned nch, scount, icount, ocount;
	unsigned f;
	unsigned ibps;
	unsigned i;
	int s = 0xdeadbeef;
	unsigned char *idata;
	int ibnext;
	int isnext;
	int isigbit;
	unsigned ishift;
	short *odata;

	/*
	 * Calculate max frames readable at once from the input buffer.
	 */
	idata = abuf_rgetblk(ibuf, &icount, 0);
	icount /= ibuf->bpf;
	if (icount == 0)
		return;
	odata = (short *)abuf_wgetblk(obuf, &ocount, 0);
	ocount /= obuf->bpf;
	if (ocount == 0)
		return;
	scount = (icount < ocount) ? icount : ocount;
	nch = obuf->cmax - obuf->cmin + 1;
#ifdef DEBUG
	if (debug_level >= 4) {
		aproc_dbg(p);
		dbg_puts(": bcopy ");
		dbg_putu(scount);
		dbg_puts(" fr * ");
		dbg_putu(nch);
		dbg_puts(" ch\n");
	}
#endif
	/*
	 * Partially copy structures into local variables, to avoid
	 * unnecessary indirections; this also allows the compiler to
	 * order local variables more "cache-friendly".
	 */
	ibps = p->u.conv.bps;
	ibnext = p->u.conv.bnext;
	isigbit = p->u.conv.sigbit;
	ishift = p->u.conv.shift;
	isnext = p->u.conv.snext;

	/*
	 * Start conversion.
	 */
	idata += p->u.conv.bfirst;
	for (f = scount * nch; f > 0; f--) {
		for (i = ibps; i > 0; i--) {
			s <<= 8;
			s |= *idata;
			idata += ibnext;
		}
		idata += isnext;
		s ^= isigbit;
		s <<= ishift;
		s >>= 16;
		*odata++ = s;
	}

	/*
	 * Update FIFO pointers.
	 */
	abuf_rdiscard(ibuf, scount * ibuf->bpf);
	abuf_wcommit(obuf, scount * obuf->bpf);
}

int
dec_in(struct aproc *p, struct abuf *ibuf)
{
	struct abuf *obuf = LIST_FIRST(&p->obuflist);

	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	dec_bcopy(p, ibuf, obuf);
	if (!abuf_flush(obuf))
		return 0;
	return 1;
}

int
dec_out(struct aproc *p, struct abuf *obuf)
{
	struct abuf *ibuf = LIST_FIRST(&p->ibuflist);

	if (!abuf_fill(ibuf))
		return 0;
	if (!ABUF_WOK(obuf) || !ABUF_ROK(ibuf))
		return 0;
	dec_bcopy(p, ibuf, obuf);
	return 1;
}

void
dec_eof(struct aproc *p, struct abuf *ibuf)
{
	aproc_del(p);
}

void
dec_hup(struct aproc *p, struct abuf *obuf)
{
	aproc_del(p);
}

struct aproc_ops dec_ops = {
	"dec",
	dec_in,
	dec_out,
	dec_eof,
	dec_hup,
	NULL,
	NULL,
	aproc_ipos,
	aproc_opos,
	NULL
};

struct aproc *
dec_new(char *name, struct aparams *par)
{
	struct aproc *p;

	p = aproc_new(&dec_ops, name);
	p->u.conv.bps = par->bps;
	p->u.conv.sigbit = par->sig ? 0 : 1 << (par->bits - 1);
	if (par->msb) {
		p->u.conv.shift = 32 - par->bps * 8;
	} else {
		p->u.conv.shift = 32 - par->bits;
	}
	if (par->le) {
		p->u.conv.bfirst = par->bps - 1;
		p->u.conv.bnext = -1;
		p->u.conv.snext = 2 * par->bps;
	} else {
		p->u.conv.bfirst = 0;
		p->u.conv.bnext = 1;
		p->u.conv.snext = 0;
	}
#ifdef DEBUG
	if (debug_level >= 3) {
		aproc_dbg(p);
		dbg_puts(": new ");
		aparams_dbg(par);
		dbg_puts("\n");
	}
#endif
	return p;
}