formats/format_ilbc.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Brian K. West <brian@bkw.org>
   5  *
   6  * Copyright (C) 1999 - 2005, Digium, Inc.
   7  *
   8  * Mark Spencer <markster@digium.com>
   9  *
  10  * See http://www.asterisk.org for more information about
  11  * the Asterisk project. Please do not directly contact
  12  * any of the maintainers of this project for assistance;
  13  * the project provides a web site, mailing lists and IRC
  14  * channels for your use.
  15  *
  16  * This program is free software, distributed under the terms of
  17  * the GNU General Public License Version 2. See the LICENSE file
  18  * at the top of the source tree.
  19  */
  20
  21 /*! \file
  22  *
  23  * \brief Save to raw, headerless iLBC data.
  24  * \arg File name extension: ilbc
  25  * \ingroup formats
  26  */
  27
  28 #include "asterisk.h"
  29
  30 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  31
  32 #include "asterisk/mod_format.h"
  33 #include "asterisk/module.h"
  34 #include "asterisk/endian.h"
  35
  36 /* Some Ideas for this code came from makeg729e.c by Jeffrey Chilton */
  37
  38 /* Portions of the conversion code are by guido@sienanet.it */
  39
  40 #define ILBC_BUF_SIZE   50      /* One Real iLBC Frame */
  41 #define ILBC_SAMPLES    240
  42
  43 static struct ast_frame *ilbc_read(struct ast_filestream *s, int *whennext)
  44 {
  45         int res;
  46         /* Send a frame from the file to the appropriate channel */
  47         s->fr.frametype = AST_FRAME_VOICE;
  48         s->fr.subclass = AST_FORMAT_ILBC;
  49         s->fr.mallocd = 0;
  50         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, ILBC_BUF_SIZE);
  51         if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
  52                 if (res)
  53                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
  54                 return NULL;
  55         }
  56         *whennext = s->fr.samples = ILBC_SAMPLES;
  57         return &s->fr;
  58 }
  59
  60 static int ilbc_write(struct ast_filestream *fs, struct ast_frame *f)
  61 {
  62         int res;
  63         if (f->frametype != AST_FRAME_VOICE) {
  64                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
  65                 return -1;
  66         }
  67         if (f->subclass != AST_FORMAT_ILBC) {
  68                 ast_log(LOG_WARNING, "Asked to write non-iLBC frame (%d)!\n", f->subclass);
  69                 return -1;
  70         }
  71         if (f->datalen % 50) {
  72                 ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 50\n", f->datalen);
  73                 return -1;
  74         }
  75         if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
  76                         ast_log(LOG_WARNING, "Bad write (%d/50): %s\n", res, strerror(errno));
  77                         return -1;
  78         }
  79         return 0;
  80 }
  81
  82 static int ilbc_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
  83 {
  84         long bytes;
  85         off_t min,cur,max,offset=0;
  86         min = 0;
  87         cur = ftello(fs->f);
  88         fseeko(fs->f, 0, SEEK_END);
  89         max = ftello(fs->f);
  90
  91         bytes = ILBC_BUF_SIZE * (sample_offset / ILBC_SAMPLES);
  92         if (whence == SEEK_SET)
  93                 offset = bytes;
  94         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
  95                 offset = cur + bytes;
  96         else if (whence == SEEK_END)
  97                 offset = max - bytes;
  98         if (whence != SEEK_FORCECUR) {
  99                 offset = (offset > max)?max:offset;
 100         }
 101         /* protect against seeking beyond begining. */
 102         offset = (offset < min)?min:offset;
 103         if (fseeko(fs->f, offset, SEEK_SET) < 0)
 104                 return -1;
 105         return 0;
 106 }
 107
 108 static int ilbc_trunc(struct ast_filestream *fs)
 109 {
 110         /* Truncate file to current length */
 111         if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
 112                 return -1;
 113         return 0;
 114 }
 115
 116 static off_t ilbc_tell(struct ast_filestream *fs)
 117 {
 118         off_t offset = ftello(fs->f);
 119         return (offset/ILBC_BUF_SIZE)*ILBC_SAMPLES;
 120 }
 121
 122 static const struct ast_format ilbc_f = {
 123         .name = "iLBC",
 124         .exts = "ilbc",
 125         .format = AST_FORMAT_ILBC,
 126         .write = ilbc_write,
 127         .seek = ilbc_seek,
 128         .trunc = ilbc_trunc,
 129         .tell = ilbc_tell,
 130         .read = ilbc_read,
 131         .buf_size = ILBC_BUF_SIZE + AST_FRIENDLY_OFFSET,
 132 };
 133
 134 static int load_module(void)
 135 {
 136         if (ast_format_register(&ilbc_f))
 137                 return AST_MODULE_LOAD_FAILURE;
 138         return AST_MODULE_LOAD_SUCCESS;
 139 }
 140
 141 static int unload_module(void)
 142 {
 143         return ast_format_unregister(ilbc_f.name);
 144 }
 145
 146 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw iLBC data");