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Diffstat (limited to '1.2-netsec/include/asterisk/tdd.h')
-rw-r--r-- | 1.2-netsec/include/asterisk/tdd.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/1.2-netsec/include/asterisk/tdd.h b/1.2-netsec/include/asterisk/tdd.h new file mode 100644 index 000000000..66af1e52f --- /dev/null +++ b/1.2-netsec/include/asterisk/tdd.h @@ -0,0 +1,82 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 1999 - 2005, Digium, Inc. + * + * Mark Spencer <markster@digium.com> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/*! \file + * \brief TTY/TDD Generation support + * \note Includes code and algorithms from the Zapata library. + */ + +#ifndef _ASTERISK_TDD_H +#define _ASTERISK_TDD_H + +#define TDD_BYTES_PER_CHAR 2700 + +struct tdd_state; +typedef struct tdd_state TDDSTATE; + +/*! CallerID Initialization */ +/*! + * Initializes the TDD system. Mostly stuff for inverse FFT + */ +extern void tdd_init(void); + +/*! Generates a CallerID FSK stream in ulaw format suitable for transmission. */ +/*! + * \param tdd tdd structure + * \param buf Buffer to use. This needs to be large enough to accomodate all the generated samples. + * \param string This is the string to send. + * This function creates a stream of TDD data in ulaw format. It returns the size + * (in bytes) of the data (if it returns a size of 0, there is probably an error) +*/ +extern int tdd_generate(struct tdd_state *tdd, unsigned char *buf, const char *string); + +/*! Create a TDD state machine */ +/*! + * This function returns a malloc'd instance of the tdd_state data structure. + * Returns a pointer to a malloc'd tdd_state structure, or NULL on error. + */ +extern struct tdd_state *tdd_new(void); + +/*! Read samples into the state machine, and return character (if any). */ +/*! + * \param tdd Which state machine to act upon + * \param ubuf containing your samples + * \param samples number of samples contained within the buffer. + * + * Send received audio to the TDD demodulator. + * Returns -1 on error, 0 for "needs more samples", + * and > 0 (the character) if reception of a character is complete. + */ +extern int tdd_feed(struct tdd_state *tdd, unsigned char *ubuf, int samples); + +/*! Free a TDD state machine */ +/*! + * \param tdd This is the tdd_state state machine to free + * This function frees tdd_state tdd. + */ +extern void tdd_free(struct tdd_state *tdd); + +/*! Generate Echo Canceller diable tone (2100HZ) */ +/*! + * \param outbuf This is the buffer to receive the tone data + * \param len This is the length (in samples) of the tone data to generate + * Returns 0 if no error, and -1 if error. + */ +extern int ast_tdd_gen_ecdisa(unsigned char *outbuf, int len); + +#endif /* _ASTERISK_TDD_H */ |