1 /* -*- Mode: C; tab-width: 2; indent-tabs-mode: t; c-basic-offset: 2 -*- */
2 /* GStreamer ID3 tag demuxer
3 * Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
4 * Copyright (C) 2003-2004 Benjamin Otte <otte@gnome.org>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 /**
23 * SECTION:element-id3demux
24 *
25 * id3demux accepts data streams with either (or both) ID3v2 regions at the
26 * start, or ID3v1 at the end. The mime type of the data between the tag blocks
27 * is detected using typefind functions, and the appropriate output mime type
28 * set on outgoing buffers.
29 *
30 * The element is only able to read ID3v1 tags from a seekable stream, because
31 * they are at the end of the stream. That is, when get_range mode is supported
32 * by the upstream elements. If get_range operation is available, id3demux makes
33 * it available downstream. This means that elements which require get_range
34 * mode, such as wavparse, can operate on files containing ID3 tag information.
35 *
36 * This id3demux element replaced an older element with the same name which
37 * relied on libid3tag from the MAD project.
38 *
39 * <refsect2>
40 * <title>Example launch line</title>
41 * |[
42 * gst-launch-1.0 filesrc location=file.mp3 ! id3demux ! fakesink -t
43 * ]| This pipeline should read any available ID3 tag information and output it.
44 * The contents of the file inside the ID3 tag regions should be detected, and
45 * the appropriate mime type set on buffers produced from id3demux.
46 * </refsect2>
47 */
48 #ifdef HAVE_CONFIG_H
49 #include "config.h"
50 #endif
51 #include <gst/gst.h>
52 #include <gst/gst-i18n-plugin.h>
53 #include <gst/tag/tag.h>
54 #include <gst/pbutils/pbutils.h>
55 #include <string.h>
56
57 #include "gstid3demux.h"
58
59 enum
60 {
61 PROP_0,
62 PROP_PREFER_V1
63 };
64
65 #define DEFAULT_PREFER_V1 FALSE
66
67 GST_DEBUG_CATEGORY (id3demux_debug);
68 #define GST_CAT_DEFAULT (id3demux_debug)
69
70 #define ID3V1_TAG_SIZE 128
71 #define ID3V2_HDR_SIZE GST_TAG_ID3V2_HEADER_SIZE
72
73 static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
74 GST_PAD_SINK,
75 GST_PAD_ALWAYS,
76 GST_STATIC_CAPS ("application/x-id3")
77 );
78
79 static gboolean gst_id3demux_identify_tag (GstTagDemux * demux,
80 GstBuffer * buffer, gboolean start_tag, guint * tag_size);
81 static GstTagDemuxResult gst_id3demux_parse_tag (GstTagDemux * demux,
82 GstBuffer * buffer, gboolean start_tag, guint * tag_size,
83 GstTagList ** tags);
84 static GstTagList *gst_id3demux_merge_tags (GstTagDemux * tagdemux,
85 const GstTagList * start_tags, const GstTagList * end_tags);
86
87 static void gst_id3demux_set_property (GObject * object, guint prop_id,
88 const GValue * value, GParamSpec * pspec);
89 static void gst_id3demux_get_property (GObject * object, guint prop_id,
90 GValue * value, GParamSpec * pspec);
91
92 #define gst_id3demux_parent_class parent_class
93 G_DEFINE_TYPE (GstID3Demux, gst_id3demux, GST_TYPE_TAG_DEMUX);
94
95 static void
gst_id3demux_class_init(GstID3DemuxClass * klass)96 gst_id3demux_class_init (GstID3DemuxClass * klass)
97 {
98 GObjectClass *gobject_class = (GObjectClass *) klass;
99 GstElementClass *gstelement_class = (GstElementClass *) klass;
100 GstTagDemuxClass *tagdemux_class = (GstTagDemuxClass *) klass;
101
102 gobject_class->set_property = gst_id3demux_set_property;
103 gobject_class->get_property = gst_id3demux_get_property;
104
105 g_object_class_install_property (gobject_class, PROP_PREFER_V1,
106 g_param_spec_boolean ("prefer-v1", "Prefer version 1 tag",
107 "Prefer tags from ID3v1 tag at end of file when both ID3v1 "
108 "and ID3v2 tags are present", DEFAULT_PREFER_V1,
109 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
110
111 gst_element_class_add_static_pad_template (gstelement_class, &sink_factory);
112
113 gst_element_class_set_static_metadata (gstelement_class, "ID3 tag demuxer",
114 "Codec/Demuxer/Metadata",
115 "Read and output ID3v1 and ID3v2 tags while demuxing the contents",
116 "Jan Schmidt <thaytan@mad.scientist.com>");
117
118 tagdemux_class->identify_tag = GST_DEBUG_FUNCPTR (gst_id3demux_identify_tag);
119 tagdemux_class->parse_tag = GST_DEBUG_FUNCPTR (gst_id3demux_parse_tag);
120 tagdemux_class->merge_tags = GST_DEBUG_FUNCPTR (gst_id3demux_merge_tags);
121
122 tagdemux_class->min_start_size = ID3V2_HDR_SIZE;
123 tagdemux_class->min_end_size = ID3V1_TAG_SIZE;
124 }
125
126 static void
gst_id3demux_init(GstID3Demux * id3demux)127 gst_id3demux_init (GstID3Demux * id3demux)
128 {
129 id3demux->prefer_v1 = DEFAULT_PREFER_V1;
130 }
131
132 static gboolean
gst_id3demux_identify_tag(GstTagDemux * demux,GstBuffer * buf,gboolean start_tag,guint * tag_size)133 gst_id3demux_identify_tag (GstTagDemux * demux, GstBuffer * buf,
134 gboolean start_tag, guint * tag_size)
135 {
136 guint8 data[3];
137
138 gst_buffer_extract (buf, 0, data, 3);
139
140 if (start_tag) {
141 if (data[0] != 'I' || data[1] != 'D' || data[2] != '3')
142 goto no_marker;
143
144 *tag_size = gst_tag_get_id3v2_tag_size (buf);
145 } else {
146 if (data[0] != 'T' || data[1] != 'A' || data[2] != 'G')
147 goto no_marker;
148
149 *tag_size = ID3V1_TAG_SIZE;
150 }
151
152 GST_INFO_OBJECT (demux, "Found ID3v%u marker, tag_size = %u",
153 (start_tag) ? 2 : 1, *tag_size);
154
155 return TRUE;
156
157 no_marker:
158 {
159 GST_DEBUG_OBJECT (demux, "No ID3v%u marker found", (start_tag) ? 2 : 1);
160 return FALSE;
161 }
162 }
163
164 static void
gst_id3demux_add_container_format(GstTagList * tags)165 gst_id3demux_add_container_format (GstTagList * tags)
166 {
167 GstCaps *sink_caps;
168
169 sink_caps = gst_static_pad_template_get_caps (&sink_factory);
170 gst_pb_utils_add_codec_description_to_tag_list (tags,
171 GST_TAG_CONTAINER_FORMAT, sink_caps);
172 gst_caps_unref (sink_caps);
173 }
174
175 static GstTagDemuxResult
gst_id3demux_parse_tag(GstTagDemux * demux,GstBuffer * buffer,gboolean start_tag,guint * tag_size,GstTagList ** tags)176 gst_id3demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
177 gboolean start_tag, guint * tag_size, GstTagList ** tags)
178 {
179 if (start_tag) {
180 *tag_size = gst_tag_get_id3v2_tag_size (buffer);
181 *tags = gst_tag_list_from_id3v2_tag (buffer);
182
183 if (G_LIKELY (*tags != NULL)) {
184 gst_id3demux_add_container_format (*tags);
185 return GST_TAG_DEMUX_RESULT_OK;
186 } else {
187 return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
188 }
189 } else {
190 GstMapInfo map;
191
192 gst_buffer_map (buffer, &map, GST_MAP_READ);
193 *tags = gst_tag_list_new_from_id3v1 (map.data);
194 gst_buffer_unmap (buffer, &map);
195
196 if (G_UNLIKELY (*tags == NULL))
197 return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
198
199 gst_id3demux_add_container_format (*tags);
200 *tag_size = ID3V1_TAG_SIZE;
201 return GST_TAG_DEMUX_RESULT_OK;
202 }
203 }
204
205 static GstTagList *
gst_id3demux_merge_tags(GstTagDemux * tagdemux,const GstTagList * start_tags,const GstTagList * end_tags)206 gst_id3demux_merge_tags (GstTagDemux * tagdemux, const GstTagList * start_tags,
207 const GstTagList * end_tags)
208 {
209 GstID3Demux *id3demux;
210 GstTagList *merged;
211 gboolean prefer_v1;
212
213 id3demux = GST_ID3DEMUX (tagdemux);
214
215 GST_OBJECT_LOCK (id3demux);
216 prefer_v1 = id3demux->prefer_v1;
217 GST_OBJECT_UNLOCK (id3demux);
218
219 /* we merge in REPLACE mode, so put the less important tags first */
220 if (prefer_v1)
221 merged = gst_tag_list_merge (start_tags, end_tags, GST_TAG_MERGE_REPLACE);
222 else
223 merged = gst_tag_list_merge (end_tags, start_tags, GST_TAG_MERGE_REPLACE);
224
225 GST_LOG_OBJECT (id3demux, "start tags: %" GST_PTR_FORMAT, start_tags);
226 GST_LOG_OBJECT (id3demux, "end tags: %" GST_PTR_FORMAT, end_tags);
227 GST_LOG_OBJECT (id3demux, "merged tags: %" GST_PTR_FORMAT, merged);
228
229 return merged;
230 }
231
232 static void
gst_id3demux_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)233 gst_id3demux_set_property (GObject * object, guint prop_id,
234 const GValue * value, GParamSpec * pspec)
235 {
236 GstID3Demux *id3demux;
237
238 id3demux = GST_ID3DEMUX (object);
239
240 switch (prop_id) {
241 case PROP_PREFER_V1:{
242 GST_OBJECT_LOCK (id3demux);
243 id3demux->prefer_v1 = g_value_get_boolean (value);
244 GST_OBJECT_UNLOCK (id3demux);
245 break;
246 }
247 default:
248 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
249 break;
250 }
251 }
252
253 static void
gst_id3demux_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)254 gst_id3demux_get_property (GObject * object, guint prop_id,
255 GValue * value, GParamSpec * pspec)
256 {
257 GstID3Demux *id3demux;
258
259 id3demux = GST_ID3DEMUX (object);
260
261 switch (prop_id) {
262 case PROP_PREFER_V1:
263 GST_OBJECT_LOCK (id3demux);
264 g_value_set_boolean (value, id3demux->prefer_v1);
265 GST_OBJECT_UNLOCK (id3demux);
266 break;
267 default:
268 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
269 break;
270 }
271 }
272
273 static gboolean
plugin_init(GstPlugin * plugin)274 plugin_init (GstPlugin * plugin)
275 {
276 GST_DEBUG_CATEGORY_INIT (id3demux_debug, "id3demux", 0,
277 "GStreamer ID3 tag demuxer");
278
279 gst_tag_register_musicbrainz_tags ();
280
281 return gst_element_register (plugin, "id3demux",
282 GST_RANK_PRIMARY, GST_TYPE_ID3DEMUX);
283 }
284
285 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
286 GST_VERSION_MINOR,
287 id3demux,
288 "Demux ID3v1 and ID3v2 tags from a file",
289 plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
290