Sat Aug 6 00:39:56 2011

Asterisk developer's documentation


format_sln.c File Reference

RAW SLINEAR Format. 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   320
#define SLIN_SAMPLES   160

Functions

static void __reg_module (void)
static void __unreg_module (void)
static int load_module (void)
static struct ast_frameslinear_read (struct ast_filestream *s, int *whennext)
static int slinear_seek (struct ast_filestream *fs, off_t sample_offset, int whence)
static off_t slinear_tell (struct ast_filestream *fs)
static int slinear_trunc (struct ast_filestream *fs)
static int slinear_write (struct ast_filestream *fs, struct ast_frame *f)
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 Signed Linear Audio support (SLN)" , .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 slin_f


Detailed Description

RAW SLINEAR Format.

Definition in file format_sln.c.


Define Documentation

#define BUF_SIZE   320

Definition at line 46 of file format_sln.c.

#define SLIN_SAMPLES   160

Definition at line 47 of file format_sln.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 144 of file format_sln.c.

static void __unreg_module ( void   )  [static]

Definition at line 144 of file format_sln.c.

static int load_module ( void   )  [static]

Definition at line 131 of file format_sln.c.

References ast_format_register, and slin_f.

00132 {
00133    return ast_format_register(&slin_f);
00134 }

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

Definition at line 49 of file format_sln.c.

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

00050 {
00051    int res;
00052    /* Send a frame from the file to the appropriate channel */
00053 
00054    s->fr.frametype = AST_FRAME_VOICE;
00055    s->fr.subclass = AST_FORMAT_SLINEAR;
00056    s->fr.mallocd = 0;
00057    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00058    if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) < 1) {
00059       if (res)
00060          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00061       return NULL;
00062    }
00063    *whennext = s->fr.samples = res/2;
00064    s->fr.datalen = res;
00065    return &s->fr;
00066 }

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

Definition at line 86 of file format_sln.c.

References ast_filestream::f, offset, and SEEK_FORCECUR.

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

static off_t slinear_tell ( struct ast_filestream fs  )  [static]

Definition at line 114 of file format_sln.c.

References ast_filestream::f.

00115 {
00116    return ftello(fs->f) / 2;
00117 }

static int slinear_trunc ( struct ast_filestream fs  )  [static]

Definition at line 109 of file format_sln.c.

References ast_filestream::f.

00110 {
00111    return ftruncate(fileno(fs->f), ftello(fs->f));
00112 }

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

Definition at line 68 of file format_sln.c.

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

00069 {
00070    int res;
00071    if (f->frametype != AST_FRAME_VOICE) {
00072       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00073       return -1;
00074    }
00075    if (f->subclass != AST_FORMAT_SLINEAR) {
00076       ast_log(LOG_WARNING, "Asked to write non-slinear frame (%d)!\n", f->subclass);
00077       return -1;
00078    }
00079    if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
00080          ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
00081          return -1;
00082    }
00083    return 0;
00084 }

static int unload_module ( void   )  [static]

Definition at line 136 of file format_sln.c.

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

00137 {
00138    return ast_format_unregister(slin_f.name);
00139 }  


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_FIRST | AST_MODFLAG_BUILDSUM, .description = "Raw Signed Linear Audio support (SLN)" , .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 144 of file format_sln.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 144 of file format_sln.c.

struct ast_format slin_f [static]

Definition at line 119 of file format_sln.c.

Referenced by load_module(), and unload_module().


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