1 /*
2 * Copyright 2006, 2007, 2008 Fluendo S.A.
3 * Authors: Jan Schmidt <jan@fluendo.com>
4 * Kapil Agrawal <kapil@fluendo.com>
5 * Julien Moutte <julien@fluendo.com>
6 *
7 * This library is licensed under 4 different licenses and you
8 * can choose to use it under the terms of any one of them. The
9 * four licenses are the MPL 1.1, the LGPL, the GPL and the MIT
10 * license.
11 *
12 * MPL:
13 *
14 * The contents of this file are subject to the Mozilla Public License
15 * Version 1.1 (the "License"); you may not use this file except in
16 * compliance with the License. You may obtain a copy of the License at
17 * http://www.mozilla.org/MPL/.
18 *
19 * Software distributed under the License is distributed on an "AS IS"
20 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
21 * License for the specific language governing rights and limitations
22 * under the License.
23 *
24 * LGPL:
25 *
26 * This library is free software; you can redistribute it and/or
27 * modify it under the terms of the GNU Library General Public
28 * License as published by the Free Software Foundation; either
29 * version 2 of the License, or (at your option) any later version.
30 *
31 * This library is distributed in the hope that it will be useful,
32 * but WITHOUT ANY WARRANTY; without even the implied warranty of
33 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
34 * Library General Public License for more details.
35 *
36 * You should have received a copy of the GNU Library General Public
37 * License along with this library; if not, write to the
38 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
39 * Boston, MA 02110-1301, USA.
40 *
41 * GPL:
42 *
43 * This program is free software; you can redistribute it and/or modify
44 * it under the terms of the GNU General Public License as published by
45 * the Free Software Foundation; either version 2 of the License, or
46 * (at your option) any later version.
47 *
48 * This program is distributed in the hope that it will be useful,
49 * but WITHOUT ANY WARRANTY; without even the implied warranty of
50 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
51 * GNU General Public License for more details.
52 *
53 * You should have received a copy of the GNU General Public License
54 * along with this program; if not, write to the Free Software
55 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
56 *
57 * MIT:
58 *
59 * Unless otherwise indicated, Source Code is licensed under MIT license.
60 * See further explanation attached in License Statement (distributed in the file
61 * LICENSE).
62 *
63 * Permission is hereby granted, free of charge, to any person obtaining a copy of
64 * this software and associated documentation files (the "Software"), to deal in
65 * the Software without restriction, including without limitation the rights to
66 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
67 * of the Software, and to permit persons to whom the Software is furnished to do
68 * so, subject to the following conditions:
69 *
70 * The above copyright notice and this permission notice shall be included in all
71 * copies or substantial portions of the Software.
72 *
73 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
74 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
75 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
76 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
77 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
78 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
79 * SOFTWARE.
80 *
81 */
82
83 #ifdef HAVE_CONFIG_H
84 #include "config.h"
85 #endif
86
87 #include "mpegtsmux_ttxt.h"
88 #include <string.h>
89
90 #define GST_CAT_DEFAULT mpegtsmux_debug
91
92 /* from EN 300 472 spec: ITU-R System B Teletext in DVB
93 *
94 * PES packet = PES header + PES payload data
95 * where PES header must be fixed at 45 bytes (likely by using PES stuffing)
96 * PES packet must completely fill an integral number of TS packets
97 * using (184 bytes) payload data only (so no adaptation field stuffing)
98 */
99
100 GstBuffer *
mpegtsmux_prepare_teletext(GstBuffer * buf,MpegTsPadData * pad_data,MpegTsMux * mux)101 mpegtsmux_prepare_teletext (GstBuffer * buf, MpegTsPadData * pad_data,
102 MpegTsMux * mux)
103 {
104 GstBuffer *out_buf;
105 guint8 *data, *odata;
106 gint size, stuff;
107 gboolean add_id = FALSE;
108 GstMapInfo map, omap;
109
110 gst_buffer_map (buf, &map, GST_MAP_READ);
111 size = map.size;
112 data = map.data;
113
114 /* check if leading data_identifier byte is already present,
115 * if not increase size since it will need to be added */
116 if (data[0] < 0x10 || data[0] > 0x1F) {
117 size += 1;
118 add_id = TRUE;
119 }
120
121 if (size <= 184 - 45) {
122 stuff = 184 - 45 - size;
123 } else {
124 stuff = size - (184 - 45);
125 stuff = 184 - (stuff % 184);
126 }
127 if (G_UNLIKELY (stuff == 1))
128 stuff += 184;
129
130 GST_DEBUG_OBJECT (mux, "Preparing teletext buffer for output");
131
132 out_buf = gst_buffer_new_and_alloc (size + stuff);
133 gst_buffer_copy_into (out_buf, buf,
134 GST_BUFFER_COPY_METADATA | GST_BUFFER_COPY_TIMESTAMPS, 0, 0);
135
136 /* copy data */
137 gst_buffer_map (out_buf, &omap, GST_MAP_WRITE);
138 odata = omap.data;
139 /* add data_identifier if needed */
140 if (add_id) {
141 *odata = 0x10;
142 memcpy (odata + 1, data, size - 1);
143 } else {
144 memcpy (odata, data, size);
145 }
146
147 /* add stuffing data_unit */
148 odata += size;
149 *odata++ = 0xFF;
150 *odata = stuff;
151
152 gst_buffer_unmap (buf, &map);
153 gst_buffer_unmap (out_buf, &omap);
154
155 return out_buf;
156 }
157