Jan Schmidt | 0951e00 | 2008-06-17 01:08:14 +0000 | [diff] [blame] | 1 | /* |
| 2 | * The contents of this file are subject to the Mozilla Public License |
| 3 | * Version 1.1 (the "License"); you may not use this file except in |
| 4 | * compliance with the License. You may obtain a copy of the License at |
| 5 | * http://www.mozilla.org/MPL/. |
| 6 | * |
| 7 | * Software distributed under the License is distributed on an "AS IS" |
| 8 | * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the |
| 9 | * License for the specific language governing rights and limitations |
| 10 | * under the License. |
| 11 | * |
| 12 | * The Original Code is Fluendo MPEG Demuxer plugin. |
| 13 | * |
| 14 | * The Initial Developer of the Original Code is Fluendo, S.L. |
| 15 | * Portions created by Fluendo, S.L. are Copyright (C) 2005 |
| 16 | * Fluendo, S.L. All Rights Reserved. |
| 17 | * |
| 18 | * Contributor(s): Wim Taymans <wim@fluendo.com> |
| 19 | * Jan Schmidt <thaytan@noraisin.net> |
| 20 | */ |
| 21 | |
| 22 | #include <string.h> |
| 23 | |
| 24 | #include <gst/gst.h> |
| 25 | |
| 26 | #include "gstmpegdesc.h" |
| 27 | |
| 28 | void |
| 29 | gst_mpeg_descriptor_free (GstMPEGDescriptor * desc) |
| 30 | { |
| 31 | g_return_if_fail (desc != NULL); |
| 32 | |
| 33 | g_free (desc); |
| 34 | } |
| 35 | |
| 36 | static guint |
| 37 | gst_mpeg_descriptor_parse_1 (guint8 * data, guint size) |
| 38 | { |
Edward Hervey | 97426a1 | 2013-07-29 09:35:08 +0200 | [diff] [blame] | 39 | #ifndef GST_DISABLE_GST_DEBUG |
Jan Schmidt | 0951e00 | 2008-06-17 01:08:14 +0000 | [diff] [blame] | 40 | guint8 tag; |
Edward Hervey | 97426a1 | 2013-07-29 09:35:08 +0200 | [diff] [blame] | 41 | #endif |
Jan Schmidt | 0951e00 | 2008-06-17 01:08:14 +0000 | [diff] [blame] | 42 | guint8 length; |
| 43 | |
| 44 | /* need at least 2 bytes for tag and length */ |
| 45 | if (size < 2) |
| 46 | return 0; |
| 47 | |
Edward Hervey | 97426a1 | 2013-07-29 09:35:08 +0200 | [diff] [blame] | 48 | #ifndef GST_DISABLE_GST_DEBUG |
| 49 | tag = *data; |
| 50 | #endif |
| 51 | data += 1; |
Jan Schmidt | 0951e00 | 2008-06-17 01:08:14 +0000 | [diff] [blame] | 52 | length = *data++; |
| 53 | size -= 2; |
| 54 | |
| 55 | GST_DEBUG ("tag: 0x%02x, length: %d", tag, length); |
| 56 | |
| 57 | if (length > size) |
| 58 | return 0; |
| 59 | |
Jan Schmidt | f150cf2 | 2015-03-11 16:55:14 +1100 | [diff] [blame] | 60 | return length + 2; |
Jan Schmidt | 0951e00 | 2008-06-17 01:08:14 +0000 | [diff] [blame] | 61 | } |
| 62 | |
| 63 | GstMPEGDescriptor * |
| 64 | gst_mpeg_descriptor_parse (guint8 * data, guint size) |
| 65 | { |
| 66 | guint8 *current; |
| 67 | guint consumed, total, n_desc; |
| 68 | GstMPEGDescriptor *result; |
| 69 | |
| 70 | g_return_val_if_fail (data != NULL, NULL); |
| 71 | |
| 72 | current = data; |
| 73 | total = 0; |
| 74 | n_desc = 0; |
| 75 | |
| 76 | do { |
| 77 | consumed = gst_mpeg_descriptor_parse_1 (current, size); |
| 78 | |
| 79 | if (consumed > 0) { |
| 80 | current += consumed; |
| 81 | total += consumed; |
| 82 | size -= consumed; |
| 83 | n_desc++; |
| 84 | } |
| 85 | } |
| 86 | while (consumed > 0); |
| 87 | |
| 88 | GST_DEBUG ("parsed %d descriptors", n_desc); |
| 89 | |
| 90 | if (total == 0) |
| 91 | return NULL; |
| 92 | |
| 93 | result = g_malloc (sizeof (GstMPEGDescriptor) + total); |
| 94 | result->n_desc = n_desc; |
| 95 | result->data_length = total; |
| 96 | result->data = ((guint8 *) result) + sizeof (GstMPEGDescriptor); |
| 97 | |
| 98 | memcpy (result->data, data, total); |
| 99 | |
| 100 | return result; |
| 101 | } |
| 102 | |
| 103 | guint |
| 104 | gst_mpeg_descriptor_n_desc (GstMPEGDescriptor * desc) |
| 105 | { |
| 106 | g_return_val_if_fail (desc != NULL, 0); |
| 107 | |
| 108 | return desc->n_desc; |
| 109 | } |
| 110 | |
| 111 | guint8 * |
| 112 | gst_mpeg_descriptor_find (GstMPEGDescriptor * desc, gint tag) |
| 113 | { |
| 114 | gint length; |
| 115 | guint8 *current; |
| 116 | guint size; |
| 117 | |
| 118 | g_return_val_if_fail (desc != NULL, NULL); |
| 119 | |
| 120 | current = desc->data; |
| 121 | length = desc->data_length; |
| 122 | |
| 123 | while (length > 0) { |
| 124 | if (DESC_TAG (current) == tag) |
| 125 | return current; |
| 126 | |
| 127 | size = DESC_LENGTH (current) + 2; |
| 128 | |
| 129 | current += size; |
| 130 | length -= size; |
| 131 | } |
| 132 | return NULL; |
| 133 | } |
| 134 | |
| 135 | guint8 * |
| 136 | gst_mpeg_descriptor_nth (GstMPEGDescriptor * desc, guint i) |
| 137 | { |
| 138 | gint length; |
| 139 | guint8 *current; |
| 140 | guint size; |
| 141 | |
| 142 | g_return_val_if_fail (desc != NULL, NULL); |
| 143 | |
| 144 | if (i > desc->n_desc) |
| 145 | return NULL; |
| 146 | |
| 147 | current = desc->data; |
| 148 | length = desc->data_length; |
| 149 | |
| 150 | while (length > 0) { |
| 151 | if (i == 0) |
| 152 | return current; |
| 153 | |
| 154 | size = DESC_LENGTH (current) + 2; |
| 155 | |
| 156 | current += size; |
| 157 | length -= size; |
| 158 | i--; |
| 159 | } |
| 160 | return NULL; |
| 161 | } |