1 /* GStreamer tag muxer base class
2 * Copyright (C) 2006 Christophe Fergeau <teuf@gnome.org>
3 * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
4 * Copyright (C) 2006 Sebastian Dröge <slomo@circular-chaos.org>
5 * Copyright (C) 2009 Pioneers of the Inevitable <songbird@songbirdnest.com>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
25 * @see_also: GstApeMux, GstId3Mux
26 * @short_description: Base class for adding tags that are in one single chunk
27 * directly at the beginning or at the end of a file
31 * Provides a base class for adding tags at the beginning or end of a
34 * <title>Deriving from GstTagMux</title>
36 * Subclasses have to do the following things:
39 * In their base init function, they must add pad templates for the sink
40 * pad and the source pad to the element class, describing the media type
41 * they accept and output in the caps of the pad template.
44 * In their class init function, they must override the
45 * GST_TAG_MUX_CLASS(mux_klass)->render_start_tag and/or
46 * GST_TAG_MUX_CLASS(mux_klass)->render_end_tag vfuncs and set up a render
60 #include <gst/gsttagsetter.h>
61 #include <gst/tag/tag.h>
63 #include "gsttagmux.h"
65 struct _GstTagMuxPrivate
69 GstTagList *event_tags; /* tags received from upstream elements */
70 GstTagList *final_tags; /* Final set of tags used for muxing */
73 gboolean render_start_tag;
74 gboolean render_end_tag;
76 gint64 current_offset;
79 GstEvent *newsegment_ev; /* cached newsegment event from upstream */
82 GST_DEBUG_CATEGORY_STATIC (gst_tag_mux_debug);
83 #define GST_CAT_DEFAULT gst_tag_mux_debug
86 gst_tag_mux_iface_init (GType tag_type)
88 static const GInterfaceInfo tag_setter_info = {
94 g_type_add_interface_static (tag_type, GST_TYPE_TAG_SETTER, &tag_setter_info);
97 GST_BOILERPLATE_FULL (GstTagMux, gst_tag_mux,
98 GstElement, GST_TYPE_ELEMENT, gst_tag_mux_iface_init);
101 static GstStateChangeReturn
102 gst_tag_mux_change_state (GstElement * element, GstStateChange transition);
103 static GstFlowReturn gst_tag_mux_chain (GstPad * pad, GstBuffer * buffer);
104 static gboolean gst_tag_mux_sink_event (GstPad * pad, GstEvent * event);
107 gst_tag_mux_finalize (GObject * obj)
109 GstTagMux *mux = GST_TAG_MUX (obj);
111 if (mux->priv->newsegment_ev) {
112 gst_event_unref (mux->priv->newsegment_ev);
113 mux->priv->newsegment_ev = NULL;
116 if (mux->priv->event_tags) {
117 gst_tag_list_free (mux->priv->event_tags);
118 mux->priv->event_tags = NULL;
121 if (mux->priv->final_tags) {
122 gst_tag_list_free (mux->priv->final_tags);
123 mux->priv->final_tags = NULL;
126 G_OBJECT_CLASS (parent_class)->finalize (obj);
130 gst_tag_mux_base_init (gpointer g_class)
132 GST_DEBUG_CATEGORY_INIT (gst_tag_mux_debug, "tagmux", 0,
133 "tag muxer base class");
137 gst_tag_mux_class_init (GstTagMuxClass * klass)
139 GObjectClass *gobject_class;
140 GstElementClass *gstelement_class;
142 gobject_class = (GObjectClass *) klass;
143 gstelement_class = (GstElementClass *) klass;
145 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_tag_mux_finalize);
146 gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_tag_mux_change_state);
148 g_type_class_add_private (klass, sizeof (GstTagMuxPrivate));
152 gst_tag_mux_init (GstTagMux * mux, GstTagMuxClass * mux_class)
154 GstElementClass *element_klass = GST_ELEMENT_CLASS (mux_class);
155 GstPadTemplate *tmpl;
158 G_TYPE_INSTANCE_GET_PRIVATE (mux, GST_TYPE_TAG_MUX, GstTagMuxPrivate);
160 /* pad through which data comes in to the element */
161 tmpl = gst_element_class_get_pad_template (element_klass, "sink");
163 mux->priv->sinkpad = gst_pad_new_from_template (tmpl, "sink");
165 g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
166 G_OBJECT_CLASS_NAME (mux_class), "sink");
167 mux->priv->sinkpad = gst_pad_new ("sink", GST_PAD_SINK);
169 gst_pad_set_chain_function (mux->priv->sinkpad,
170 GST_DEBUG_FUNCPTR (gst_tag_mux_chain));
171 gst_pad_set_event_function (mux->priv->sinkpad,
172 GST_DEBUG_FUNCPTR (gst_tag_mux_sink_event));
173 gst_element_add_pad (GST_ELEMENT (mux), mux->priv->sinkpad);
175 /* pad through which data goes out of the element */
176 tmpl = gst_element_class_get_pad_template (element_klass, "src");
178 GstCaps *tmpl_caps = gst_pad_template_get_caps (tmpl);
180 mux->priv->srcpad = gst_pad_new_from_template (tmpl, "src");
181 gst_pad_use_fixed_caps (mux->priv->srcpad);
182 if (tmpl_caps != NULL && gst_caps_is_fixed (tmpl_caps)) {
183 gst_pad_set_caps (mux->priv->srcpad, tmpl_caps);
186 g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
187 G_OBJECT_CLASS_NAME (mux_class), "source");
188 mux->priv->srcpad = gst_pad_new ("src", GST_PAD_SRC);
190 gst_element_add_pad (GST_ELEMENT (mux), mux->priv->srcpad);
192 mux->priv->render_start_tag = TRUE;
193 mux->priv->render_end_tag = TRUE;
197 gst_tag_mux_get_tags (GstTagMux * mux)
199 GstTagSetter *tagsetter = GST_TAG_SETTER (mux);
200 const GstTagList *tagsetter_tags;
201 GstTagMergeMode merge_mode;
203 if (mux->priv->final_tags)
204 return mux->priv->final_tags;
206 tagsetter_tags = gst_tag_setter_get_tag_list (tagsetter);
207 merge_mode = gst_tag_setter_get_tag_merge_mode (tagsetter);
209 GST_LOG_OBJECT (mux, "merging tags, merge mode = %d", merge_mode);
210 GST_LOG_OBJECT (mux, "event tags: %" GST_PTR_FORMAT, mux->priv->event_tags);
211 GST_LOG_OBJECT (mux, "set tags: %" GST_PTR_FORMAT, tagsetter_tags);
213 mux->priv->final_tags =
214 gst_tag_list_merge (tagsetter_tags, mux->priv->event_tags, merge_mode);
216 GST_LOG_OBJECT (mux, "final tags: %" GST_PTR_FORMAT, mux->priv->final_tags);
218 return mux->priv->final_tags;
222 gst_tag_mux_render_start_tag (GstTagMux * mux)
224 GstTagMuxClass *klass;
230 taglist = gst_tag_mux_get_tags (mux);
232 klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
234 if (klass->render_start_tag == NULL)
237 buffer = klass->render_start_tag (mux, taglist);
239 /* Null buffer is ok, just means we're not outputting anything */
240 if (buffer == NULL) {
241 GST_INFO_OBJECT (mux, "No start tag generated");
242 mux->priv->start_tag_size = 0;
246 if (GST_BUFFER_CAPS (buffer) == NULL) {
247 buffer = gst_buffer_make_metadata_writable (buffer);
248 gst_buffer_set_caps (buffer, GST_PAD_CAPS (mux->priv->srcpad));
251 mux->priv->start_tag_size = GST_BUFFER_SIZE (buffer);
252 GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
253 mux->priv->start_tag_size);
255 /* Send newsegment event from byte position 0, so the tag really gets
256 * written to the start of the file, independent of the upstream segment */
257 gst_pad_push_event (mux->priv->srcpad,
258 gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, 0, -1, 0));
260 /* Send an event about the new tags to downstream elements */
261 /* gst_event_new_tag takes ownership of the list, so use a copy */
262 event = gst_event_new_tag (gst_tag_list_copy (taglist));
263 gst_pad_push_event (mux->priv->srcpad, event);
265 GST_BUFFER_OFFSET (buffer) = 0;
266 ret = gst_pad_push (mux->priv->srcpad, buffer);
268 mux->priv->current_offset = mux->priv->start_tag_size;
269 mux->priv->max_offset =
270 MAX (mux->priv->max_offset, mux->priv->current_offset);
276 GST_ERROR_OBJECT (mux, "Subclass does not implement "
277 "render_start_tag vfunc!");
278 return GST_FLOW_ERROR;
283 gst_tag_mux_render_end_tag (GstTagMux * mux)
285 GstTagMuxClass *klass;
290 taglist = gst_tag_mux_get_tags (mux);
292 klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
294 if (klass->render_end_tag == NULL)
297 buffer = klass->render_end_tag (mux, taglist);
299 if (buffer == NULL) {
300 GST_INFO_OBJECT (mux, "No end tag generated");
301 mux->priv->end_tag_size = 0;
305 if (GST_BUFFER_CAPS (buffer) == NULL) {
306 buffer = gst_buffer_make_metadata_writable (buffer);
307 gst_buffer_set_caps (buffer, GST_PAD_CAPS (mux->priv->srcpad));
310 mux->priv->end_tag_size = GST_BUFFER_SIZE (buffer);
311 GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
312 mux->priv->end_tag_size);
314 /* Send newsegment event from the end of the file, so it gets written there,
315 independent of whatever new segment events upstream has sent us */
316 gst_pad_push_event (mux->priv->srcpad,
317 gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES,
318 mux->priv->max_offset, -1, 0));
320 GST_BUFFER_OFFSET (buffer) = mux->priv->max_offset;
321 ret = gst_pad_push (mux->priv->srcpad, buffer);
327 GST_ERROR_OBJECT (mux, "Subclass does not implement "
328 "render_end_tag vfunc!");
329 return GST_FLOW_ERROR;
334 gst_tag_mux_adjust_event_offsets (GstTagMux * mux,
335 const GstEvent * newsegment_event)
338 gint64 start, stop, cur;
340 gst_event_parse_new_segment ((GstEvent *) newsegment_event, NULL, NULL,
341 &format, &start, &stop, &cur);
343 g_assert (format == GST_FORMAT_BYTES);
346 start += mux->priv->start_tag_size;
348 stop += mux->priv->start_tag_size;
350 cur += mux->priv->start_tag_size;
352 GST_DEBUG_OBJECT (mux, "adjusting newsegment event offsets to start=%"
353 G_GINT64_FORMAT ", stop=%" G_GINT64_FORMAT ", cur=%" G_GINT64_FORMAT
354 " (delta = +%" G_GSIZE_FORMAT ")", start, stop, cur,
355 mux->priv->start_tag_size);
357 return gst_event_new_new_segment (TRUE, 1.0, format, start, stop, cur);
361 gst_tag_mux_chain (GstPad * pad, GstBuffer * buffer)
363 GstTagMux *mux = GST_TAG_MUX (GST_OBJECT_PARENT (pad));
367 if (mux->priv->render_start_tag) {
369 GST_INFO_OBJECT (mux, "Adding tags to stream");
370 ret = gst_tag_mux_render_start_tag (mux);
371 if (ret != GST_FLOW_OK) {
372 GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
373 gst_buffer_unref (buffer);
377 /* Now send the cached newsegment event that we got from upstream */
378 if (mux->priv->newsegment_ev) {
382 GST_DEBUG_OBJECT (mux, "sending cached newsegment event");
383 newseg = gst_tag_mux_adjust_event_offsets (mux, mux->priv->newsegment_ev);
384 gst_event_unref (mux->priv->newsegment_ev);
385 mux->priv->newsegment_ev = NULL;
387 gst_event_parse_new_segment (newseg, NULL, NULL, NULL, &start, NULL,
390 gst_pad_push_event (mux->priv->srcpad, newseg);
391 mux->priv->current_offset = start;
392 mux->priv->max_offset =
393 MAX (mux->priv->max_offset, mux->priv->current_offset);
395 /* upstream sent no newsegment event or only one in a non-BYTE format */
398 mux->priv->render_start_tag = FALSE;
401 buffer = gst_buffer_make_metadata_writable (buffer);
403 if (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE) {
404 GST_LOG_OBJECT (mux, "Adjusting buffer offset from %" G_GINT64_FORMAT
405 " to %" G_GINT64_FORMAT, GST_BUFFER_OFFSET (buffer),
406 GST_BUFFER_OFFSET (buffer) + mux->priv->start_tag_size);
407 GST_BUFFER_OFFSET (buffer) += mux->priv->start_tag_size;
410 length = GST_BUFFER_SIZE (buffer);
412 gst_buffer_set_caps (buffer, GST_PAD_CAPS (mux->priv->srcpad));
413 ret = gst_pad_push (mux->priv->srcpad, buffer);
415 mux->priv->current_offset += length;
416 mux->priv->max_offset =
417 MAX (mux->priv->max_offset, mux->priv->current_offset);
423 gst_tag_mux_sink_event (GstPad * pad, GstEvent * event)
428 mux = GST_TAG_MUX (gst_pad_get_parent (pad));
431 switch (GST_EVENT_TYPE (event)) {
435 gst_event_parse_tag (event, &tags);
437 GST_INFO_OBJECT (mux, "Got tag event: %" GST_PTR_FORMAT, tags);
439 if (mux->priv->event_tags != NULL) {
440 gst_tag_list_insert (mux->priv->event_tags, tags,
441 GST_TAG_MERGE_REPLACE);
443 mux->priv->event_tags = gst_tag_list_copy (tags);
446 GST_INFO_OBJECT (mux, "Event tags are now: %" GST_PTR_FORMAT,
447 mux->priv->event_tags);
449 /* just drop the event, we'll push a new tag event in render_start_tag */
450 gst_event_unref (event);
454 case GST_EVENT_NEWSEGMENT:{
458 gst_event_parse_new_segment (event, NULL, NULL, &fmt, &start, NULL, NULL);
460 if (fmt != GST_FORMAT_BYTES) {
461 GST_WARNING_OBJECT (mux, "dropping newsegment event in %s format",
462 gst_format_get_name (fmt));
463 gst_event_unref (event);
467 if (mux->priv->render_start_tag) {
468 /* we have not rendered the tag yet, which means that we don't know
469 * how large it is going to be yet, so we can't adjust the offsets
470 * here at this point and need to cache the newsegment event for now
471 * (also, there could be tag events coming after this newsegment event
472 * and before the first buffer). */
473 if (mux->priv->newsegment_ev) {
474 GST_WARNING_OBJECT (mux, "discarding old cached newsegment event");
475 gst_event_unref (mux->priv->newsegment_ev);
478 GST_LOG_OBJECT (mux, "caching newsegment event for later");
479 mux->priv->newsegment_ev = event;
481 GST_DEBUG_OBJECT (mux, "got newsegment event, adjusting offsets");
482 gst_pad_push_event (mux->priv->srcpad,
483 gst_tag_mux_adjust_event_offsets (mux, event));
484 gst_event_unref (event);
486 mux->priv->current_offset = start;
487 mux->priv->max_offset =
488 MAX (mux->priv->max_offset, mux->priv->current_offset);
495 if (mux->priv->render_end_tag) {
498 GST_INFO_OBJECT (mux, "Adding tags to stream");
499 ret = gst_tag_mux_render_end_tag (mux);
500 if (ret != GST_FLOW_OK) {
501 GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
505 mux->priv->render_end_tag = FALSE;
508 /* Now forward EOS */
509 result = gst_pad_event_default (pad, event);
513 result = gst_pad_event_default (pad, event);
517 gst_object_unref (mux);
523 static GstStateChangeReturn
524 gst_tag_mux_change_state (GstElement * element, GstStateChange transition)
527 GstStateChangeReturn result;
529 mux = GST_TAG_MUX (element);
531 result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
532 if (result != GST_STATE_CHANGE_SUCCESS) {
536 switch (transition) {
537 case GST_STATE_CHANGE_PAUSED_TO_READY:{
538 if (mux->priv->newsegment_ev) {
539 gst_event_unref (mux->priv->newsegment_ev);
540 mux->priv->newsegment_ev = NULL;
542 if (mux->priv->event_tags) {
543 gst_tag_list_free (mux->priv->event_tags);
544 mux->priv->event_tags = NULL;
546 mux->priv->start_tag_size = 0;
547 mux->priv->end_tag_size = 0;
548 mux->priv->render_start_tag = TRUE;
549 mux->priv->render_end_tag = TRUE;
550 mux->priv->current_offset = 0;
551 mux->priv->max_offset = 0;