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