Sat Aug 6 00:39:56 2011

Asterisk developer's documentation


format_g729.c File Reference

Save to raw, headerless G729 data. More...

#include "asterisk.h"
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/sched.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"

Go to the source code of this file.

Defines

#define BUF_SIZE   20
#define G729A_SAMPLES   160

Functions

static void __reg_module (void)
static void __unreg_module (void)
static struct ast_frameg729_read (struct ast_filestream *s, int *whennext)
static int g729_seek (struct ast_filestream *fs, off_t sample_offset, int whence)
static off_t g729_tell (struct ast_filestream *fs)
static int g729_trunc (struct ast_filestream *fs)
static int g729_write (struct ast_filestream *fs, struct ast_frame *f)
static int load_module (void)
static int unload_module (void)

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_FIRST | AST_MODFLAG_BUILDSUM, .description = "Raw G729 data" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "361d7bb937402d51e4658efb5b4d76e4" , .load = load_module, .unload = unload_module, }
static const struct ast_module_infoast_module_info = &__mod_info
static struct ast_format g729_f


Detailed Description

Save to raw, headerless G729 data.

Note:
This is not an encoder/decoder. The codec fo g729 is only available with a commercial license from Digium, due to patent restrictions. Check http://www.digium.com for information.

Definition in file format_g729.c.


Define Documentation

#define BUF_SIZE   20

Definition at line 54 of file format_g729.c.

#define G729A_SAMPLES   160

Definition at line 55 of file format_g729.c.

Referenced by g729_read(), g729_seek(), and g729_tell().


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 162 of file format_g729.c.

static void __unreg_module ( void   )  [static]

Definition at line 162 of file format_g729.c.

static struct ast_frame* g729_read ( struct ast_filestream s,
int *  whennext 
) [static]

Definition at line 57 of file format_g729.c.

References AST_FORMAT_G729A, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), BUF_SIZE, errno, G729A_SAMPLES, LOG_WARNING, and s.

00058 {
00059    int res;
00060    /* Send a frame from the file to the appropriate channel */
00061    s->fr.frametype = AST_FRAME_VOICE;
00062    s->fr.subclass = AST_FORMAT_G729A;
00063    s->fr.mallocd = 0;
00064    s->fr.samples = G729A_SAMPLES;
00065    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00066    if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
00067       if (res && (res != 10)) /* XXX what for ? */
00068          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00069       return NULL;
00070    }
00071    *whennext = s->fr.samples;
00072    return &s->fr;
00073 }

static int g729_seek ( struct ast_filestream fs,
off_t  sample_offset,
int  whence 
) [static]

Definition at line 97 of file format_g729.c.

References BUF_SIZE, ast_filestream::f, G729A_SAMPLES, offset, and SEEK_FORCECUR.

00098 {
00099    long bytes;
00100    off_t min,cur,max,offset=0;
00101    min = 0;
00102    cur = ftello(fs->f);
00103    fseeko(fs->f, 0, SEEK_END);
00104    max = ftello(fs->f);
00105    
00106    bytes = BUF_SIZE * (sample_offset / G729A_SAMPLES);
00107    if (whence == SEEK_SET)
00108       offset = bytes;
00109    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00110       offset = cur + bytes;
00111    else if (whence == SEEK_END)
00112       offset = max - bytes;
00113    if (whence != SEEK_FORCECUR) {
00114       offset = (offset > max)?max:offset;
00115    }
00116    /* protect against seeking beyond begining. */
00117    offset = (offset < min)?min:offset;
00118    if (fseeko(fs->f, offset, SEEK_SET) < 0)
00119       return -1;
00120    return 0;
00121 }

static off_t g729_tell ( struct ast_filestream fs  )  [static]

Definition at line 131 of file format_g729.c.

References BUF_SIZE, ast_filestream::f, G729A_SAMPLES, and offset.

00132 {
00133    off_t offset = ftello(fs->f);
00134    return (offset/BUF_SIZE)*G729A_SAMPLES;
00135 }

static int g729_trunc ( struct ast_filestream fs  )  [static]

Definition at line 123 of file format_g729.c.

References ast_filestream::f.

00124 {
00125    /* Truncate file to current length */
00126    if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
00127       return -1;
00128    return 0;
00129 }

static int g729_write ( struct ast_filestream fs,
struct ast_frame f 
) [static]

Definition at line 75 of file format_g729.c.

References AST_FORMAT_G729A, AST_FRAME_VOICE, ast_log(), errno, ast_filestream::f, f, and LOG_WARNING.

00076 {
00077    int res;
00078    if (f->frametype != AST_FRAME_VOICE) {
00079       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00080       return -1;
00081    }
00082    if (f->subclass != AST_FORMAT_G729A) {
00083       ast_log(LOG_WARNING, "Asked to write non-G729 frame (%d)!\n", f->subclass);
00084       return -1;
00085    }
00086    if (f->datalen % 10) {
00087       ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 10\n", f->datalen);
00088       return -1;
00089    }
00090    if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
00091          ast_log(LOG_WARNING, "Bad write (%d/10): %s\n", res, strerror(errno));
00092          return -1;
00093    }
00094    return 0;
00095 }

static int load_module ( void   )  [static]

Definition at line 149 of file format_g729.c.

References ast_format_register, and g729_f.

00150 {
00151    return ast_format_register(&g729_f);
00152 }

static int unload_module ( void   )  [static]

Definition at line 154 of file format_g729.c.

References ast_format_unregister(), g729_f, and ast_format::name.

00155 {
00156    return ast_format_unregister(g729_f.name);
00157 }  


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_FIRST | AST_MODFLAG_BUILDSUM, .description = "Raw G729 data" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "361d7bb937402d51e4658efb5b4d76e4" , .load = load_module, .unload = unload_module, } [static]

Definition at line 162 of file format_g729.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 162 of file format_g729.c.

struct ast_format g729_f [static]

Definition at line 137 of file format_g729.c.

Referenced by load_module(), and unload_module().


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