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/* $OpenBSD: abuf.h,v 1.9 2008/10/26 08:49:43 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.
*/
#ifndef ABUF_H
#define ABUF_H
#include <sys/queue.h>
struct abuf;
struct aproc;
struct abuf {
/*
* Misc aproc-specific per-buffer parameters.
* since the buffer can connect any pair of aproc structure,
* each aproc must have it's own specific data. Thus we cannot
* use an union. The only exception is the xrun field, because
* there can be only one aproc that absorbs xruns in any
* intput->output path.
*/
int mixvol; /* input gain */
unsigned mixdone; /* input of mixer */
unsigned mixtodo; /* output of mixer */
unsigned subdone; /* output if sub */
#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 */
unsigned xrun; /* common to mix and sub */
LIST_ENTRY(abuf) ient; /* for mix inputs list */
LIST_ENTRY(abuf) oent; /* for sub outputs list */
/*
* fifo parameters
*/
unsigned bpf; /* bytes per frame */
unsigned start; /* offset where data starts */
unsigned used; /* valid data */
unsigned len; /* size of the ring */
unsigned abspos; /* frame number of the start position */
unsigned silence; /* silence to insert on next write */
unsigned drop; /* bytes to drop on next read */
struct aproc *rproc; /* reader */
struct aproc *wproc; /* writer */
struct abuf *duplex; /* link to buffer of the other direction */
unsigned inuse; /* in abuf_{flush,fill,run}() */
unsigned char *data; /* actual data (immediately following) */
};
/*
* the buffer contains at least one frame. This macro should
* be used to check if the buffer can be flushed
*/
#define ABUF_ROK(b) ((b)->used >= (b)->bpf)
/*
* there's room for at least one frame
*/
#define ABUF_WOK(b) ((b)->len - (b)->used >= (b)->bpf)
/*
* the buffer is empty and has no more writer
*/
#define ABUF_EOF(b) (!ABUF_ROK(b) && (b)->wproc == NULL)
/*
* the buffer is empty and has no more writer
*/
#define ABUF_HUP(b) (!ABUF_WOK(b) && (b)->rproc == NULL)
/*
* similar to !ABUF_WOK, but is used for file i/o, where
* operation may not involve an integer number of frames
*/
#define ABUF_FULL(b) ((b)->used == (b)->len)
/*
* same as !ABUF_ROK, but used for files, where
* operations are byte orientated, not frame-oriented
*/
#define ABUF_EMPTY(b) ((b)->used == 0)
struct abuf *abuf_new(unsigned, unsigned);
void abuf_del(struct abuf *);
unsigned char *abuf_rgetblk(struct abuf *, unsigned *, unsigned);
unsigned char *abuf_wgetblk(struct abuf *, unsigned *, unsigned);
void abuf_rdiscard(struct abuf *, unsigned);
void abuf_wcommit(struct abuf *, unsigned);
int abuf_fill(struct abuf *);
int abuf_flush(struct abuf *);
void abuf_eof(struct abuf *);
void abuf_hup(struct abuf *);
void abuf_run(struct abuf *);
void abuf_ipos(struct abuf *, int);
void abuf_opos(struct abuf *, int);
#endif /* !defined(ABUF_H) */
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