include/asterisk/dsp.h

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  * \brief Convenient Signal Processing routines
  21  */
  22
  23 #ifndef _ASTERISK_DSP_H
  24 #define _ASTERISK_DSP_H
  25
  26 #define DSP_FEATURE_SILENCE_SUPPRESS    (1 << 0)
  27 #define DSP_FEATURE_BUSY_DETECT         (1 << 1)
  28 #define DSP_FEATURE_DTMF_DETECT         (1 << 3)
  29 #define DSP_FEATURE_FAX_DETECT          (1 << 4)
  30
  31 #define DSP_DIGITMODE_DTMF                      0                               /* Detect DTMF digits */
  32 #define DSP_DIGITMODE_MF                        1                               /* Detect MF digits */
  33
  34 #define DSP_DIGITMODE_NOQUELCH          (1 << 8)                /* Do not quelch DTMF from in-band */
  35 #define DSP_DIGITMODE_MUTECONF          (1 << 9)                /* Mute conference */
  36 #define DSP_DIGITMODE_MUTEMAX           (1 << 10)               /* Delay audio by a frame to try to extra quelch */
  37 #define DSP_DIGITMODE_RELAXDTMF         (1 << 11)               /* "Radio" mode (relaxed DTMF) */
  38
  39 #define DSP_PROGRESS_TALK               (1 << 16)               /* Enable talk detection */
  40 #define DSP_PROGRESS_RINGING            (1 << 17)               /* Enable calling tone detection */
  41 #define DSP_PROGRESS_BUSY               (1 << 18)               /* Enable busy tone detection */
  42 #define DSP_PROGRESS_CONGESTION         (1 << 19)               /* Enable congestion tone detection */
  43 #define DSP_FEATURE_CALL_PROGRESS       (DSP_PROGRESS_TALK | DSP_PROGRESS_RINGING | DSP_PROGRESS_BUSY | DSP_PROGRESS_CONGESTION)
  44
  45 #define DSP_TONE_STATE_SILENCE  0
  46 #define DSP_TONE_STATE_RINGING  1
  47 #define DSP_TONE_STATE_DIALTONE 2
  48 #define DSP_TONE_STATE_TALKING  3
  49 #define DSP_TONE_STATE_BUSY     4
  50 #define DSP_TONE_STATE_SPECIAL1 5
  51 #define DSP_TONE_STATE_SPECIAL2 6
  52 #define DSP_TONE_STATE_SPECIAL3 7
  53 #define DSP_TONE_STATE_HUNGUP   8
  54
  55 struct ast_dsp;
  56
  57 struct ast_dsp *ast_dsp_new(void);
  58 void ast_dsp_free(struct ast_dsp *dsp);
  59
  60 /*! \brief Set threshold value for silence */
  61 void ast_dsp_set_threshold(struct ast_dsp *dsp, int threshold);
  62
  63 /*! \brief Set number of required cadences for busy */
  64 void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences);
  65
  66 /*! \brief Set expected lengths of the busy tone */
  67 void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength);
  68
  69 /*! \brief Scans for progress indication in audio */
  70 int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf);
  71
  72 /*! \brief Set zone for doing progress detection */
  73 int ast_dsp_set_call_progress_zone(struct ast_dsp *dsp, char *zone);
  74
  75 /*! \brief Return AST_FRAME_NULL frames when there is silence, AST_FRAME_BUSY on
  76    busies, and call progress, all dependent upon which features are enabled */
  77 struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp, struct ast_frame *inf);
  78
  79 /*! \brief Return non-zero if this is silence.  Updates "totalsilence" with the total
  80    number of seconds of silence  */
  81 int ast_dsp_silence(struct ast_dsp *dsp, struct ast_frame *f, int *totalsilence);
  82
  83 /*! \brief Return non-zero if historically this should be a busy, request that
  84   ast_dsp_silence has already been called */
  85 int ast_dsp_busydetect(struct ast_dsp *dsp);
  86
  87 /*! \brief Return non-zero if DTMF hit was found */
  88 int ast_dsp_digitdetect(struct ast_dsp *dsp, struct ast_frame *f);
  89
  90 /*! \brief Reset total silence count */
  91 void ast_dsp_reset(struct ast_dsp *dsp);
  92
  93 /*! \brief Reset DTMF detector */
  94 void ast_dsp_digitreset(struct ast_dsp *dsp);
  95
  96 /*! \brief Select feature set */
  97 void ast_dsp_set_features(struct ast_dsp *dsp, int features);
  98
  99 /*! \brief Get pending DTMF/MF digits */
 100 int ast_dsp_getdigits(struct ast_dsp *dsp, char *buf, int max);
 101
 102 /*! \brief Set digit mode */
 103 int ast_dsp_digitmode(struct ast_dsp *dsp, int digitmode);
 104
 105 /*! \brief Get tstate (Tone State) */
 106 int ast_dsp_get_tstate(struct ast_dsp *dsp);
 107
 108 /*! \brief Get tcount (Threshold counter) */
 109 int ast_dsp_get_tcount(struct ast_dsp *dsp);
 110
 111 /*!
 112  * \brief Hint that a frame from a dsp was freed
 113  *
 114  * This is called from ast_frame_free if AST_FRFLAG_FROM_DSP is set. This occurs
 115  * because it is possible for the dsp to be freed while someone still holds a reference
 116  * to the frame that is in that dsp. This has been known to happen when the dsp on a Zap
 117  * channel detects a busy signal. The channel is hung up, and the application that read the
 118  * frame to begin with still has a reference to the frame.
 119  *
 120  * \return nothing
 121  */
 122 void ast_dsp_frame_freed(struct ast_frame *fr);
 123
 124 #endif /* _ASTERISK_DSP_H */