formats/format_jpeg.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 JPEG File format support.
  22  *
  23  * \arg File name extension: jpeg, jpg
  24  * \ingroup formats
  25  */
  26
  27 #include "asterisk.h"
  28
  29 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  30
  31 #include "asterisk/mod_format.h"
  32 #include "asterisk/module.h"
  33 #include "asterisk/image.h"
  34 #include "asterisk/endian.h"
  35
  36 static struct ast_frame *jpeg_read_image(int fd, int len)
  37 {
  38         struct ast_frame fr;
  39         int res;
  40         char buf[65536];
  41         if (len > sizeof(buf) || len < 0) {
  42                 ast_log(LOG_WARNING, "JPEG image too large to read\n");
  43                 return NULL;
  44         }
  45         res = read(fd, buf, len);
  46         if (res < len) {
  47                 ast_log(LOG_WARNING, "Only read %d of %d bytes: %s\n", res, len, strerror(errno));
  48         }
  49         memset(&fr, 0, sizeof(fr));
  50         fr.frametype = AST_FRAME_IMAGE;
  51         fr.subclass = AST_FORMAT_JPEG;
  52         fr.data.ptr = buf;
  53         fr.src = "JPEG Read";
  54         fr.datalen = len;
  55         return ast_frisolate(&fr);
  56 }
  57
  58 static int jpeg_identify(int fd)
  59 {
  60         char buf[10];
  61         int res;
  62         res = read(fd, buf, sizeof(buf));
  63         if (res < sizeof(buf))
  64                 return 0;
  65         if (memcmp(buf + 6, "JFIF", 4))
  66                 return 0;
  67         return 1;
  68 }
  69
  70 static int jpeg_write_image(int fd, struct ast_frame *fr)
  71 {
  72         int res=0;
  73         if (fr->frametype != AST_FRAME_IMAGE) {
  74                 ast_log(LOG_WARNING, "Not an image\n");
  75                 return -1;
  76         }
  77         if (fr->subclass != AST_FORMAT_JPEG) {
  78                 ast_log(LOG_WARNING, "Not a jpeg image\n");
  79                 return -1;
  80         }
  81         if (fr->datalen) {
  82                 res = write(fd, fr->data.ptr, fr->datalen);
  83                 if (res != fr->datalen) {
  84                         ast_log(LOG_WARNING, "Only wrote %d of %d bytes: %s\n", res, fr->datalen, strerror(errno));
  85                         return -1;
  86                 }
  87         }
  88         return res;
  89 }
  90
  91 static struct ast_imager jpeg_format = {
  92         .name = "jpg",
  93         .desc = "JPEG (Joint Picture Experts Group)",
  94         .exts = "jpg|jpeg",
  95         .format = AST_FORMAT_JPEG,
  96         .read_image = jpeg_read_image,
  97         .identify = jpeg_identify,
  98         .write_image = jpeg_write_image,
  99 };
 100
 101 static int load_module(void)
 102 {
 103         if (ast_image_register(&jpeg_format))
 104                 return AST_MODULE_LOAD_FAILURE;
 105         return AST_MODULE_LOAD_SUCCESS;
 106 }
 107
 108 static int unload_module(void)
 109 {
 110         ast_image_unregister(&jpeg_format);
 111
 112         return 0;
 113 }
 114
 115 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "JPEG (Joint Picture Experts Group) Image Format");