Wed Oct 28 11:45:37 2009

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_DTMF_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 struct ast_dsp *ast_dsp_new(void);
00062 void ast_dsp_free(struct ast_dsp *dsp);
00063 
00064 /*! \brief Set threshold value for silence */
00065 void ast_dsp_set_threshold(struct ast_dsp *dsp, int threshold);
00066 
00067 /*! \brief Set number of required cadences for busy */
00068 void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences);
00069 
00070 /*! \brief Set expected lengths of the busy tone */
00071 void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength);
00072 
00073 /*! \brief Scans for progress indication in audio */
00074 int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf);
00075 
00076 /*! \brief Set zone for doing progress detection */
00077 int ast_dsp_set_call_progress_zone(struct ast_dsp *dsp, char *zone);
00078 
00079 /*! \brief Return AST_FRAME_NULL frames when there is silence, AST_FRAME_BUSY on 
00080    busies, and call progress, all dependent upon which features are enabled */
00081 struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp, struct ast_frame *inf);
00082 
00083 /*! \brief Return non-zero if this is silence.  Updates "totalsilence" with the total
00084    number of seconds of silence  */
00085 int ast_dsp_silence(struct ast_dsp *dsp, struct ast_frame *f, int *totalsilence);
00086 
00087 /*! \brief Return non-zero if historically this should be a busy, request that
00088   ast_dsp_silence has already been called */
00089 int ast_dsp_busydetect(struct ast_dsp *dsp);
00090 
00091 /*! \brief Return non-zero if DTMF hit was found */
00092 int ast_dsp_digitdetect(struct ast_dsp *dsp, struct ast_frame *f);
00093 
00094 /*! \brief Reset total silence count */
00095 void ast_dsp_reset(struct ast_dsp *dsp);
00096 
00097 /*! \brief Reset DTMF detector */
00098 void ast_dsp_digitreset(struct ast_dsp *dsp);
00099 
00100 /*! \brief Select feature set */
00101 void ast_dsp_set_features(struct ast_dsp *dsp, int features);
00102 
00103 /*! \brief Get pending DTMF/MF digits */
00104 int ast_dsp_getdigits(struct ast_dsp *dsp, char *buf, int max);
00105 
00106 /*! \brief Set digit mode */
00107 int ast_dsp_digitmode(struct ast_dsp *dsp, int digitmode);
00108 
00109 /*! \brief Set fax mode */
00110 int ast_dsp_set_faxmode(struct ast_dsp *dsp, int faxmode);
00111 
00112 /*! \brief Get tstate (Tone State) */
00113 int ast_dsp_get_tstate(struct ast_dsp *dsp);
00114 
00115 /*! \brief Get tcount (Threshold counter) */
00116 int ast_dsp_get_tcount(struct ast_dsp *dsp);
00117 
00118 #endif /* _ASTERISK_DSP_H */

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