1 /* GStreamer APEv1/2 tag reader
2 * Copyright (C) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>
3 * Copyright (C) 2006 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., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21 /**
22 * SECTION:element-apedemux
23 *
24 * apedemux accepts data streams with APE tags at the start or at the end
25 * (or both). The mime type of the data between the tag blocks is detected
26 * using typefind functions, and the appropriate output mime type set on
27 * outgoing buffers.
28 *
29 * The element is only able to read APE tags at the end of a stream from
30 * a seekable stream, ie. when get_range mode is supported by the upstream
31 * elements. If get_range operation is available, apedemux makes it available
32 * downstream. This means that elements which require get_range mode, such as
33 * wavparse or musepackdec, can operate on files containing APE tag
34 * information.
35 *
36 * <refsect2>
37 * <title>Example launch line</title>
38 * |[
39 * gst-launch-1.0 -t filesrc location=file.mpc ! apedemux ! fakesink
40 * ]| This pipeline should read any available APE tag information and output it.
41 * The contents of the file inside the APE tag regions should be detected, and
42 * the appropriate mime type set on buffers produced from apedemux.
43 * </refsect2>
44 */
45 #ifdef HAVE_CONFIG_H
46 #include "config.h"
47 #endif
48
49 #include <gst/gst.h>
50 #include <gst/gst-i18n-plugin.h>
51 #include <gst/pbutils/pbutils.h>
52
53 #include "gstapedemux.h"
54
55 #include <stdio.h>
56 #include <string.h>
57
58 #define APE_VERSION_MAJOR(ver) ((ver)/1000)
59
60 GST_DEBUG_CATEGORY_STATIC (apedemux_debug);
61 #define GST_CAT_DEFAULT (apedemux_debug)
62
63 static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
64 GST_PAD_SINK,
65 GST_PAD_ALWAYS,
66 GST_STATIC_CAPS ("application/x-apetag")
67 );
68
69 static gboolean gst_ape_demux_identify_tag (GstTagDemux * demux,
70 GstBuffer * buffer, gboolean start_tag, guint * tag_size);
71 static GstTagDemuxResult gst_ape_demux_parse_tag (GstTagDemux * demux,
72 GstBuffer * buffer, gboolean start_tag, guint * tag_size,
73 GstTagList ** tags);
74
75 G_DEFINE_TYPE (GstApeDemux, gst_ape_demux, GST_TYPE_TAG_DEMUX);
76
77 static void
gst_ape_demux_class_init(GstApeDemuxClass * klass)78 gst_ape_demux_class_init (GstApeDemuxClass * klass)
79 {
80 GstElementClass *element_class;
81 GstTagDemuxClass *tagdemux_class;
82
83 GST_DEBUG_CATEGORY_INIT (apedemux_debug, "apedemux", 0,
84 "GStreamer APE tag demuxer");
85
86 tagdemux_class = GST_TAG_DEMUX_CLASS (klass);
87 element_class = GST_ELEMENT_CLASS (klass);
88
89 gst_element_class_set_static_metadata (element_class, "APE tag demuxer",
90 "Codec/Demuxer/Metadata",
91 "Read and output APE tags while demuxing the contents",
92 "Tim-Philipp Müller <tim centricular net>");
93
94 gst_element_class_add_static_pad_template (element_class, &sink_factory);
95
96 tagdemux_class->identify_tag = GST_DEBUG_FUNCPTR (gst_ape_demux_identify_tag);
97 tagdemux_class->parse_tag = GST_DEBUG_FUNCPTR (gst_ape_demux_parse_tag);
98
99 /* no need for a merge function, the default behaviour to prefer start
100 * tags (APEv2) over end tags (usually APEv1, but could theoretically also
101 * be APEv2) is fine */
102
103 tagdemux_class->min_start_size = 32;
104 tagdemux_class->min_end_size = 32;
105 }
106
107 static void
gst_ape_demux_init(GstApeDemux * apedemux)108 gst_ape_demux_init (GstApeDemux * apedemux)
109 {
110 /* nothing to do here */
111 }
112
113 static const struct _GstApeDemuxTagTableEntry
114 {
115 const gchar *ape_tag;
116 const gchar *gst_tag;
117 } tag_table[] = {
118 {
119 "replaygain_track_gain", GST_TAG_TRACK_GAIN}, {
120 "replaygain_track_peak", GST_TAG_TRACK_PEAK}, {
121 "replaygain_album_gain", GST_TAG_ALBUM_GAIN}, {
122 "replaygain_album_peak", GST_TAG_ALBUM_PEAK}, {
123 "title", GST_TAG_TITLE}, {
124 "artist", GST_TAG_ARTIST}, {
125 "album", GST_TAG_ALBUM}, {
126 "composer", GST_TAG_COMPOSER}, {
127 "comment", GST_TAG_COMMENT}, {
128 "comments", GST_TAG_COMMENT}, {
129 "copyright", GST_TAG_COPYRIGHT}, {
130 "genre", GST_TAG_GENRE}, {
131 "isrc", GST_TAG_ISRC}, {
132 "disc", GST_TAG_ALBUM_VOLUME_NUMBER}, {
133 "disk", GST_TAG_ALBUM_VOLUME_NUMBER}, {
134 "discnumber", GST_TAG_ALBUM_VOLUME_NUMBER}, {
135 "disknumber", GST_TAG_ALBUM_VOLUME_NUMBER}, {
136 "track", GST_TAG_TRACK_NUMBER}, {
137 "tracknumber", GST_TAG_TRACK_NUMBER}, {
138 "year", GST_TAG_DATE}, {
139 "file", GST_TAG_LOCATION}
140 };
141
142 static gboolean
ape_demux_get_gst_tag_from_tag(const gchar * ape_tag,const gchar ** gst_tag,GType * gst_tag_type)143 ape_demux_get_gst_tag_from_tag (const gchar * ape_tag,
144 const gchar ** gst_tag, GType * gst_tag_type)
145 {
146 gint i;
147
148 for (i = 0; i < G_N_ELEMENTS (tag_table); ++i) {
149 if (g_ascii_strcasecmp (tag_table[i].ape_tag, ape_tag) == 0) {
150 *gst_tag = tag_table[i].gst_tag;
151 *gst_tag_type = gst_tag_get_type (tag_table[i].gst_tag);
152 GST_LOG ("Mapped APE tag '%s' to GStreamer tag '%s'", ape_tag, *gst_tag);
153 return TRUE;
154 }
155 }
156
157 GST_WARNING ("Could not map APE tag '%s' to a GStreamer tag", ape_tag);
158 return FALSE;
159 }
160
161 static GstTagList *
ape_demux_parse_tags(const guint8 * data,gint size)162 ape_demux_parse_tags (const guint8 * data, gint size)
163 {
164 GstTagList *taglist = gst_tag_list_new_empty ();
165
166 GST_LOG ("Reading tags from chunk of size %u bytes", size);
167
168 /* get rid of header/footer */
169 if (size >= 32 && memcmp (data, "APETAGEX", 8) == 0) {
170 data += 32;
171 size -= 32;
172 }
173 if (size > 32 && memcmp (data + size - 32, "APETAGEX", 8) == 0) {
174 size -= 32;
175 }
176
177 /* read actual tags - at least 10 bytes for tag header */
178 while (size >= 10) {
179 guint len, n = 8;
180 gchar *tag, *val;
181 const gchar *gst_tag;
182 GType gst_tag_type;
183
184 /* find tag type and size */
185 len = GST_READ_UINT32_LE (data);
186 while (n < size && data[n] != 0x0)
187 n++;
188 if (n == size)
189 break;
190 g_assert (data[n] == 0x0);
191 n++;
192 if (size - n < len)
193 break;
194
195 /* If the tag is empty, skip to the next one */
196 if (len == 0)
197 goto next_tag;
198
199 /* read */
200 tag = g_strndup ((gchar *) data + 8, n - 9);
201 val = g_strndup ((gchar *) data + n, len);
202
203 GST_LOG ("tag [%s], val[%s]", tag, val);
204
205 /* special-case 'media' tag, could be e.g. "CD 1/2" */
206 if (g_ascii_strcasecmp (tag, "media") == 0) {
207 gchar *sp, *sp2;
208
209 g_free (tag);
210 tag = g_strdup ("discnumber");
211 /* get rid of the medium in front */
212 sp = strchr (val, ' ');
213 while (sp != NULL && (sp2 = strchr (sp + 1, ' ')) != NULL)
214 sp = sp2;
215 if (sp) {
216 memmove (val, sp + 1, strlen (sp + 1) + 1);
217 }
218 }
219
220 if (ape_demux_get_gst_tag_from_tag (tag, &gst_tag, &gst_tag_type)) {
221 GValue v = { 0, };
222
223 switch (gst_tag_type) {
224 case G_TYPE_INT:{
225 gint v_int;
226
227 if (sscanf (val, "%d", &v_int) == 1) {
228 g_value_init (&v, G_TYPE_INT);
229 g_value_set_int (&v, v_int);
230 }
231 break;
232 }
233 case G_TYPE_UINT:{
234 guint v_uint, count;
235
236 if (strcmp (gst_tag, GST_TAG_TRACK_NUMBER) == 0) {
237 gint dummy;
238
239 if (sscanf (val, "%u", &v_uint) == 1 && v_uint > 0) {
240 g_value_init (&v, G_TYPE_UINT);
241 g_value_set_uint (&v, v_uint);
242 }
243 GST_LOG ("checking for track count: %s", val);
244 /* might be 0/N or -1/N to specify that there is only a count */
245 if (sscanf (val, "%d/%u", &dummy, &count) == 2 && count > 0) {
246 gst_tag_list_add (taglist, GST_TAG_MERGE_APPEND,
247 GST_TAG_TRACK_COUNT, count, NULL);
248 }
249 } else if (strcmp (gst_tag, GST_TAG_ALBUM_VOLUME_NUMBER) == 0) {
250 gint dummy;
251
252 if (sscanf (val, "%u", &v_uint) == 1 && v_uint > 0) {
253 g_value_init (&v, G_TYPE_UINT);
254 g_value_set_uint (&v, v_uint);
255 }
256 GST_LOG ("checking for volume count: %s", val);
257 /* might be 0/N or -1/N to specify that there is only a count */
258 if (sscanf (val, "%d/%u", &dummy, &count) == 2 && count > 0) {
259 gst_tag_list_add (taglist, GST_TAG_MERGE_APPEND,
260 GST_TAG_ALBUM_VOLUME_COUNT, count, NULL);
261 }
262 } else if (sscanf (val, "%u", &v_uint) == 1) {
263 g_value_init (&v, G_TYPE_UINT);
264 g_value_set_uint (&v, v_uint);
265 }
266 break;
267 }
268 case G_TYPE_STRING:{
269 g_value_init (&v, G_TYPE_STRING);
270 g_value_set_string (&v, val);
271 break;
272 }
273 case G_TYPE_DOUBLE:{
274 gdouble v_double;
275 gchar *endptr;
276
277 /* floating point strings can be "4,123" or "4.123" depending on
278 * the locale. We need to be able to parse and read either version
279 * no matter what our current locale is */
280 g_strdelimit (val, ",", '.');
281 v_double = g_ascii_strtod (val, &endptr);
282 if (endptr != val) {
283 g_value_init (&v, G_TYPE_DOUBLE);
284 g_value_set_double (&v, v_double);
285 }
286
287 break;
288 }
289 default:{
290 if (gst_tag_type == G_TYPE_DATE) {
291 gint v_int;
292
293 if (sscanf (val, "%d", &v_int) == 1) {
294 GDate *date = g_date_new_dmy (1, 1, v_int);
295
296 g_value_init (&v, G_TYPE_DATE);
297 g_value_take_boxed (&v, date);
298 }
299 } else {
300 GST_WARNING ("Unhandled tag type '%s' for tag '%s'",
301 g_type_name (gst_tag_type), gst_tag);
302 }
303 break;
304 }
305 }
306 if (G_VALUE_TYPE (&v) != 0) {
307 gst_tag_list_add_values (taglist, GST_TAG_MERGE_APPEND,
308 gst_tag, &v, NULL);
309 g_value_unset (&v);
310 }
311 }
312 GST_DEBUG ("Read tag %s: %s", tag, val);
313 g_free (tag);
314 g_free (val);
315
316 /* move data pointer */
317 next_tag:
318 size -= len + n;
319 data += len + n;
320 }
321
322 GST_DEBUG ("Taglist: %" GST_PTR_FORMAT, taglist);
323 return taglist;
324 }
325
326 static gboolean
gst_ape_demux_identify_tag(GstTagDemux * demux,GstBuffer * buffer,gboolean start_tag,guint * tag_size)327 gst_ape_demux_identify_tag (GstTagDemux * demux, GstBuffer * buffer,
328 gboolean start_tag, guint * tag_size)
329 {
330 GstMapInfo map;
331
332 gst_buffer_map (buffer, &map, GST_MAP_READ);
333
334 if (memcmp (map.data, "APETAGEX", 8) != 0) {
335 GST_DEBUG_OBJECT (demux, "No APETAGEX marker at %s - not an APE file",
336 (start_tag) ? "start" : "end");
337 gst_buffer_unmap (buffer, &map);
338 return FALSE;
339 }
340
341 *tag_size = GST_READ_UINT32_LE (map.data + 12);
342
343 /* size is without header, so add 32 to account for that */
344 *tag_size += 32;
345
346 gst_buffer_unmap (buffer, &map);
347
348 return TRUE;
349 }
350
351 static GstTagDemuxResult
gst_ape_demux_parse_tag(GstTagDemux * demux,GstBuffer * buffer,gboolean start_tag,guint * tag_size,GstTagList ** tags)352 gst_ape_demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
353 gboolean start_tag, guint * tag_size, GstTagList ** tags)
354 {
355 guint8 *data;
356 guint8 *footer;
357 gboolean have_header;
358 gboolean end_tag = !start_tag;
359 GstCaps *sink_caps;
360 guint version, footer_size;
361 GstMapInfo map;
362 gsize size;
363
364 gst_buffer_map (buffer, &map, GST_MAP_READ);
365 data = map.data;
366 size = map.size;
367
368 GST_LOG_OBJECT (demux, "Parsing buffer of size %" G_GSIZE_FORMAT, size);
369
370 footer = data + size - 32;
371
372 GST_LOG_OBJECT (demux, "Checking for footer at offset 0x%04x",
373 (guint) (footer - data));
374 if (footer > data && memcmp (footer, "APETAGEX", 8) == 0) {
375 GST_DEBUG_OBJECT (demux, "Found footer");
376 footer_size = 32;
377 } else {
378 GST_DEBUG_OBJECT (demux, "No footer");
379 footer_size = 0;
380 }
381
382 /* APE tags at the end must have a footer */
383 if (end_tag && footer_size == 0) {
384 GST_WARNING_OBJECT (demux, "Tag at end of file without footer!");
385 return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
386 }
387
388 /* don't trust the header/footer flags, better detect them ourselves */
389 have_header = (memcmp (data, "APETAGEX", 8) == 0);
390
391 if (start_tag && !have_header) {
392 GST_DEBUG_OBJECT (demux, "Tag at beginning of file without header!");
393 return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
394 }
395
396 if (end_tag && !have_header) {
397 GST_DEBUG_OBJECT (demux, "Tag at end of file has no header (APEv1)");
398 *tag_size -= 32; /* adjust tag size */
399 }
400
401 if (have_header) {
402 version = GST_READ_UINT32_LE (data + 8);
403 } else {
404 version = GST_READ_UINT32_LE (footer + 8);
405 }
406
407 /* skip header */
408 if (have_header) {
409 data += 32;
410 }
411
412 GST_DEBUG_OBJECT (demux, "APE tag with version %u, size %u at offset 0x%08"
413 G_GINT64_MODIFIER "x", version, *tag_size,
414 GST_BUFFER_OFFSET (buffer) + ((have_header) ? 0 : 32));
415
416 if (APE_VERSION_MAJOR (version) != 1 && APE_VERSION_MAJOR (version) != 2) {
417 GST_WARNING ("APE tag is version %u.%03u, but decoder only supports "
418 "v1 or v2. Ignoring.", APE_VERSION_MAJOR (version), version % 1000);
419 return GST_TAG_DEMUX_RESULT_OK;
420 }
421
422 *tags = ape_demux_parse_tags (data, *tag_size - footer_size);
423
424 sink_caps = gst_static_pad_template_get_caps (&sink_factory);
425 gst_pb_utils_add_codec_description_to_tag_list (*tags,
426 GST_TAG_CONTAINER_FORMAT, sink_caps);
427 gst_caps_unref (sink_caps);
428
429 gst_buffer_unmap (buffer, &map);
430
431 return GST_TAG_DEMUX_RESULT_OK;
432 }
433
434 static gboolean
plugin_init(GstPlugin * plugin)435 plugin_init (GstPlugin * plugin)
436 {
437 return gst_element_register (plugin, "apedemux",
438 GST_RANK_PRIMARY, GST_TYPE_APE_DEMUX);
439 }
440
441 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
442 GST_VERSION_MINOR,
443 apetag,
444 "APEv1/2 tag reader",
445 plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
446