formats/format_g723.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 /*!
  20  * \file
  21  *
  22  * \brief Old-style G.723.1 frame/timestamp format.
  23  *
  24  * \arg Extensions: g723, g723sf
  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
  35 #define G723_MAX_SIZE 1024
  36
  37 static struct ast_frame *g723_read(struct ast_filestream *s, int *whennext)
  38 {
  39         unsigned short size;
  40         int res;
  41         int delay;
  42         /* Read the delay for the next packet, and schedule again if necessary */
  43         /* XXX is this ignored ? */
  44         if (fread(&delay, 1, 4, s->f) == 4)
  45                 delay = ntohl(delay);
  46         else
  47                 delay = -1;
  48         if (fread(&size, 1, 2, s->f) != 2) {
  49                 /* Out of data, or the file is no longer valid.  In any case
  50                    go ahead and stop the stream */
  51                 return NULL;
  52         }
  53         /* Looks like we have a frame to read from here */
  54         size = ntohs(size);
  55         if (size > G723_MAX_SIZE) {
  56                 ast_log(LOG_WARNING, "Size %d is invalid\n", size);
  57                 /* The file is apparently no longer any good, as we
  58                    shouldn't ever get frames even close to this
  59                    size.  */
  60                 return NULL;
  61         }
  62         /* Read the data into the buffer */
  63         s->fr.frametype = AST_FRAME_VOICE;
  64         s->fr.subclass = AST_FORMAT_G723_1;
  65         s->fr.mallocd = 0;
  66         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, size);
  67         if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != size) {
  68                 ast_log(LOG_WARNING, "Short read (%d of %d bytes) (%s)!\n", res, size, strerror(errno));
  69                 return NULL;
  70         }
  71         *whennext = s->fr.samples = 240;
  72         return &s->fr;
  73 }
  74
  75 static int g723_write(struct ast_filestream *s, struct ast_frame *f)
  76 {
  77         uint32_t delay;
  78         uint16_t size;
  79         int res;
  80         /* XXX there used to be a check s->fr means a read stream */
  81         if (f->frametype != AST_FRAME_VOICE) {
  82                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
  83                 return -1;
  84         }
  85         if (f->subclass != AST_FORMAT_G723_1) {
  86                 ast_log(LOG_WARNING, "Asked to write non-g723 frame!\n");
  87                 return -1;
  88         }
  89         delay = 0;
  90         if (f->datalen <= 0) {
  91                 ast_log(LOG_WARNING, "Short frame ignored (%d bytes long?)\n", f->datalen);
  92                 return 0;
  93         }
  94         if ((res = fwrite(&delay, 1, 4, s->f)) != 4) {
  95                 ast_log(LOG_WARNING, "Unable to write delay: res=%d (%s)\n", res, strerror(errno));
  96                 return -1;
  97         }
  98         size = htons(f->datalen);
  99         if ((res = fwrite(&size, 1, 2, s->f)) != 2) {
 100                 ast_log(LOG_WARNING, "Unable to write size: res=%d (%s)\n", res, strerror(errno));
 101                 return -1;
 102         }
 103         if ((res = fwrite(f->data.ptr, 1, f->datalen, s->f)) != f->datalen) {
 104                 ast_log(LOG_WARNING, "Unable to write frame: res=%d (%s)\n", res, strerror(errno));
 105                 return -1;
 106         }
 107         return 0;
 108 }
 109
 110 static int g723_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 111 {
 112         return -1;
 113 }
 114
 115 static int g723_trunc(struct ast_filestream *fs)
 116 {
 117         /* Truncate file to current length */
 118         if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
 119                 return -1;
 120         return 0;
 121 }
 122
 123 static off_t g723_tell(struct ast_filestream *fs)
 124 {
 125         return -1;
 126 }
 127
 128 static const struct ast_format g723_1_f = {
 129         .name = "g723sf",
 130         .exts = "g723|g723sf",
 131         .format = AST_FORMAT_G723_1,
 132         .write = g723_write,
 133         .seek = g723_seek,
 134         .trunc = g723_trunc,
 135         .tell = g723_tell,
 136         .read = g723_read,
 137         .buf_size = G723_MAX_SIZE + AST_FRIENDLY_OFFSET,
 138 };
 139
 140 static int load_module(void)
 141 {
 142         if (ast_format_register(&g723_1_f))
 143                 return AST_MODULE_LOAD_FAILURE;
 144         return AST_MODULE_LOAD_SUCCESS;
 145 }
 146
 147 static int unload_module(void)
 148 {
 149         return ast_format_unregister(g723_1_f.name);
 150 }
 151
 152 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "G.723.1 Simple Timestamp File Format");