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 Asterisk internal frame definitions. 00021 * \arg For an explanation of frames, see \ref Def_Frame 00022 * \arg Frames are send of Asterisk channels, see \ref Def_Channel 00023 */ 00024 00025 #ifndef _ASTERISK_FRAME_H 00026 #define _ASTERISK_FRAME_H 00027 00028 #if defined(__cplusplus) || defined(c_plusplus) 00029 extern "C" { 00030 #endif 00031 00032 #include <sys/types.h> 00033 #include <sys/time.h> 00034 00035 #include "asterisk/compiler.h" 00036 #include "asterisk/endian.h" 00037 #include "asterisk/linkedlists.h" 00038 00039 struct ast_codec_pref { 00040 char order[32]; 00041 char framing[32]; 00042 }; 00043 00044 /*! \page Def_Frame AST Multimedia and signalling frames 00045 \section Def_AstFrame What is an ast_frame ? 00046 A frame of data read used to communicate between 00047 between channels and applications. 00048 Frames are divided into frame types and subclasses. 00049 00050 \par Frame types 00051 \arg \b VOICE: Voice data, subclass is codec (AST_FORMAT_*) 00052 \arg \b VIDEO: Video data, subclass is codec (AST_FORMAT_*) 00053 \arg \b DTMF: A DTMF digit, subclass is the digit 00054 \arg \b IMAGE: Image transport, mostly used in IAX 00055 \arg \b TEXT: Text messages 00056 \arg \b HTML: URL's and web pages 00057 \arg \b MODEM: Modulated data encodings, such as T.38 and V.150 00058 \arg \b IAX: Private frame type for the IAX protocol 00059 \arg \b CNG: Comfort noice frames 00060 \arg \b CONTROL: A control frame, subclass defined as AST_CONTROL_ 00061 \arg \b NULL: Empty, useless frame 00062 00063 \par Files 00064 \arg frame.h Definitions 00065 \arg frame.c Function library 00066 \arg \ref Def_Channel Asterisk channels 00067 \section Def_ControlFrame Control Frames 00068 Control frames send signalling information between channels 00069 and devices. They are prefixed with AST_CONTROL_, like AST_CONTROL_FRAME_HANGUP 00070 \arg \b HANGUP The other end has hungup 00071 \arg \b RING Local ring 00072 \arg \b RINGING The other end is ringing 00073 \arg \b ANSWER The other end has answered 00074 \arg \b BUSY Remote end is busy 00075 \arg \b TAKEOFFHOOK Make it go off hook (what's "it" ? ) 00076 \arg \b OFFHOOK Line is off hook 00077 \arg \b CONGESTION Congestion (circuit is busy, not available) 00078 \arg \b FLASH Other end sends flash hook 00079 \arg \b WINK Other end sends wink 00080 \arg \b OPTION Send low-level option 00081 \arg \b RADIO_KEY Key radio (see app_rpt.c) 00082 \arg \b RADIO_UNKEY Un-key radio (see app_rpt.c) 00083 \arg \b PROGRESS Other end indicates call progress 00084 \arg \b PROCEEDING Indicates proceeding 00085 \arg \b HOLD Call is placed on hold 00086 \arg \b UNHOLD Call is back from hold 00087 \arg \b VIDUPDATE Video update requested 00088 \arg \b SRCUPDATE The source of media has changed (RTP marker bit must change) 00089 \arg \b SRCCHANGE Media source has changed (RTP marker bit and SSRC must change) 00090 00091 */ 00092 00093 /*! 00094 * \brief Frame types 00095 * 00096 * \note It is important that the values of each frame type are never changed, 00097 * because it will break backwards compatability with older versions. 00098 */ 00099 enum ast_frame_type { 00100 /*! DTMF end event, subclass is the digit */ 00101 AST_FRAME_DTMF_END = 1, 00102 /*! Voice data, subclass is AST_FORMAT_* */ 00103 AST_FRAME_VOICE, 00104 /*! Video frame, maybe?? :) */ 00105 AST_FRAME_VIDEO, 00106 /*! A control frame, subclass is AST_CONTROL_* */ 00107 AST_FRAME_CONTROL, 00108 /*! An empty, useless frame */ 00109 AST_FRAME_NULL, 00110 /*! Inter Asterisk Exchange private frame type */ 00111 AST_FRAME_IAX, 00112 /*! Text messages */ 00113 AST_FRAME_TEXT, 00114 /*! Image Frames */ 00115 AST_FRAME_IMAGE, 00116 /*! HTML Frame */ 00117 AST_FRAME_HTML, 00118 /*! Comfort Noise frame (subclass is level of CNG in -dBov), 00119 body may include zero or more 8-bit quantization coefficients */ 00120 AST_FRAME_CNG, 00121 /*! Modem-over-IP data streams */ 00122 AST_FRAME_MODEM, 00123 /*! DTMF begin event, subclass is the digit */ 00124 AST_FRAME_DTMF_BEGIN, 00125 }; 00126 #define AST_FRAME_DTMF AST_FRAME_DTMF_END 00127 00128 enum { 00129 /*! This frame contains valid timing information */ 00130 AST_FRFLAG_HAS_TIMING_INFO = (1 << 0), 00131 }; 00132 00133 /*! \brief Data structure associated with a single frame of data 00134 */ 00135 struct ast_frame { 00136 /*! Kind of frame */ 00137 enum ast_frame_type frametype; 00138 /*! Subclass, frame dependent */ 00139 int subclass; 00140 /*! Length of data */ 00141 int datalen; 00142 /*! Number of samples in this frame */ 00143 int samples; 00144 /*! Was the data malloc'd? i.e. should we free it when we discard the frame? */ 00145 int mallocd; 00146 /*! The number of bytes allocated for a malloc'd frame header */ 00147 size_t mallocd_hdr_len; 00148 /*! How many bytes exist _before_ "data" that can be used if needed */ 00149 int offset; 00150 /*! Optional source of frame for debugging */ 00151 const char *src; 00152 /*! Pointer to actual data */ 00153 void *data; 00154 /*! Global delivery time */ 00155 struct timeval delivery; 00156 /*! For placing in a linked list */ 00157 AST_LIST_ENTRY(ast_frame) frame_list; 00158 /*! Misc. frame flags */ 00159 unsigned int flags; 00160 /*! Timestamp in milliseconds */ 00161 long ts; 00162 /*! Length in milliseconds */ 00163 long len; 00164 /*! Sequence number */ 00165 int seqno; 00166 }; 00167 00168 /*! 00169 * Set the various field of a frame to point to a buffer. 00170 * Typically you set the base address of the buffer, the offset as 00171 * AST_FRIENDLY_OFFSET, and the datalen as the amount of bytes queued. 00172 * The remaining things (to be done manually) is set the number of 00173 * samples, which cannot be derived from the datalen unless you know 00174 * the number of bits per sample. 00175 */ 00176 #define AST_FRAME_SET_BUFFER(fr, _base, _ofs, _datalen) \ 00177 { \ 00178 (fr)->data = (char *)_base + (_ofs); \ 00179 (fr)->offset = (_ofs); \ 00180 (fr)->datalen = (_datalen); \ 00181 } 00182 00183 /*! Queueing a null frame is fairly common, so we declare a global null frame object 00184 for this purpose instead of having to declare one on the stack */ 00185 extern struct ast_frame ast_null_frame; 00186 00187 #define AST_FRIENDLY_OFFSET 64 /*! It's polite for a a new frame to 00188 have this number of bytes for additional 00189 headers. */ 00190 #define AST_MIN_OFFSET 32 /*! Make sure we keep at least this much handy */ 00191 00192 /*! Need the header be free'd? */ 00193 #define AST_MALLOCD_HDR (1 << 0) 00194 /*! Need the data be free'd? */ 00195 #define AST_MALLOCD_DATA (1 << 1) 00196 /*! Need the source be free'd? (haha!) */ 00197 #define AST_MALLOCD_SRC (1 << 2) 00198 00199 /* MODEM subclasses */ 00200 /*! T.38 Fax-over-IP */ 00201 #define AST_MODEM_T38 1 00202 /*! V.150 Modem-over-IP */ 00203 #define AST_MODEM_V150 2 00204 00205 /* HTML subclasses */ 00206 /*! Sending a URL */ 00207 #define AST_HTML_URL 1 00208 /*! Data frame */ 00209 #define AST_HTML_DATA 2 00210 /*! Beginning frame */ 00211 #define AST_HTML_BEGIN 4 00212 /*! End frame */ 00213 #define AST_HTML_END 8 00214 /*! Load is complete */ 00215 #define AST_HTML_LDCOMPLETE 16 00216 /*! Peer is unable to support HTML */ 00217 #define AST_HTML_NOSUPPORT 17 00218 /*! Send URL, and track */ 00219 #define AST_HTML_LINKURL 18 00220 /*! No more HTML linkage */ 00221 #define AST_HTML_UNLINK 19 00222 /*! Reject link request */ 00223 #define AST_HTML_LINKREJECT 20 00224 00225 /* Data formats for capabilities and frames alike */ 00226 /*! G.723.1 compression */ 00227 #define AST_FORMAT_G723_1 (1 << 0) 00228 /*! GSM compression */ 00229 #define AST_FORMAT_GSM (1 << 1) 00230 /*! Raw mu-law data (G.711) */ 00231 #define AST_FORMAT_ULAW (1 << 2) 00232 /*! Raw A-law data (G.711) */ 00233 #define AST_FORMAT_ALAW (1 << 3) 00234 /*! ADPCM (G.726, 32kbps, AAL2 codeword packing) */ 00235 #define AST_FORMAT_G726_AAL2 (1 << 4) 00236 /*! ADPCM (IMA) */ 00237 #define AST_FORMAT_ADPCM (1 << 5) 00238 /*! Raw 16-bit Signed Linear (8000 Hz) PCM */ 00239 #define AST_FORMAT_SLINEAR (1 << 6) 00240 /*! LPC10, 180 samples/frame */ 00241 #define AST_FORMAT_LPC10 (1 << 7) 00242 /*! G.729A audio */ 00243 #define AST_FORMAT_G729A (1 << 8) 00244 /*! SpeeX Free Compression */ 00245 #define AST_FORMAT_SPEEX (1 << 9) 00246 /*! iLBC Free Compression */ 00247 #define AST_FORMAT_ILBC (1 << 10) 00248 /*! ADPCM (G.726, 32kbps, RFC3551 codeword packing) */ 00249 #define AST_FORMAT_G726 (1 << 11) 00250 /*! G.722 */ 00251 #define AST_FORMAT_G722 (1 << 12) 00252 /*! Unsupported audio bits */ 00253 #define AST_FORMAT_AUDIO_UNDEFINED ((1 << 13) | (1 << 14) | (1 << 15)) 00254 /*! Maximum audio format */ 00255 #define AST_FORMAT_MAX_AUDIO (1 << 15) 00256 /*! Maximum audio mask */ 00257 #define AST_FORMAT_AUDIO_MASK ((1 << 16)-1) 00258 /*! JPEG Images */ 00259 #define AST_FORMAT_JPEG (1 << 16) 00260 /*! PNG Images */ 00261 #define AST_FORMAT_PNG (1 << 17) 00262 /*! H.261 Video */ 00263 #define AST_FORMAT_H261 (1 << 18) 00264 /*! H.263 Video */ 00265 #define AST_FORMAT_H263 (1 << 19) 00266 /*! H.263+ Video */ 00267 #define AST_FORMAT_H263_PLUS (1 << 20) 00268 /*! H.264 Video */ 00269 #define AST_FORMAT_H264 (1 << 21) 00270 /*! Maximum video format */ 00271 #define AST_FORMAT_MAX_VIDEO (1 << 24) 00272 #define AST_FORMAT_VIDEO_MASK (((1 << 25)-1) & ~(AST_FORMAT_AUDIO_MASK)) 00273 00274 enum ast_control_frame_type { 00275 AST_CONTROL_HANGUP = 1, /*!< Other end has hungup */ 00276 AST_CONTROL_RING = 2, /*!< Local ring */ 00277 AST_CONTROL_RINGING = 3, /*!< Remote end is ringing */ 00278 AST_CONTROL_ANSWER = 4, /*!< Remote end has answered */ 00279 AST_CONTROL_BUSY = 5, /*!< Remote end is busy */ 00280 AST_CONTROL_TAKEOFFHOOK = 6, /*!< Make it go off hook */ 00281 AST_CONTROL_OFFHOOK = 7, /*!< Line is off hook */ 00282 AST_CONTROL_CONGESTION = 8, /*!< Congestion (circuits busy) */ 00283 AST_CONTROL_FLASH = 9, /*!< Flash hook */ 00284 AST_CONTROL_WINK = 10, /*!< Wink */ 00285 AST_CONTROL_OPTION = 11, /*!< Set a low-level option */ 00286 AST_CONTROL_RADIO_KEY = 12, /*!< Key Radio */ 00287 AST_CONTROL_RADIO_UNKEY = 13, /*!< Un-Key Radio */ 00288 AST_CONTROL_PROGRESS = 14, /*!< Indicate PROGRESS */ 00289 AST_CONTROL_PROCEEDING = 15, /*!< Indicate CALL PROCEEDING */ 00290 AST_CONTROL_HOLD = 16, /*!< Indicate call is placed on hold */ 00291 AST_CONTROL_UNHOLD = 17, /*!< Indicate call is left from hold */ 00292 AST_CONTROL_VIDUPDATE = 18, /*!< Indicate video frame update */ 00293 AST_CONTROL_SRCUPDATE = 20, /*!< Indicate source of media has changed */ 00294 AST_CONTROL_SRCCHANGE = 21, /*!< Media has changed and requires a new RTP SSRC */ 00295 AST_CONTROL_END_OF_Q = 22, /*!< Indicate that this position was the end of the channel queue for a softhangup. */ 00296 }; 00297 00298 #define AST_SMOOTHER_FLAG_G729 (1 << 0) 00299 #define AST_SMOOTHER_FLAG_BE (1 << 1) 00300 00301 /* Option identifiers and flags */ 00302 #define AST_OPTION_FLAG_REQUEST 0 00303 #define AST_OPTION_FLAG_ACCEPT 1 00304 #define AST_OPTION_FLAG_REJECT 2 00305 #define AST_OPTION_FLAG_QUERY 4 00306 #define AST_OPTION_FLAG_ANSWER 5 00307 #define AST_OPTION_FLAG_WTF 6 00308 00309 /*! Verify touchtones by muting audio transmission 00310 (and reception) and verify the tone is still present */ 00311 #define AST_OPTION_TONE_VERIFY 1 00312 00313 /*! Put a compatible channel into TDD (TTY for the hearing-impared) mode */ 00314 #define AST_OPTION_TDD 2 00315 00316 /*! Relax the parameters for DTMF reception (mainly for radio use) */ 00317 #define AST_OPTION_RELAXDTMF 3 00318 00319 /*! Set (or clear) Audio (Not-Clear) Mode */ 00320 #define AST_OPTION_AUDIO_MODE 4 00321 00322 /*! Set channel transmit gain 00323 * Option data is a single signed char 00324 representing number of decibels (dB) 00325 to set gain to (on top of any gain 00326 specified in channel driver) 00327 */ 00328 #define AST_OPTION_TXGAIN 5 00329 00330 /*! Set channel receive gain 00331 * Option data is a single signed char 00332 representing number of decibels (dB) 00333 to set gain to (on top of any gain 00334 specified in channel driver) 00335 */ 00336 #define AST_OPTION_RXGAIN 6 00337 00338 /* set channel into "Operator Services" mode */ 00339 #define AST_OPTION_OPRMODE 7 00340 00341 /*! Explicitly enable or disable echo cancelation for the given channel */ 00342 #define AST_OPTION_ECHOCAN 8 00343 00344 /*! \brief Handle channel write data 00345 * If a channel needs to process the data from a func_channel write operation 00346 * after func_channel_write executes, it can define the setoption callback 00347 * and process this option. A pointer to an ast_chan_write_info_t will be passed. 00348 * */ 00349 #define AST_OPTION_CHANNEL_WRITE 9 00350 00351 struct oprmode { 00352 struct ast_channel *peer; 00353 int mode; 00354 } ; 00355 00356 struct ast_option_header { 00357 /* Always keep in network byte order */ 00358 #if __BYTE_ORDER == __BIG_ENDIAN 00359 uint16_t flag:3; 00360 uint16_t option:13; 00361 #else 00362 #if __BYTE_ORDER == __LITTLE_ENDIAN 00363 uint16_t option:13; 00364 uint16_t flag:3; 00365 #else 00366 #error Byte order not defined 00367 #endif 00368 #endif 00369 uint8_t data[0]; 00370 }; 00371 00372 00373 /*! \brief Definition of supported media formats (codecs) */ 00374 struct ast_format_list { 00375 int visible; /*!< Can we see this entry */ 00376 int bits; /*!< bitmask value */ 00377 char *name; /*!< short name */ 00378 char *desc; /*!< Description */ 00379 int fr_len; /*!< Single frame length in bytes */ 00380 int min_ms; /*!< Min value */ 00381 int max_ms; /*!< Max value */ 00382 int inc_ms; /*!< Increment */ 00383 int def_ms; /*!< Default value */ 00384 unsigned int flags; /*!< Smoother flags */ 00385 int cur_ms; /*!< Current value */ 00386 }; 00387 00388 00389 /*! \brief Requests a frame to be allocated 00390 * 00391 * \param source 00392 * Request a frame be allocated. source is an optional source of the frame, 00393 * len is the requested length, or "0" if the caller will supply the buffer 00394 */ 00395 #if 0 /* Unimplemented */ 00396 struct ast_frame *ast_fralloc(char *source, int len); 00397 #endif 00398 00399 /*! 00400 * \brief Frees a frame or list of frames 00401 * 00402 * \param fr Frame to free, or head of list to free 00403 * \param cache Whether to consider this frame for frame caching 00404 */ 00405 void ast_frame_free(struct ast_frame *fr, int cache); 00406 00407 #define ast_frfree(fr) ast_frame_free(fr, 1) 00408 00409 /*! \brief Makes a frame independent of any static storage 00410 * \param fr frame to act upon 00411 * Take a frame, and if it's not been malloc'd, make a malloc'd copy 00412 * and if the data hasn't been malloced then make the 00413 * data malloc'd. If you need to store frames, say for queueing, then 00414 * you should call this function. 00415 * \return Returns a frame on success, NULL on error 00416 * \note This function may modify the frame passed to it, so you must 00417 * not assume the frame will be intact after the isolated frame has 00418 * been produced. In other words, calling this function on a frame 00419 * should be the last operation you do with that frame before freeing 00420 * it (or exiting the block, if the frame is on the stack.) 00421 */ 00422 struct ast_frame *ast_frisolate(struct ast_frame *fr); 00423 00424 /*! \brief Copies a frame 00425 * \param fr frame to copy 00426 * Duplicates a frame -- should only rarely be used, typically frisolate is good enough 00427 * \return Returns a frame on success, NULL on error 00428 */ 00429 struct ast_frame *ast_frdup(const struct ast_frame *fr); 00430 00431 void ast_swapcopy_samples(void *dst, const void *src, int samples); 00432 00433 /* Helpers for byteswapping native samples to/from 00434 little-endian and big-endian. */ 00435 #if __BYTE_ORDER == __LITTLE_ENDIAN 00436 #define ast_frame_byteswap_le(fr) do { ; } while(0) 00437 #define ast_frame_byteswap_be(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data, __f->data, __f->samples); } while(0) 00438 #else 00439 #define ast_frame_byteswap_le(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data, __f->data, __f->samples); } while(0) 00440 #define ast_frame_byteswap_be(fr) do { ; } while(0) 00441 #endif 00442 00443 00444 /*! \brief Get the name of a format 00445 * \param format id of format 00446 * \return A static string containing the name of the format or "unknown" if unknown. 00447 */ 00448 char* ast_getformatname(int format); 00449 00450 /*! \brief Get the names of a set of formats 00451 * \param buf a buffer for the output string 00452 * \param size size of buf (bytes) 00453 * \param format the format (combined IDs of codecs) 00454 * Prints a list of readable codec names corresponding to "format". 00455 * ex: for format=AST_FORMAT_GSM|AST_FORMAT_SPEEX|AST_FORMAT_ILBC it will return "0x602 (GSM|SPEEX|ILBC)" 00456 * \return The return value is buf. 00457 */ 00458 char* ast_getformatname_multiple(char *buf, size_t size, int format); 00459 00460 /*! 00461 * \brief Gets a format from a name. 00462 * \param name string of format 00463 * \return This returns the form of the format in binary on success, 0 on error. 00464 */ 00465 int ast_getformatbyname(const char *name); 00466 00467 /*! \brief Get a name from a format 00468 * Gets a name from a format 00469 * \param codec codec number (1,2,4,8,16,etc.) 00470 * \return This returns a static string identifying the format on success, 0 on error. 00471 */ 00472 char *ast_codec2str(int codec); 00473 00474 struct ast_smoother; 00475 00476 struct ast_format_list *ast_get_format_list_index(int index); 00477 struct ast_format_list *ast_get_format_list(size_t *size); 00478 struct ast_smoother *ast_smoother_new(int bytes); 00479 void ast_smoother_set_flags(struct ast_smoother *smoother, int flags); 00480 int ast_smoother_get_flags(struct ast_smoother *smoother); 00481 int ast_smoother_test_flag(struct ast_smoother *s, int flag); 00482 void ast_smoother_free(struct ast_smoother *s); 00483 void ast_smoother_reset(struct ast_smoother *s, int bytes); 00484 00485 /*! 00486 * \brief Reconfigure an existing smoother to output a different number of bytes per frame 00487 * \param s the smoother to reconfigure 00488 * \param bytes the desired number of bytes per output frame 00489 * \return nothing 00490 * 00491 */ 00492 void ast_smoother_reconfigure(struct ast_smoother *s, int bytes); 00493 00494 int __ast_smoother_feed(struct ast_smoother *s, struct ast_frame *f, int swap); 00495 struct ast_frame *ast_smoother_read(struct ast_smoother *s); 00496 #define ast_smoother_feed(s,f) __ast_smoother_feed(s, f, 0) 00497 #if __BYTE_ORDER == __LITTLE_ENDIAN 00498 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 1) 00499 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 0) 00500 #else 00501 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 0) 00502 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 1) 00503 #endif 00504 00505 void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix); 00506 00507 /*! \page AudioCodecPref Audio Codec Preferences 00508 In order to negotiate audio codecs in the order they are configured 00509 in <channel>.conf for a device, we set up codec preference lists 00510 in addition to the codec capabilities setting. The capabilities 00511 setting is a bitmask of audio and video codecs with no internal 00512 order. This will reflect the offer given to the other side, where 00513 the prefered codecs will be added to the top of the list in the 00514 order indicated by the "allow" lines in the device configuration. 00515 00516 Video codecs are not included in the preference lists since they 00517 can't be transcoded and we just have to pick whatever is supported 00518 */ 00519 00520 /*! \brief Initialize an audio codec preference to "no preference" See \ref AudioCodecPref */ 00521 void ast_codec_pref_init(struct ast_codec_pref *pref); 00522 00523 /*! \brief Codec located at a particular place in the preference index See \ref AudioCodecPref */ 00524 int ast_codec_pref_index(struct ast_codec_pref *pref, int index); 00525 00526 /*! \brief Remove audio a codec from a preference list */ 00527 void ast_codec_pref_remove(struct ast_codec_pref *pref, int format); 00528 00529 /*! \brief Append a audio codec to a preference list, removing it first if it was already there 00530 */ 00531 int ast_codec_pref_append(struct ast_codec_pref *pref, int format); 00532 00533 /*! \brief Prepend an audio codec to a preference list, removing it first if it was already there 00534 */ 00535 void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing); 00536 00537 /*! \brief Select the best audio format according to preference list from supplied options. 00538 If "find_best" is non-zero then if nothing is found, the "Best" format of 00539 the format list is selected, otherwise 0 is returned. */ 00540 int ast_codec_choose(struct ast_codec_pref *pref, int formats, int find_best); 00541 00542 /*! \brief Set packet size for codec 00543 */ 00544 int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems); 00545 00546 /*! \brief Get packet size for codec 00547 */ 00548 struct ast_format_list ast_codec_pref_getsize(struct ast_codec_pref *pref, int format); 00549 00550 /*! \brief Parse an "allow" or "deny" line in a channel or device configuration 00551 and update the capabilities mask and pref if provided. 00552 Video codecs are not added to codec preference lists, since we can not transcode 00553 */ 00554 void ast_parse_allow_disallow(struct ast_codec_pref *pref, int *mask, const char *list, int allowing); 00555 00556 /*! \brief Dump audio codec preference list into a string */ 00557 int ast_codec_pref_string(struct ast_codec_pref *pref, char *buf, size_t size); 00558 00559 /*! \brief Shift an audio codec preference list up or down 65 bytes so that it becomes an ASCII string 00560 * \note Due to a misunderstanding in how codec preferences are stored, this 00561 * list starts at 'B', not 'A'. For backwards compatibility reasons, this 00562 * cannot change. 00563 * \param pref A codec preference list structure 00564 * \param buf A string denoting codec preference, appropriate for use in line transmission 00565 * \param size Size of \a buf 00566 * \param right Boolean: if 0, convert from \a buf to \a pref; if 1, convert from \a pref to \a buf. 00567 */ 00568 void ast_codec_pref_convert(struct ast_codec_pref *pref, char *buf, size_t size, int right); 00569 00570 /*! \brief Returns the number of samples contained in the frame */ 00571 int ast_codec_get_samples(struct ast_frame *f); 00572 00573 /*! \brief Returns the number of bytes for the number of samples of the given format */ 00574 int ast_codec_get_len(int format, int samples); 00575 00576 /*! \brief Appends a frame to the end of a list of frames, truncating the maximum length of the list */ 00577 struct ast_frame *ast_frame_enqueue(struct ast_frame *head, struct ast_frame *f, int maxlen, int dupe); 00578 00579 00580 /*! \brief Gets duration in ms of interpolation frame for a format */ 00581 static inline int ast_codec_interp_len(int format) 00582 { 00583 return (format == AST_FORMAT_ILBC) ? 30 : 20; 00584 } 00585 00586 /*! 00587 \brief Adjusts the volume of the audio samples contained in a frame. 00588 \param f The frame containing the samples (must be AST_FRAME_VOICE and AST_FORMAT_SLINEAR) 00589 \param adjustment The number of dB to adjust up or down. 00590 \return 0 for success, non-zero for an error 00591 */ 00592 int ast_frame_adjust_volume(struct ast_frame *f, int adjustment); 00593 00594 /*! 00595 \brief Sums two frames of audio samples. 00596 \param f1 The first frame (which will contain the result) 00597 \param f2 The second frame 00598 \return 0 for success, non-zero for an error 00599 00600 The frames must be AST_FRAME_VOICE and must contain AST_FORMAT_SLINEAR samples, 00601 and must contain the same number of samples. 00602 */ 00603 int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2); 00604 00605 /*! 00606 * \brief Get the sample rate for a given format. 00607 */ 00608 static force_inline int ast_format_rate(int format) 00609 { 00610 if (format == AST_FORMAT_G722) 00611 return 16000; 00612 00613 return 8000; 00614 } 00615 00616 #if defined(__cplusplus) || defined(c_plusplus) 00617 } 00618 #endif 00619 00620 #endif /* _ASTERISK_FRAME_H */