/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Convenient Signal Processing routines
 * 
 * Copyright (C) 1999, Mark Spencer
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#ifndef _ASTERISK_DSP_H
#define _ASTERISK_DSP_H

#define DSP_FEATURE_SILENCE_SUPPRESS (1 << 0)
#define DSP_FEATURE_BUSY_DETECT      (1 << 1)
#define DSP_FEATURE_CALL_PROGRESS    (1 << 2)
#define DSP_FEATURE_DTMF_DETECT		 (1 << 3)

#define	DSP_DIGITMODE_DTMF			0				/* Detect DTMF digits */
#define DSP_DIGITMODE_MF			1				/* Detect MF digits */

#define DSP_DIGITMODE_NOQUELCH		(1 << 8)		/* Do not quelch DTMF from in-band */
#define DSP_DIGITMODE_MUTECONF		(1 << 9)		/* Mute conference */
#define DSP_DIGITMODE_MUTEMAX		(1 << 10)		/* Delay audio by a frame to try to extra quelch */
#define DSP_DIGITMODE_RELAXDTMF		(1 << 11)		/* "Radio" mode (relaxed DTMF) */

struct ast_dsp;

struct ast_dsp *ast_dsp_new(void);
void ast_dsp_free(struct ast_dsp *dsp);
/* Set threshold value for silence */
void ast_dsp_set_threshold(struct ast_dsp *dsp, int threshold);

/* Set number of required cadences for busy */
void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences);

/* Scans for progress indication in audio */
int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf);

/* Return AST_FRAME_NULL frames when there is silence, AST_FRAME_BUSY on 
   busies, and call progress, all dependent upon which features are enabled */
struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp, struct ast_frame *inf, int needlock);

/* Return non-zero if this is silence.  Updates "totalsilence" with the total
   number of seconds of silence  */
int ast_dsp_silence(struct ast_dsp *dsp, struct ast_frame *f, int *totalsilence);

/* Return non-zero if historically this should be a busy, request that
  ast_dsp_silence has already been called */
int ast_dsp_busydetect(struct ast_dsp *dsp);

/* Return non-zero if DTMF hit was found */
int ast_dsp_digitdetect(struct ast_dsp *dsp, struct ast_frame *f);

/* Reset total silence count */
void ast_dsp_reset(struct ast_dsp *dsp);

/* Reset DTMF detector */
void ast_dsp_digitreset(struct ast_dsp *dsp);

/* Select feature set */
void ast_dsp_set_features(struct ast_dsp *dsp, int features);

/* Get pending DTMF/MF digits */
int ast_dsp_getdigits(struct ast_dsp *dsp, char *buf, int max);

/* Set digit mode */
int ast_dsp_digitmode(struct ast_dsp *dsp, int digitmode);

#endif