formats/format_sln.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Anthony Minessale
   5  * Anthony Minessale (anthmct@yahoo.com)
   6  *
   7  * See http://www.asterisk.org for more information about
   8  * the Asterisk project. Please do not directly contact
   9  * any of the maintainers of this project for assistance;
  10  * the project provides a web site, mailing lists and IRC
  11  * channels for your use.
  12  *
  13  * This program is free software, distributed under the terms of
  14  * the GNU General Public License Version 2. See the LICENSE file
  15  * at the top of the source tree.
  16  */
  17
  18 /*! \file
  19  *
  20  * \brief RAW SLINEAR Format
  21  * \arg File name extensions: sln, raw
  22  * \ingroup formats
  23  */
  24
  25 #include "asterisk.h"
  26
  27 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  28
  29 #include <unistd.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <stdlib.h>
  33 #include <sys/time.h>
  34 #include <stdio.h>
  35 #include <errno.h>
  36 #include <string.h>
  37
  38 #include "asterisk/lock.h"
  39 #include "asterisk/channel.h"
  40 #include "asterisk/file.h"
  41 #include "asterisk/logger.h"
  42 #include "asterisk/sched.h"
  43 #include "asterisk/module.h"
  44 #include "asterisk/endian.h"
  45
  46 #define BUF_SIZE        320             /* 320 bytes, 160 samples */
  47 #define SLIN_SAMPLES    160
  48
  49 static struct ast_frame *slinear_read(struct ast_filestream *s, int *whennext)
  50 {
  51         int res;
  52         /* Send a frame from the file to the appropriate channel */
  53
  54         s->fr.frametype = AST_FRAME_VOICE;
  55         s->fr.subclass = AST_FORMAT_SLINEAR;
  56         s->fr.mallocd = 0;
  57         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
  58         if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) < 1) {
  59                 if (res)
  60                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
  61                 return NULL;
  62         }
  63         *whennext = s->fr.samples = res/2;
  64         s->fr.datalen = res;
  65         return &s->fr;
  66 }
  67
  68 static int slinear_write(struct ast_filestream *fs, struct ast_frame *f)
  69 {
  70         int res;
  71         if (f->frametype != AST_FRAME_VOICE) {
  72                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
  73                 return -1;
  74         }
  75         if (f->subclass != AST_FORMAT_SLINEAR) {
  76                 ast_log(LOG_WARNING, "Asked to write non-slinear frame (%d)!\n", f->subclass);
  77                 return -1;
  78         }
  79         if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
  80                         ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
  81                         return -1;
  82         }
  83         return 0;
  84 }
  85
  86 static int slinear_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
  87 {
  88         off_t offset=0,min,cur,max;
  89
  90         min = 0;
  91         sample_offset <<= 1;
  92         cur = ftello(fs->f);
  93         fseeko(fs->f, 0, SEEK_END);
  94         max = ftello(fs->f);
  95         if (whence == SEEK_SET)
  96                 offset = sample_offset;
  97         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
  98                 offset = sample_offset + cur;
  99         else if (whence == SEEK_END)
 100                 offset = max - sample_offset;
 101         if (whence != SEEK_FORCECUR) {
 102                 offset = (offset > max)?max:offset;
 103         }
 104         /* always protect against seeking past begining. */
 105         offset = (offset < min)?min:offset;
 106         return fseeko(fs->f, offset, SEEK_SET);
 107 }
 108
 109 static int slinear_trunc(struct ast_filestream *fs)
 110 {
 111         return ftruncate(fileno(fs->f), ftello(fs->f));
 112 }
 113
 114 static off_t slinear_tell(struct ast_filestream *fs)
 115 {
 116         return ftello(fs->f) / 2;
 117 }
 118
 119 static const struct ast_format slin_f = {
 120         .name = "sln",
 121         .exts = "sln|raw",
 122         .format = AST_FORMAT_SLINEAR,
 123         .write = slinear_write,
 124         .seek = slinear_seek,
 125         .trunc = slinear_trunc,
 126         .tell = slinear_tell,
 127         .read = slinear_read,
 128         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 129 };
 130
 131 static int load_module(void)
 132 {
 133         return ast_format_register(&slin_f);
 134 }
 135
 136 static int unload_module(void)
 137 {
 138         return ast_format_unregister(slin_f.name);
 139 }
 140
 141 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw Signed Linear Audio support (SLN)");