Wed Aug 18 22:33:51 2010

Asterisk developer's documentation


dsp.h

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  * \brief Convenient Signal Processing routines
00021  */
00022 
00023 #ifndef _ASTERISK_DSP_H
00024 #define _ASTERISK_DSP_H
00025 
00026 #define DSP_FEATURE_SILENCE_SUPPRESS   (1 << 0)
00027 #define DSP_FEATURE_BUSY_DETECT     (1 << 1)
00028 #define DSP_FEATURE_DIGIT_DETECT (1 << 3)
00029 #define DSP_FEATURE_FAX_DETECT      (1 << 4)
00030 
00031 #define  DSP_DIGITMODE_DTMF         0           /*!< Detect DTMF digits */
00032 #define DSP_DIGITMODE_MF         1           /*!< Detect MF digits */
00033 
00034 #define DSP_DIGITMODE_NOQUELCH      (1 << 8)    /*!< Do not quelch DTMF from in-band */
00035 #define DSP_DIGITMODE_MUTECONF      (1 << 9)    /*!< Mute conference */
00036 #define DSP_DIGITMODE_MUTEMAX    (1 << 10)      /*!< Delay audio by a frame to try to extra quelch */
00037 #define DSP_DIGITMODE_RELAXDTMF     (1 << 11)      /*!< "Radio" mode (relaxed DTMF) */
00038 
00039 #define DSP_PROGRESS_TALK     (1 << 16)      /*!< Enable talk detection */
00040 #define DSP_PROGRESS_RINGING     (1 << 17)      /*!< Enable calling tone detection */
00041 #define DSP_PROGRESS_BUSY     (1 << 18)      /*!< Enable busy tone detection */
00042 #define DSP_PROGRESS_CONGESTION     (1 << 19)      /*!< Enable congestion tone detection */
00043 #define DSP_FEATURE_CALL_PROGRESS   (DSP_PROGRESS_TALK | DSP_PROGRESS_RINGING | DSP_PROGRESS_BUSY | DSP_PROGRESS_CONGESTION)
00044 
00045 #define DSP_FAXMODE_DETECT_CNG   (1 << 0)
00046 #define DSP_FAXMODE_DETECT_CED   (1 << 1)
00047 #define DSP_FAXMODE_DETECT_ALL   (DSP_FAXMODE_DETECT_CNG | DSP_FAXMODE_DETECT_CED)
00048 
00049 #define DSP_TONE_STATE_SILENCE  0
00050 #define DSP_TONE_STATE_RINGING  1
00051 #define DSP_TONE_STATE_DIALTONE 2
00052 #define DSP_TONE_STATE_TALKING  3
00053 #define DSP_TONE_STATE_BUSY     4
00054 #define DSP_TONE_STATE_SPECIAL1  5
00055 #define DSP_TONE_STATE_SPECIAL2 6
00056 #define DSP_TONE_STATE_SPECIAL3 7
00057 #define DSP_TONE_STATE_HUNGUP    8
00058 
00059 struct ast_dsp;
00060 
00061 enum threshold {
00062    /* Array offsets */
00063    THRESHOLD_SILENCE = 0,
00064    /* Always the last */
00065    THRESHOLD_MAX = 1,
00066 };
00067 
00068 struct ast_dsp *ast_dsp_new(void);
00069 void ast_dsp_free(struct ast_dsp *dsp);
00070 
00071 /*! \brief Set threshold value for silence */
00072 void ast_dsp_set_threshold(struct ast_dsp *dsp, int threshold);
00073 
00074 /*! \brief Set number of required cadences for busy */
00075 void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences);
00076 
00077 /*! \brief Set if silence and noice lengths must be compared for busy */
00078 void ast_dsp_set_busy_compare(struct ast_dsp *dsp, int compare);
00079 
00080 /*! \brief Set expected lengths of the busy tones */
00081 void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength, int fuzzy);
00082 
00083 /*! \brief Scans for progress indication in audio */
00084 int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf);
00085 
00086 /*! \brief Set zone for doing progress detection */
00087 int ast_dsp_set_call_progress_zone(struct ast_dsp *dsp, char *zone);
00088 
00089 /*! \brief Return AST_FRAME_NULL frames when there is silence, AST_FRAME_BUSY on
00090    busies, and call progress, all dependent upon which features are enabled */
00091 struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp, struct ast_frame *inf);
00092 
00093 /*! \brief Return non-zero if this is silence.  Updates "totalsilence" with the total
00094    number of seconds of silence  */
00095 int ast_dsp_silence(struct ast_dsp *dsp, struct ast_frame *f, int *totalsilence);
00096 
00097 /*!
00098  * \brief Return non-zero if this is noise.  Updates "totalnoise" with the total
00099  * number of seconds of noise
00100  * \since 1.6.1
00101  */
00102 int ast_dsp_noise(struct ast_dsp *dsp, struct ast_frame *f, int *totalnoise);
00103 
00104 /*! \brief Return non-zero if historically this should be a busy, request that
00105   ast_dsp_silence has already been called */
00106 int ast_dsp_busydetect(struct ast_dsp *dsp);
00107 
00108 /*! \brief Return non-zero if DTMF hit was found */
00109 int ast_dsp_digitdetect(struct ast_dsp *dsp, struct ast_frame *f);
00110 
00111 /*! \brief Reset total silence count */
00112 void ast_dsp_reset(struct ast_dsp *dsp);
00113 
00114 /*! \brief Reset DTMF detector */
00115 void ast_dsp_digitreset(struct ast_dsp *dsp);
00116 
00117 /*! \brief Select feature set */
00118 void ast_dsp_set_features(struct ast_dsp *dsp, int features);
00119 
00120 /*! \brief Get pending DTMF/MF digits */
00121 int ast_dsp_getdigits(struct ast_dsp *dsp, char *buf, int max);
00122 
00123 /*! \brief Set digit mode
00124  * \version 1.6.1 renamed from ast_dsp_digitmode to ast_dsp_set_digitmode
00125  */
00126 int ast_dsp_set_digitmode(struct ast_dsp *dsp, int digitmode);
00127 
00128 /*! \brief Set fax mode */
00129 int ast_dsp_set_faxmode(struct ast_dsp *dsp, int faxmode);
00130 
00131 /*!
00132  * \brief Returns true if DSP code was muting any fragment of the last processed frame.
00133  * Muting (squelching) happens when DSP code removes DTMF/MF/generic tones from the audio
00134  * \since 1.6.1
00135  */
00136 int ast_dsp_was_muted(struct ast_dsp *dsp);
00137 
00138 /*! \brief Get tstate (Tone State) */
00139 int ast_dsp_get_tstate(struct ast_dsp *dsp);
00140 
00141 /*! \brief Get tcount (Threshold counter) */
00142 int ast_dsp_get_tcount(struct ast_dsp *dsp);
00143 
00144 /*!
00145  * \brief Get silence threshold from dsp.conf
00146  * \since 1.6.1
00147  */
00148 int ast_dsp_get_threshold_from_settings(enum threshold which);
00149 
00150 /*!
00151  * \brief Reloads dsp settings from dsp.conf
00152  * \since 1.6.1
00153  */
00154 int ast_dsp_reload(void);
00155 
00156 /*!
00157  * \brief Load dsp settings from dsp.conf
00158  * \since 1.6.1
00159  */
00160 int ast_dsp_init(void);
00161 
00162 #endif /* _ASTERISK_DSP_H */

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