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Asterisk developer's documentation


frame.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 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/time.h>
00033 
00034 #include "asterisk/endian.h"
00035 #include "asterisk/linkedlists.h"
00036 
00037 struct ast_codec_pref {
00038    char order[32];
00039    char framing[32];
00040 };
00041 
00042 /*! \page Def_Frame AST Multimedia and signalling frames
00043    \section Def_AstFrame What is an ast_frame ?
00044    A frame of data read used to communicate between 
00045    between channels and applications.
00046    Frames are divided into frame types and subclasses.
00047 
00048    \par Frame types 
00049    \arg \b VOICE: Voice data, subclass is codec (AST_FORMAT_*)
00050    \arg \b VIDEO: Video data, subclass is codec (AST_FORMAT_*)
00051    \arg \b DTMF:  A DTMF digit, subclass is the digit
00052    \arg \b IMAGE: Image transport, mostly used in IAX
00053    \arg \b TEXT:  Text messages and character by character (real time text)
00054    \arg \b HTML:  URL's and web pages
00055    \arg \b MODEM: Modulated data encodings, such as T.38 and V.150
00056    \arg \b IAX:   Private frame type for the IAX protocol
00057    \arg \b CNG:   Comfort noice frames
00058    \arg \b CONTROL:  A control frame, subclass defined as AST_CONTROL_
00059    \arg \b NULL:  Empty, useless frame
00060 
00061    \par Files
00062    \arg frame.h   Definitions
00063    \arg frame.c   Function library
00064    \arg \ref Def_Channel Asterisk channels
00065    \section Def_ControlFrame Control Frames
00066    Control frames send signalling information between channels
00067    and devices. They are prefixed with AST_CONTROL_, like AST_CONTROL_FRAME_HANGUP
00068    \arg \b HANGUP The other end has hungup
00069    \arg \b RING   Local ring
00070    \arg \b RINGING   The other end is ringing
00071    \arg \b ANSWER The other end has answered
00072    \arg \b BUSY   Remote end is busy
00073    \arg \b TAKEOFFHOOK  Make it go off hook (what's "it" ? )
00074    \arg \b OFFHOOK   Line is off hook
00075    \arg \b CONGESTION   Congestion (circuit is busy, not available)
00076    \arg \b FLASH  Other end sends flash hook
00077    \arg \b WINK   Other end sends wink
00078    \arg \b OPTION Send low-level option
00079    \arg \b RADIO_KEY Key radio (see app_rpt.c)
00080    \arg \b RADIO_UNKEY  Un-key radio (see app_rpt.c)
00081    \arg \b PROGRESS  Other end indicates call progress
00082    \arg \b PROCEEDING   Indicates proceeding
00083    \arg \b HOLD   Call is placed on hold
00084    \arg \b UNHOLD Call is back from hold
00085    \arg \b VIDUPDATE Video update requested
00086    \arg \b SRCUPDATE       The source of media has changed
00087 
00088 */
00089 
00090 /*!
00091  * \brief Frame types 
00092  *
00093  * \note It is important that the values of each frame type are never changed,
00094  *       because it will break backwards compatability with older versions.
00095  *       This is because these constants are transmitted directly over IAX2.
00096  */
00097 enum ast_frame_type {
00098    /*! DTMF end event, subclass is the digit */
00099    AST_FRAME_DTMF_END = 1,
00100    /*! Voice data, subclass is AST_FORMAT_* */
00101    AST_FRAME_VOICE,
00102    /*! Video frame, maybe?? :) */
00103    AST_FRAME_VIDEO,
00104    /*! A control frame, subclass is AST_CONTROL_* */
00105    AST_FRAME_CONTROL,
00106    /*! An empty, useless frame */
00107    AST_FRAME_NULL,
00108    /*! Inter Asterisk Exchange private frame type */
00109    AST_FRAME_IAX,
00110    /*! Text messages */
00111    AST_FRAME_TEXT,
00112    /*! Image Frames */
00113    AST_FRAME_IMAGE,
00114    /*! HTML Frame */
00115    AST_FRAME_HTML,
00116    /*! Comfort Noise frame (subclass is level of CNG in -dBov), 
00117        body may include zero or more 8-bit quantization coefficients */
00118    AST_FRAME_CNG,
00119    /*! Modem-over-IP data streams */
00120    AST_FRAME_MODEM,  
00121    /*! DTMF begin event, subclass is the digit */
00122    AST_FRAME_DTMF_BEGIN,
00123 };
00124 #define AST_FRAME_DTMF AST_FRAME_DTMF_END
00125 
00126 enum {
00127    /*! This frame contains valid timing information */
00128    AST_FRFLAG_HAS_TIMING_INFO = (1 << 0),
00129 };
00130 
00131 /*! \brief Data structure associated with a single frame of data
00132  */
00133 struct ast_frame {
00134    /*! Kind of frame */
00135    enum ast_frame_type frametype;            
00136    /*! Subclass, frame dependent */
00137    int subclass;           
00138    /*! Length of data */
00139    int datalen;            
00140    /*! Number of samples in this frame */
00141    int samples;            
00142    /*! Was the data malloc'd?  i.e. should we free it when we discard the frame? */
00143    int mallocd;            
00144    /*! The number of bytes allocated for a malloc'd frame header */
00145    size_t mallocd_hdr_len;
00146    /*! How many bytes exist _before_ "data" that can be used if needed */
00147    int offset;          
00148    /*! Optional source of frame for debugging */
00149    const char *src;           
00150    /*! Pointer to actual data */
00151    union { void *ptr; uint32_t uint32; char pad[8]; } data;
00152    /*! Global delivery time */      
00153    struct timeval delivery;
00154    /*! For placing in a linked list */
00155    AST_LIST_ENTRY(ast_frame) frame_list;
00156    /*! Misc. frame flags */
00157    unsigned int flags;
00158    /*! Timestamp in milliseconds */
00159    long ts;
00160    /*! Length in milliseconds */
00161    long len;
00162    /*! Sequence number */
00163    int seqno;
00164 };
00165 
00166 /*!
00167  * Set the various field of a frame to point to a buffer.
00168  * Typically you set the base address of the buffer, the offset as
00169  * AST_FRIENDLY_OFFSET, and the datalen as the amount of bytes queued.
00170  * The remaining things (to be done manually) is set the number of
00171  * samples, which cannot be derived from the datalen unless you know
00172  * the number of bits per sample.
00173  */
00174 #define  AST_FRAME_SET_BUFFER(fr, _base, _ofs, _datalen) \
00175    {              \
00176    (fr)->data.ptr = (char *)_base + (_ofs);  \
00177    (fr)->offset = (_ofs);        \
00178    (fr)->datalen = (_datalen);      \
00179    }
00180 
00181 /*! Queueing a null frame is fairly common, so we declare a global null frame object
00182     for this purpose instead of having to declare one on the stack */
00183 extern struct ast_frame ast_null_frame;
00184 
00185 /*! \brief Offset into a frame's data buffer.
00186  *
00187  * By providing some "empty" space prior to the actual data of an ast_frame,
00188  * this gives any consumer of the frame ample space to prepend other necessary
00189  * information without having to create a new buffer.
00190  *
00191  * As an example, RTP can use the data from an ast_frame and simply prepend the
00192  * RTP header information into the space provided by AST_FRIENDLY_OFFSET instead
00193  * of having to create a new buffer with the necessary space allocated.
00194  */
00195 #define AST_FRIENDLY_OFFSET   64 
00196 #define AST_MIN_OFFSET     32 /*! Make sure we keep at least this much handy */
00197 
00198 /*! Need the header be free'd? */
00199 #define AST_MALLOCD_HDR    (1 << 0)
00200 /*! Need the data be free'd? */
00201 #define AST_MALLOCD_DATA   (1 << 1)
00202 /*! Need the source be free'd? (haha!) */
00203 #define AST_MALLOCD_SRC    (1 << 2)
00204 
00205 /* MODEM subclasses */
00206 /*! T.38 Fax-over-IP */
00207 #define AST_MODEM_T38      1
00208 /*! V.150 Modem-over-IP */
00209 #define AST_MODEM_V150     2
00210 
00211 /* HTML subclasses */
00212 /*! Sending a URL */
00213 #define AST_HTML_URL    1
00214 /*! Data frame */
00215 #define AST_HTML_DATA      2
00216 /*! Beginning frame */
00217 #define AST_HTML_BEGIN     4
00218 /*! End frame */
00219 #define AST_HTML_END    8
00220 /*! Load is complete */
00221 #define AST_HTML_LDCOMPLETE   16
00222 /*! Peer is unable to support HTML */
00223 #define AST_HTML_NOSUPPORT 17
00224 /*! Send URL, and track */
00225 #define AST_HTML_LINKURL   18
00226 /*! No more HTML linkage */
00227 #define AST_HTML_UNLINK    19
00228 /*! Reject link request */
00229 #define AST_HTML_LINKREJECT   20
00230 
00231 /* Data formats for capabilities and frames alike */
00232 /*! G.723.1 compression */
00233 #define AST_FORMAT_G723_1  (1 << 0)
00234 /*! GSM compression */
00235 #define AST_FORMAT_GSM     (1 << 1)
00236 /*! Raw mu-law data (G.711) */
00237 #define AST_FORMAT_ULAW    (1 << 2)
00238 /*! Raw A-law data (G.711) */
00239 #define AST_FORMAT_ALAW    (1 << 3)
00240 /*! ADPCM (G.726, 32kbps, AAL2 codeword packing) */
00241 #define AST_FORMAT_G726_AAL2  (1 << 4)
00242 /*! ADPCM (IMA) */
00243 #define AST_FORMAT_ADPCM   (1 << 5)
00244 /*! Raw 16-bit Signed Linear (8000 Hz) PCM */
00245 #define AST_FORMAT_SLINEAR (1 << 6)
00246 /*! LPC10, 180 samples/frame */
00247 #define AST_FORMAT_LPC10   (1 << 7)
00248 /*! G.729A audio */
00249 #define AST_FORMAT_G729A   (1 << 8)
00250 /*! SpeeX Free Compression */
00251 #define AST_FORMAT_SPEEX   (1 << 9)
00252 /*! iLBC Free Compression */
00253 #define AST_FORMAT_ILBC    (1 << 10)
00254 /*! ADPCM (G.726, 32kbps, RFC3551 codeword packing) */
00255 #define AST_FORMAT_G726    (1 << 11)
00256 /*! G.722 */
00257 #define AST_FORMAT_G722    (1 << 12)
00258 /*! Unsupported audio bits */
00259 #define AST_FORMAT_AUDIO_UNDEFINED  ((1 << 13) | (1 << 14))
00260 /*! Raw 16-bit Signed Linear (16000 Hz) PCM */
00261 #define AST_FORMAT_SLINEAR16  (1 << 15)
00262 /*! Maximum audio mask */
00263 #define AST_FORMAT_AUDIO_MASK   ((1 << 16)-1)
00264 /*! JPEG Images */
00265 #define AST_FORMAT_JPEG    (1 << 16)
00266 /*! PNG Images */
00267 #define AST_FORMAT_PNG     (1 << 17)
00268 /*! H.261 Video */
00269 #define AST_FORMAT_H261    (1 << 18)
00270 /*! H.263 Video */
00271 #define AST_FORMAT_H263    (1 << 19)
00272 /*! H.263+ Video */
00273 #define AST_FORMAT_H263_PLUS  (1 << 20)
00274 /*! H.264 Video */
00275 #define AST_FORMAT_H264    (1 << 21)
00276 /*! MPEG4 Video */
00277 #define AST_FORMAT_MP4_VIDEO  (1 << 22)
00278 #define AST_FORMAT_VIDEO_MASK   (((1 << 25)-1) & ~(AST_FORMAT_AUDIO_MASK))
00279 /*! T.140 RED Text format RFC 4103 */
00280 #define AST_FORMAT_T140RED      (1 << 26)
00281 /*! T.140 Text format - ITU T.140, RFC 4103 */
00282 #define AST_FORMAT_T140    (1 << 27)
00283 /*! Maximum text mask */
00284 #define AST_FORMAT_MAX_TEXT   (1 << 28))
00285 #define AST_FORMAT_TEXT_MASK   (((1 << 30)-1) & ~(AST_FORMAT_AUDIO_MASK) & ~(AST_FORMAT_VIDEO_MASK))
00286 
00287 enum ast_control_frame_type {
00288    AST_CONTROL_HANGUP = 1,    /*!< Other end has hungup */
00289    AST_CONTROL_RING = 2,      /*!< Local ring */
00290    AST_CONTROL_RINGING = 3,   /*!< Remote end is ringing */
00291    AST_CONTROL_ANSWER = 4,    /*!< Remote end has answered */
00292    AST_CONTROL_BUSY = 5,      /*!< Remote end is busy */
00293    AST_CONTROL_TAKEOFFHOOK = 6,  /*!< Make it go off hook */
00294    AST_CONTROL_OFFHOOK = 7,   /*!< Line is off hook */
00295    AST_CONTROL_CONGESTION = 8,   /*!< Congestion (circuits busy) */
00296    AST_CONTROL_FLASH = 9,     /*!< Flash hook */
00297    AST_CONTROL_WINK = 10,     /*!< Wink */
00298    AST_CONTROL_OPTION = 11,   /*!< Set a low-level option */
00299    AST_CONTROL_RADIO_KEY = 12,   /*!< Key Radio */
00300    AST_CONTROL_RADIO_UNKEY = 13, /*!< Un-Key Radio */
00301    AST_CONTROL_PROGRESS = 14, /*!< Indicate PROGRESS */
00302    AST_CONTROL_PROCEEDING = 15,  /*!< Indicate CALL PROCEEDING */
00303    AST_CONTROL_HOLD = 16,     /*!< Indicate call is placed on hold */
00304    AST_CONTROL_UNHOLD = 17,   /*!< Indicate call is left from hold */
00305    AST_CONTROL_VIDUPDATE = 18,   /*!< Indicate video frame update */
00306    _XXX_AST_CONTROL_T38 = 19, /*!< T38 state change request/notification \deprecated This is no longer supported. Use AST_CONTROL_T38_PARAMETERS instead. */
00307    AST_CONTROL_SRCUPDATE = 20,     /*!< Indicate source of media has changed */
00308    AST_CONTROL_T38_PARAMETERS = 24, /*!< T38 state change request/notification with parameters */
00309 };
00310 
00311 enum ast_control_t38 {
00312    AST_T38_REQUEST_NEGOTIATE = 1,   /*!< Request T38 on a channel (voice to fax) */
00313    AST_T38_REQUEST_TERMINATE, /*!< Terminate T38 on a channel (fax to voice) */
00314    AST_T38_NEGOTIATED,     /*!< T38 negotiated (fax mode) */
00315    AST_T38_TERMINATED,     /*!< T38 terminated (back to voice) */
00316    AST_T38_REFUSED         /*!< T38 refused for some reason (usually rejected by remote end) */
00317 };
00318 
00319 enum ast_control_t38_rate {
00320    AST_T38_RATE_2400 = 0,
00321    AST_T38_RATE_4800,
00322    AST_T38_RATE_7200,
00323    AST_T38_RATE_9600,
00324    AST_T38_RATE_12000,
00325    AST_T38_RATE_14400,
00326 };
00327 
00328 enum ast_control_t38_rate_management {
00329    AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF = 0,
00330    AST_T38_RATE_MANAGEMENT_LOCAL_TCF,
00331 };
00332 
00333 struct ast_control_t38_parameters {
00334    enum ast_control_t38 request_response;       /*!< Request or response of the T38 control frame */
00335    unsigned int version;               /*!< Supported T.38 version */
00336    unsigned int max_ifp;               /*!< Maximum IFP size supported */
00337    enum ast_control_t38_rate rate;           /*!< Maximum fax rate supported */
00338    enum ast_control_t38_rate_management rate_management; /*!< Rate management setting */
00339    unsigned int fill_bit_removal:1;       /*!< Set if fill bit removal can be used */
00340    unsigned int transcoding_mmr:1;           /*!< Set if MMR transcoding can be used */
00341    unsigned int transcoding_jbig:1;       /*!< Set if JBIG transcoding can be used */
00342 };
00343 
00344 #define AST_SMOOTHER_FLAG_G729      (1 << 0)
00345 #define AST_SMOOTHER_FLAG_BE     (1 << 1)
00346 
00347 /* Option identifiers and flags */
00348 #define AST_OPTION_FLAG_REQUEST     0
00349 #define AST_OPTION_FLAG_ACCEPT      1
00350 #define AST_OPTION_FLAG_REJECT      2
00351 #define AST_OPTION_FLAG_QUERY    4
00352 #define AST_OPTION_FLAG_ANSWER      5
00353 #define AST_OPTION_FLAG_WTF      6
00354 
00355 /*! Verify touchtones by muting audio transmission 
00356    (and reception) and verify the tone is still present */
00357 #define AST_OPTION_TONE_VERIFY      1     
00358 
00359 /*! Put a compatible channel into TDD (TTY for the hearing-impared) mode */
00360 #define  AST_OPTION_TDD       2
00361 
00362 /*! Relax the parameters for DTMF reception (mainly for radio use) */
00363 #define  AST_OPTION_RELAXDTMF    3
00364 
00365 /*! Set (or clear) Audio (Not-Clear) Mode */
00366 #define  AST_OPTION_AUDIO_MODE      4
00367 
00368 /*! Set channel transmit gain 
00369  * Option data is a single signed char
00370    representing number of decibels (dB)
00371    to set gain to (on top of any gain
00372    specified in channel driver)
00373 */
00374 #define AST_OPTION_TXGAIN     5
00375 
00376 /*! Set channel receive gain
00377  * Option data is a single signed char
00378    representing number of decibels (dB)
00379    to set gain to (on top of any gain
00380    specified in channel driver)
00381 */
00382 #define AST_OPTION_RXGAIN     6
00383 
00384 /* set channel into "Operator Services" mode */
00385 #define  AST_OPTION_OPRMODE      7
00386 
00387 /*! Explicitly enable or disable echo cancelation for the given channel */
00388 #define  AST_OPTION_ECHOCAN      8
00389 
00390 /* !
00391  * Read-only. Allows query current status of T38 on the channel.
00392  * data: ast_t38state
00393  */
00394 #define AST_OPTION_T38_STATE     10
00395 
00396 struct oprmode {
00397    struct ast_channel *peer;
00398    int mode;
00399 } ;
00400 
00401 struct ast_option_header {
00402    /* Always keep in network byte order */
00403 #if __BYTE_ORDER == __BIG_ENDIAN
00404         uint16_t flag:3;
00405         uint16_t option:13;
00406 #else
00407 #if __BYTE_ORDER == __LITTLE_ENDIAN
00408         uint16_t option:13;
00409         uint16_t flag:3;
00410 #else
00411 #error Byte order not defined
00412 #endif
00413 #endif
00414       uint8_t data[0];
00415 };
00416 
00417 
00418 /*! \brief Definition of supported media formats (codecs) */
00419 struct ast_format_list {
00420    int bits;   /*!< bitmask value */
00421    char *name; /*!< short name */
00422    int samplespersecond; /*!< Number of samples per second (8000/16000) */
00423    char *desc; /*!< Description */
00424    int fr_len; /*!< Single frame length in bytes */
00425    int min_ms; /*!< Min value */
00426    int max_ms; /*!< Max value */
00427    int inc_ms; /*!< Increment */
00428    int def_ms; /*!< Default value */
00429    unsigned int flags;  /*!< Smoother flags */
00430    int cur_ms; /*!< Current value */
00431 };
00432 
00433 
00434 /*! \brief  Requests a frame to be allocated 
00435  * 
00436  * \param source 
00437  * Request a frame be allocated.  source is an optional source of the frame, 
00438  * len is the requested length, or "0" if the caller will supply the buffer 
00439  */
00440 #if 0 /* Unimplemented */
00441 struct ast_frame *ast_fralloc(char *source, int len);
00442 #endif
00443 
00444 /*!  
00445  * \brief Frees a frame or list of frames
00446  * 
00447  * \param fr Frame to free, or head of list to free
00448  * \param cache Whether to consider this frame for frame caching
00449  */
00450 void ast_frame_free(struct ast_frame *fr, int cache);
00451 
00452 #define ast_frfree(fr) ast_frame_free(fr, 1)
00453 
00454 /*! \brief Makes a frame independent of any static storage
00455  * \param fr frame to act upon
00456  * Take a frame, and if it's not been malloc'd, make a malloc'd copy
00457  * and if the data hasn't been malloced then make the
00458  * data malloc'd.  If you need to store frames, say for queueing, then
00459  * you should call this function.
00460  * \return Returns a frame on success, NULL on error
00461  * \note This function may modify the frame passed to it, so you must
00462  * not assume the frame will be intact after the isolated frame has
00463  * been produced. In other words, calling this function on a frame
00464  * should be the last operation you do with that frame before freeing
00465  * it (or exiting the block, if the frame is on the stack.)
00466  */
00467 struct ast_frame *ast_frisolate(struct ast_frame *fr);
00468 
00469 /*! \brief Copies a frame 
00470  * \param fr frame to copy
00471  * Duplicates a frame -- should only rarely be used, typically frisolate is good enough
00472  * \return Returns a frame on success, NULL on error
00473  */
00474 struct ast_frame *ast_frdup(const struct ast_frame *fr);
00475 
00476 void ast_swapcopy_samples(void *dst, const void *src, int samples);
00477 
00478 /* Helpers for byteswapping native samples to/from 
00479    little-endian and big-endian. */
00480 #if __BYTE_ORDER == __LITTLE_ENDIAN
00481 #define ast_frame_byteswap_le(fr) do { ; } while(0)
00482 #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)
00483 #else
00484 #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)
00485 #define ast_frame_byteswap_be(fr) do { ; } while(0)
00486 #endif
00487 
00488 
00489 /*! \brief Get the name of a format
00490  * \param format id of format
00491  * \return A static string containing the name of the format or "unknown" if unknown.
00492  */
00493 char* ast_getformatname(int format);
00494 
00495 /*! \brief Get the names of a set of formats
00496  * \param buf a buffer for the output string
00497  * \param size size of buf (bytes)
00498  * \param format the format (combined IDs of codecs)
00499  * Prints a list of readable codec names corresponding to "format".
00500  * ex: for format=AST_FORMAT_GSM|AST_FORMAT_SPEEX|AST_FORMAT_ILBC it will return "0x602 (GSM|SPEEX|ILBC)"
00501  * \return The return value is buf.
00502  */
00503 char* ast_getformatname_multiple(char *buf, size_t size, int format);
00504 
00505 /*!
00506  * \brief Gets a format from a name.
00507  * \param name string of format
00508  * \return This returns the form of the format in binary on success, 0 on error.
00509  */
00510 int ast_getformatbyname(const char *name);
00511 
00512 /*! \brief Get a name from a format 
00513  * Gets a name from a format
00514  * \param codec codec number (1,2,4,8,16,etc.)
00515  * \return This returns a static string identifying the format on success, 0 on error.
00516  */
00517 char *ast_codec2str(int codec);
00518 
00519 /*! \name AST_Smoother 
00520 */
00521 /*@{ */
00522 /*! \page ast_smooth The AST Frame Smoother
00523 The ast_smoother interface was designed specifically
00524 to take frames of variant sizes and produce frames of a single expected
00525 size, precisely what you want to do.
00526 
00527 The basic interface is:
00528 
00529 - Initialize with ast_smoother_new()
00530 - Queue input frames with ast_smoother_feed()
00531 - Get output frames with ast_smoother_read()
00532 - when you're done, free the structure with ast_smoother_free()
00533 - Also see ast_smoother_test_flag(), ast_smoother_set_flags(), ast_smoother_get_flags(), ast_smoother_reset()
00534 */
00535 struct ast_smoother;
00536 
00537 struct ast_smoother *ast_smoother_new(int bytes);
00538 void ast_smoother_set_flags(struct ast_smoother *smoother, int flags);
00539 int ast_smoother_get_flags(struct ast_smoother *smoother);
00540 int ast_smoother_test_flag(struct ast_smoother *s, int flag);
00541 void ast_smoother_free(struct ast_smoother *s);
00542 void ast_smoother_reset(struct ast_smoother *s, int bytes);
00543 
00544 /*!
00545  * \brief Reconfigure an existing smoother to output a different number of bytes per frame
00546  * \param s the smoother to reconfigure
00547  * \param bytes the desired number of bytes per output frame
00548  * \return nothing
00549  *
00550  */
00551 void ast_smoother_reconfigure(struct ast_smoother *s, int bytes);
00552 
00553 int __ast_smoother_feed(struct ast_smoother *s, struct ast_frame *f, int swap);
00554 struct ast_frame *ast_smoother_read(struct ast_smoother *s);
00555 #define ast_smoother_feed(s,f) __ast_smoother_feed(s, f, 0)
00556 #if __BYTE_ORDER == __LITTLE_ENDIAN
00557 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 1)
00558 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 0)
00559 #else
00560 #define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 0)
00561 #define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 1)
00562 #endif
00563 /*@} Doxygen marker */
00564 
00565 struct ast_format_list *ast_get_format_list_index(int index);
00566 struct ast_format_list *ast_get_format_list(size_t *size);
00567 void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix);
00568 
00569 /*! \page AudioCodecPref Audio Codec Preferences
00570 
00571    In order to negotiate audio codecs in the order they are configured
00572    in <channel>.conf for a device, we set up codec preference lists
00573    in addition to the codec capabilities setting. The capabilities
00574    setting is a bitmask of audio and video codecs with no internal
00575    order. This will reflect the offer given to the other side, where
00576    the prefered codecs will be added to the top of the list in the
00577    order indicated by the "allow" lines in the device configuration.
00578    
00579    Video codecs are not included in the preference lists since they
00580    can't be transcoded and we just have to pick whatever is supported
00581 */
00582 
00583 /*! 
00584  *\brief Initialize an audio codec preference to "no preference".
00585  * \arg \ref AudioCodecPref 
00586 */
00587 void ast_codec_pref_init(struct ast_codec_pref *pref);
00588 
00589 /*! 
00590  * \brief Codec located at a particular place in the preference index.
00591  * \arg \ref AudioCodecPref 
00592 */
00593 int ast_codec_pref_index(struct ast_codec_pref *pref, int index);
00594 
00595 /*! \brief Remove audio a codec from a preference list */
00596 void ast_codec_pref_remove(struct ast_codec_pref *pref, int format);
00597 
00598 /*! \brief Append a audio codec to a preference list, removing it first if it was already there 
00599 */
00600 int ast_codec_pref_append(struct ast_codec_pref *pref, int format);
00601 
00602 /*! \brief Prepend an audio codec to a preference list, removing it first if it was already there 
00603 */
00604 void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing);
00605 
00606 /*! \brief Select the best audio format according to preference list from supplied options. 
00607    If "find_best" is non-zero then if nothing is found, the "Best" format of 
00608    the format list is selected, otherwise 0 is returned. */
00609 int ast_codec_choose(struct ast_codec_pref *pref, int formats, int find_best);
00610 
00611 /*! \brief Set packet size for codec
00612 */
00613 int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems);
00614 
00615 /*! \brief Get packet size for codec
00616 */
00617 struct ast_format_list ast_codec_pref_getsize(struct ast_codec_pref *pref, int format);
00618 
00619 /*! \brief Parse an "allow" or "deny" line in a channel or device configuration 
00620         and update the capabilities mask and pref if provided.
00621    Video codecs are not added to codec preference lists, since we can not transcode
00622    \return Returns number of errors encountered during parsing
00623  */
00624 int ast_parse_allow_disallow(struct ast_codec_pref *pref, int *mask, const char *list, int allowing);
00625 
00626 /*! \brief Dump audio codec preference list into a string */
00627 int ast_codec_pref_string(struct ast_codec_pref *pref, char *buf, size_t size);
00628 
00629 /*! \brief Shift an audio codec preference list up or down 65 bytes so that it becomes an ASCII string */
00630 void ast_codec_pref_convert(struct ast_codec_pref *pref, char *buf, size_t size, int right);
00631 
00632 /*! \brief Returns the number of samples contained in the frame */
00633 int ast_codec_get_samples(struct ast_frame *f);
00634 
00635 /*! \brief Returns the number of bytes for the number of samples of the given format */
00636 int ast_codec_get_len(int format, int samples);
00637 
00638 /*! \brief Appends a frame to the end of a list of frames, truncating the maximum length of the list */
00639 struct ast_frame *ast_frame_enqueue(struct ast_frame *head, struct ast_frame *f, int maxlen, int dupe);
00640 
00641 
00642 /*! \brief Gets duration in ms of interpolation frame for a format */
00643 static inline int ast_codec_interp_len(int format) 
00644 { 
00645    return (format == AST_FORMAT_ILBC) ? 30 : 20;
00646 }
00647 
00648 /*!
00649   \brief Adjusts the volume of the audio samples contained in a frame.
00650   \param f The frame containing the samples (must be AST_FRAME_VOICE and AST_FORMAT_SLINEAR)
00651   \param adjustment The number of dB to adjust up or down.
00652   \return 0 for success, non-zero for an error
00653  */
00654 int ast_frame_adjust_volume(struct ast_frame *f, int adjustment);
00655 
00656 /*!
00657   \brief Sums two frames of audio samples.
00658   \param f1 The first frame (which will contain the result)
00659   \param f2 The second frame
00660   \return 0 for success, non-zero for an error
00661 
00662   The frames must be AST_FRAME_VOICE and must contain AST_FORMAT_SLINEAR samples,
00663   and must contain the same number of samples.
00664  */
00665 int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2);
00666 
00667 /*!
00668  * \brief Get the sample rate for a given format.
00669  */
00670 static force_inline int ast_format_rate(int format)
00671 {
00672    if (format == AST_FORMAT_G722 || format == AST_FORMAT_SLINEAR16)
00673       return 16000;
00674 
00675    return 8000;
00676 }
00677 
00678 #if defined(__cplusplus) || defined(c_plusplus)
00679 }
00680 #endif
00681 
00682 #endif /* _ASTERISK_FRAME_H */

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