Thu Sep 7 01:03:29 2017

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

 AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER,"Raw Signed Linear Audio support (SLN)",.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 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

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

Definition at line 146 of file format_sln.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, and AST_MODULE_LOAD_SUCCESS.

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, read]

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(), 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.

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(), and ast_format::name.

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


Variable Documentation

struct ast_format slin_f [static]

Definition at line 134 of file format_sln.c.


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