1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/* GStreamer
* Copyright (C) <2007> Thijs Vermeir <thijsvermeir@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/* example of a subtitle chunk in an avi file
* 00000000 (0x8051700): 47 41 42 32 00 02 00 10 00 00 00 45 00 6e 00 67 GAB2.......E.n.g
* 00000010 (0x8051710): 00 6c 00 69 00 73 00 68 00 00 00 04 00 8e 00 00 .l.i.s.h........
* 00000020 (0x8051720): 00 ef bb bf 31 0d 0a 30 30 3a 30 30 3a 30 30 2c ....1..00:00:00,
* 00000030 (0x8051730): 31 30 30 20 2d 2d 3e 20 30 30 3a 30 30 3a 30 32 100 --> 00:00:02
* 00000040 (0x8051740): 2c 30 30 30 0d 0a 3c 62 3e 41 6e 20 55 54 46 38 ,000..<b>An UTF8
* 00000050 (0x8051750): 20 53 75 62 74 69 74 6c 65 20 77 69 74 68 20 42 Subtitle with B
* 00000060 (0x8051760): 4f 4d 3c 2f 62 3e 0d 0a 0d 0a 32 0d 0a 30 30 3a OM</b>....2..00:
* 00000070 (0x8051770): 30 30 3a 30 32 2c 31 30 30 20 2d 2d 3e 20 30 30 00:02,100 --> 00
* 00000080 (0x8051780): 3a 30 30 3a 30 34 2c 30 30 30 0d 0a 53 6f 6d 65 :00:04,000..Some
* 00000090 (0x8051790): 74 68 69 6e 67 20 6e 6f 6e 41 53 43 49 49 20 2d thing nonASCII -
* 000000a0 (0x80517a0): 20 c2 b5 c3 b6 c3 a4 c3 bc c3 9f 0d 0a 0d 0a ..............
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstavisubtitle.h"
GST_DEBUG_CATEGORY_STATIC (avisubtitle_debug);
#define GST_CAT_DEFAULT avisubtitle_debug
GST_DEBUG_CATEGORY_EXTERN (GST_CAT_EVENT);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-subtitle-avi")
);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-subtitle")
);
static GstFlowReturn gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer);
GST_BOILERPLATE (GstAviSubtitle, gst_avi_subtitle, GstElement,
GST_TYPE_ELEMENT);
static GstBuffer *
gst_avi_subtitle_utf8_file (GstBuffer * buffer, guint offset)
{
guint8 *file = GST_BUFFER_DATA (buffer) + offset;
if (file[0] == 0xEF && file[1] == 0xBB && file[2] == 0xBF) {
/* UTF-8 */
return gst_buffer_create_sub (buffer, offset + 3,
GST_BUFFER_SIZE (buffer) - offset - 3);
}
/* TODO Check for:
* 00 00 FE FF UTF-32, big-endian
* FF FE 00 00 UTF-32, little-endian
* FE FF UTF-16, big-endian
* FF FE UTF-16, little-endian
*/
/* No BOM detected assuming UTF-8 */
return gst_buffer_create_sub (buffer, offset,
GST_BUFFER_SIZE (buffer) - offset);
}
static GstFlowReturn
gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer)
{
guint name_length, file_length;
gunichar2 *name;
// gchar* name_utf8;
GstFlowReturn ret;
GstAviSubtitle *avisubtitle = GST_AVI_SUBTITLE (GST_PAD_PARENT (pad));
/* we expext only one buffer packet with the whole srt/ssa file in it */
/* check the magic word "GAB2\0" */
if (GST_BUFFER_SIZE (buffer) <= 11
|| memcmp (GST_BUFFER_DATA (buffer), "GAB2\0", 5) != 0)
goto wrong_magic_word;
/* next word must be 2 */
if (GST_READ_UINT16_LE (GST_BUFFER_DATA (buffer) + 5) != 0x2)
goto wrong_fixed_word_1;
name_length = GST_READ_UINT32_LE (GST_BUFFER_DATA (buffer) + 7);
GST_LOG ("length of name: %d", name_length);
if (GST_BUFFER_SIZE (buffer) <= 17 + name_length)
goto wrong_length_1;
name = (gunichar2 *) & (GST_BUFFER_DATA (buffer)[11]);
// FIXME Take care for endianess in UTF-16
// name_utf8 = g_utf16_to_utf8( name, name_length, NULL, NULL, NULL);
// GST_LOG("avi subtitle name: %s", name_utf8);
// g_free (name_utf8);
/* next word must be 4 */
if (GST_READ_UINT16_LE (GST_BUFFER_DATA (buffer) + 11 + name_length) != 0x4)
goto wrong_fixed_word_2;
file_length =
GST_READ_UINT32_LE (GST_BUFFER_DATA (buffer) + 13 + name_length);
GST_LOG ("length srt/ssa file: %d", file_length);
if (GST_BUFFER_SIZE (buffer) != 17 + name_length + file_length)
goto wrong_total_length;
/* push the file over the src pad */
ret =
gst_pad_push (avisubtitle->src, gst_avi_subtitle_utf8_file (buffer,
17 + name_length));
gst_buffer_unref (buffer);
return ret;
/* all the errors */
wrong_magic_word:
GST_ELEMENT_ERROR (avisubtitle, STREAM, DECODE, NULL, ("Wrong magic word"));
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
wrong_fixed_word_1:
GST_ELEMENT_ERROR (avisubtitle, STREAM, DECODE, NULL,
("wrong fixed word: expected %d found %d", 2,
GST_READ_UINT16_LE (GST_BUFFER_DATA (buffer) + 5)));
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
wrong_length_1:
GST_ELEMENT_ERROR (avisubtitle, STREAM, DECODE, NULL,
("length of the buffer is too small (%d < %d)", GST_BUFFER_SIZE (buffer),
17 + name_length));
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
wrong_fixed_word_2:
GST_ELEMENT_ERROR (avisubtitle, STREAM, DECODE, NULL,
("wrong fixed word: expected %d found %d", 4,
GST_READ_UINT16_LE (GST_BUFFER_DATA (buffer) + 11 + name_length)));
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
wrong_total_length:
GST_ELEMENT_ERROR (avisubtitle, STREAM, DECODE, NULL,
("buffer size is wrong: need %d bytes, have %d bytes",
17 + name_length + file_length, GST_BUFFER_SIZE (buffer)));
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
}
static void
gst_avi_subtitle_base_init (gpointer klass)
{
static const GstElementDetails gst_avi_demux_details =
GST_ELEMENT_DETAILS ("Avi subtitle parser",
"Codec/Demuxer",
"Parse avi subtitle stream",
"Thijs Vermeir <thijsvermeir@gmail.com>");
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
/* add the pad templates to the element */
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_template));
/* set the element details */
gst_element_class_set_details (element_class, &gst_avi_demux_details);
}
static void
gst_avi_subtitle_class_init (GstAviSubtitleClass * klass)
{
GST_DEBUG_CATEGORY_INIT (avisubtitle_debug, "avisubtitle", 0,
"parse avi subtitle stream");
}
static void
gst_avi_subtitle_init (GstAviSubtitle * self, GstAviSubtitleClass * klass)
{
self->src = gst_pad_new_from_static_template (&src_template, "src");
gst_element_add_pad (GST_ELEMENT (self), self->src);
self->sink = gst_pad_new_from_static_template (&sink_template, "sink");
gst_element_add_pad (GST_ELEMENT (self), self->sink);
gst_pad_set_chain_function (self->sink, gst_avi_subtitle_chain);
}
|
