2 * Asterisk -- An open source telephony toolkit.
4 * Copyright (C) 1999 - 2005, Digium, Inc.
6 * Mark Spencer <markster@digium.com>
8 * See http://www.asterisk.org for more information about
9 * the Asterisk project. Please do not directly contact
10 * any of the maintainers of this project for assistance;
11 * the project provides a web site, mailing lists and IRC
12 * channels for your use.
14 * This program is free software, distributed under the terms of
15 * the GNU General Public License Version 2. See the LICENSE file
16 * at the top of the source tree.
20 * \brief Asterisk internal frame definitions.
21 * \arg For an explanation of frames, see \ref Def_Frame
22 * \arg Frames are send of Asterisk channels, see \ref Def_Channel
25 #ifndef _ASTERISK_FRAME_H
26 #define _ASTERISK_FRAME_H
28 #if defined(__cplusplus) || defined(c_plusplus)
34 #include "asterisk/endian.h"
35 #include "asterisk/linkedlists.h"
37 struct ast_codec_pref {
42 /*! \page Def_Frame AST Multimedia and signalling frames
43 \section Def_AstFrame What is an ast_frame ?
44 A frame of data read used to communicate between
45 between channels and applications.
46 Frames are divided into frame types and subclasses.
49 \arg \b VOICE: Voice data, subclass is codec (AST_FORMAT_*)
50 \arg \b VIDEO: Video data, subclass is codec (AST_FORMAT_*)
51 \arg \b DTMF: A DTMF digit, subclass is the digit
52 \arg \b IMAGE: Image transport, mostly used in IAX
53 \arg \b TEXT: Text messages and character by character (real time text)
54 \arg \b HTML: URL's and web pages
55 \arg \b MODEM: Modulated data encodings, such as T.38 and V.150
56 \arg \b IAX: Private frame type for the IAX protocol
57 \arg \b CNG: Comfort noice frames
58 \arg \b CONTROL: A control frame, subclass defined as AST_CONTROL_
59 \arg \b NULL: Empty, useless frame
62 \arg frame.h Definitions
63 \arg frame.c Function library
64 \arg \ref Def_Channel Asterisk channels
65 \section Def_ControlFrame Control Frames
66 Control frames send signalling information between channels
67 and devices. They are prefixed with AST_CONTROL_, like AST_CONTROL_FRAME_HANGUP
68 \arg \b HANGUP The other end has hungup
69 \arg \b RING Local ring
70 \arg \b RINGING The other end is ringing
71 \arg \b ANSWER The other end has answered
72 \arg \b BUSY Remote end is busy
73 \arg \b TAKEOFFHOOK Make it go off hook (what's "it" ? )
74 \arg \b OFFHOOK Line is off hook
75 \arg \b CONGESTION Congestion (circuit is busy, not available)
76 \arg \b FLASH Other end sends flash hook
77 \arg \b WINK Other end sends wink
78 \arg \b OPTION Send low-level option
79 \arg \b RADIO_KEY Key radio (see app_rpt.c)
80 \arg \b RADIO_UNKEY Un-key radio (see app_rpt.c)
81 \arg \b PROGRESS Other end indicates call progress
82 \arg \b PROCEEDING Indicates proceeding
83 \arg \b HOLD Call is placed on hold
84 \arg \b UNHOLD Call is back from hold
85 \arg \b VIDUPDATE Video update requested
86 \arg \b SRCUPDATE The source of media has changed
93 * \note It is important that the values of each frame type are never changed,
94 * because it will break backwards compatability with older versions.
95 * This is because these constants are transmitted directly over IAX2.
98 /*! DTMF end event, subclass is the digit */
99 AST_FRAME_DTMF_END = 1,
100 /*! Voice data, subclass is AST_FORMAT_* */
102 /*! Video frame, maybe?? :) */
104 /*! A control frame, subclass is AST_CONTROL_* */
106 /*! An empty, useless frame */
108 /*! Inter Asterisk Exchange private frame type */
116 /*! Comfort Noise frame (subclass is level of CNG in -dBov),
117 body may include zero or more 8-bit quantization coefficients */
119 /*! Modem-over-IP data streams */
121 /*! DTMF begin event, subclass is the digit */
122 AST_FRAME_DTMF_BEGIN,
124 #define AST_FRAME_DTMF AST_FRAME_DTMF_END
127 /*! This frame contains valid timing information */
128 AST_FRFLAG_HAS_TIMING_INFO = (1 << 0),
129 /*! This frame came from a translator and is still the original frame.
130 * The translator can not be free'd if the frame inside of it still has
132 AST_FRFLAG_FROM_TRANSLATOR = (1 << 1),
133 /*! This frame came from a dsp and is still the original frame.
134 * The dsp cannot be free'd if the frame inside of it still has
136 AST_FRFLAG_FROM_DSP = (1 << 2),
137 /*! This frame came from a filestream and is still the original frame.
138 * The filestream cannot be free'd if the frame inside of it still has
140 AST_FRFLAG_FROM_FILESTREAM = (1 << 3),
143 /*! \brief Data structure associated with a single frame of data
147 enum ast_frame_type frametype;
148 /*! Subclass, frame dependent */
150 /*! Length of data */
152 /*! Number of 8khz samples in this frame */
154 /*! Was the data malloc'd? i.e. should we free it when we discard the frame? */
156 /*! The number of bytes allocated for a malloc'd frame header */
157 size_t mallocd_hdr_len;
158 /*! How many bytes exist _before_ "data" that can be used if needed */
160 /*! Optional source of frame for debugging */
162 /*! Pointer to actual data */
163 union { void *ptr; uint32_t uint32; char pad[8]; } data;
164 /*! Global delivery time */
165 struct timeval delivery;
166 /*! For placing in a linked list */
167 AST_LIST_ENTRY(ast_frame) frame_list;
168 /*! Misc. frame flags */
170 /*! Timestamp in milliseconds */
172 /*! Length in milliseconds */
174 /*! Sequence number */
179 * Set the various field of a frame to point to a buffer.
180 * Typically you set the base address of the buffer, the offset as
181 * AST_FRIENDLY_OFFSET, and the datalen as the amount of bytes queued.
182 * The remaining things (to be done manually) is set the number of
183 * samples, which cannot be derived from the datalen unless you know
184 * the number of bits per sample.
186 #define AST_FRAME_SET_BUFFER(fr, _base, _ofs, _datalen) \
188 (fr)->data.ptr = (char *)_base + (_ofs); \
189 (fr)->offset = (_ofs); \
190 (fr)->datalen = (_datalen); \
193 /*! Queueing a null frame is fairly common, so we declare a global null frame object
194 for this purpose instead of having to declare one on the stack */
195 extern struct ast_frame ast_null_frame;
197 /*! \brief Offset into a frame's data buffer.
199 * By providing some "empty" space prior to the actual data of an ast_frame,
200 * this gives any consumer of the frame ample space to prepend other necessary
201 * information without having to create a new buffer.
203 * As an example, RTP can use the data from an ast_frame and simply prepend the
204 * RTP header information into the space provided by AST_FRIENDLY_OFFSET instead
205 * of having to create a new buffer with the necessary space allocated.
207 #define AST_FRIENDLY_OFFSET 64
208 #define AST_MIN_OFFSET 32 /*! Make sure we keep at least this much handy */
210 /*! Need the header be free'd? */
211 #define AST_MALLOCD_HDR (1 << 0)
212 /*! Need the data be free'd? */
213 #define AST_MALLOCD_DATA (1 << 1)
214 /*! Need the source be free'd? (haha!) */
215 #define AST_MALLOCD_SRC (1 << 2)
217 /* MODEM subclasses */
218 /*! T.38 Fax-over-IP */
219 #define AST_MODEM_T38 1
220 /*! V.150 Modem-over-IP */
221 #define AST_MODEM_V150 2
223 /* HTML subclasses */
225 #define AST_HTML_URL 1
227 #define AST_HTML_DATA 2
228 /*! Beginning frame */
229 #define AST_HTML_BEGIN 4
231 #define AST_HTML_END 8
232 /*! Load is complete */
233 #define AST_HTML_LDCOMPLETE 16
234 /*! Peer is unable to support HTML */
235 #define AST_HTML_NOSUPPORT 17
236 /*! Send URL, and track */
237 #define AST_HTML_LINKURL 18
238 /*! No more HTML linkage */
239 #define AST_HTML_UNLINK 19
240 /*! Reject link request */
241 #define AST_HTML_LINKREJECT 20
243 /* Data formats for capabilities and frames alike */
244 /*! G.723.1 compression */
245 #define AST_FORMAT_G723_1 (1 << 0)
246 /*! GSM compression */
247 #define AST_FORMAT_GSM (1 << 1)
248 /*! Raw mu-law data (G.711) */
249 #define AST_FORMAT_ULAW (1 << 2)
250 /*! Raw A-law data (G.711) */
251 #define AST_FORMAT_ALAW (1 << 3)
252 /*! ADPCM (G.726, 32kbps, AAL2 codeword packing) */
253 #define AST_FORMAT_G726_AAL2 (1 << 4)
255 #define AST_FORMAT_ADPCM (1 << 5)
256 /*! Raw 16-bit Signed Linear (8000 Hz) PCM */
257 #define AST_FORMAT_SLINEAR (1 << 6)
258 /*! LPC10, 180 samples/frame */
259 #define AST_FORMAT_LPC10 (1 << 7)
261 #define AST_FORMAT_G729A (1 << 8)
262 /*! SpeeX Free Compression */
263 #define AST_FORMAT_SPEEX (1 << 9)
264 /*! iLBC Free Compression */
265 #define AST_FORMAT_ILBC (1 << 10)
266 /*! ADPCM (G.726, 32kbps, RFC3551 codeword packing) */
267 #define AST_FORMAT_G726 (1 << 11)
269 #define AST_FORMAT_G722 (1 << 12)
270 /*! G.722.1 (also known as Siren7, 32kbps assumed) */
271 #define AST_FORMAT_SIREN7 (1 << 13)
272 /*! G.722.1 Annex C (also known as Siren14, 48kbps assumed) */
273 #define AST_FORMAT_SIREN14 (1 << 14)
274 /*! Raw 16-bit Signed Linear (16000 Hz) PCM */
275 #define AST_FORMAT_SLINEAR16 (1 << 15)
276 /*! Maximum audio mask */
277 #define AST_FORMAT_AUDIO_MASK ((1 << 16)-1)
279 #define AST_FORMAT_JPEG (1 << 16)
281 #define AST_FORMAT_PNG (1 << 17)
283 #define AST_FORMAT_H261 (1 << 18)
285 #define AST_FORMAT_H263 (1 << 19)
287 #define AST_FORMAT_H263_PLUS (1 << 20)
289 #define AST_FORMAT_H264 (1 << 21)
291 #define AST_FORMAT_MP4_VIDEO (1 << 22)
292 #define AST_FORMAT_VIDEO_MASK (((1 << 25)-1) & ~(AST_FORMAT_AUDIO_MASK))
293 /*! T.140 RED Text format RFC 4103 */
294 #define AST_FORMAT_T140RED (1 << 26)
295 /*! T.140 Text format - ITU T.140, RFC 4103 */
296 #define AST_FORMAT_T140 (1 << 27)
297 /*! Maximum text mask */
298 #define AST_FORMAT_MAX_TEXT (1 << 28))
299 #define AST_FORMAT_TEXT_MASK (((1 << 30)-1) & ~(AST_FORMAT_AUDIO_MASK) & ~(AST_FORMAT_VIDEO_MASK))
301 enum ast_control_frame_type {
302 AST_CONTROL_HANGUP = 1, /*!< Other end has hungup */
303 AST_CONTROL_RING = 2, /*!< Local ring */
304 AST_CONTROL_RINGING = 3, /*!< Remote end is ringing */
305 AST_CONTROL_ANSWER = 4, /*!< Remote end has answered */
306 AST_CONTROL_BUSY = 5, /*!< Remote end is busy */
307 AST_CONTROL_TAKEOFFHOOK = 6, /*!< Make it go off hook */
308 AST_CONTROL_OFFHOOK = 7, /*!< Line is off hook */
309 AST_CONTROL_CONGESTION = 8, /*!< Congestion (circuits busy) */
310 AST_CONTROL_FLASH = 9, /*!< Flash hook */
311 AST_CONTROL_WINK = 10, /*!< Wink */
312 AST_CONTROL_OPTION = 11, /*!< Set a low-level option */
313 AST_CONTROL_RADIO_KEY = 12, /*!< Key Radio */
314 AST_CONTROL_RADIO_UNKEY = 13, /*!< Un-Key Radio */
315 AST_CONTROL_PROGRESS = 14, /*!< Indicate PROGRESS */
316 AST_CONTROL_PROCEEDING = 15, /*!< Indicate CALL PROCEEDING */
317 AST_CONTROL_HOLD = 16, /*!< Indicate call is placed on hold */
318 AST_CONTROL_UNHOLD = 17, /*!< Indicate call is left from hold */
319 AST_CONTROL_VIDUPDATE = 18, /*!< Indicate video frame update */
320 AST_CONTROL_T38 = 19, /*!< T38 state change request/notification */
321 AST_CONTROL_SRCUPDATE = 20, /*!< Indicate source of media has changed */
324 enum ast_control_t38 {
325 AST_T38_REQUEST_NEGOTIATE = 1, /*!< Request T38 on a channel (voice to fax) */
326 AST_T38_REQUEST_TERMINATE, /*!< Terminate T38 on a channel (fax to voice) */
327 AST_T38_NEGOTIATED, /*!< T38 negotiated (fax mode) */
328 AST_T38_TERMINATED, /*!< T38 terminated (back to voice) */
329 AST_T38_REFUSED /*!< T38 refused for some reason (usually rejected by remote end) */
332 #define AST_SMOOTHER_FLAG_G729 (1 << 0)
333 #define AST_SMOOTHER_FLAG_BE (1 << 1)
335 /* Option identifiers and flags */
336 #define AST_OPTION_FLAG_REQUEST 0
337 #define AST_OPTION_FLAG_ACCEPT 1
338 #define AST_OPTION_FLAG_REJECT 2
339 #define AST_OPTION_FLAG_QUERY 4
340 #define AST_OPTION_FLAG_ANSWER 5
341 #define AST_OPTION_FLAG_WTF 6
343 /*! Verify touchtones by muting audio transmission
344 (and reception) and verify the tone is still present */
345 #define AST_OPTION_TONE_VERIFY 1
347 /*! Put a compatible channel into TDD (TTY for the hearing-impared) mode */
348 #define AST_OPTION_TDD 2
350 /*! Relax the parameters for DTMF reception (mainly for radio use) */
351 #define AST_OPTION_RELAXDTMF 3
353 /*! Set (or clear) Audio (Not-Clear) Mode */
354 #define AST_OPTION_AUDIO_MODE 4
356 /*! Set channel transmit gain
357 * Option data is a single signed char
358 representing number of decibels (dB)
359 to set gain to (on top of any gain
360 specified in channel driver)
362 #define AST_OPTION_TXGAIN 5
364 /*! Set channel receive gain
365 * Option data is a single signed char
366 representing number of decibels (dB)
367 to set gain to (on top of any gain
368 specified in channel driver)
370 #define AST_OPTION_RXGAIN 6
372 /* set channel into "Operator Services" mode */
373 #define AST_OPTION_OPRMODE 7
375 /*! Explicitly enable or disable echo cancelation for the given channel */
376 #define AST_OPTION_ECHOCAN 8
379 * Read-only. Allows query current status of T38 on the channel.
382 #define AST_OPTION_T38_STATE 10
385 struct ast_channel *peer;
389 struct ast_option_header {
390 /* Always keep in network byte order */
391 #if __BYTE_ORDER == __BIG_ENDIAN
395 #if __BYTE_ORDER == __LITTLE_ENDIAN
399 #error Byte order not defined
406 /*! \brief Definition of supported media formats (codecs) */
407 struct ast_format_list {
408 int bits; /*!< bitmask value */
409 char *name; /*!< short name */
410 int samplespersecond; /*!< Number of samples per second (8000/16000) */
411 char *desc; /*!< Description */
412 int fr_len; /*!< Single frame length in bytes */
413 int min_ms; /*!< Min value */
414 int max_ms; /*!< Max value */
415 int inc_ms; /*!< Increment */
416 int def_ms; /*!< Default value */
417 unsigned int flags; /*!< Smoother flags */
418 int cur_ms; /*!< Current value */
422 /*! \brief Requests a frame to be allocated
425 * Request a frame be allocated. source is an optional source of the frame,
426 * len is the requested length, or "0" if the caller will supply the buffer
428 #if 0 /* Unimplemented */
429 struct ast_frame *ast_fralloc(char *source, int len);
433 * \brief Frees a frame
435 * \param fr Frame to free
436 * \param cache Whether to consider this frame for frame caching
438 void ast_frame_free(struct ast_frame *fr, int cache);
440 #define ast_frfree(fr) ast_frame_free(fr, 1)
442 /*! \brief Makes a frame independent of any static storage
443 * \param fr frame to act upon
444 * Take a frame, and if it's not been malloc'd, make a malloc'd copy
445 * and if the data hasn't been malloced then make the
446 * data malloc'd. If you need to store frames, say for queueing, then
447 * you should call this function.
448 * \return Returns a frame on success, NULL on error
450 struct ast_frame *ast_frisolate(struct ast_frame *fr);
452 /*! \brief Copies a frame
453 * \param fr frame to copy
454 * Duplicates a frame -- should only rarely be used, typically frisolate is good enough
455 * \return Returns a frame on success, NULL on error
457 struct ast_frame *ast_frdup(const struct ast_frame *fr);
459 void ast_swapcopy_samples(void *dst, const void *src, int samples);
461 /* Helpers for byteswapping native samples to/from
462 little-endian and big-endian. */
463 #if __BYTE_ORDER == __LITTLE_ENDIAN
464 #define ast_frame_byteswap_le(fr) do { ; } while(0)
465 #define ast_frame_byteswap_be(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data.ptr, __f->data.ptr, __f->samples); } while(0)
467 #define ast_frame_byteswap_le(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data.ptr, __f->data.ptr, __f->samples); } while(0)
468 #define ast_frame_byteswap_be(fr) do { ; } while(0)
472 /*! \brief Get the name of a format
473 * \param format id of format
474 * \return A static string containing the name of the format or "unknown" if unknown.
476 char* ast_getformatname(int format);
478 /*! \brief Get the names of a set of formats
479 * \param buf a buffer for the output string
480 * \param size size of buf (bytes)
481 * \param format the format (combined IDs of codecs)
482 * Prints a list of readable codec names corresponding to "format".
483 * ex: for format=AST_FORMAT_GSM|AST_FORMAT_SPEEX|AST_FORMAT_ILBC it will return "0x602 (GSM|SPEEX|ILBC)"
484 * \return The return value is buf.
486 char* ast_getformatname_multiple(char *buf, size_t size, int format);
489 * \brief Gets a format from a name.
490 * \param name string of format
491 * \return This returns the form of the format in binary on success, 0 on error.
493 int ast_getformatbyname(const char *name);
495 /*! \brief Get a name from a format
496 * Gets a name from a format
497 * \param codec codec number (1,2,4,8,16,etc.)
498 * \return This returns a static string identifying the format on success, 0 on error.
500 char *ast_codec2str(int codec);
502 /*! \name AST_Smoother
505 /*! \page ast_smooth The AST Frame Smoother
506 The ast_smoother interface was designed specifically
507 to take frames of variant sizes and produce frames of a single expected
508 size, precisely what you want to do.
510 The basic interface is:
512 - Initialize with ast_smoother_new()
513 - Queue input frames with ast_smoother_feed()
514 - Get output frames with ast_smoother_read()
515 - when you're done, free the structure with ast_smoother_free()
516 - Also see ast_smoother_test_flag(), ast_smoother_set_flags(), ast_smoother_get_flags(), ast_smoother_reset()
520 struct ast_smoother *ast_smoother_new(int bytes);
521 void ast_smoother_set_flags(struct ast_smoother *smoother, int flags);
522 int ast_smoother_get_flags(struct ast_smoother *smoother);
523 int ast_smoother_test_flag(struct ast_smoother *s, int flag);
524 void ast_smoother_free(struct ast_smoother *s);
525 void ast_smoother_reset(struct ast_smoother *s, int bytes);
526 int __ast_smoother_feed(struct ast_smoother *s, struct ast_frame *f, int swap);
527 struct ast_frame *ast_smoother_read(struct ast_smoother *s);
528 #define ast_smoother_feed(s,f) __ast_smoother_feed(s, f, 0)
529 #if __BYTE_ORDER == __LITTLE_ENDIAN
530 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 1)
531 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 0)
533 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 0)
534 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 1)
536 /*@} Doxygen marker */
538 const struct ast_format_list *ast_get_format_list_index(int index);
539 const struct ast_format_list *ast_get_format_list(size_t *size);
540 void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix);
542 /*! \page AudioCodecPref Audio Codec Preferences
544 In order to negotiate audio codecs in the order they are configured
545 in \<channel\>.conf for a device, we set up codec preference lists
546 in addition to the codec capabilities setting. The capabilities
547 setting is a bitmask of audio and video codecs with no internal
548 order. This will reflect the offer given to the other side, where
549 the prefered codecs will be added to the top of the list in the
550 order indicated by the "allow" lines in the device configuration.
552 Video codecs are not included in the preference lists since they
553 can't be transcoded and we just have to pick whatever is supported
557 *\brief Initialize an audio codec preference to "no preference".
558 * \arg \ref AudioCodecPref
560 void ast_codec_pref_init(struct ast_codec_pref *pref);
563 * \brief Codec located at a particular place in the preference index.
564 * \arg \ref AudioCodecPref
566 int ast_codec_pref_index(struct ast_codec_pref *pref, int index);
568 /*! \brief Remove audio a codec from a preference list */
569 void ast_codec_pref_remove(struct ast_codec_pref *pref, int format);
571 /*! \brief Append a audio codec to a preference list, removing it first if it was already there
573 int ast_codec_pref_append(struct ast_codec_pref *pref, int format);
575 /*! \brief Prepend an audio codec to a preference list, removing it first if it was already there
577 void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing);
579 /*! \brief Select the best audio format according to preference list from supplied options.
580 If "find_best" is non-zero then if nothing is found, the "Best" format of
581 the format list is selected, otherwise 0 is returned. */
582 int ast_codec_choose(struct ast_codec_pref *pref, int formats, int find_best);
584 /*! \brief Set packet size for codec
586 int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems);
588 /*! \brief Get packet size for codec
590 struct ast_format_list ast_codec_pref_getsize(struct ast_codec_pref *pref, int format);
592 /*! \brief Parse an "allow" or "deny" line in a channel or device configuration
593 and update the capabilities mask and pref if provided.
594 Video codecs are not added to codec preference lists, since we can not transcode
595 \return Returns number of errors encountered during parsing
597 int ast_parse_allow_disallow(struct ast_codec_pref *pref, int *mask, const char *list, int allowing);
599 /*! \brief Dump audio codec preference list into a string */
600 int ast_codec_pref_string(struct ast_codec_pref *pref, char *buf, size_t size);
602 /*! \brief Shift an audio codec preference list up or down 65 bytes so that it becomes an ASCII string */
603 void ast_codec_pref_convert(struct ast_codec_pref *pref, char *buf, size_t size, int right);
605 /*! \brief Returns the number of samples contained in the frame */
606 int ast_codec_get_samples(struct ast_frame *f);
608 /*! \brief Returns the number of bytes for the number of samples of the given format */
609 int ast_codec_get_len(int format, int samples);
611 /*! \brief Appends a frame to the end of a list of frames, truncating the maximum length of the list */
612 struct ast_frame *ast_frame_enqueue(struct ast_frame *head, struct ast_frame *f, int maxlen, int dupe);
615 /*! \brief Gets duration in ms of interpolation frame for a format */
616 static inline int ast_codec_interp_len(int format)
618 return (format == AST_FORMAT_ILBC) ? 30 : 20;
622 \brief Adjusts the volume of the audio samples contained in a frame.
623 \param f The frame containing the samples (must be AST_FRAME_VOICE and AST_FORMAT_SLINEAR)
624 \param adjustment The number of dB to adjust up or down.
625 \return 0 for success, non-zero for an error
627 int ast_frame_adjust_volume(struct ast_frame *f, int adjustment);
630 \brief Sums two frames of audio samples.
631 \param f1 The first frame (which will contain the result)
632 \param f2 The second frame
633 \return 0 for success, non-zero for an error
635 The frames must be AST_FRAME_VOICE and must contain AST_FORMAT_SLINEAR samples,
636 and must contain the same number of samples.
638 int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2);
641 * \brief Get the sample rate for a given format.
643 static force_inline int ast_format_rate(int format)
646 case AST_FORMAT_G722:
647 case AST_FORMAT_SLINEAR16:
648 case AST_FORMAT_SIREN7:
650 case AST_FORMAT_SIREN14:
657 #if defined(__cplusplus) || defined(c_plusplus)
661 #endif /* _ASTERISK_FRAME_H */