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Last updated: Sat Feb 3 05:01:57 2007

Asterisk developer's documentation :: Codename Pineapple

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translate.h File Reference

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Detailed Description

Support for translation of data formats.

Definition in file translate.h.

#include "asterisk/frame.h"
#include "asterisk/plc.h"
#include "asterisk/linkedlists.h"

Include dependency graph for translate.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	ast_trans_pvt
	Default structure for translators, with the basic fields and buffers, all allocated as part of the same chunk of memory. The buffer is preceded by AST_FRIENDLY_OFFSET bytes in front of the user portion. 'buf' points right after this space. More...
struct	ast_translator
	Descriptor of a translator. Name, callbacks, and various options related to run-time operation (size of buffers, auxiliary descriptors, etc). More...
Defines
#define	ast_register_translator(t)   __ast_register_translator(t, ast_module_info->self)
#define	MAX_FORMAT   32
Functions
int	__ast_register_translator (struct ast_translator *t, struct ast_module *module)
	Register a translator This registers a codec translator with asterisk.
ast_frame *	ast_trans_frameout (struct ast_trans_pvt *pvt, int datalen, int samples)
	generic frameout function
ast_frame *	ast_translate (struct ast_trans_pvt *tr, struct ast_frame *f, int consume)
	translates one or more frames Apply an input frame into the translator and receive zero or one output frames. Consume determines whether the original frame should be freed
unsigned int	ast_translate_available_formats (unsigned int dest, unsigned int src)
	Mask off unavailable formats from a format bitmask.
unsigned int	ast_translate_path_steps (unsigned int dest, unsigned int src)
	Returns the number of steps required to convert from 'src' to 'dest'.
void	ast_translator_activate (struct ast_translator *t)
	Activate a previously deactivated translator.
int	ast_translator_best_choice (int *dsts, int *srcs)
	Chooses the best translation path.
ast_trans_pvt *	ast_translator_build_path (int dest, int source)
	Builds a translator path Build a path (possibly NULL) from source to dest.
void	ast_translator_deactivate (struct ast_translator *t)
	Deactivate a translator.
void	ast_translator_free_path (struct ast_trans_pvt *tr)
	Frees a translator path Frees the given translator path structure.
int	ast_unregister_translator (struct ast_translator *t)
	Unregister a translator Unregisters the given tranlator.

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Define Documentation

#define ast_register_translator (  t   )     __ast_register_translator(t, ast_module_info->self)

Definition at line 160 of file translate.h.

#define MAX_FORMAT   32

Definition at line 27 of file translate.h. Referenced by __ast_register_translator(), ast_translator_best_choice(), and rebuild_matrix().

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Function Documentation

int __ast_register_translator (  struct ast_translator *  t, struct ast_module *  module )

Register a translator This registers a codec translator with asterisk. Parameters: t  populated ast_translator structure module  handle to the module that owns this translator Returns: 0 on success, -1 on failure Definition at line 572 of file translate.c. References ast_translator::active, ast_cli_register_multiple(), AST_FORMAT_SLINEAR, ast_getformatname(), ast_log(), AST_RWLIST_INSERT_BEFORE_CURRENT, AST_RWLIST_INSERT_HEAD, AST_RWLIST_TRAVERSE_SAFE_BEGIN, AST_RWLIST_TRAVERSE_SAFE_END, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, ast_verbose(), ast_translator::buf_size, ast_translator::buffer_samples, calc_cost(), cli_translate, COLOR_BLACK, COLOR_MAGENTA, ast_translator::cost, default_frameout(), ast_translator::dstfmt, ast_translator::frameout, LOG_WARNING, MAX_FORMAT, ast_translator::module, ast_translator::name, option_verbose, ast_translator::plc_samples, powerof(), rebuild_matrix(), ast_translator::srcfmt, term_color(), and VERBOSE_PREFIX_2. { static int added_cli = 0; struct ast_translator *u; if (!mod) { ast_log(LOG_WARNING, "Missing module pointer, you need to supply one\n"); return -1; } if (!t->buf_size) { ast_log(LOG_WARNING, "empty buf size, you need to supply one\n"); return -1; } t->module = mod; t->srcfmt = powerof(t->srcfmt); t->dstfmt = powerof(t->dstfmt); t->active = 1; if (t->plc_samples) { if (t->buffer_samples < t->plc_samples) { ast_log(LOG_WARNING, "plc_samples %d buffer_samples %d\n", t->plc_samples, t->buffer_samples); return -1; } if (t->dstfmt != AST_FORMAT_SLINEAR) ast_log(LOG_WARNING, "plc_samples %d format %x\n", t->plc_samples, t->dstfmt); } if (t->srcfmt >= MAX_FORMAT) { ast_log(LOG_WARNING, "Source format %s is larger than MAX_FORMAT\n", ast_getformatname(t->srcfmt)); return -1; } if (t->dstfmt >= MAX_FORMAT) { ast_log(LOG_WARNING, "Destination format %s is larger than MAX_FORMAT\n", ast_getformatname(t->dstfmt)); return -1; } if (t->buf_size) { /* * Align buf_size properly, rounding up to the machine-specific * alignment for pointers. */ struct _test_align { void *a, *b; } p; int align = (char *)&p.b - (char *)&p.a; t->buf_size = ((t->buf_size + align - 1) / align) * align; } if (t->frameout == NULL) t->frameout = default_frameout; calc_cost(t, 1); if (option_verbose > 1) { char tmp[80]; ast_verbose(VERBOSE_PREFIX_2 "Registered translator '%s' from format %s to %s, cost %d\n", term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)), ast_getformatname(1 << t->srcfmt), ast_getformatname(1 << t->dstfmt), t->cost); } if (!added_cli) { ast_cli_register_multiple(cli_translate, sizeof(cli_translate) / sizeof(struct ast_cli_entry)); added_cli++; } AST_RWLIST_WRLOCK(&translators); /* find any existing translators that provide this same srcfmt/dstfmt, and put this one in order based on cost */ AST_RWLIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) { if ((u->srcfmt == t->srcfmt) && (u->dstfmt == t->dstfmt) && (u->cost > t->cost)) { AST_RWLIST_INSERT_BEFORE_CURRENT(&translators, t, list); t = NULL; } } AST_RWLIST_TRAVERSE_SAFE_END; /* if no existing translator was found for this format combination, add it to the beginning of the list */ if (t) AST_RWLIST_INSERT_HEAD(&translators, t, list); rebuild_matrix(0); AST_RWLIST_UNLOCK(&translators); return 0; }

struct ast_frame* ast_trans_frameout (  struct ast_trans_pvt *  pvt, int  datalen, int  samples )

generic frameout function Definition at line 207 of file translate.c. References AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_frame::data, ast_trans_pvt::datalen, ast_frame::datalen, ast_translator::dstfmt, ast_trans_pvt::f, ast_frame::frametype, ast_frame::mallocd, ast_translator::name, ast_frame::offset, ast_trans_pvt::outbuf, ast_trans_pvt::samples, ast_frame::samples, ast_frame::src, ast_frame::subclass, and ast_trans_pvt::t. Referenced by default_frameout(). { struct ast_frame *f = &pvt->f; if (samples) f->samples = samples; else { if (pvt->samples == 0) return NULL; f->samples = pvt->samples; pvt->samples = 0; } if (datalen) f->datalen = datalen; else { f->datalen = pvt->datalen; pvt->datalen = 0; } f->frametype = AST_FRAME_VOICE; f->subclass = 1 << (pvt->t->dstfmt); f->mallocd = 0; f->offset = AST_FRIENDLY_OFFSET; f->src = pvt->t->name; f->data = pvt->outbuf; return f; }

struct ast_frame* ast_translate (  struct ast_trans_pvt *  tr, struct ast_frame *  f, int  consume )

translates one or more frames Apply an input frame into the translator and receive zero or one output frames. Consume determines whether the original frame should be freed Parameters: tr  translator structure to use for translation f  frame to translate consume  Whether or not to free the original frame Returns: an ast_frame of the new translation format on success, NULL on failure Definition at line 293 of file translate.c. References ast_tvadd(), ast_tvsub(), ast_frame::delivery, framein(), ast_frame::has_timing_info, ast_frame::len, len, ast_trans_pvt::next, ast_trans_pvt::nextin, ast_trans_pvt::nextout, ast_frame::samples, ast_frame::seqno, and ast_frame::ts. Referenced by __ast_read(), ast_slinfactory_feed(), ast_write(), ast_writestream(), process_ast_dsp(), and queue_frame_to_spies(). { struct ast_trans_pvt *p = path; struct ast_frame *out = f; struct timeval delivery; int has_timing_info; long ts; long len; int seqno; has_timing_info = f->has_timing_info; ts = f->ts; len = f->len; seqno = f->seqno; /* XXX hmmm... check this below */ if (!ast_tvzero(f->delivery)) { if (!ast_tvzero(path->nextin)) { /* Make sure this is in line with what we were expecting */ if (!ast_tveq(path->nextin, f->delivery)) { /* The time has changed between what we expected and this most recent time on the new packet. If we have a valid prediction adjust our output time appropriately */ if (!ast_tvzero(path->nextout)) { path->nextout = ast_tvadd(path->nextout, ast_tvsub(f->delivery, path->nextin)); } path->nextin = f->delivery; } } else { /* This is our first pass. Make sure the timing looks good */ path->nextin = f->delivery; path->nextout = f->delivery; } /* Predict next incoming sample */ path->nextin = ast_tvadd(path->nextin, ast_samp2tv(f->samples, 8000)); } delivery = f->delivery; for ( ; out && p ; p = p->next) { framein(p, out); out = p->t->frameout(p); } if (consume) ast_frfree(f); if (out == NULL) return NULL; /* we have a frame, play with times */ if (!ast_tvzero(delivery)) { /* Regenerate prediction after a discontinuity */ if (ast_tvzero(path->nextout)) path->nextout = ast_tvnow(); /* Use next predicted outgoing timestamp */ out->delivery = path->nextout; /* Predict next outgoing timestamp from samples in this frame. */ path->nextout = ast_tvadd(path->nextout, ast_samp2tv( out->samples, 8000)); } else { out->delivery = ast_tv(0, 0); out->has_timing_info = has_timing_info; if (has_timing_info) { out->ts = ts; out->len = len; out->seqno = seqno; } } /* Invalidate prediction if we're entering a silence period */ if (out->frametype == AST_FRAME_CNG) path->nextout = ast_tv(0, 0); return out; }

unsigned int ast_translate_available_formats (  unsigned int  dest, unsigned int  src )

Mask off unavailable formats from a format bitmask. Parameters: dest  possible destination formats src  source formats Returns: the destination formats that are available in the source or translatable The result will include all formats from 'dest' that are either present in 'src' or translatable from a format present in 'src'. Note that only a single audio format and a single video format can be present in 'src', or the function will produce unexpected results. Definition at line 777 of file translate.c. References AST_FORMAT_AUDIO_MASK, AST_FORMAT_MAX_AUDIO, AST_FORMAT_VIDEO_MASK, AST_RWLIST_RDLOCK, powerof(), and tr_matrix. Referenced by sip_call(). { unsigned int res = dest; unsigned int x; unsigned int src_audio = src & AST_FORMAT_AUDIO_MASK; unsigned int src_video = src & AST_FORMAT_VIDEO_MASK; /* if we don't have a source format, we just have to try all possible destination formats */ if (!src) return dest; /* If we have a source audio format, get its format index */ if (src_audio) src_audio = powerof(src_audio); /* If we have a source video format, get its format index */ if (src_video) src_video = powerof(src_video); AST_RWLIST_RDLOCK(&translators); /* For a given source audio format, traverse the list of known audio formats to determine whether there exists a translation path from the source format to the destination format. */ for (x = 1; src_audio && x < AST_FORMAT_MAX_AUDIO; x <<= 1) { /* if this is not a desired format, nothing to do */ if (!dest & x) continue; /* if the source is supplying this format, then we can leave it in the result */ if (src & x) continue; /* if we don't have a translation path from the src to this format, remove it from the result */ if (!tr_matrix[src_audio][powerof(x)].step) { res &= ~x; continue; } /* now check the opposite direction */ if (!tr_matrix[powerof(x)][src_audio].step) res &= ~x; } /* For a given source video format, traverse the list of known video formats to determine whether there exists a translation path from the source format to the destination format. */ for (; src_video && x < AST_FORMAT_MAX_VIDEO; x <<= 1) { /* if this is not a desired format, nothing to do */ if (!dest & x) continue; /* if the source is supplying this format, then we can leave it in the result */ if (src & x) continue; /* if we don't have a translation path from the src to this format, remove it from the result */ if (!tr_matrix[src_video][powerof(x)].step) { res &= ~x; continue; } /* now check the opposite direction */ if (!tr_matrix[powerof(x)][src_video].step) res &= ~x; } AST_RWLIST_UNLOCK(&translators); return res; }

unsigned int ast_translate_path_steps (  unsigned int  dest, unsigned int  src )

Returns the number of steps required to convert from 'src' to 'dest'. Parameters: dest  destination format src  source format Returns: the number of translation steps required, or -1 if no path is available Definition at line 759 of file translate.c. References AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK, translator_path::multistep, powerof(), and tr_matrix. Referenced by ast_channel_make_compatible_helper(). { unsigned int res = -1; /* convert bitwise format numbers into array indices */ src = powerof(src); dest = powerof(dest); AST_RWLIST_RDLOCK(&translators); if (tr_matrix[src][dest].step) res = tr_matrix[src][dest].multistep + 1; AST_RWLIST_UNLOCK(&translators); return res; }

void ast_translator_activate (  struct ast_translator *  t  )

Activate a previously deactivated translator. Parameters: t  translator to activate Returns: nothing Enables the specified translator for use. Definition at line 695 of file translate.c. References ast_translator::active, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, and rebuild_matrix(). { AST_RWLIST_WRLOCK(&translators); t->active = 1; rebuild_matrix(0); AST_RWLIST_UNLOCK(&translators); }

int ast_translator_best_choice (  int *  dsts, int *  srcs )

Chooses the best translation path. Given a list of sources, and a designed destination format, which should I choose? Returns: Returns 0 on success, -1 if no path could be found. Note: Modifies dests and srcs in place Definition at line 712 of file translate.c. References MAX_FORMAT. Referenced by ast_channel_make_compatible_helper(), ast_request(), iax2_request(), and set_format(). { int x,y; int best = -1; int bestdst = 0; int cur, cursrc; int besttime = INT_MAX; int beststeps = INT_MAX; int common = (*dst) & (*srcs); /* are there common formats ? */ if (common) { /* yes, pick one and return */ for (cur = 1, y = 0; y < MAX_FORMAT; cur <<= 1, y++) { if (cur & common) /* guaranteed to find one */ break; } /* We are done, this is a common format to both. */ *srcs = *dst = cur; return 0; } else { /* No, we will need to translate */ AST_RWLIST_RDLOCK(&translators); for (cur = 1, y = 0; y < MAX_FORMAT; cur <<= 1, y++) { if (! (cur & *dst)) continue; for (cursrc = 1, x = 0; x < MAX_FORMAT; cursrc <<= 1, x++) { if (!(*srcs & cursrc) || !tr_matrix[x][y].step || tr_matrix[x][y].cost > besttime) continue; /* not existing or no better */ if (tr_matrix[x][y].cost < besttime || tr_matrix[x][y].multistep < beststeps) { /* better than what we have so far */ best = cursrc; bestdst = cur; besttime = tr_matrix[x][y].cost; beststeps = tr_matrix[x][y].multistep; } } } AST_RWLIST_UNLOCK(&translators); if (best > -1) { *srcs = best; *dst = bestdst; best = 0; } return best; } }

struct ast_trans_pvt* ast_translator_build_path (  int  dest, int  source )

Builds a translator path Build a path (possibly NULL) from source to dest. Parameters: dest  destination format source  source format Returns: ast_trans_pvt on success, NULL on failure Definition at line 253 of file translate.c. References ast_getformatname(), ast_log(), AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK, ast_translator_free_path(), ast_translator::dstfmt, LOG_WARNING, newpvt(), ast_trans_pvt::next, ast_trans_pvt::nextin, ast_trans_pvt::nextout, powerof(), translator_path::step, ast_trans_pvt::t, and tr_matrix. Referenced by ast_slinfactory_feed(), ast_write(), ast_writestream(), queue_frame_to_spies(), read_config(), and set_format(). { struct ast_trans_pvt *head = NULL, *tail = NULL; source = powerof(source); dest = powerof(dest); AST_RWLIST_RDLOCK(&translators); while (source != dest) { struct ast_trans_pvt *cur; struct ast_translator *t = tr_matrix[source][dest].step; if (!t) { ast_log(LOG_WARNING, "No translator path from %s to %s\n", ast_getformatname(source), ast_getformatname(dest)); AST_RWLIST_UNLOCK(&translators); return NULL; } if (!(cur = newpvt(t))) { ast_log(LOG_WARNING, "Failed to build translator step from %d to %d\n", source, dest); if (head) ast_translator_free_path(head); AST_RWLIST_UNLOCK(&translators); return NULL; } if (!head) head = cur; else tail->next = cur; tail = cur; cur->nextin = cur->nextout = ast_tv(0, 0); /* Keep going if this isn't the final destination */ source = cur->t->dstfmt; } AST_RWLIST_UNLOCK(&translators); return head; }

void ast_translator_deactivate (  struct ast_translator *  t  )

Deactivate a translator. Parameters: t  translator to deactivate Returns: nothing Disables the specified translator from being used. Definition at line 703 of file translate.c. References ast_translator::active, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, and rebuild_matrix(). { AST_RWLIST_WRLOCK(&translators); t->active = 0; rebuild_matrix(0); AST_RWLIST_UNLOCK(&translators); }

void ast_translator_free_path (  struct ast_trans_pvt *  tr  )

Frees a translator path Frees the given translator path structure. Parameters: tr  translator path to get rid of Definition at line 243 of file translate.c. References destroy(), and ast_trans_pvt::next. Referenced by ast_channel_free(), ast_channel_whisper_stop(), ast_closestream(), ast_slinfactory_destroy(), ast_slinfactory_feed(), ast_translator_build_path(), ast_write(), ast_writestream(), cl_dequeue_chan(), free_translation(), queue_frame_to_spies(), set_format(), and spy_cleanup(). { struct ast_trans_pvt *pn = p; while ( (p = pn) ) { pn = p->next; destroy(p); } }

int ast_unregister_translator (  struct ast_translator *  t  )

Unregister a translator Unregisters the given tranlator. Parameters: t  translator to unregister Returns: 0 on success, -1 on failure Definition at line 669 of file translate.c. References ast_getformatname(), AST_RWLIST_REMOVE_CURRENT, AST_RWLIST_TRAVERSE_SAFE_BEGIN, AST_RWLIST_TRAVERSE_SAFE_END, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, ast_verbose(), COLOR_BLACK, COLOR_MAGENTA, ast_translator::dstfmt, ast_translator::name, option_verbose, rebuild_matrix(), ast_translator::srcfmt, term_color(), and VERBOSE_PREFIX_2. { char tmp[80]; struct ast_translator *u; int found = 0; AST_RWLIST_WRLOCK(&translators); AST_RWLIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) { if (u == t) { AST_RWLIST_REMOVE_CURRENT(&translators, list); if (option_verbose > 1) ast_verbose(VERBOSE_PREFIX_2 "Unregistered translator '%s' from format %s to %s\n", term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)), ast_getformatname(1 << t->srcfmt), ast_getformatname(1 << t->dstfmt)); found = 1; break; } } AST_RWLIST_TRAVERSE_SAFE_END; if (found) rebuild_matrix(0); AST_RWLIST_UNLOCK(&translators); return (u ? 0 : -1); }

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