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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  * Copyright 2008 Lin YANG <oxcsnicho@gmail.com>
8  *
9  * This library is licensed under 4 different licenses and you
10  * can choose to use it under the terms of any one of them. The
11  * four licenses are the MPL 1.1, the LGPL, the GPL and the MIT
12  * license.
13  *
14  * MPL:
15  *
16  * The contents of this file are subject to the Mozilla Public License
17  * Version 1.1 (the "License"); you may not use this file except in
18  * compliance with the License. You may obtain a copy of the License at
19  * http://www.mozilla.org/MPL/.
20  *
21  * Software distributed under the License is distributed on an "AS IS"
22  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
23  * License for the specific language governing rights and limitations
24  * under the License.
25  *
26  * LGPL:
27  *
28  * This library is free software; you can redistribute it and/or
29  * modify it under the terms of the GNU Library General Public
30  * License as published by the Free Software Foundation; either
31  * version 2 of the License, or (at your option) any later version.
32  *
33  * This library is distributed in the hope that it will be useful,
34  * but WITHOUT ANY WARRANTY; without even the implied warranty of
35  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
36  * Library General Public License for more details.
37  *
38  * You should have received a copy of the GNU Library General Public
39  * License along with this library; if not, write to the
40  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
41  * Boston, MA 02110-1301, USA.
42  *
43  * GPL:
44  *
45  * This program is free software; you can redistribute it and/or modify
46  * it under the terms of the GNU General Public License as published by
47  * the Free Software Foundation; either version 2 of the License, or
48  * (at your option) any later version.
49  *
50  * This program is distributed in the hope that it will be useful,
51  * but WITHOUT ANY WARRANTY; without even the implied warranty of
52  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
53  * GNU General Public License for more details.
54  *
55  * You should have received a copy of the GNU General Public License
56  * along with this program; if not, write to the Free Software
57  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
58  *
59  * MIT:
60  *
61  * Unless otherwise indicated, Source Code is licensed under MIT license.
62  * See further explanation attached in License Statement (distributed in the file
63  * LICENSE).
64  *
65  * Permission is hereby granted, free of charge, to any person obtaining a copy of
66  * this software and associated documentation files (the "Software"), to deal in
67  * the Software without restriction, including without limitation the rights to
68  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
69  * of the Software, and to permit persons to whom the Software is furnished to do
70  * so, subject to the following conditions:
71  *
72  * The above copyright notice and this permission notice shall be included in all
73  * copies or substantial portions of the Software.
74  *
75  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
76  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
77  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
78  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
79  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
80  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
81  * SOFTWARE.
82  *
83  */
84 
85 #ifdef HAVE_CONFIG_H
86 #include "config.h"
87 #endif
88 
89 #include "mpegpsmux_h264.h"
90 #include <gst/base/gstbytewriter.h>
91 #include <string.h>
92 
93 GST_DEBUG_CATEGORY_EXTERN (mpegpsmux_debug);
94 #define GST_CAT_DEFAULT mpegpsmux_debug
95 
96 GstBuffer *
mpegpsmux_prepare_h264(GstBuffer * buf,MpegPsPadData * data,MpegPsMux * mux)97 mpegpsmux_prepare_h264 (GstBuffer * buf, MpegPsPadData * data, MpegPsMux * mux)
98 {
99   GstByteWriter bw;
100   GstMapInfo codec_data, map;
101   guint8 nal_length_size = 0;
102   GstBuffer *out_buf;
103   guint8 nb_sps = 0, nb_pps = 0;
104   gint offset = 4, i = 0;
105   gsize in_offset;
106 
107   GST_DEBUG_OBJECT (mux, "Preparing H264 buffer for output");
108 
109   /* FIXME: are we prepending SPS/PPS in front of every single buffer?
110    * (should only be in front of keyframes really, if at all) */
111   /* FIXME: create a byte-stream version of SPS/PPS once in set_caps */
112   if (!gst_buffer_map (data->codec_data, &codec_data, GST_MAP_READ))
113     return NULL;
114 
115   gst_byte_writer_init_with_size (&bw, gst_buffer_get_size (buf) * 2, FALSE);
116 
117   /* Get NAL length size */
118   nal_length_size = (codec_data.data[offset] & 0x03) + 1;
119   GST_LOG_OBJECT (mux, "NAL length will be coded on %u bytes", nal_length_size);
120   offset++;
121 
122   /* Generate SPS */
123   nb_sps = codec_data.data[offset] & 0x1f;
124   GST_DEBUG_OBJECT (mux, "we have %d Sequence Parameter Set", nb_sps);
125   offset++;
126 
127   /* For each SPS */
128   for (i = 0; i < nb_sps; i++) {
129     guint16 sps_size = GST_READ_UINT16_BE (codec_data.data + offset);
130 
131     GST_LOG_OBJECT (mux, "Sequence Parameter Set is %d bytes", sps_size);
132 
133     /* Jump over SPS size */
134     offset += 2;
135 
136     /* Fake a start code */
137     gst_byte_writer_put_uint32_be (&bw, 0x00000001);
138 
139     /* Now push the SPS */
140     gst_byte_writer_put_data (&bw, codec_data.data + offset, sps_size);
141 
142     offset += sps_size;
143   }
144 
145   nb_pps = codec_data.data[offset];
146   GST_LOG_OBJECT (mux, "we have %d Picture Parameter Set", nb_sps);
147   offset++;
148 
149   /* For each PPS */
150   for (i = 0; i < nb_pps; i++) {
151     gint pps_size = GST_READ_UINT16_BE (codec_data.data + offset);
152 
153     GST_LOG_OBJECT (mux, "Picture Parameter Set is %d bytes", pps_size);
154 
155     /* Jump over PPS size */
156     offset += 2;
157 
158     /* Fake a start code */
159     gst_byte_writer_put_uint32_be (&bw, 0x00000001);
160 
161     /* Now push the PPS */
162     gst_byte_writer_put_data (&bw, codec_data.data + offset, pps_size);
163 
164     offset += pps_size;
165   }
166 
167   gst_buffer_unmap (data->codec_data, &codec_data);
168 
169   if (!gst_buffer_map (buf, &map, GST_MAP_READ))
170     return NULL;
171 
172   /* now process NALs and change them to byte-stream format */
173   in_offset = 0;
174   while (in_offset < map.size) {
175     guint32 nal_size = 0;
176 
177     switch (nal_length_size) {
178       case 1:
179         nal_size = GST_READ_UINT8 (map.data + in_offset);
180         break;
181       case 2:
182         nal_size = GST_READ_UINT16_BE (map.data + in_offset);
183         break;
184       case 4:
185         nal_size = GST_READ_UINT32_BE (map.data + in_offset);
186         break;
187       default:
188         GST_WARNING_OBJECT (mux, "unsupported NAL length size %u",
189             nal_length_size);
190         break;
191     }
192     in_offset += nal_length_size;
193 
194     /* Generate an Elementary stream buffer by inserting a startcode */
195     gst_byte_writer_put_uint32_be (&bw, 0x00000001);
196     gst_byte_writer_put_data (&bw, map.data + in_offset,
197         MIN (nal_size, map.size - in_offset));
198     in_offset += nal_size;
199   }
200   gst_buffer_unmap (buf, &map);
201 
202   out_buf = gst_byte_writer_reset_and_get_buffer (&bw);
203 
204   /* We want the same metadata */
205   gst_buffer_copy_into (out_buf, buf, GST_BUFFER_COPY_METADATA, 0, 0);
206 
207   return out_buf;
208 }
209