Sun Aug 6 15:16:59 2006

Asterisk developer's documentation

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translate.c File Reference

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

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "asterisk.h"
#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/translate.h"
#include "asterisk/options.h"
#include "asterisk/frame.h"
#include "asterisk/sched.h"
#include "asterisk/cli.h"
#include "asterisk/term.h"

Include dependency graph for translate.c:

Go to the source code of this file.

Defines
#define	MAX_RECALC   200
#define	SHOW_TRANS   11
Functions
	AST_MUTEX_DEFINE_STATIC (list_lock)
int	ast_register_translator (struct ast_translator *t)
ast_frame *	ast_translate (struct ast_trans_pvt *path, struct ast_frame *f, int consume)
int	ast_translator_best_choice (int *dst, 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 *p)
int	ast_unregister_translator (struct ast_translator *t)
	unregister codec translator
static void	calc_cost (struct ast_translator *t, int samples)
static int	powerof (int d)
static void	rebuild_matrix (int samples)
	Use the list of translators to build a translation matrix.
static int	show_translation (int fd, int argc, char *argv[])
	CLI "show translation" command handler.
Variables
static int	added_cli = 0
static struct ast_translator *	list = NULL
static struct ast_cli_entry	show_trans
static char	show_trans_usage []
static struct ast_translator_dir	tr_matrix [MAX_FORMAT][MAX_FORMAT]

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Detailed Description

Translate via the use of pseudo channels.

Definition in file translate.c.

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Define Documentation

#define MAX_RECALC   200

Definition at line 47 of file translate.c. Referenced by show_translation().

#define SHOW_TRANS   11

Referenced by show_translation().

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Function Documentation

AST_MUTEX_DEFINE_STATIC (  list_lock   )

Note: This could all be done more efficiently *IF* we chained packets together by default, but it would also complicate virtually every application.

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::cost, ast_translator_dir::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_trans_pvt::step, and ast_translator_dir::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); }

static void calc_cost (  struct ast_translator *  t, int  samples )  [static]

Definition at line 223 of file translate.c. References ast_frfree(), ast_log(), ast_translator::cost, ast_translator::destroy, ast_translator::framein, ast_translator::frameout, LOG_WARNING, ast_translator::name, ast_translator::newpvt, ast_translator::sample, and ast_frame::samples. Referenced by ast_register_translator(), and rebuild_matrix(). { int sofar=0; struct ast_translator_pvt *pvt; struct ast_frame *f, *out; struct timeval start; int cost; if(!samples) samples = 1; /* If they don't make samples, give them a terrible score */ if (!t->sample) { ast_log(LOG_WARNING, "Translator '%s' does not produce sample frames.\n", t->name); t->cost = 99999; return; } pvt = t->newpvt(); if (!pvt) { ast_log(LOG_WARNING, "Translator '%s' appears to be broken and will probably fail.\n", t->name); t->cost = 99999; return; } start = ast_tvnow(); /* Call the encoder until we've processed one second of time */ while(sofar < samples * 8000) { f = t->sample(); if (!f) { ast_log(LOG_WARNING, "Translator '%s' failed to produce a sample frame.\n", t->name); t->destroy(pvt); t->cost = 99999; return; } t->framein(pvt, f); ast_frfree(f); while((out = t->frameout(pvt))) { sofar += out->samples; ast_frfree(out); } } cost = ast_tvdiff_ms(ast_tvnow(), start); t->destroy(pvt); t->cost = cost / samples; if (!t->cost) t->cost = 1; }

static int powerof (  int  d  )  [static]

Definition at line 82 of file translate.c. References ast_log(), and LOG_WARNING. Referenced by agents_show(), ast_register_translator(), and ast_translator_build_path(). { int x; for (x = 0; x < 32; x++) if ((1 << x) & d) return x; ast_log(LOG_WARNING, "Powerof %d: No power??\n", d); return -1; }

static void rebuild_matrix (  int  samples  )  [static]

Use the list of translators to build a translation matrix. Definition at line 271 of file translate.c. References ast_getformatname(), ast_log(), calc_cost(), ast_translator::cost, LOG_DEBUG, ast_translator::next, option_debug, and t. Referenced by ast_register_translator(), ast_unregister_translator(), and show_translation(). { struct ast_translator *t; int changed; int x, y, z; if (option_debug) ast_log(LOG_DEBUG, "Resetting translation matrix\n"); bzero(tr_matrix, sizeof(tr_matrix)); for (t = list; t; t = t->next) { if (samples) calc_cost(t, samples); if (!tr_matrix[t->srcfmt][t->dstfmt].step || tr_matrix[t->srcfmt][t->dstfmt].cost > t->cost) { tr_matrix[t->srcfmt][t->dstfmt].step = t; tr_matrix[t->srcfmt][t->dstfmt].cost = t->cost; } } do { changed = 0; /* Don't you just love O(N^3) operations? */ for (x = 0; x< MAX_FORMAT; x++) { /* For each source format */ for (y = 0; y < MAX_FORMAT; y++) { /* And each destination format */ if (x == y) /* Except ourselves, of course */ continue; for (z=0; z < MAX_FORMAT; z++) { /* And each format it might convert to */ if ((x == z) || (y == z)) /* Don't ever convert back to us */ continue; if (tr_matrix[x][y].step && /* We can convert from x to y */ tr_matrix[y][z].step && /* And from y to z and... */ (!tr_matrix[x][z].step || /* Either there isn't an x->z conversion */ (tr_matrix[x][y].cost + tr_matrix[y][z].cost < /* Or we're cheaper than the existing */ tr_matrix[x][z].cost) /* solution */ )) { /* We can get from x to z via y with a cost that is the sum of the transition from x to y and from y to z */ tr_matrix[x][z].step = tr_matrix[x][y].step; tr_matrix[x][z].cost = tr_matrix[x][y].cost + tr_matrix[y][z].cost; tr_matrix[x][z].multistep = 1; if (option_debug) ast_log(LOG_DEBUG, "Discovered %d cost path from %s to %s, via %d\n", tr_matrix[x][z].cost, ast_getformatname(x), ast_getformatname(z), y); changed++; } } } } } while (changed); }

static int show_translation (  int  fd, int  argc, char *  argv[] )  [static]

CLI "show translation" command handler. Definition at line 333 of file translate.c. References ast_cli(), ast_getformatname(), ast_mutex_lock(), ast_mutex_unlock(), ast_translator::cost, MAX_RECALC, rebuild_matrix(), RESULT_SHOWUSAGE, RESULT_SUCCESS, and SHOW_TRANS. { #define SHOW_TRANS 11 int x, y, z; char line[80]; if (argc > 4) return RESULT_SHOWUSAGE; ast_mutex_lock(&list_lock); if (argv[2] && !strcasecmp(argv[2],"recalc")) { z = argv[3] ? atoi(argv[3]) : 1; if (z <= 0) { ast_cli(fd," C'mon let's be serious here... defaulting to 1.\n"); z = 1; } if (z > MAX_RECALC) { ast_cli(fd," Maximum limit of recalc exceeded by %d, truncating value to %d\n",z-MAX_RECALC,MAX_RECALC); z = MAX_RECALC; } ast_cli(fd," Recalculating Codec Translation (number of sample seconds: %d)\n\n",z); rebuild_matrix(z); } ast_cli(fd, " Translation times between formats (in milliseconds)\n"); ast_cli(fd, " Source Format (Rows) Destination Format(Columns)\n\n"); for (x = -1; x < SHOW_TRANS; x++) { /* next 2 lines run faster than using strcpy() */ line[0] = ' '; line[1] = '\0'; for (y=-1;y<SHOW_TRANS;y++) { if (x >= 0 && y >= 0 && tr_matrix[x][y].step) snprintf(line + strlen(line), sizeof(line) - strlen(line), " %5d", tr_matrix[x][y].cost >= 99999 ? tr_matrix[x][y].cost-99999 : tr_matrix[x][y].cost); else if (((x == -1 && y >= 0) || (y == -1 && x >= 0))) { snprintf(line + strlen(line), sizeof(line) - strlen(line), " %5s", ast_getformatname(1<<(x+y+1)) ); } else if (x != -1 && y != -1) { snprintf(line + strlen(line), sizeof(line) - strlen(line), " -"); } else { snprintf(line + strlen(line), sizeof(line) - strlen(line), " "); } } snprintf(line + strlen(line), sizeof(line) - strlen(line), "\n"); ast_cli(fd, line); } ast_mutex_unlock(&list_lock); return RESULT_SUCCESS; }

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Variable Documentation

int added_cli = 0 [static]

Definition at line 384 of file translate.c. Referenced by ast_register_translator().

struct ast_translator* list = NULL [static]

Definition at line 54 of file translate.c.

struct ast_cli_entry show_trans [static]

Initial value: { { "show", "translation", NULL }, show_translation, "Display translation matrix", show_trans_usage } Definition at line 393 of file translate.c.

char show_trans_usage[] [static]

Definition at line 386 of file translate.c.

struct ast_translator_dir tr_matrix[MAX_FORMAT][MAX_FORMAT] [static]

Definition at line 71 of file translate.c.

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