Thu Sep 7 01:03:29 2017

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

 AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER,"Raw Signed Linear 16KHz Audio support (SLN16)",.load=load_module,.unload=unload_module,.load_pri=AST_MODPRI_APP_DEPEND)
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_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

AST_MODULE_INFO ( ASTERISK_GPL_KEY  ,
AST_MODFLAG_LOAD_ORDER  ,
"Raw Signed Linear 16KHz Audio support (SLN16)"  ,
load = load_module,
unload = unload_module,
load_pri = AST_MODPRI_APP_DEPEND 
)
static int load_module ( void   )  [static]

Definition at line 150 of file format_sln16.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, and AST_MODULE_LOAD_SUCCESS.

00151 {
00152    if (ast_format_register(&slin_f))
00153       return AST_MODULE_LOAD_FAILURE;
00154 
00155    return AST_MODULE_LOAD_SUCCESS;
00156 }

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

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_log(), AST_LOG_WARNING, errno, 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    if ((cur = ftello(fs->f)) < 0) {
00086       ast_log(AST_LOG_WARNING, "Unable to determine current position in sln16 filestream %p: %s\n", fs, strerror(errno));
00087       return -1;
00088    }
00089 
00090    if (fseeko(fs->f, 0, SEEK_END) < 0) {
00091       ast_log(AST_LOG_WARNING, "Unable to seek to end of sln16 filestream %p: %s\n", fs, strerror(errno));
00092       return -1;
00093    }
00094 
00095    if ((max = ftello(fs->f)) < 0) {
00096       ast_log(AST_LOG_WARNING, "Unable to determine max position in sln16 filestream %p: %s\n", fs, strerror(errno));
00097       return -1;
00098    }
00099 
00100    if (whence == SEEK_SET)
00101       offset = sample_offset;
00102    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00103       offset = sample_offset + cur;
00104    else if (whence == SEEK_END)
00105       offset = max - sample_offset;
00106 
00107    if (whence != SEEK_FORCECUR)
00108       offset = (offset > max) ? max : offset;
00109 
00110    /* always protect against seeking past begining. */
00111    offset = (offset < min) ? min : offset;
00112 
00113    return fseeko(fs->f, offset, SEEK_SET);
00114 }

static off_t slinear_tell ( struct ast_filestream fs  )  [static]

Definition at line 133 of file format_sln16.c.

References ast_filestream::f.

00134 {
00135    return ftello(fs->f) / 2;
00136 }

static int slinear_trunc ( struct ast_filestream fs  )  [static]

Definition at line 116 of file format_sln16.c.

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

00117 {
00118    int fd;
00119    off_t cur;
00120 
00121    if ((fd = fileno(fs->f)) < 0) {
00122       ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for sln16 filestream %p: %s\n", fs, strerror(errno));
00123       return -1;
00124    }
00125    if ((cur = ftello(fs->f)) < 0) {
00126       ast_log(AST_LOG_WARNING, "Unable to determine current position in sln16 filestream %p: %s\n", fs, strerror(errno));
00127       return -1;
00128    }
00129    /* Truncate file to current length */
00130    return ftruncate(fd, cur);
00131 }

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(), ast_frame_subclass::codec, ast_frame::data, ast_frame::datalen, errno, ast_filestream::f, ast_frame::frametype, LOG_WARNING, ast_frame::ptr, and ast_frame::subclass.

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 158 of file format_sln16.c.

References ast_format_unregister(), and ast_format::name.

00159 {
00160    return ast_format_unregister(slin_f.name);
00161 }


Variable Documentation

struct ast_format slin_f [static]

Definition at line 138 of file format_sln16.c.


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