format_gsm.c File Reference

Save to raw, headerless GSM data. More...

#include "asterisk.h"
#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
#include "asterisk/format_cache.h"
#include "msgsm.h"

Include dependency graph for format_gsm.c:

Go to the source code of this file.

Macros
#define	GSM_FRAME_SIZE   33
#define	GSM_SAMPLES   160

Functions
static void	__reg_module (void)
static void	__unreg_module (void)
struct ast_module *	AST_MODULE_SELF_SYM (void)
static struct ast_frame *	gsm_read (struct ast_filestream *s, int *whennext)
static int	gsm_seek (struct ast_filestream *fs, off_t sample_offset, int whence)
static off_t	gsm_tell (struct ast_filestream *fs)
static int	gsm_trunc (struct ast_filestream *fs)
static int	gsm_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_LOAD_ORDER , .description = "Raw GSM 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, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND }
static const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_format_def	gsm_f
static const char	gsm_silence []

Detailed Description

Save to raw, headerless GSM data.

• File name extension: gsm

Definition in file format_gsm.c.

Macro Definition Documentation

GSM_FRAME_SIZE

#define GSM_FRAME_SIZE   33

Definition at line 43 of file format_gsm.c.

GSM_SAMPLES

#define GSM_SAMPLES   160

Definition at line 44 of file format_gsm.c.

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 204 of file format_gsm.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 204 of file format_gsm.c.

AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM

(

void

)

Definition at line 204 of file format_gsm.c.

gsm_read()

static struct ast_frame * gsm_read ( struct ast_filestream *  s, int *  whennext  )

static

Definition at line 54 of file format_gsm.c.

{
    size_t res;
 
    AST_FRAME_SET_BUFFER(&(s->fr), s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE);
    if ((res = fread(s->fr.data.ptr, 1, GSM_FRAME_SIZE, s->f)) != GSM_FRAME_SIZE) {
        if (res) {
            ast_log(LOG_WARNING, "Short read of %s data (expected %d bytes, read %zu): %s\n",
                    ast_format_get_name(s->fr.subclass.format), GSM_FRAME_SIZE, res,
                    strerror(errno));
        }
        return NULL;
    }
    *whennext = s->fr.samples = GSM_SAMPLES;
    return &s->fr;
}

References ast_format_get_name(), AST_FRAME_SET_BUFFER, AST_FRIENDLY_OFFSET, ast_log, ast_filestream::buf, ast_frame::data, errno, ast_filestream::f, ast_frame_subclass::format, ast_filestream::fr, GSM_FRAME_SIZE, GSM_SAMPLES, LOG_WARNING, NULL, ast_frame::ptr, ast_frame::samples, and ast_frame::subclass.

gsm_seek()

static int gsm_seek ( struct ast_filestream *  fs, off_t  sample_offset, int  whence  )

static

Definition at line 100 of file format_gsm.c.

{
    off_t offset = 0, min = 0, cur, max, distance;
 
    if ((cur = ftello(fs->f)) < 0) {
        ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
        return -1;
    }
 
    if (fseeko(fs->f, 0, SEEK_END) < 0) {
        ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
        return -1;
    }
 
    if ((max = ftello(fs->f)) < 0) {
        ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
        return -1;
    }
 
    /* have to fudge to frame here, so not fully to sample */
    distance = (sample_offset / GSM_SAMPLES) * GSM_FRAME_SIZE;
    if (whence == SEEK_SET) {
        offset = distance;
    } else if (whence == SEEK_CUR || whence == SEEK_FORCECUR) {
        offset = distance + cur;
    } else if (whence == SEEK_END) {
        offset = max - distance;
    }
 
    /* Always protect against seeking past the begining. */
    offset = (offset < min)?min:offset;
    if (whence != SEEK_FORCECUR) {
        offset = (offset > max)?max:offset;
    } else if (offset > max) {
        int i;
        fseeko(fs->f, 0, SEEK_END);
        for (i=0; i< (offset - max) / GSM_FRAME_SIZE; i++) {
            if (fwrite(gsm_silence, 1, GSM_FRAME_SIZE, fs->f) != GSM_FRAME_SIZE) {
                ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
            }
        }
    }
    return fseeko(fs->f, offset, SEEK_SET);
}

References ast_log, AST_LOG_WARNING, errno, ast_filestream::f, GSM_FRAME_SIZE, GSM_SAMPLES, gsm_silence, LOG_WARNING, max, min, ast_frame::offset, and SEEK_FORCECUR.

gsm_tell()

static off_t gsm_tell ( struct ast_filestream *  fs )

static

Definition at line 162 of file format_gsm.c.

{
    off_t offset = ftello(fs->f);
 
    if (offset < 0) {
        ast_log(AST_LOG_WARNING, "Unable to determine offset for gsm filestream %p: %s\n", fs, strerror(errno));
        return 0;
    }
 
    return (offset / GSM_FRAME_SIZE) * GSM_SAMPLES;
}

References ast_log, AST_LOG_WARNING, errno, ast_filestream::f, GSM_FRAME_SIZE, GSM_SAMPLES, and ast_frame::offset.

gsm_trunc()

static int gsm_trunc ( struct ast_filestream *  fs )

static

Definition at line 145 of file format_gsm.c.

{
    int fd;
    off_t cur;
 
    if ((fd = fileno(fs->f)) < 0) {
        ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for gsm filestream %p: %s\n", fs, strerror(errno));
        return -1;
    }
    if ((cur = ftello(fs->f)) < 0) {
        ast_log(AST_LOG_WARNING, "Unable to determine current position in gsm filestream %p: %s\n", fs, strerror(errno));
        return -1;
    }
    /* Truncate file to current length */
    return ftruncate(fd, cur);
}

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

gsm_write()

static int gsm_write ( struct ast_filestream *  fs, struct ast_frame *  f  )

static

Definition at line 71 of file format_gsm.c.

{
    int res;
    unsigned char gsm[2*GSM_FRAME_SIZE];
 
    if (!(f->datalen % 65)) {
        /* This is in MSGSM format, need to be converted */
        int len=0;
        while(len < f->datalen) {
            conv65(f->data.ptr + len, gsm);
            if ((res = fwrite(gsm, 1, 2*GSM_FRAME_SIZE, fs->f)) != 2*GSM_FRAME_SIZE) {
                ast_log(LOG_WARNING, "Bad write (%d/66): %s\n", res, strerror(errno));
                return -1;
            }
            len += 65;
        }
    } else {
        if (f->datalen % GSM_FRAME_SIZE) {
            ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 33\n", f->datalen);
            return -1;
        }
        if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
                ast_log(LOG_WARNING, "Bad write (%d/33): %s\n", res, strerror(errno));
                return -1;
        }
    }
    return 0;
}

References ast_log, conv65(), ast_frame::data, ast_frame::datalen, errno, ast_filestream::f, GSM_FRAME_SIZE, len(), LOG_WARNING, and ast_frame::ptr.

load_module()

static int load_module ( void  )

static

Definition at line 186 of file format_gsm.c.

{
    gsm_f.format = ast_format_gsm;
    if (ast_format_def_register(&gsm_f))
        return AST_MODULE_LOAD_DECLINE;
    return AST_MODULE_LOAD_SUCCESS;
}

References ast_format_def_register, ast_format_gsm, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, ast_format_def::format, and gsm_f.

unload_module()

static int unload_module ( void  )

static

Definition at line 194 of file format_gsm.c.

{
    return ast_format_def_unregister(gsm_f.name);
}

References ast_format_def_unregister(), gsm_f, and ast_format_def::name.

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Raw GSM 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, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_APP_DEPEND }

static

Definition at line 204 of file format_gsm.c.

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 204 of file format_gsm.c.

gsm_f

struct ast_format_def gsm_f

static

Definition at line 174 of file format_gsm.c.

Referenced by load_module(), and unload_module().

gsm_silence

const char gsm_silence[]

static

Initial value:

= 
{0xD8,0x20,0xA2,0xE1,0x5A,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49
,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24
,0x92,0x49,0x24}

Definition at line 48 of file format_gsm.c.

Referenced by gsm_seek().