Wed Oct 28 11:46:09 2009

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"

Include dependency graph for format_g729.c:

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_DEFAULT , .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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, }
static const struct
ast_module_info
ast_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.
  • Extensions: g729

Definition in file format_g729.c.


Define Documentation

#define BUF_SIZE   20

Definition at line 41 of file format_g729.c.

#define G729A_SAMPLES   160

Definition at line 42 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 148 of file format_g729.c.

static void __unreg_module ( void   )  [static]

Definition at line 148 of file format_g729.c.

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

Definition at line 44 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::data, ast_frame::datalen, errno, ast_filestream::f, ast_filestream::fr, ast_frame::frametype, G729A_SAMPLES, LOG_WARNING, ast_frame::mallocd, ast_frame::samples, and ast_frame::subclass.

00045 {
00046    int res;
00047    /* Send a frame from the file to the appropriate channel */
00048    s->fr.frametype = AST_FRAME_VOICE;
00049    s->fr.subclass = AST_FORMAT_G729A;
00050    s->fr.mallocd = 0;
00051    s->fr.samples = G729A_SAMPLES;
00052    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00053    if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
00054       if (res && (res != 10)) /* XXX what for ? */
00055          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00056       return NULL;
00057    }
00058    *whennext = s->fr.samples;
00059    return &s->fr;
00060 }

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

Definition at line 84 of file format_g729.c.

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

00085 {
00086    long bytes;
00087    off_t min,cur,max,offset=0;
00088    min = 0;
00089    cur = ftello(fs->f);
00090    fseeko(fs->f, 0, SEEK_END);
00091    max = ftello(fs->f);
00092    
00093    bytes = BUF_SIZE * (sample_offset / G729A_SAMPLES);
00094    if (whence == SEEK_SET)
00095       offset = bytes;
00096    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00097       offset = cur + bytes;
00098    else if (whence == SEEK_END)
00099       offset = max - bytes;
00100    if (whence != SEEK_FORCECUR) {
00101       offset = (offset > max)?max:offset;
00102    }
00103    /* protect against seeking beyond begining. */
00104    offset = (offset < min)?min:offset;
00105    if (fseeko(fs->f, offset, SEEK_SET) < 0)
00106       return -1;
00107    return 0;
00108 }

static off_t g729_tell ( struct ast_filestream fs  )  [static]

Definition at line 118 of file format_g729.c.

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

00119 {
00120    off_t offset = ftello(fs->f);
00121    return (offset/BUF_SIZE)*G729A_SAMPLES;
00122 }

static int g729_trunc ( struct ast_filestream fs  )  [static]

Definition at line 110 of file format_g729.c.

References ast_filestream::f.

00111 {
00112    /* Truncate file to current length */
00113    if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
00114       return -1;
00115    return 0;
00116 }

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

Definition at line 62 of file format_g729.c.

References AST_FORMAT_G729A, AST_FRAME_VOICE, ast_log(), ast_frame::data, ast_frame::datalen, errno, ast_filestream::f, ast_frame::frametype, LOG_WARNING, and ast_frame::subclass.

00063 {
00064    int res;
00065    if (f->frametype != AST_FRAME_VOICE) {
00066       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00067       return -1;
00068    }
00069    if (f->subclass != AST_FORMAT_G729A) {
00070       ast_log(LOG_WARNING, "Asked to write non-G729 frame (%d)!\n", f->subclass);
00071       return -1;
00072    }
00073    if (f->datalen % 10) {
00074       ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 10\n", f->datalen);
00075       return -1;
00076    }
00077    if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
00078          ast_log(LOG_WARNING, "Bad write (%d/10): %s\n", res, strerror(errno));
00079          return -1;
00080    }
00081    return 0;
00082 }

static int load_module ( void   )  [static]

Definition at line 136 of file format_g729.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, and AST_MODULE_LOAD_SUCCESS.

00137 {
00138    if (ast_format_register(&g729_f))
00139       return AST_MODULE_LOAD_FAILURE;
00140    return AST_MODULE_LOAD_SUCCESS;
00141 }

static int unload_module ( void   )  [static]

Definition at line 143 of file format_g729.c.

References ast_format_unregister(), and ast_format::name.

00144 {
00145    return ast_format_unregister(g729_f.name);
00146 }  


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, } [static]

Definition at line 148 of file format_g729.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 148 of file format_g729.c.

struct ast_format g729_f [static]

Definition at line 124 of file format_g729.c.


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