Sat Mar 10 01:55:23 2012

Asterisk developer's documentation


format_g729.c File Reference

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

#include "asterisk.h"
#include "asterisk/mod_format.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_ORDER , .description = "Raw G.729 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 = "88eaa8f5c1bd988bedd71113385e0886" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND }
static 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 45 of file format_g729.c.

#define G729A_SAMPLES   160

Definition at line 46 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 156 of file format_g729.c.

static void __unreg_module ( void   )  [static]

Definition at line 156 of file format_g729.c.

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

Definition at line 48 of file format_g729.c.

References AST_FORMAT_G729A, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), ast_filestream::buf, BUF_SIZE, ast_frame_subclass::codec, ast_frame::data, ast_frame::datalen, errno, ast_filestream::f, ast_filestream::fr, ast_frame::frametype, G729A_SAMPLES, LOG_WARNING, ast_frame::mallocd, ast_frame::ptr, ast_frame::samples, and ast_frame::subclass.

00049 {
00050    int res;
00051    /* Send a frame from the file to the appropriate channel */
00052    s->fr.frametype = AST_FRAME_VOICE;
00053    s->fr.subclass.codec = AST_FORMAT_G729A;
00054    s->fr.mallocd = 0;
00055    s->fr.samples = G729A_SAMPLES;
00056    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00057    if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
00058       if (res && (res != 10)) /* XXX what for ? */
00059          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00060       return NULL;
00061    }
00062    *whennext = s->fr.samples;
00063    return &s->fr;
00064 }

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

Definition at line 88 of file format_g729.c.

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

00089 {
00090    long bytes;
00091    off_t min,cur,max,offset=0;
00092    min = 0;
00093    cur = ftello(fs->f);
00094    fseeko(fs->f, 0, SEEK_END);
00095    max = ftello(fs->f);
00096    
00097    bytes = BUF_SIZE * (sample_offset / G729A_SAMPLES);
00098    if (whence == SEEK_SET)
00099       offset = bytes;
00100    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00101       offset = cur + bytes;
00102    else if (whence == SEEK_END)
00103       offset = max - bytes;
00104    if (whence != SEEK_FORCECUR) {
00105       offset = (offset > max)?max:offset;
00106    }
00107    /* protect against seeking beyond begining. */
00108    offset = (offset < min)?min:offset;
00109    if (fseeko(fs->f, offset, SEEK_SET) < 0)
00110       return -1;
00111    return 0;
00112 }

static off_t g729_tell ( struct ast_filestream fs  )  [static]

Definition at line 122 of file format_g729.c.

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

00123 {
00124    off_t offset = ftello(fs->f);
00125    return (offset/BUF_SIZE)*G729A_SAMPLES;
00126 }

static int g729_trunc ( struct ast_filestream fs  )  [static]

Definition at line 114 of file format_g729.c.

References ast_filestream::f.

00115 {
00116    /* Truncate file to current length */
00117    if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
00118       return -1;
00119    return 0;
00120 }

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

Definition at line 66 of file format_g729.c.

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

00067 {
00068    int res;
00069    if (f->frametype != AST_FRAME_VOICE) {
00070       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00071       return -1;
00072    }
00073    if (f->subclass.codec != AST_FORMAT_G729A) {
00074       ast_log(LOG_WARNING, "Asked to write non-G729 frame (%s)!\n", ast_getformatname(f->subclass.codec));
00075       return -1;
00076    }
00077    if (f->datalen % 10) {
00078       ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 10\n", f->datalen);
00079       return -1;
00080    }
00081    if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
00082          ast_log(LOG_WARNING, "Bad write (%d/10): %s\n", res, strerror(errno));
00083          return -1;
00084    }
00085    return 0;
00086 }

static int load_module ( void   )  [static]

Definition at line 140 of file format_g729.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, and g729_f.

00141 {
00142    if (ast_format_register(&g729_f))
00143       return AST_MODULE_LOAD_FAILURE;
00144    return AST_MODULE_LOAD_SUCCESS;
00145 }

static int unload_module ( void   )  [static]

Definition at line 147 of file format_g729.c.

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

00148 {
00149    return ast_format_unregister(g729_f.name);
00150 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Raw G.729 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 = "88eaa8f5c1bd988bedd71113385e0886" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND } [static]

Definition at line 156 of file format_g729.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 156 of file format_g729.c.

struct ast_format g729_f [static]

Definition at line 128 of file format_g729.c.

Referenced by load_module(), and unload_module().


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