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asterisk
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Merged revisions 11062,11089 via svnmerge from

Browse Source 
https://origsvn.digium.com/svn/asterisk/branches/1.2

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r11062 | kpfleming | 2006-02-24 22:59:50 -0600 (Fri, 24 Feb 2006) | 3 lines

reformat code to fit guidelines
remember which translation paths are multi-step paths

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r11089 | kpfleming | 2006-02-24 23:08:46 -0600 (Fri, 24 Feb 2006) | 2 lines

factor the number of translation steps required into translation path decisions, so that equal cost paths that require fewer translations are preferred

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@11090 65c4cc65-6c06-0410-ace0-fbb531ad65f3
1.4
Kevin P. Fleming 20 years ago
parent 50765d9aa5
commit 50794ec318
1 changed files with 66 additions and 44 deletions
Show Stats Download Patch File Download Diff File

110
translate.c
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@ -1,7 +1,7 @@
/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2005, Digium, Inc.
* Copyright (C) 1999 - 2006, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
*
@ -55,7 +55,8 @@ static AST_LIST_HEAD_STATIC(translators, ast_translator);
struct ast_translator_dir {
struct ast_translator *step; /*!< Next step translator */
int cost; /*!< Complete cost to destination */
unsigned int cost; /*!< Complete cost to destination */
unsigned int multistep; /*!< Multiple conversions required for this translation */
};
struct ast_frame_delivery {
@ -275,55 +276,63 @@ static void rebuild_matrix(int samples)
{
struct ast_translator *t;
int changed;
int x,y,z;
int x, y, z;
if (option_debug)
ast_log(LOG_DEBUG, "Resetting translation matrix\n");
bzero(tr_matrix, sizeof(tr_matrix));
AST_LIST_TRAVERSE(&translators, t, list) {
if(samples)
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].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 */
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 */
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;
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++;
}
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);
}
/*! \brief CLI "show translation" command handler */
static int show_translation(int fd, int argc, char *argv[])
{
@ -444,14 +453,14 @@ int ast_translator_best_choice(int *dst, int *srcs)
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++) {
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 */
besttime = 0;
bestdst = cur;
best = cur;
}
@ -460,25 +469,38 @@ int ast_translator_best_choice(int *dst, int *srcs)
} else {
/* We will need to translate */
AST_LIST_LOCK(&translators);
for (y=0; y < MAX_FORMAT; y++) {
if (cur & *dst)
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 */
(tr_matrix[x][y].cost < besttime)) { /* It's better than what we have so far */
best = 1 << x;
bestdst = cur;
besttime = tr_matrix[x][y].cost;
}
for (y = 0; y < MAX_FORMAT; y++) {
if (!(cur & *dst))
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_LIST_UNLOCK(&translators);
}
if (best > -1) {
*srcs = best;
*dst = bestdst;
best = 0;
}
return best;
}

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