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
85 #define gst_tag_mux_parent_class parent_class
86 G_DEFINE_TYPE_WITH_CODE (GstTagMux, gst_tag_mux, GST_TYPE_ELEMENT,
87 G_IMPLEMENT_INTERFACE (GST_TYPE_TAG_SETTER, NULL));
89 static GstStateChangeReturn
90 gst_tag_mux_change_state (GstElement * element, GstStateChange transition);
91 static GstFlowReturn gst_tag_mux_chain (GstPad * pad, GstObject * parent,
93 static gboolean gst_tag_mux_sink_event (GstPad * pad, GstObject * parent,
97 gst_tag_mux_finalize (GObject * obj)
99 GstTagMux *mux = GST_TAG_MUX (obj);
101 if (mux->priv->newsegment_ev) {
102 gst_event_unref (mux->priv->newsegment_ev);
103 mux->priv->newsegment_ev = NULL;
106 if (mux->priv->event_tags) {
107 gst_tag_list_free (mux->priv->event_tags);
108 mux->priv->event_tags = NULL;
111 if (mux->priv->final_tags) {
112 gst_tag_list_free (mux->priv->final_tags);
113 mux->priv->final_tags = NULL;
116 G_OBJECT_CLASS (parent_class)->finalize (obj);
120 gst_tag_mux_class_init (GstTagMuxClass * klass)
122 GObjectClass *gobject_class;
123 GstElementClass *gstelement_class;
125 gobject_class = (GObjectClass *) klass;
126 gstelement_class = (GstElementClass *) klass;
128 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_tag_mux_finalize);
129 gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_tag_mux_change_state);
131 g_type_class_add_private (klass, sizeof (GstTagMuxPrivate));
133 GST_DEBUG_CATEGORY_INIT (gst_tag_mux_debug, "tagmux", 0,
134 "tag muxer base class");
138 gst_tag_mux_init (GstTagMux * mux)
140 GstElementClass *element_klass = GST_ELEMENT_GET_CLASS (mux);
141 GstPadTemplate *tmpl;
144 G_TYPE_INSTANCE_GET_PRIVATE (mux, GST_TYPE_TAG_MUX, GstTagMuxPrivate);
146 /* pad through which data comes in to the element */
147 tmpl = gst_element_class_get_pad_template (element_klass, "sink");
149 mux->priv->sinkpad = gst_pad_new_from_template (tmpl, "sink");
151 g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
152 G_OBJECT_CLASS_NAME (element_klass), "sink");
153 mux->priv->sinkpad = gst_pad_new ("sink", GST_PAD_SINK);
155 gst_pad_set_chain_function (mux->priv->sinkpad,
156 GST_DEBUG_FUNCPTR (gst_tag_mux_chain));
157 gst_pad_set_event_function (mux->priv->sinkpad,
158 GST_DEBUG_FUNCPTR (gst_tag_mux_sink_event));
159 gst_element_add_pad (GST_ELEMENT (mux), mux->priv->sinkpad);
161 /* pad through which data goes out of the element */
162 tmpl = gst_element_class_get_pad_template (element_klass, "src");
164 GstCaps *tmpl_caps = gst_pad_template_get_caps (tmpl);
166 mux->priv->srcpad = gst_pad_new_from_template (tmpl, "src");
167 gst_pad_use_fixed_caps (mux->priv->srcpad);
168 if (tmpl_caps != NULL && gst_caps_is_fixed (tmpl_caps)) {
169 gst_pad_set_caps (mux->priv->srcpad, tmpl_caps);
172 g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
173 G_OBJECT_CLASS_NAME (element_klass), "source");
174 mux->priv->srcpad = gst_pad_new ("src", GST_PAD_SRC);
176 gst_element_add_pad (GST_ELEMENT (mux), mux->priv->srcpad);
178 mux->priv->render_start_tag = TRUE;
179 mux->priv->render_end_tag = TRUE;
183 gst_tag_mux_get_tags (GstTagMux * mux)
185 GstTagSetter *tagsetter = GST_TAG_SETTER (mux);
186 const GstTagList *tagsetter_tags;
187 GstTagMergeMode merge_mode;
189 if (mux->priv->final_tags)
190 return mux->priv->final_tags;
192 tagsetter_tags = gst_tag_setter_get_tag_list (tagsetter);
193 merge_mode = gst_tag_setter_get_tag_merge_mode (tagsetter);
195 GST_LOG_OBJECT (mux, "merging tags, merge mode = %d", merge_mode);
196 GST_LOG_OBJECT (mux, "event tags: %" GST_PTR_FORMAT, mux->priv->event_tags);
197 GST_LOG_OBJECT (mux, "set tags: %" GST_PTR_FORMAT, tagsetter_tags);
199 mux->priv->final_tags =
200 gst_tag_list_merge (tagsetter_tags, mux->priv->event_tags, merge_mode);
202 GST_LOG_OBJECT (mux, "final tags: %" GST_PTR_FORMAT, mux->priv->final_tags);
204 return mux->priv->final_tags;
208 gst_tag_mux_render_start_tag (GstTagMux * mux)
210 GstTagMuxClass *klass;
217 taglist = gst_tag_mux_get_tags (mux);
219 klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
221 if (klass->render_start_tag == NULL)
224 buffer = klass->render_start_tag (mux, taglist);
226 /* Null buffer is ok, just means we're not outputting anything */
227 if (buffer == NULL) {
228 GST_INFO_OBJECT (mux, "No start tag generated");
229 mux->priv->start_tag_size = 0;
233 mux->priv->start_tag_size = gst_buffer_get_size (buffer);
234 GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
235 mux->priv->start_tag_size);
237 /* Send newsegment event from byte position 0, so the tag really gets
238 * written to the start of the file, independent of the upstream segment */
239 gst_segment_init (&segment, GST_FORMAT_BYTES);
240 gst_pad_push_event (mux->priv->srcpad, gst_event_new_segment (&segment));
242 /* Send an event about the new tags to downstream elements */
243 /* gst_event_new_tag takes ownership of the list, so use a copy */
244 event = gst_event_new_tag (gst_tag_list_copy (taglist));
245 gst_pad_push_event (mux->priv->srcpad, event);
247 GST_BUFFER_OFFSET (buffer) = 0;
248 ret = gst_pad_push (mux->priv->srcpad, buffer);
250 mux->priv->current_offset = mux->priv->start_tag_size;
251 mux->priv->max_offset =
252 MAX (mux->priv->max_offset, mux->priv->current_offset);
258 GST_ERROR_OBJECT (mux, "Subclass does not implement "
259 "render_start_tag vfunc!");
260 return GST_FLOW_ERROR;
265 gst_tag_mux_render_end_tag (GstTagMux * mux)
267 GstTagMuxClass *klass;
273 taglist = gst_tag_mux_get_tags (mux);
275 klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
277 if (klass->render_end_tag == NULL)
280 buffer = klass->render_end_tag (mux, taglist);
282 if (buffer == NULL) {
283 GST_INFO_OBJECT (mux, "No end tag generated");
284 mux->priv->end_tag_size = 0;
288 mux->priv->end_tag_size = gst_buffer_get_size (buffer);
289 GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
290 mux->priv->end_tag_size);
292 /* Send newsegment event from the end of the file, so it gets written there,
293 independent of whatever new segment events upstream has sent us */
294 gst_segment_init (&segment, GST_FORMAT_BYTES);
295 segment.start = mux->priv->max_offset;
296 gst_pad_push_event (mux->priv->srcpad, gst_event_new_segment (&segment));
298 GST_BUFFER_OFFSET (buffer) = mux->priv->max_offset;
299 ret = gst_pad_push (mux->priv->srcpad, buffer);
305 GST_ERROR_OBJECT (mux, "Subclass does not implement "
306 "render_end_tag vfunc!");
307 return GST_FLOW_ERROR;
312 gst_tag_mux_adjust_event_offsets (GstTagMux * mux,
313 const GstEvent * newsegment_event)
317 gst_event_copy_segment ((GstEvent *) newsegment_event, &segment);
319 g_assert (segment.format == GST_FORMAT_BYTES);
321 if (segment.start != -1)
322 segment.start += mux->priv->start_tag_size;
323 if (segment.stop != -1)
324 segment.stop += mux->priv->start_tag_size;
325 if (segment.time != -1)
326 segment.time += mux->priv->start_tag_size;
328 GST_DEBUG_OBJECT (mux, "adjusting newsegment event offsets to start=%"
329 G_GINT64_FORMAT ", stop=%" G_GINT64_FORMAT ", cur=%" G_GINT64_FORMAT
330 " (delta = +%" G_GSIZE_FORMAT ")", segment.start, segment.stop,
331 segment.time, mux->priv->start_tag_size);
333 return gst_event_new_segment (&segment);
337 gst_tag_mux_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
339 GstTagMux *mux = GST_TAG_MUX (parent);
343 if (mux->priv->render_start_tag) {
345 GST_INFO_OBJECT (mux, "Adding tags to stream");
346 ret = gst_tag_mux_render_start_tag (mux);
347 if (ret != GST_FLOW_OK) {
348 GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
349 gst_buffer_unref (buffer);
353 /* Now send the cached newsegment event that we got from upstream */
354 if (mux->priv->newsegment_ev) {
358 GST_DEBUG_OBJECT (mux, "sending cached newsegment event");
359 newseg = gst_tag_mux_adjust_event_offsets (mux, mux->priv->newsegment_ev);
360 gst_event_unref (mux->priv->newsegment_ev);
361 mux->priv->newsegment_ev = NULL;
363 gst_event_copy_segment (newseg, &segment);
365 gst_pad_push_event (mux->priv->srcpad, newseg);
366 mux->priv->current_offset = segment.start;
367 mux->priv->max_offset =
368 MAX (mux->priv->max_offset, mux->priv->current_offset);
370 /* upstream sent no newsegment event or only one in a non-BYTE format */
373 mux->priv->render_start_tag = FALSE;
376 buffer = gst_buffer_make_writable (buffer);
378 if (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE) {
379 GST_LOG_OBJECT (mux, "Adjusting buffer offset from %" G_GINT64_FORMAT
380 " to %" G_GINT64_FORMAT, GST_BUFFER_OFFSET (buffer),
381 GST_BUFFER_OFFSET (buffer) + mux->priv->start_tag_size);
382 GST_BUFFER_OFFSET (buffer) += mux->priv->start_tag_size;
385 length = gst_buffer_get_size (buffer);
387 ret = gst_pad_push (mux->priv->srcpad, buffer);
389 mux->priv->current_offset += length;
390 mux->priv->max_offset =
391 MAX (mux->priv->max_offset, mux->priv->current_offset);
397 gst_tag_mux_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
402 mux = GST_TAG_MUX (parent);
405 switch (GST_EVENT_TYPE (event)) {
409 gst_event_parse_tag (event, &tags);
411 GST_INFO_OBJECT (mux, "Got tag event: %" GST_PTR_FORMAT, tags);
413 if (mux->priv->event_tags != NULL) {
414 gst_tag_list_insert (mux->priv->event_tags, tags,
415 GST_TAG_MERGE_REPLACE);
417 mux->priv->event_tags = gst_tag_list_copy (tags);
420 GST_INFO_OBJECT (mux, "Event tags are now: %" GST_PTR_FORMAT,
421 mux->priv->event_tags);
423 /* just drop the event, we'll push a new tag event in render_start_tag */
424 gst_event_unref (event);
428 case GST_EVENT_SEGMENT:
432 gst_event_copy_segment (event, &segment);
434 if (segment.format != GST_FORMAT_BYTES) {
435 GST_WARNING_OBJECT (mux, "dropping newsegment event in %s format",
436 gst_format_get_name (segment.format));
437 gst_event_unref (event);
441 if (mux->priv->render_start_tag) {
442 /* we have not rendered the tag yet, which means that we don't know
443 * how large it is going to be yet, so we can't adjust the offsets
444 * here at this point and need to cache the newsegment event for now
445 * (also, there could be tag events coming after this newsegment event
446 * and before the first buffer). */
447 if (mux->priv->newsegment_ev) {
448 GST_WARNING_OBJECT (mux, "discarding old cached newsegment event");
449 gst_event_unref (mux->priv->newsegment_ev);
452 GST_LOG_OBJECT (mux, "caching newsegment event for later");
453 mux->priv->newsegment_ev = event;
455 GST_DEBUG_OBJECT (mux, "got newsegment event, adjusting offsets");
456 gst_pad_push_event (mux->priv->srcpad,
457 gst_tag_mux_adjust_event_offsets (mux, event));
458 gst_event_unref (event);
460 mux->priv->current_offset = segment.start;
461 mux->priv->max_offset =
462 MAX (mux->priv->max_offset, mux->priv->current_offset);
469 if (mux->priv->render_end_tag) {
472 GST_INFO_OBJECT (mux, "Adding tags to stream");
473 ret = gst_tag_mux_render_end_tag (mux);
474 if (ret != GST_FLOW_OK) {
475 GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
479 mux->priv->render_end_tag = FALSE;
482 /* Now forward EOS */
483 result = gst_pad_event_default (pad, parent, event);
487 result = gst_pad_event_default (pad, parent, event);
495 static GstStateChangeReturn
496 gst_tag_mux_change_state (GstElement * element, GstStateChange transition)
499 GstStateChangeReturn result;
501 mux = GST_TAG_MUX (element);
503 result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
504 if (result != GST_STATE_CHANGE_SUCCESS) {
508 switch (transition) {
509 case GST_STATE_CHANGE_PAUSED_TO_READY:{
510 if (mux->priv->newsegment_ev) {
511 gst_event_unref (mux->priv->newsegment_ev);
512 mux->priv->newsegment_ev = NULL;
514 if (mux->priv->event_tags) {
515 gst_tag_list_free (mux->priv->event_tags);
516 mux->priv->event_tags = NULL;
518 mux->priv->start_tag_size = 0;
519 mux->priv->end_tag_size = 0;
520 mux->priv->render_start_tag = TRUE;
521 mux->priv->render_end_tag = TRUE;
522 mux->priv->current_offset = 0;
523 mux->priv->max_offset = 0;