Mon Oct 8 12:39:22 2012

Asterisk developer's documentation


format_sln.c File Reference

RAW SLINEAR 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   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_ORDER , .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 = "ac1f6a56484a8820659555499174e588" , .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 Format.

Definition in file format_sln.c.


Define Documentation

#define BUF_SIZE   320

Definition at line 37 of file format_sln.c.

#define SLIN_SAMPLES   160

Definition at line 38 of file format_sln.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 162 of file format_sln.c.

static void __unreg_module ( void   )  [static]

Definition at line 162 of file format_sln.c.

static int load_module ( void   )  [static]

Definition at line 146 of file format_sln.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, and slin_f.

00147 {
00148    if (ast_format_register(&slin_f))
00149       return AST_MODULE_LOAD_FAILURE;
00150    return AST_MODULE_LOAD_SUCCESS;
00151 }

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

Definition at line 40 of file format_sln.c.

References AST_FORMAT_SLINEAR, 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.

00041 {
00042    int res;
00043    /* Send a frame from the file to the appropriate channel */
00044 
00045    s->fr.frametype = AST_FRAME_VOICE;
00046    s->fr.subclass.codec = AST_FORMAT_SLINEAR;
00047    s->fr.mallocd = 0;
00048    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00049    if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
00050       if (res)
00051          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00052       return NULL;
00053    }
00054    *whennext = s->fr.samples = res/2;
00055    s->fr.datalen = res;
00056    return &s->fr;
00057 }

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

Definition at line 77 of file format_sln.c.

References ast_log(), AST_LOG_WARNING, errno, ast_filestream::f, ast_frame::offset, and SEEK_FORCECUR.

00078 {
00079    off_t offset=0, min = 0, cur, max;
00080 
00081    sample_offset <<= 1;
00082 
00083    if ((cur = ftello(fs->f)) < 0) {
00084       ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
00085       return -1;
00086    }
00087 
00088    if (fseeko(fs->f, 0, SEEK_END) < 0) {
00089       ast_log(AST_LOG_WARNING, "Unable to seek to end of sln filestream %p: %s\n", fs, strerror(errno));
00090       return -1;
00091    }
00092 
00093    if ((max = ftello(fs->f)) < 0) {
00094       ast_log(AST_LOG_WARNING, "Unable to determine max position in sln filestream %p: %s\n", fs, strerror(errno));
00095       return -1;
00096    }
00097 
00098    if (whence == SEEK_SET)
00099       offset = sample_offset;
00100    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00101       offset = sample_offset + cur;
00102    else if (whence == SEEK_END)
00103       offset = max - sample_offset;
00104    if (whence != SEEK_FORCECUR) {
00105       offset = (offset > max)?max:offset;
00106    }
00107    /* always protect against seeking past begining. */
00108    offset = (offset < min)?min:offset;
00109    return fseeko(fs->f, offset, SEEK_SET);
00110 }

static off_t slinear_tell ( struct ast_filestream fs  )  [static]

Definition at line 129 of file format_sln.c.

References ast_filestream::f.

00130 {
00131    return ftello(fs->f) / 2;
00132 }

static int slinear_trunc ( struct ast_filestream fs  )  [static]

Definition at line 112 of file format_sln.c.

References ast_log(), AST_LOG_WARNING, errno, and ast_filestream::f.

00113 {
00114    int fd;
00115    off_t cur;
00116 
00117    if ((fd = fileno(fs->f)) < 0) {
00118       ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for sln filestream %p: %s\n", fs, strerror(errno));
00119       return -1;
00120    }
00121    if ((cur = ftello(fs->f)) < 0) {
00122       ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
00123       return -1;
00124    }
00125    /* Truncate file to current length */
00126    return ftruncate(fd, cur);
00127 }

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

Definition at line 59 of file format_sln.c.

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

00060 {
00061    int res;
00062    if (f->frametype != AST_FRAME_VOICE) {
00063       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00064       return -1;
00065    }
00066    if (f->subclass.codec != AST_FORMAT_SLINEAR) {
00067       ast_log(LOG_WARNING, "Asked to write non-slinear frame (%s)!\n", ast_getformatname(f->subclass.codec));
00068       return -1;
00069    }
00070    if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
00071          ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
00072          return -1;
00073    }
00074    return 0;
00075 }

static int unload_module ( void   )  [static]

Definition at line 153 of file format_sln.c.

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

00154 {
00155    return ast_format_unregister(slin_f.name);
00156 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .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 = "ac1f6a56484a8820659555499174e588" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND } [static]

Definition at line 162 of file format_sln.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 162 of file format_sln.c.

struct ast_format slin_f [static]

Definition at line 134 of file format_sln.c.

Referenced by load_module(), and unload_module().


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