Sat Mar 10 01:55:24 2012

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 = "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 slin_f


Detailed Description

RAW SLINEAR 16 Format.

Definition in file format_sln16.c.


Define Documentation

#define BUF_SIZE   640

Definition at line 38 of file format_sln16.c.

#define SLIN_SAMPLES   320

Definition at line 39 of file format_sln16.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 146 of file format_sln16.c.

static void __unreg_module ( void   )  [static]

Definition at line 146 of file format_sln16.c.

static int load_module ( void   )  [static]

Definition at line 129 of file format_sln16.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, and slin_f.

00130 {
00131    if (ast_format_register(&slin_f))
00132       return AST_MODULE_LOAD_FAILURE;
00133 
00134    return AST_MODULE_LOAD_SUCCESS;
00135 }

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

Definition at line 41 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.

00042 {
00043    int res;
00044    /* Send a frame from the file to the appropriate channel */
00045 
00046    s->fr.frametype = AST_FRAME_VOICE;
00047    s->fr.subclass.codec = AST_FORMAT_SLINEAR16;
00048    s->fr.mallocd = 0;
00049    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00050    if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
00051       if (res)
00052          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00053       return NULL;
00054    }
00055    *whennext = s->fr.samples = res/2;
00056    s->fr.datalen = res;
00057    return &s->fr;
00058 }

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

Definition at line 79 of file format_sln16.c.

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

00080 {
00081    off_t offset = 0, min = 0, cur, max;
00082 
00083    sample_offset <<= 1;
00084 
00085    cur = ftello(fs->f);
00086 
00087    fseeko(fs->f, 0, SEEK_END);
00088 
00089    max = ftello(fs->f);
00090 
00091    if (whence == SEEK_SET)
00092       offset = sample_offset;
00093    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00094       offset = sample_offset + cur;
00095    else if (whence == SEEK_END)
00096       offset = max - sample_offset;
00097 
00098    if (whence != SEEK_FORCECUR)
00099       offset = (offset > max) ? max : offset;
00100 
00101    /* always protect against seeking past begining. */
00102    offset = (offset < min) ? min : offset;
00103 
00104    return fseeko(fs->f, offset, SEEK_SET);
00105 }

static off_t slinear_tell ( struct ast_filestream fs  )  [static]

Definition at line 112 of file format_sln16.c.

References ast_filestream::f.

00113 {
00114    return ftello(fs->f) / 2;
00115 }

static int slinear_trunc ( struct ast_filestream fs  )  [static]

Definition at line 107 of file format_sln16.c.

References ast_filestream::f.

00108 {
00109    return ftruncate(fileno(fs->f), ftello(fs->f));
00110 }

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

Definition at line 60 of file format_sln16.c.

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

00061 {
00062    int res;
00063 
00064    if (f->frametype != AST_FRAME_VOICE) {
00065       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00066       return -1;
00067    }
00068    if (f->subclass.codec != AST_FORMAT_SLINEAR16) {
00069       ast_log(LOG_WARNING, "Asked to write non-slinear16 frame (%s)!\n", ast_getformatname(f->subclass.codec));
00070       return -1;
00071    }
00072    if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
00073       ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
00074       return -1;
00075    }
00076    return 0;
00077 }

static int unload_module ( void   )  [static]

Definition at line 137 of file format_sln16.c.

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

00138 {
00139    return ast_format_unregister(slin_f.name);
00140 }


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 = "88eaa8f5c1bd988bedd71113385e0886" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND } [static]

Definition at line 146 of file format_sln16.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 146 of file format_sln16.c.

struct ast_format slin_f [static]

Definition at line 117 of file format_sln16.c.


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