Sun Aug 6 15:17:00 2006

Asterisk developer's documentation

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translate.h File Reference

Translate via the use of pseudo channels. More...

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

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Defines
#define	MAX_FORMAT   32
Functions
int	ast_register_translator (struct ast_translator *t)
ast_frame *	ast_translate (struct ast_trans_pvt *tr, struct ast_frame *f, int consume)
int	ast_translator_best_choice (int *dsts, int *srcs)
	Calculate our best translator source format, given costs, and a desired destination.
ast_trans_pvt *	ast_translator_build_path (int dest, int source)
void	ast_translator_free_path (struct ast_trans_pvt *tr)
int	ast_unregister_translator (struct ast_translator *t)
	unregister codec translator

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Detailed Description

Translate via the use of pseudo channels.

Definition in file translate.h.

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Define Documentation

#define MAX_FORMAT   32

Definition at line 26 of file translate.h.

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Function Documentation

int ast_register_translator (  struct ast_translator *  t  )

Parameters: t  populated ast_translator structure This registers a codec translator with asterisk Returns 0 on success, -1 on failure Definition at line 396 of file translate.c. References added_cli, ast_cli_register(), ast_getformatname(), ast_log(), ast_mutex_lock(), ast_mutex_unlock(), ast_verbose(), calc_cost(), COLOR_BLACK, COLOR_MAGENTA, ast_translator::cost, ast_translator::dstfmt, LOG_WARNING, ast_translator::name, ast_translator::next, option_verbose, powerof(), rebuild_matrix(), ast_translator::srcfmt, term_color(), and VERBOSE_PREFIX_2. Referenced by load_module(). { char tmp[80]; t->srcfmt = powerof(t->srcfmt); t->dstfmt = powerof(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; } calc_cost(t,1); if (option_verbose > 1) 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); ast_mutex_lock(&list_lock); if (!added_cli) { ast_cli_register(&show_trans); added_cli++; } t->next = list; list = t; rebuild_matrix(0); ast_mutex_unlock(&list_lock); return 0; }

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

Parameters: tr  translator structure to use for translation f  frame to translate consume  Whether or not to free the original frame Apply an input frame into the translator and receive zero or one output frames. Consume determines whether the original frame should be freed Returns an ast_frame of the new translation format on success, NULL on failure Definition at line 155 of file translate.c. References AST_FRAME_CNG, ast_frfree(), ast_log(), ast_tvadd(), ast_tvsub(), ast_frame::delivery, ast_translator::framein, ast_frame::frametype, LOG_WARNING, ast_frame::next, ast_trans_pvt::nextin, ast_trans_pvt::nextout, ast_frame::samples, and ast_trans_pvt::step. Referenced by ast_read(), ast_slinfactory_feed(), ast_write(), ast_writestream(), misdn_tx2ast_frm(), and queue_frame_to_spies(). { struct ast_trans_pvt *p; struct ast_frame *out; struct timeval delivery; p = path; /* Feed the first frame into the first translator */ p->step->framein(p->state, f); 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; if (consume) ast_frfree(f); while(p) { out = p->step->frameout(p->state); /* If we get nothing out, return NULL */ if (!out) return NULL; /* If there is a next state, feed it in there. If not, return this frame */ if (p->next) p->next->step->framein(p->next->state, out); else { 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); } /* Invalidate prediction if we're entering a silence period */ if (out->frametype == AST_FRAME_CNG) path->nextout = ast_tv(0, 0); return out; } p = p->next; } ast_log(LOG_WARNING, "I should never get here...\n"); return NULL; }

int ast_translator_best_choice (  int *  dsts, int *  srcs )

Calculate our best translator source format, given costs, and a desired destination. Given a list of sources, and a designed destination format, which should I choose? Returns 0 on success, -1 if no path could be found. Modifies dests and srcs in place Definition at line 450 of file translate.c. References ast_mutex_lock(), ast_mutex_unlock(), ast_translator_dir::cost, ast_translator::cost, and ast_translator_dir::multistep. Referenced by ast_channel_make_compatible(), ast_request(), iax2_request(), and set_format(). { int x,y; int best = -1; int bestdst = 0; int cur = 1; int besttime = INT_MAX; int beststeps = INT_MAX; int common; if ((common = (*dst) & (*srcs))) { /* We have a format in common */ for (y = 0; y < MAX_FORMAT; y++) { if (cur & common) { /* This is a common format to both. Pick it if we don't have one already */ bestdst = cur; best = cur; } cur = cur << 1; } } else { /* We will need to translate */ ast_mutex_lock(&list_lock); for (y = 0; y < MAX_FORMAT; y++) { if (!(cur & *dst)) { cur = cur << 1; continue; } for (x = 0; x < MAX_FORMAT; x++) { if ((*srcs & (1 << x)) && /* x is a valid source format */ tr_matrix[x][y].step) { /* There's a step */ if (tr_matrix[x][y].cost > besttime) continue; /* It's more expensive, skip it */ if (tr_matrix[x][y].cost == besttime && tr_matrix[x][y].multistep >= beststeps) continue; /* It requires the same (or more) steps, skip it */ /* It's better than what we have so far */ best = 1 << x; bestdst = cur; besttime = tr_matrix[x][y].cost; beststeps = tr_matrix[x][y].multistep; } } cur = cur << 1; } ast_mutex_unlock(&list_lock); } if (best > -1) { *srcs = best; *dst = bestdst; best = 0; } return best; }

struct ast_trans_pvt* ast_translator_build_path (  int  dest, int  source )

Build a set of translators based upon the given source and destination formats Definition at line 106 of file translate.c. References ast_getformatname(), ast_log(), ast_translator_free_path(), LOG_WARNING, malloc, ast_translator::newpvt, ast_trans_pvt::next, ast_trans_pvt::nextin, powerof(), ast_translator_dir::step, and ast_trans_pvt::step. Referenced by ast_slinfactory_feed(), ast_writestream(), misdn_set_opt_exec(), queue_frame_to_spies(), and set_format(). { struct ast_trans_pvt *tmpr = NULL, *tmp = NULL; source = powerof(source); dest = powerof(dest); while(source != dest) { if (!tr_matrix[source][dest].step) { /* We shouldn't have allocated any memory */ ast_log(LOG_WARNING, "No translator path from %s to %s\n", ast_getformatname(source), ast_getformatname(dest)); return NULL; } if (tmp) { tmp->next = malloc(sizeof(*tmp)); tmp = tmp->next; } else tmp = malloc(sizeof(*tmp)); if (!tmp) { ast_log(LOG_WARNING, "Out of memory\n"); if (tmpr) ast_translator_free_path(tmpr); return NULL; } /* Set the root, if it doesn't exist yet... */ if (!tmpr) tmpr = tmp; tmp->next = NULL; tmp->nextin = tmp->nextout = ast_tv(0, 0); tmp->step = tr_matrix[source][dest].step; tmp->state = tmp->step->newpvt(); if (!tmp->state) { ast_log(LOG_WARNING, "Failed to build translator step from %d to %d\n", source, dest); ast_translator_free_path(tmpr); return NULL; } /* Keep going if this isn't the final destination */ source = tmp->step->dstfmt; } return tmpr; }

void ast_translator_free_path (  struct ast_trans_pvt *  tr  )

Parameters: tr  translator path to get rid of Frees the given translator path structure Definition at line 92 of file translate.c. References ast_translator::destroy, free, ast_trans_pvt::next, ast_trans_pvt::state, and ast_trans_pvt::step. Referenced by ast_channel_free(), ast_channel_spy_remove(), ast_closestream(), ast_slinfactory_destroy(), ast_slinfactory_feed(), ast_translator_build_path(), ast_writestream(), cl_dequeue_chan(), free_translation(), iax2_destroy(), queue_frame_to_spies(), and set_format(). { struct ast_trans_pvt *pl, *pn; pn = p; while(pn) { pl = pn; pn = pn->next; if (pl->state && pl->step->destroy) pl->step->destroy(pl->state); free(pl); } }

int ast_unregister_translator (  struct ast_translator *  t  )

unregister codec translator Parameters: t  translator to unregister Unregisters the given tranlator Returns 0 on success, -1 on failure Definition at line 425 of file translate.c. References ast_getformatname(), ast_mutex_lock(), ast_mutex_unlock(), ast_verbose(), COLOR_BLACK, COLOR_MAGENTA, ast_translator::dstfmt, ast_translator::name, ast_translator::next, option_verbose, rebuild_matrix(), ast_translator::srcfmt, term_color(), and VERBOSE_PREFIX_2. Referenced by load_module(), and unload_module(). { char tmp[80]; struct ast_translator *u, *ul = NULL; ast_mutex_lock(&list_lock); u = list; while(u) { if (u == t) { if (ul) ul->next = u->next; else list = u->next; 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)); break; } ul = u; u = u->next; } rebuild_matrix(0); ast_mutex_unlock(&list_lock); return (u ? 0 : -1); }

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