Wed Apr 6 11:30:04 2011

Asterisk developer's documentation


format_sln16.c File Reference

RAW SLINEAR 16 Format. 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   640
#define SLIN_SAMPLES   320

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_ORDER , .description = "Raw Signed Linear 16KHz Audio support (SLN16)" , .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 = "8586c2a7d357cb591cc3a6607a8f62d1" , .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 slin_f


Detailed Description

RAW SLINEAR 16 Format.

Definition in file format_sln16.c.


Define Documentation

#define BUF_SIZE   640

Definition at line 34 of file format_sln16.c.

#define SLIN_SAMPLES   320

Definition at line 35 of file format_sln16.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 142 of file format_sln16.c.

static void __unreg_module ( void   )  [static]

Definition at line 142 of file format_sln16.c.

static int load_module ( void   )  [static]

Definition at line 125 of file format_sln16.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, and slin_f.

00126 {
00127    if (ast_format_register(&slin_f))
00128       return AST_MODULE_LOAD_FAILURE;
00129 
00130    return AST_MODULE_LOAD_SUCCESS;
00131 }

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

Definition at line 37 of file format_sln16.c.

References AST_FORMAT_SLINEAR16, 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, LOG_WARNING, ast_frame::mallocd, ast_frame::ptr, ast_frame::samples, and ast_frame::subclass.

00038 {
00039    int res;
00040    /* Send a frame from the file to the appropriate channel */
00041 
00042    s->fr.frametype = AST_FRAME_VOICE;
00043    s->fr.subclass.codec = AST_FORMAT_SLINEAR16;
00044    s->fr.mallocd = 0;
00045    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00046    if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
00047       if (res)
00048          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00049       return NULL;
00050    }
00051    *whennext = s->fr.samples = res/2;
00052    s->fr.datalen = res;
00053    return &s->fr;
00054 }

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

Definition at line 75 of file format_sln16.c.

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

00076 {
00077    off_t offset = 0, min = 0, cur, max;
00078 
00079    sample_offset <<= 1;
00080 
00081    cur = ftello(fs->f);
00082 
00083    fseeko(fs->f, 0, SEEK_END);
00084 
00085    max = ftello(fs->f);
00086 
00087    if (whence == SEEK_SET)
00088       offset = sample_offset;
00089    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00090       offset = sample_offset + cur;
00091    else if (whence == SEEK_END)
00092       offset = max - sample_offset;
00093 
00094    if (whence != SEEK_FORCECUR)
00095       offset = (offset > max) ? max : offset;
00096 
00097    /* always protect against seeking past begining. */
00098    offset = (offset < min) ? min : offset;
00099 
00100    return fseeko(fs->f, offset, SEEK_SET);
00101 }

static off_t slinear_tell ( struct ast_filestream fs  )  [static]

Definition at line 108 of file format_sln16.c.

References ast_filestream::f.

00109 {
00110    return ftello(fs->f) / 2;
00111 }

static int slinear_trunc ( struct ast_filestream fs  )  [static]

Definition at line 103 of file format_sln16.c.

References ast_filestream::f.

00104 {
00105    return ftruncate(fileno(fs->f), ftello(fs->f));
00106 }

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

Definition at line 56 of file format_sln16.c.

References AST_FORMAT_SLINEAR16, AST_FRAME_VOICE, ast_getformatname(), ast_log(), errno, ast_filestream::f, f, fwrite, and LOG_WARNING.

00057 {
00058    int res;
00059 
00060    if (f->frametype != AST_FRAME_VOICE) {
00061       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00062       return -1;
00063    }
00064    if (f->subclass.codec != AST_FORMAT_SLINEAR16) {
00065       ast_log(LOG_WARNING, "Asked to write non-slinear16 frame (%s)!\n", ast_getformatname(f->subclass.codec));
00066       return -1;
00067    }
00068    if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
00069       ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
00070       return -1;
00071    }
00072    return 0;
00073 }

static int unload_module ( void   )  [static]

Definition at line 133 of file format_sln16.c.

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

00134 {
00135    return ast_format_unregister(slin_f.name);
00136 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Raw Signed Linear 16KHz Audio support (SLN16)" , .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 = "8586c2a7d357cb591cc3a6607a8f62d1" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND } [static]

Definition at line 142 of file format_sln16.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 142 of file format_sln16.c.

struct ast_format slin_f [static]

Definition at line 113 of file format_sln16.c.


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