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/* $OpenBSD: aproc.h,v 1.3 2008/08/14 09:45:23 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.
*/
#ifndef APROC_H
#define APROC_H
#include <sys/queue.h>
#include "aparams.h"
struct abuf;
struct aproc;
struct file;
struct aproc_ops {
/*
* Name of the ops structure, ie type of the unit.
*/
char *name;
/*
* The state of the given input abuf changed (eg. an input block
* is ready for processing). This function must get the block
* from the input, process it and remove it from the buffer.
*
* Processing the block will result in a change of the state of
* OTHER buffers that are attached to the aproc (eg. the output
* buffer was filled), thus this routine MUST notify ALL aproc
* structures that are waiting on it; most of the time this
* means just calling abuf_flush() on the output buffer.
*/
int (*in)(struct aproc *, struct abuf *);
/*
* The state of the given output abuf changed (eg. space for a
* new output block was made available) so processing can
* continue. This function must process more input in order to
* fill the output block.
*
* Producing a block will result in the change of the state of
* OTHER buffers that are attached to the aproc, thus this
* routine MUST notify ALL aproc structures that are waiting on
* it; most of the time this means calling abuf_fill() on the
* source buffers.
*
* Before filling input buffers (using abuf_fill()), this
* routine must ALWAYS check for eof condition, and if needed,
* handle it appropriately and call abuf_hup() to free the input
* buffer.
*/
int (*out)(struct aproc *, struct abuf *);
/*
* The input buffer is empty and we can no more receive data
* from it. The buffer will be destroyed as soon as this call
* returns so the abuf pointer will stop being valid after this
* call returns. There's no need to drain the buffer because the
* in() call-back was just called before.
*
* If this call reads and/or writes data on other buffers,
* abuf_flush() and abuf_fill() must be called appropriately.
*/
void (*eof)(struct aproc *, struct abuf *);
/*
* The output buffer can no more accept data (it should be
* considered as full). After this function returns, it will be
* destroyed and the "abuf" pointer will be no more valid.
*/
void (*hup)(struct aproc *, struct abuf *);
/*
* A new input was connected.
*/
void (*newin)(struct aproc *, struct abuf *);
/*
* A new output was connected
*/
void (*newout)(struct aproc *, struct abuf *);
/*
* destroy the aproc, called just before to free the
* aproc structure
*/
void (*done)(struct aproc *);
};
struct aconv {
/*
* Format of the buffer. This part is used by conversion code.
*/
int bfirst; /* bytes to skip at startup */
unsigned rate; /* frames per second */
unsigned pos; /* current position in the stream */
unsigned nch; /* number of channels: nch = cmax - cmin + 1 */
unsigned bps; /* bytes per sample (padding included) */
unsigned shift; /* shift to get 32bit MSB-justified int */
int sigbit; /* sign bits to XOR to unsigned samples */
int bnext; /* bytes to skip to reach the next byte */
int snext; /* bytes to skip to reach the next sample */
unsigned cmin; /* provided/consumed channels */
unsigned bpf; /* bytes per frame: bpf = nch * bps */
int ctx[CHAN_MAX]; /* current frame (for resampling) */
};
/*
* The aproc structure represents a simple audio processing unit; they are
* interconnected by abuf structures and form a kind of "circuit". The circuit
* cannot have loops.
*/
struct aproc {
char *name; /* for debug purposes */
struct aproc_ops *ops; /* call-backs */
LIST_HEAD(, abuf) ibuflist; /* list of inputs */
LIST_HEAD(, abuf) obuflist; /* list of outputs */
union { /* follow type-specific data */
struct { /* file/device io */
struct file *file; /* file to read/write */
} io;
struct {
struct aconv ist, ost;
} conv;
struct {
#define MIX_DROP 1
unsigned flags;
} mix;
struct {
#define SUB_DROP 1
unsigned flags;
} sub;
} u;
};
struct aproc *aproc_new(struct aproc_ops *, char *);
void aproc_del(struct aproc *);
void aproc_setin(struct aproc *, struct abuf *);
void aproc_setout(struct aproc *, struct abuf *);
struct aproc *rpipe_new(struct file *);
int rpipe_in(struct aproc *, struct abuf *);
int rpipe_out(struct aproc *, struct abuf *);
void rpipe_done(struct aproc *);
void rpipe_eof(struct aproc *, struct abuf *);
void rpipe_hup(struct aproc *, struct abuf *);
struct aproc *wpipe_new(struct file *);
void wpipe_done(struct aproc *);
int wpipe_in(struct aproc *, struct abuf *);
int wpipe_out(struct aproc *, struct abuf *);
void wpipe_eof(struct aproc *, struct abuf *);
void wpipe_hup(struct aproc *, struct abuf *);
struct aproc *mix_new(void);
struct aproc *sub_new(void);
struct aproc *conv_new(char *, struct aparams *, struct aparams *);
#endif /* !defined(FIFO_H) */
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