formats/format_g729.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Save to raw, headerless G729 data.
  22  * \note This is not an encoder/decoder. The codec fo g729 is only
  23  * available with a commercial license from Digium, due to patent
  24  * restrictions. Check http://www.digium.com for information.
  25  * \arg Extensions: g729
  26  * \ingroup formats
  27  */
  28
  29 #include "asterisk.h"
  30
  31 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  32
  33 #include "asterisk/mod_format.h"
  34 #include "asterisk/module.h"
  35 #include "asterisk/endian.h"
  36
  37 /* Some Ideas for this code came from makeg729e.c by Jeffrey Chilton */
  38
  39 /* Portions of the conversion code are by guido@sienanet.it */
  40
  41 #define BUF_SIZE        20      /* two G729 frames */
  42 #define G729A_SAMPLES   160
  43
  44 static struct ast_frame *g729_read(struct ast_filestream *s, int *whennext)
  45 {
  46         int res;
  47         /* Send a frame from the file to the appropriate channel */
  48         s->fr.frametype = AST_FRAME_VOICE;
  49         s->fr.subclass = AST_FORMAT_G729A;
  50         s->fr.mallocd = 0;
  51         s->fr.samples = G729A_SAMPLES;
  52         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
  53         if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
  54                 if (res && (res != 10)) /* XXX what for ? */
  55                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
  56                 return NULL;
  57         }
  58         *whennext = s->fr.samples;
  59         return &s->fr;
  60 }
  61
  62 static int g729_write(struct ast_filestream *fs, struct ast_frame *f)
  63 {
  64         int res;
  65         if (f->frametype != AST_FRAME_VOICE) {
  66                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
  67                 return -1;
  68         }
  69         if (f->subclass != AST_FORMAT_G729A) {
  70                 ast_log(LOG_WARNING, "Asked to write non-G729 frame (%d)!\n", f->subclass);
  71                 return -1;
  72         }
  73         if (f->datalen % 10) {
  74                 ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 10\n", f->datalen);
  75                 return -1;
  76         }
  77         if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
  78                         ast_log(LOG_WARNING, "Bad write (%d/10): %s\n", res, strerror(errno));
  79                         return -1;
  80         }
  81         return 0;
  82 }
  83
  84 static int g729_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
  85 {
  86         long bytes;
  87         off_t min,cur,max,offset=0;
  88         min = 0;
  89         cur = ftello(fs->f);
  90         fseeko(fs->f, 0, SEEK_END);
  91         max = ftello(fs->f);
  92
  93         bytes = BUF_SIZE * (sample_offset / G729A_SAMPLES);
  94         if (whence == SEEK_SET)
  95                 offset = bytes;
  96         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
  97                 offset = cur + bytes;
  98         else if (whence == SEEK_END)
  99                 offset = max - bytes;
 100         if (whence != SEEK_FORCECUR) {
 101                 offset = (offset > max)?max:offset;
 102         }
 103         /* protect against seeking beyond begining. */
 104         offset = (offset < min)?min:offset;
 105         if (fseeko(fs->f, offset, SEEK_SET) < 0)
 106                 return -1;
 107         return 0;
 108 }
 109
 110 static int g729_trunc(struct ast_filestream *fs)
 111 {
 112         /* Truncate file to current length */
 113         if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
 114                 return -1;
 115         return 0;
 116 }
 117
 118 static off_t g729_tell(struct ast_filestream *fs)
 119 {
 120         off_t offset = ftello(fs->f);
 121         return (offset/BUF_SIZE)*G729A_SAMPLES;
 122 }
 123
 124 static const struct ast_format g729_f = {
 125         .name = "g729",
 126         .exts = "g729",
 127         .format = AST_FORMAT_G729A,
 128         .write = g729_write,
 129         .seek = g729_seek,
 130         .trunc = g729_trunc,
 131         .tell = g729_tell,
 132         .read = g729_read,
 133         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 134 };
 135
 136 static int load_module(void)
 137 {
 138         if (ast_format_register(&g729_f))
 139                 return AST_MODULE_LOAD_FAILURE;
 140         return AST_MODULE_LOAD_SUCCESS;
 141 }
 142
 143 static int unload_module(void)
 144 {
 145         return ast_format_unregister(g729_f.name);
 146 }
 147
 148 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw G729 data");