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 = ASTERISK_GPL_KEY , .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 = ASTERISK_GPL_KEY , .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.

                                     {
    .name = "gsm",
    .exts = "gsm",
    .mime_types = "audio/gsm",
    .write = gsm_write,
    .seek = gsm_seek,
    .trunc = gsm_trunc,
    .tell = gsm_tell,
    .read = gsm_read,
    .buf_size = 2*GSM_FRAME_SIZE + AST_FRIENDLY_OFFSET, /* 2 gsm frames */
};

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.

{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};

Referenced by gsm_seek().