Fri Aug 24 02:27:52 2007

Asterisk developer's documentation


translate.h File Reference

Support for translation of data formats. More...

#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_frameast_trans_frameout (struct ast_trans_pvt *pvt, int datalen, int samples)
 generic frameout function
ast_frameast_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_pvtast_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.


Detailed Description

Support for translation of data formats.

Definition in file translate.h.


Define Documentation

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

Definition at line 161 of file translate.h.

Referenced by load_module(), and register_translator().

#define MAX_FORMAT   32

Definition at line 27 of file translate.h.

Referenced by __ast_register_translator(), ast_translator_best_choice(), and rebuild_matrix().


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 653 of file translate.c.

References ast_cli_register_multiple(), AST_FORMAT_SLINEAR, ast_getformatname(), AST_LIST_INSERT_BEFORE_CURRENT, AST_LIST_INSERT_HEAD, AST_LIST_LOCK, AST_LIST_TRAVERSE_SAFE_BEGIN, AST_LIST_TRAVERSE_SAFE_END, AST_LIST_UNLOCK, ast_log(), ast_verbose(), calc_cost(), cli_translate, COLOR_BLACK, COLOR_MAGENTA, ast_translator::cost, default_frameout(), ast_translator::dstfmt, LOG_WARNING, MAX_FORMAT, option_verbose, powerof(), rebuild_matrix(), ast_translator::srcfmt, t, term_color(), and VERBOSE_PREFIX_2.

00654 {
00655    static int added_cli = 0;
00656    struct ast_translator *u;
00657 
00658    if (!mod) {
00659       ast_log(LOG_WARNING, "Missing module pointer, you need to supply one\n");
00660       return -1;
00661    }
00662 
00663    if (!t->buf_size) {
00664       ast_log(LOG_WARNING, "empty buf size, you need to supply one\n");
00665       return -1;
00666    }
00667 
00668    t->module = mod;
00669 
00670    t->srcfmt = powerof(t->srcfmt);
00671    t->dstfmt = powerof(t->dstfmt);
00672    t->active = 1;
00673 
00674    if (t->plc_samples) {
00675       if (t->buffer_samples < t->plc_samples) {
00676          ast_log(LOG_WARNING, "plc_samples %d buffer_samples %d\n",
00677             t->plc_samples, t->buffer_samples);
00678          return -1;
00679       }
00680       if (t->dstfmt != powerof(AST_FORMAT_SLINEAR))
00681          ast_log(LOG_WARNING, "plc_samples %d format %x\n",
00682             t->plc_samples, t->dstfmt);
00683    }
00684    if (t->srcfmt >= MAX_FORMAT) {
00685       ast_log(LOG_WARNING, "Source format %s is larger than MAX_FORMAT\n", ast_getformatname(t->srcfmt));
00686       return -1;
00687    }
00688 
00689    if (t->dstfmt >= MAX_FORMAT) {
00690       ast_log(LOG_WARNING, "Destination format %s is larger than MAX_FORMAT\n", ast_getformatname(t->dstfmt));
00691       return -1;
00692    }
00693 
00694    if (t->buf_size) {
00695                /*
00696       * Align buf_size properly, rounding up to the machine-specific
00697       * alignment for pointers.
00698       */
00699       struct _test_align { void *a, *b; } p;
00700       int align = (char *)&p.b - (char *)&p.a;
00701 
00702       t->buf_size = ((t->buf_size + align - 1) / align) * align;
00703    }
00704 
00705    if (t->frameout == NULL)
00706       t->frameout = default_frameout;
00707   
00708    calc_cost(t, 1);
00709 
00710    if (option_verbose > 1) {
00711       char tmp[80];
00712 
00713       ast_verbose(VERBOSE_PREFIX_2 "Registered translator '%s' from format %s to %s, cost %d\n",
00714              term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)),
00715              ast_getformatname(1 << t->srcfmt), ast_getformatname(1 << t->dstfmt), t->cost);
00716    }
00717 
00718    if (!added_cli) {
00719       ast_cli_register_multiple(cli_translate, sizeof(cli_translate) / sizeof(struct ast_cli_entry));
00720       added_cli++;
00721    }
00722 
00723    AST_LIST_LOCK(&translators);
00724 
00725    /* find any existing translators that provide this same srcfmt/dstfmt,
00726       and put this one in order based on cost */
00727    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) {
00728       if ((u->srcfmt == t->srcfmt) &&
00729           (u->dstfmt == t->dstfmt) &&
00730           (u->cost > t->cost)) {
00731          AST_LIST_INSERT_BEFORE_CURRENT(&translators, t, list);
00732          t = NULL;
00733       }
00734    }
00735    AST_LIST_TRAVERSE_SAFE_END;
00736 
00737    /* if no existing translator was found for this format combination,
00738       add it to the beginning of the list */
00739    if (t)
00740       AST_LIST_INSERT_HEAD(&translators, t, list);
00741 
00742    rebuild_matrix(0);
00743 
00744    AST_LIST_UNLOCK(&translators);
00745 
00746    return 0;
00747 }

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

generic frameout function

Definition at line 213 of file translate.c.

References AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_trans_pvt::datalen, ast_translator::dstfmt, ast_trans_pvt::f, f, ast_translator::name, ast_trans_pvt::outbuf, ast_trans_pvt::samples, and ast_trans_pvt::t.

Referenced by default_frameout(), lintoadpcm_frameout(), lintogsm_frameout(), lintoilbc_frameout(), and lintolpc10_frameout().

00215 {
00216    struct ast_frame *f = &pvt->f;
00217 
00218         if (samples)
00219       f->samples = samples;
00220    else {
00221       if (pvt->samples == 0)
00222          return NULL;
00223       f->samples = pvt->samples;
00224       pvt->samples = 0;
00225    }
00226    if (datalen)
00227       f->datalen = datalen;
00228    else {
00229       f->datalen = pvt->datalen;
00230       pvt->datalen = 0;
00231    }
00232 
00233    f->frametype = AST_FRAME_VOICE;
00234    f->subclass = 1 << (pvt->t->dstfmt);
00235    f->mallocd = 0;
00236    f->offset = AST_FRIENDLY_OFFSET;
00237    f->src = pvt->t->name;
00238    f->data = pvt->outbuf;
00239    return f;
00240 }

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 299 of file translate.c.

References AST_FRAME_CNG, ast_frfree(), ast_tvadd(), ast_tvsub(), ast_frame::delivery, f, framein(), ast_frame::frametype, 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(), conf_run(), process_ast_dsp(), and queue_frame_to_spies().

00300 {
00301    struct ast_trans_pvt *p = path;
00302    struct ast_frame *out = f;
00303    struct timeval delivery;
00304    int has_timing_info;
00305    long ts;
00306    long len;
00307    int seqno;
00308 
00309    has_timing_info = f->has_timing_info;
00310    ts = f->ts;
00311    len = f->len;
00312    seqno = f->seqno;
00313 
00314    /* XXX hmmm... check this below */
00315    if (!ast_tvzero(f->delivery)) {
00316       if (!ast_tvzero(path->nextin)) {
00317          /* Make sure this is in line with what we were expecting */
00318          if (!ast_tveq(path->nextin, f->delivery)) {
00319             /* The time has changed between what we expected and this
00320                most recent time on the new packet.  If we have a
00321                valid prediction adjust our output time appropriately */
00322             if (!ast_tvzero(path->nextout)) {
00323                path->nextout = ast_tvadd(path->nextout,
00324                           ast_tvsub(f->delivery, path->nextin));
00325             }
00326             path->nextin = f->delivery;
00327          }
00328       } else {
00329          /* This is our first pass.  Make sure the timing looks good */
00330          path->nextin = f->delivery;
00331          path->nextout = f->delivery;
00332       }
00333       /* Predict next incoming sample */
00334       path->nextin = ast_tvadd(path->nextin, ast_samp2tv(f->samples, 8000));
00335    }
00336    delivery = f->delivery;
00337    for ( ; out && p ; p = p->next) {
00338       framein(p, out);
00339       out = p->t->frameout(p);
00340    }
00341    if (consume)
00342       ast_frfree(f);
00343    if (out == NULL)
00344       return NULL;
00345    /* we have a frame, play with times */
00346    if (!ast_tvzero(delivery)) {
00347       /* Regenerate prediction after a discontinuity */
00348       if (ast_tvzero(path->nextout))
00349          path->nextout = ast_tvnow();
00350 
00351       /* Use next predicted outgoing timestamp */
00352       out->delivery = path->nextout;
00353       
00354       /* Predict next outgoing timestamp from samples in this
00355          frame. */
00356       path->nextout = ast_tvadd(path->nextout, ast_samp2tv( out->samples, 8000));
00357    } else {
00358       out->delivery = ast_tv(0, 0);
00359       out->has_timing_info = has_timing_info;
00360       if (has_timing_info) {
00361          out->ts = ts;
00362          out->len = len;
00363          out->seqno = seqno;
00364       }
00365    }
00366    /* Invalidate prediction if we're entering a silence period */
00367    if (out->frametype == AST_FRAME_CNG)
00368       path->nextout = ast_tv(0, 0);
00369    return out;
00370 }

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 858 of file translate.c.

References AST_FORMAT_AUDIO_MASK, AST_FORMAT_MAX_AUDIO, AST_FORMAT_MAX_VIDEO, AST_FORMAT_VIDEO_MASK, AST_LIST_LOCK, AST_LIST_UNLOCK, powerof(), and tr_matrix.

Referenced by sip_call().

00859 {
00860    unsigned int res = dest;
00861    unsigned int x;
00862    unsigned int src_audio = src & AST_FORMAT_AUDIO_MASK;
00863    unsigned int src_video = src & AST_FORMAT_VIDEO_MASK;
00864 
00865    /* if we don't have a source format, we just have to try all
00866       possible destination formats */
00867    if (!src)
00868       return dest;
00869 
00870    /* If we have a source audio format, get its format index */
00871    if (src_audio)
00872       src_audio = powerof(src_audio);
00873 
00874    /* If we have a source video format, get its format index */
00875    if (src_video)
00876       src_video = powerof(src_video);
00877 
00878    AST_LIST_LOCK(&translators);
00879 
00880    /* For a given source audio format, traverse the list of
00881       known audio formats to determine whether there exists
00882       a translation path from the source format to the
00883       destination format. */
00884    for (x = 1; src_audio && x < AST_FORMAT_MAX_AUDIO; x <<= 1) {
00885       /* if this is not a desired format, nothing to do */
00886       if (!dest & x)
00887          continue;
00888 
00889       /* if the source is supplying this format, then
00890          we can leave it in the result */
00891       if (src & x)
00892          continue;
00893 
00894       /* if we don't have a translation path from the src
00895          to this format, remove it from the result */
00896       if (!tr_matrix[src_audio][powerof(x)].step) {
00897          res &= ~x;
00898          continue;
00899       }
00900 
00901       /* now check the opposite direction */
00902       if (!tr_matrix[powerof(x)][src_audio].step)
00903          res &= ~x;
00904    }
00905 
00906    /* For a given source video format, traverse the list of
00907       known video formats to determine whether there exists
00908       a translation path from the source format to the
00909       destination format. */
00910    for (; src_video && x < AST_FORMAT_MAX_VIDEO; x <<= 1) {
00911       /* if this is not a desired format, nothing to do */
00912       if (!dest & x)
00913          continue;
00914 
00915       /* if the source is supplying this format, then
00916          we can leave it in the result */
00917       if (src & x)
00918          continue;
00919 
00920       /* if we don't have a translation path from the src
00921          to this format, remove it from the result */
00922       if (!tr_matrix[src_video][powerof(x)].step) {
00923          res &= ~x;
00924          continue;
00925       }
00926 
00927       /* now check the opposite direction */
00928       if (!tr_matrix[powerof(x)][src_video].step)
00929          res &= ~x;
00930    }
00931 
00932    AST_LIST_UNLOCK(&translators);
00933 
00934    return res;
00935 }

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 840 of file translate.c.

References AST_LIST_LOCK, AST_LIST_UNLOCK, translator_path::multistep, powerof(), and tr_matrix.

Referenced by ast_channel_make_compatible().

00841 {
00842    unsigned int res = -1;
00843 
00844    /* convert bitwise format numbers into array indices */
00845    src = powerof(src);
00846    dest = powerof(dest);
00847 
00848    AST_LIST_LOCK(&translators);
00849 
00850    if (tr_matrix[src][dest].step)
00851       res = tr_matrix[src][dest].multistep + 1;
00852 
00853    AST_LIST_UNLOCK(&translators);
00854 
00855    return res;
00856 }

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 776 of file translate.c.

References AST_LIST_LOCK, AST_LIST_UNLOCK, rebuild_matrix(), and t.

00777 {
00778    AST_LIST_LOCK(&translators);
00779    t->active = 1;
00780    rebuild_matrix(0);
00781    AST_LIST_UNLOCK(&translators);
00782 }

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 793 of file translate.c.

References AST_LIST_LOCK, AST_LIST_UNLOCK, translator_path::cost, ast_translator::cost, MAX_FORMAT, translator_path::multistep, and tr_matrix.

Referenced by ast_channel_make_compatible(), ast_request(), iax2_request(), and set_format().

00794 {
00795    int x,y;
00796    int best = -1;
00797    int bestdst = 0;
00798    int cur, cursrc;
00799    int besttime = INT_MAX;
00800    int beststeps = INT_MAX;
00801    int common = (*dst) & (*srcs);   /* are there common formats ? */
00802 
00803    if (common) { /* yes, pick one and return */
00804       for (cur = 1, y = 0; y < MAX_FORMAT; cur <<= 1, y++) {
00805          if (cur & common) /* guaranteed to find one */
00806             break;
00807       }
00808       /* We are done, this is a common format to both. */
00809       *srcs = *dst = cur;
00810       return 0;
00811    } else { /* No, we will need to translate */
00812       AST_LIST_LOCK(&translators);
00813       for (cur = 1, y = 0; y < MAX_FORMAT; cur <<= 1, y++) {
00814          if (! (cur & *dst))
00815             continue;
00816          for (cursrc = 1, x = 0; x < MAX_FORMAT; cursrc <<= 1, x++) {
00817             if (!(*srcs & cursrc) || !tr_matrix[x][y].step ||
00818                 tr_matrix[x][y].cost >  besttime)
00819                continue;   /* not existing or no better */
00820             if (tr_matrix[x][y].cost < besttime ||
00821                 tr_matrix[x][y].multistep < beststeps) {
00822                /* better than what we have so far */
00823                best = cursrc;
00824                bestdst = cur;
00825                besttime = tr_matrix[x][y].cost;
00826                beststeps = tr_matrix[x][y].multistep;
00827             }
00828          }
00829       }
00830       AST_LIST_UNLOCK(&translators);
00831       if (best > -1) {
00832          *srcs = best;
00833          *dst = bestdst;
00834          best = 0;
00835       }
00836       return best;
00837    }
00838 }

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 259 of file translate.c.

References ast_getformatname(), AST_LIST_LOCK, AST_LIST_UNLOCK, ast_log(), 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, t, and tr_matrix.

Referenced by ast_slinfactory_feed(), ast_write(), ast_writestream(), conf_run(), misdn_set_opt_exec(), queue_frame_to_spies(), read_config(), and set_format().

00260 {
00261    struct ast_trans_pvt *head = NULL, *tail = NULL;
00262    
00263    source = powerof(source);
00264    dest = powerof(dest);
00265    
00266    AST_LIST_LOCK(&translators);
00267 
00268    while (source != dest) {
00269       struct ast_trans_pvt *cur;
00270       struct ast_translator *t = tr_matrix[source][dest].step;
00271       if (!t) {
00272          ast_log(LOG_WARNING, "No translator path from %s to %s\n", 
00273             ast_getformatname(source), ast_getformatname(dest));
00274          AST_LIST_UNLOCK(&translators);
00275          return NULL;
00276       }
00277       if (!(cur = newpvt(t))) {
00278          ast_log(LOG_WARNING, "Failed to build translator step from %d to %d\n", source, dest);
00279          if (head)
00280             ast_translator_free_path(head);  
00281          AST_LIST_UNLOCK(&translators);
00282          return NULL;
00283       }
00284       if (!head)
00285          head = cur;
00286       else
00287          tail->next = cur;
00288       tail = cur;
00289       cur->nextin = cur->nextout = ast_tv(0, 0);
00290       /* Keep going if this isn't the final destination */
00291       source = cur->t->dstfmt;
00292    }
00293 
00294    AST_LIST_UNLOCK(&translators);
00295    return head;
00296 }

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 784 of file translate.c.

References AST_LIST_LOCK, AST_LIST_UNLOCK, rebuild_matrix(), and t.

00785 {
00786    AST_LIST_LOCK(&translators);
00787    t->active = 0;
00788    rebuild_matrix(0);
00789    AST_LIST_UNLOCK(&translators);
00790 }

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 249 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(), conf_free(), free_translation(), queue_frame_to_spies(), set_format(), and spy_cleanup().

00250 {
00251    struct ast_trans_pvt *pn = p;
00252    while ( (p = pn) ) {
00253       pn = p->next;
00254       destroy(p);
00255    }
00256 }

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 750 of file translate.c.

References ast_getformatname(), AST_LIST_LOCK, AST_LIST_REMOVE_CURRENT, AST_LIST_TRAVERSE_SAFE_BEGIN, AST_LIST_TRAVERSE_SAFE_END, AST_LIST_UNLOCK, ast_verbose(), COLOR_BLACK, COLOR_MAGENTA, option_verbose, rebuild_matrix(), t, term_color(), and VERBOSE_PREFIX_2.

Referenced by drop_translator(), load_module(), unload_module(), and unregister_translators().

00751 {
00752    char tmp[80];
00753    struct ast_translator *u;
00754    int found = 0;
00755 
00756    AST_LIST_LOCK(&translators);
00757    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) {
00758       if (u == t) {
00759          AST_LIST_REMOVE_CURRENT(&translators, list);
00760          if (option_verbose > 1)
00761             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));
00762          found = 1;
00763          break;
00764       }
00765    }
00766    AST_LIST_TRAVERSE_SAFE_END;
00767 
00768    if (found)
00769       rebuild_matrix(0);
00770 
00771    AST_LIST_UNLOCK(&translators);
00772 
00773    return (u ? 0 : -1);
00774 }


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