|
1 /* GStreamer AVI GAB2 subtitle parser |
|
2 * Copyright (C) <2007> Thijs Vermeir <thijsvermeir@gmail.com> |
|
3 * Copyright (C) <2007> Tim-Philipp Müller <tim centricular net> |
|
4 * |
|
5 * This library is free software; you can redistribute it and/or |
|
6 * modify it under the terms of the GNU Library General Public |
|
7 * License as published by the Free Software Foundation; either |
|
8 * version 2 of the License, or (at your option) any later version. |
|
9 * |
|
10 * This library is distributed in the hope that it will be useful, |
|
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
13 * Library General Public License for more details. |
|
14 * |
|
15 * You should have received a copy of the GNU Library General Public |
|
16 * License along with this library; if not, write to the |
|
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
|
18 * Boston, MA 02111-1307, USA. |
|
19 */ |
|
20 |
|
21 /** |
|
22 * SECTION:element-avisubtitle |
|
23 * |
|
24 * <refsect2> |
|
25 * <para> |
|
26 * Parses the subtitle stream from an avi file. |
|
27 * </para> |
|
28 * <title>Example launch line</title> |
|
29 * <para> |
|
30 * <programlisting> |
|
31 * gst-launch filesrc location=subtitle.avi ! avidemux name=demux ! queue ! avisubtitle ! subparse ! textoverlay name=overlay ! ffmpegcolorspace ! autovideosink demux. ! queue ! decodebin ! overlay. |
|
32 * </programlisting> |
|
33 * This plays an avi file with a video and subtitle stream. |
|
34 * </para> |
|
35 * </refsect2> |
|
36 * |
|
37 * Last reviewed on 2008-02-01 |
|
38 */ |
|
39 |
|
40 /* example of a subtitle chunk in an avi file |
|
41 * 00000000: 47 41 42 32 00 02 00 10 00 00 00 45 00 6e 00 67 GAB2.......E.n.g |
|
42 * 00000010: 00 6c 00 69 00 73 00 68 00 00 00 04 00 8e 00 00 .l.i.s.h........ |
|
43 * 00000020: 00 ef bb bf 31 0d 0a 30 30 3a 30 30 3a 30 30 2c ....1..00:00:00, |
|
44 * 00000030: 31 30 30 20 2d 2d 3e 20 30 30 3a 30 30 3a 30 32 100 --> 00:00:02 |
|
45 * 00000040: 2c 30 30 30 0d 0a 3c 62 3e 41 6e 20 55 54 46 38 ,000..<b>An UTF8 |
|
46 * 00000050: 20 53 75 62 74 69 74 6c 65 20 77 69 74 68 20 42 Subtitle with B |
|
47 * 00000060: 4f 4d 3c 2f 62 3e 0d 0a 0d 0a 32 0d 0a 30 30 3a OM</b>....2..00: |
|
48 * 00000070: 30 30 3a 30 32 2c 31 30 30 20 2d 2d 3e 20 30 30 00:02,100 --> 00 |
|
49 * 00000080: 3a 30 30 3a 30 34 2c 30 30 30 0d 0a 53 6f 6d 65 :00:04,000..Some |
|
50 * 00000090: 74 68 69 6e 67 20 6e 6f 6e 41 53 43 49 49 20 2d thing nonASCII - |
|
51 * 000000a0: 20 c2 b5 c3 b6 c3 a4 c3 bc c3 9f 0d 0a 0d 0a .............. |
|
52 */ |
|
53 |
|
54 #ifdef HAVE_CONFIG_H |
|
55 #include "config.h" |
|
56 #endif |
|
57 |
|
58 #include <string.h> |
|
59 |
|
60 #include "gstavisubtitle.h" |
|
61 |
|
62 GST_DEBUG_CATEGORY_STATIC (avisubtitle_debug); |
|
63 #define GST_CAT_DEFAULT avisubtitle_debug |
|
64 |
|
65 static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink", |
|
66 GST_PAD_SINK, |
|
67 GST_PAD_ALWAYS, |
|
68 GST_STATIC_CAPS ("application/x-subtitle-avi") |
|
69 ); |
|
70 |
|
71 static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src", |
|
72 GST_PAD_SRC, |
|
73 GST_PAD_ALWAYS, |
|
74 GST_STATIC_CAPS ("application/x-subtitle") |
|
75 ); |
|
76 |
|
77 static void gst_avi_subtitle_title_tag (GstAviSubtitle * sub, gchar * title); |
|
78 static GstFlowReturn gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer); |
|
79 static GstStateChangeReturn gst_avi_subtitle_change_state (GstElement * element, |
|
80 GstStateChange transition); |
|
81 static gboolean gst_avi_subtitle_send_event (GstElement * element, |
|
82 GstEvent * event); |
|
83 |
|
84 GST_BOILERPLATE (GstAviSubtitle, gst_avi_subtitle, GstElement, |
|
85 GST_TYPE_ELEMENT); |
|
86 |
|
87 #define IS_BOM_UTF8(data) ((GST_READ_UINT32_BE(data) >> 8) == 0xEFBBBF) |
|
88 #define IS_BOM_UTF16_BE(data) (GST_READ_UINT16_BE(data) == 0xFEFF) |
|
89 #define IS_BOM_UTF16_LE(data) (GST_READ_UINT16_LE(data) == 0xFEFF) |
|
90 #define IS_BOM_UTF32_BE(data) (GST_READ_UINT32_BE(data) == 0xFEFF) |
|
91 #define IS_BOM_UTF32_LE(data) (GST_READ_UINT32_LE(data) == 0xFEFF) |
|
92 |
|
93 static GstBuffer * |
|
94 gst_avi_subtitle_extract_file (GstAviSubtitle * sub, GstBuffer * buffer, |
|
95 guint offset, guint len) |
|
96 { |
|
97 const gchar *input_enc = NULL; |
|
98 GstBuffer *ret = NULL; |
|
99 gchar *data; |
|
100 |
|
101 data = (gchar *) GST_BUFFER_DATA (buffer) + offset; |
|
102 |
|
103 if (len >= (3 + 1) && IS_BOM_UTF8 (data) && |
|
104 g_utf8_validate (data + 3, len - 3, NULL)) { |
|
105 ret = gst_buffer_create_sub (buffer, offset + 3, len - 3); |
|
106 } else if (len >= 2 && IS_BOM_UTF16_BE (data)) { |
|
107 input_enc = "UTF-16BE"; |
|
108 data += 2; |
|
109 len -= 2; |
|
110 } else if (len >= 2 && IS_BOM_UTF16_LE (data)) { |
|
111 input_enc = "UTF-16LE"; |
|
112 data += 2; |
|
113 len -= 2; |
|
114 } else if (len >= 4 && IS_BOM_UTF32_BE (data)) { |
|
115 input_enc = "UTF-32BE"; |
|
116 data += 4; |
|
117 len -= 4; |
|
118 } else if (len >= 4 && IS_BOM_UTF32_LE (data)) { |
|
119 input_enc = "UTF-32LE"; |
|
120 data += 4; |
|
121 len -= 4; |
|
122 } else if (g_utf8_validate (data, len, NULL)) { |
|
123 /* not specified, check if it's UTF-8 */ |
|
124 ret = gst_buffer_create_sub (buffer, offset, len); |
|
125 } else { |
|
126 /* we could fall back to gst_tag_freeform_to_utf8() here */ |
|
127 GST_WARNING_OBJECT (sub, "unspecified encoding, and not UTF-8"); |
|
128 return NULL; |
|
129 } |
|
130 |
|
131 g_return_val_if_fail (ret != NULL || input_enc != NULL, NULL); |
|
132 |
|
133 if (input_enc) { |
|
134 GError *err = NULL; |
|
135 gchar *utf8; |
|
136 |
|
137 GST_DEBUG_OBJECT (sub, "converting subtitles from %s to UTF-8", input_enc); |
|
138 utf8 = g_convert (data, len, "UTF-8", input_enc, NULL, NULL, &err); |
|
139 |
|
140 if (err != NULL) { |
|
141 GST_WARNING_OBJECT (sub, "conversion to UTF-8 failed : %s", err->message); |
|
142 g_error_free (err); |
|
143 return NULL; |
|
144 } |
|
145 |
|
146 ret = gst_buffer_new (); |
|
147 GST_BUFFER_DATA (ret) = (guint8 *) utf8; |
|
148 GST_BUFFER_MALLOCDATA (ret) = (guint8 *) utf8; |
|
149 GST_BUFFER_SIZE (ret) = strlen (utf8); |
|
150 GST_BUFFER_OFFSET (ret) = 0; |
|
151 } |
|
152 |
|
153 GST_BUFFER_CAPS (ret) = gst_caps_new_simple ("application/x-subtitle", NULL); |
|
154 return ret; |
|
155 } |
|
156 |
|
157 /** |
|
158 * gst_avi_subtitle_title_tag: |
|
159 * @sub: subtitle element |
|
160 * @title: the title of this subtitle stream |
|
161 * |
|
162 * Send an event to the srcpad of the @sub element with the title |
|
163 * of the subtitle stream as a GST_TAG_TITLE |
|
164 */ |
|
165 static void |
|
166 gst_avi_subtitle_title_tag (GstAviSubtitle * sub, gchar * title) |
|
167 { |
|
168 GstTagList *temp_list = gst_tag_list_new (); |
|
169 |
|
170 gst_tag_list_add (temp_list, GST_TAG_MERGE_APPEND, GST_TAG_TITLE, title, |
|
171 NULL); |
|
172 gst_pad_push_event (sub->src, gst_event_new_tag (temp_list)); |
|
173 } |
|
174 |
|
175 static GstFlowReturn |
|
176 gst_avi_subtitle_parse_gab2_chunk (GstAviSubtitle * sub, GstBuffer * buf) |
|
177 { |
|
178 const guint8 *data; |
|
179 gchar *name_utf8; |
|
180 guint name_length; |
|
181 guint file_length; |
|
182 guint size; |
|
183 |
|
184 data = GST_BUFFER_DATA (buf); |
|
185 size = GST_BUFFER_SIZE (buf); |
|
186 |
|
187 /* check the magic word "GAB2\0", and the next word must be 2 */ |
|
188 if (size < 12 || memcmp (data, "GAB2\0\2\0", 5 + 2) != 0) |
|
189 goto wrong_magic_word; |
|
190 |
|
191 /* read 'name' of subtitle */ |
|
192 name_length = GST_READ_UINT32_LE (data + 5 + 2); |
|
193 GST_LOG_OBJECT (sub, "length of name: %u", name_length); |
|
194 if (size <= 17 + name_length) |
|
195 goto wrong_name_length; |
|
196 |
|
197 name_utf8 = g_convert ((gchar *) data + 11, name_length, "UTF-8", "UTF-16LE", |
|
198 NULL, NULL, NULL); |
|
199 |
|
200 if (name_utf8) { |
|
201 GST_LOG_OBJECT (sub, "subtitle name: %s", name_utf8); |
|
202 gst_avi_subtitle_title_tag (sub, name_utf8); |
|
203 g_free (name_utf8); |
|
204 } |
|
205 |
|
206 /* next word must be 4 */ |
|
207 if (GST_READ_UINT16_LE (data + 11 + name_length) != 0x4) |
|
208 goto wrong_fixed_word_2; |
|
209 |
|
210 file_length = GST_READ_UINT32_LE (data + 13 + name_length); |
|
211 GST_LOG_OBJECT (sub, "length srt/ssa file: %u", file_length); |
|
212 |
|
213 if (size < (17 + name_length + file_length)) |
|
214 goto wrong_total_length; |
|
215 |
|
216 /* store this, so we can send it again after a seek; note that we shouldn't |
|
217 * assume all the remaining data in the chunk is subtitle data, there may |
|
218 * be padding at the end for some reason, so only parse file_length bytes */ |
|
219 sub->subfile = |
|
220 gst_avi_subtitle_extract_file (sub, buf, 17 + name_length, file_length); |
|
221 |
|
222 if (sub->subfile == NULL) |
|
223 goto extract_failed; |
|
224 |
|
225 return GST_FLOW_OK; |
|
226 |
|
227 /* ERRORS */ |
|
228 wrong_magic_word: |
|
229 { |
|
230 GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), ("Wrong magic word")); |
|
231 return GST_FLOW_ERROR; |
|
232 } |
|
233 wrong_name_length: |
|
234 { |
|
235 GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), |
|
236 ("name doesn't fit in buffer (%d < %d)", size, 17 + name_length)); |
|
237 return GST_FLOW_ERROR; |
|
238 } |
|
239 wrong_fixed_word_2: |
|
240 { |
|
241 GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), |
|
242 ("wrong fixed word: expected %u, got %u", 4, |
|
243 GST_READ_UINT16_LE (data + 11 + name_length))); |
|
244 return GST_FLOW_ERROR; |
|
245 } |
|
246 wrong_total_length: |
|
247 { |
|
248 GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), |
|
249 ("buffer size is wrong: need %d bytes, have %d bytes", |
|
250 17 + name_length + file_length, size)); |
|
251 return GST_FLOW_ERROR; |
|
252 } |
|
253 extract_failed: |
|
254 { |
|
255 GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), |
|
256 ("could not extract subtitles")); |
|
257 return GST_FLOW_ERROR; |
|
258 } |
|
259 } |
|
260 |
|
261 static GstFlowReturn |
|
262 gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer) |
|
263 { |
|
264 GstAviSubtitle *sub = GST_AVI_SUBTITLE (GST_PAD_PARENT (pad)); |
|
265 GstFlowReturn ret; |
|
266 |
|
267 if (sub->subfile != NULL) { |
|
268 GST_WARNING_OBJECT (sub, "Got more buffers than expected, dropping"); |
|
269 ret = GST_FLOW_UNEXPECTED; |
|
270 goto done; |
|
271 } |
|
272 |
|
273 /* we expect exactly one buffer with the whole srt/ssa file in it */ |
|
274 ret = gst_avi_subtitle_parse_gab2_chunk (sub, buffer); |
|
275 if (ret != GST_FLOW_OK) |
|
276 goto done; |
|
277 |
|
278 /* now push the subtitle data downstream */ |
|
279 ret = gst_pad_push (sub->src, gst_buffer_ref (sub->subfile)); |
|
280 |
|
281 done: |
|
282 |
|
283 gst_buffer_unref (buffer); |
|
284 return ret; |
|
285 } |
|
286 |
|
287 static gboolean |
|
288 gst_avi_subtitle_send_event (GstElement * element, GstEvent * event) |
|
289 { |
|
290 GstAviSubtitle *avisubtitle = GST_AVI_SUBTITLE (element); |
|
291 gboolean ret = FALSE; |
|
292 |
|
293 if (GST_EVENT_TYPE (event) == GST_EVENT_SEEK) { |
|
294 if (avisubtitle->subfile) { |
|
295 if (gst_pad_push (avisubtitle->src, |
|
296 gst_buffer_ref (avisubtitle->subfile)) == GST_FLOW_OK) |
|
297 ret = TRUE; |
|
298 } |
|
299 } |
|
300 gst_event_unref (event); |
|
301 return ret; |
|
302 } |
|
303 |
|
304 static void |
|
305 gst_avi_subtitle_base_init (gpointer klass) |
|
306 { |
|
307 GstElementClass *element_class = GST_ELEMENT_CLASS (klass); |
|
308 |
|
309 GST_DEBUG_CATEGORY_INIT (avisubtitle_debug, "avisubtitle", 0, |
|
310 "parse avi subtitle stream"); |
|
311 |
|
312 gst_element_class_add_pad_template (element_class, |
|
313 gst_static_pad_template_get (&sink_template)); |
|
314 gst_element_class_add_pad_template (element_class, |
|
315 gst_static_pad_template_get (&src_template)); |
|
316 |
|
317 gst_element_class_set_details_simple (element_class, |
|
318 "Avi subtitle parser", "Codec/Parser/Subtitle", |
|
319 "Parse avi subtitle stream", "Thijs Vermeir <thijsvermeir@gmail.com>"); |
|
320 } |
|
321 |
|
322 static void |
|
323 gst_avi_subtitle_class_init (GstAviSubtitleClass * klass) |
|
324 { |
|
325 GstElementClass *gstelement_class = (GstElementClass *) klass; |
|
326 |
|
327 gstelement_class->change_state = |
|
328 GST_DEBUG_FUNCPTR (gst_avi_subtitle_change_state); |
|
329 gstelement_class->send_event = |
|
330 GST_DEBUG_FUNCPTR (gst_avi_subtitle_send_event); |
|
331 } |
|
332 |
|
333 static void |
|
334 gst_avi_subtitle_init (GstAviSubtitle * self, GstAviSubtitleClass * klass) |
|
335 { |
|
336 self->src = gst_pad_new_from_static_template (&src_template, "src"); |
|
337 gst_element_add_pad (GST_ELEMENT (self), self->src); |
|
338 |
|
339 self->sink = gst_pad_new_from_static_template (&sink_template, "sink"); |
|
340 gst_pad_set_chain_function (self->sink, |
|
341 GST_DEBUG_FUNCPTR (gst_avi_subtitle_chain)); |
|
342 gst_element_add_pad (GST_ELEMENT (self), self->sink); |
|
343 |
|
344 self->subfile = NULL; |
|
345 } |
|
346 |
|
347 static GstStateChangeReturn |
|
348 gst_avi_subtitle_change_state (GstElement * element, GstStateChange transition) |
|
349 { |
|
350 GstStateChangeReturn ret; |
|
351 GstAviSubtitle *sub = GST_AVI_SUBTITLE (element); |
|
352 |
|
353 switch (transition) { |
|
354 case GST_STATE_CHANGE_NULL_TO_READY: |
|
355 case GST_STATE_CHANGE_READY_TO_PAUSED: |
|
356 default: |
|
357 break; |
|
358 } |
|
359 |
|
360 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); |
|
361 if (ret == GST_STATE_CHANGE_FAILURE) |
|
362 return ret; |
|
363 |
|
364 switch (transition) { |
|
365 case GST_STATE_CHANGE_PAUSED_TO_READY: |
|
366 if (sub->subfile) { |
|
367 gst_buffer_unref (sub->subfile); |
|
368 sub->subfile = NULL; |
|
369 } |
|
370 break; |
|
371 default: |
|
372 break; |
|
373 } |
|
374 |
|
375 return ret; |
|
376 } |