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/* GStreamer tag muxer base class
* Copyright (C) 2006 Christophe Fergeau <teuf@gnome.org>
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
* Copyright (C) 2006 Sebastian Dröge <slomo@circular-chaos.org>
* Copyright (C) 2009 Pioneers of the Inevitable <songbird@songbirdnest.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gsttagmux
* @title: GstTagMux
* @see_also: GstApeMux, GstId3Mux
* @short_description: Base class for adding tags that are in one single chunk
* directly at the beginning or at the end of a file
*
* Provides a base class for adding tags at the beginning or end of a
* stream.
*
* ## Deriving from GstTagMux
*
* Subclasses have to do the following things:
*
* * In their base init function, they must add pad templates for the sink
* pad and the source pad to the element class, describing the media type
* they accept and output in the caps of the pad template.
* * In their class init function, they must override the
* GST_TAG_MUX_CLASS(mux_klass)->render_start_tag and/or
* GST_TAG_MUX_CLASS(mux_klass)->render_end_tag vfuncs and set up a render
* function.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include <gst/gsttagsetter.h>
#include <gst/tag/tag.h>
#include "gsttagmux.h"
struct _GstTagMuxPrivate
{
GstPad *srcpad;
GstPad *sinkpad;
GstTagList *event_tags; /* tags received from upstream elements */
GstTagList *final_tags; /* Final set of tags used for muxing */
gsize start_tag_size;
gsize end_tag_size;
gboolean render_start_tag;
gboolean render_end_tag;
gint64 current_offset;
gint64 max_offset;
GstEvent *newsegment_ev; /* cached newsegment event from upstream */
};
GST_DEBUG_CATEGORY_STATIC (gst_tag_mux_debug);
#define GST_CAT_DEFAULT gst_tag_mux_debug
static GstElementClass *parent_class;
static void gst_tag_mux_class_init (GstTagMuxClass * klass);
static void gst_tag_mux_init (GstTagMux * mux, GstTagMuxClass * mux_class);
static GstStateChangeReturn
gst_tag_mux_change_state (GstElement * element, GstStateChange transition);
static GstFlowReturn gst_tag_mux_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer);
static gboolean gst_tag_mux_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event);
/* we can't use G_DEFINE_ABSTRACT_TYPE because we need the klass in the _init
* method to get to the padtemplates */
GType
gst_tag_mux_get_type (void)
{
static volatile gsize tag_mux_type = 0;
if (g_once_init_enter (&tag_mux_type)) {
const GInterfaceInfo interface_info = { NULL, NULL, NULL };
GType _type;
_type = g_type_register_static_simple (GST_TYPE_ELEMENT,
"GstTagMux", sizeof (GstTagMuxClass),
(GClassInitFunc) gst_tag_mux_class_init, sizeof (GstTagMux),
(GInstanceInitFunc) gst_tag_mux_init, G_TYPE_FLAG_ABSTRACT);
g_type_add_interface_static (_type, GST_TYPE_TAG_SETTER, &interface_info);
g_once_init_leave (&tag_mux_type, _type);
}
return tag_mux_type;
}
static void
gst_tag_mux_finalize (GObject * obj)
{
GstTagMux *mux = GST_TAG_MUX (obj);
if (mux->priv->newsegment_ev) {
gst_event_unref (mux->priv->newsegment_ev);
mux->priv->newsegment_ev = NULL;
}
if (mux->priv->event_tags) {
gst_tag_list_unref (mux->priv->event_tags);
mux->priv->event_tags = NULL;
}
if (mux->priv->final_tags) {
gst_tag_list_unref (mux->priv->final_tags);
mux->priv->final_tags = NULL;
}
G_OBJECT_CLASS (parent_class)->finalize (obj);
}
static void
gst_tag_mux_class_init (GstTagMuxClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_peek_parent (klass);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_tag_mux_finalize);
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_tag_mux_change_state);
g_type_class_add_private (klass, sizeof (GstTagMuxPrivate));
GST_DEBUG_CATEGORY_INIT (gst_tag_mux_debug, "tagmux", 0,
"tag muxer base class");
}
static void
gst_tag_mux_init (GstTagMux * mux, GstTagMuxClass * mux_class)
{
GstElementClass *element_klass = GST_ELEMENT_CLASS (mux_class);
GstPadTemplate *tmpl;
mux->priv =
G_TYPE_INSTANCE_GET_PRIVATE (mux, GST_TYPE_TAG_MUX, GstTagMuxPrivate);
/* pad through which data comes in to the element */
tmpl = gst_element_class_get_pad_template (element_klass, "sink");
if (tmpl) {
mux->priv->sinkpad = gst_pad_new_from_template (tmpl, "sink");
} else {
g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
G_OBJECT_CLASS_NAME (element_klass), "sink");
mux->priv->sinkpad = gst_pad_new ("sink", GST_PAD_SINK);
}
gst_pad_set_chain_function (mux->priv->sinkpad,
GST_DEBUG_FUNCPTR (gst_tag_mux_chain));
gst_pad_set_event_function (mux->priv->sinkpad,
GST_DEBUG_FUNCPTR (gst_tag_mux_sink_event));
gst_element_add_pad (GST_ELEMENT (mux), mux->priv->sinkpad);
/* pad through which data goes out of the element */
tmpl = gst_element_class_get_pad_template (element_klass, "src");
if (tmpl) {
GstCaps *tmpl_caps = gst_pad_template_get_caps (tmpl);
mux->priv->srcpad = gst_pad_new_from_template (tmpl, "src");
gst_pad_use_fixed_caps (mux->priv->srcpad);
if (tmpl_caps != NULL && gst_caps_is_fixed (tmpl_caps)) {
gst_pad_set_caps (mux->priv->srcpad, tmpl_caps);
}
} else {
g_warning ("GstTagMux subclass '%s' did not install a %s pad template!\n",
G_OBJECT_CLASS_NAME (element_klass), "source");
mux->priv->srcpad = gst_pad_new ("src", GST_PAD_SRC);
}
gst_element_add_pad (GST_ELEMENT (mux), mux->priv->srcpad);
mux->priv->render_start_tag = TRUE;
mux->priv->render_end_tag = TRUE;
}
static GstTagList *
gst_tag_mux_get_tags (GstTagMux * mux)
{
GstTagSetter *tagsetter = GST_TAG_SETTER (mux);
const GstTagList *tagsetter_tags;
GstTagMergeMode merge_mode;
if (mux->priv->final_tags)
return mux->priv->final_tags;
tagsetter_tags = gst_tag_setter_get_tag_list (tagsetter);
merge_mode = gst_tag_setter_get_tag_merge_mode (tagsetter);
GST_LOG_OBJECT (mux, "merging tags, merge mode = %d", merge_mode);
GST_LOG_OBJECT (mux, "event tags: %" GST_PTR_FORMAT, mux->priv->event_tags);
GST_LOG_OBJECT (mux, "set tags: %" GST_PTR_FORMAT, tagsetter_tags);
mux->priv->final_tags =
gst_tag_list_merge (tagsetter_tags, mux->priv->event_tags, merge_mode);
if (mux->priv->final_tags == NULL)
mux->priv->final_tags = gst_tag_list_new_empty ();
GST_LOG_OBJECT (mux, "final tags: %" GST_PTR_FORMAT, mux->priv->final_tags);
return mux->priv->final_tags;
}
static GstFlowReturn
gst_tag_mux_render_start_tag (GstTagMux * mux)
{
GstTagMuxClass *klass;
GstBuffer *buffer;
GstTagList *taglist;
GstEvent *event;
GstFlowReturn ret;
GstSegment segment;
taglist = gst_tag_mux_get_tags (mux);
klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
if (klass->render_start_tag == NULL)
goto no_vfunc;
buffer = klass->render_start_tag (mux, taglist);
/* Null buffer is ok, just means we're not outputting anything */
if (buffer == NULL) {
GST_INFO_OBJECT (mux, "No start tag generated");
mux->priv->start_tag_size = 0;
return GST_FLOW_OK;
}
mux->priv->start_tag_size = gst_buffer_get_size (buffer);
GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
mux->priv->start_tag_size);
/* Send newsegment event from byte position 0, so the tag really gets
* written to the start of the file, independent of the upstream segment */
gst_segment_init (&segment, GST_FORMAT_BYTES);
gst_pad_push_event (mux->priv->srcpad, gst_event_new_segment (&segment));
/* Send an event about the new tags to downstream elements */
/* gst_event_new_tag takes ownership of the list, so use a copy */
event = gst_event_new_tag (gst_tag_list_ref (taglist));
gst_pad_push_event (mux->priv->srcpad, event);
GST_BUFFER_OFFSET (buffer) = 0;
ret = gst_pad_push (mux->priv->srcpad, buffer);
mux->priv->current_offset = mux->priv->start_tag_size;
mux->priv->max_offset =
MAX (mux->priv->max_offset, mux->priv->current_offset);
return ret;
no_vfunc:
{
GST_ERROR_OBJECT (mux, "Subclass does not implement "
"render_start_tag vfunc!");
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_tag_mux_render_end_tag (GstTagMux * mux)
{
GstTagMuxClass *klass;
GstBuffer *buffer;
GstTagList *taglist;
GstFlowReturn ret;
GstSegment segment;
taglist = gst_tag_mux_get_tags (mux);
klass = GST_TAG_MUX_CLASS (G_OBJECT_GET_CLASS (mux));
if (klass->render_end_tag == NULL)
goto no_vfunc;
buffer = klass->render_end_tag (mux, taglist);
if (buffer == NULL) {
GST_INFO_OBJECT (mux, "No end tag generated");
mux->priv->end_tag_size = 0;
return GST_FLOW_OK;
}
mux->priv->end_tag_size = gst_buffer_get_size (buffer);
GST_LOG_OBJECT (mux, "tag size = %" G_GSIZE_FORMAT " bytes",
mux->priv->end_tag_size);
/* Send newsegment event from the end of the file, so it gets written there,
independent of whatever new segment events upstream has sent us */
gst_segment_init (&segment, GST_FORMAT_BYTES);
segment.start = mux->priv->max_offset;
gst_pad_push_event (mux->priv->srcpad, gst_event_new_segment (&segment));
GST_BUFFER_OFFSET (buffer) = mux->priv->max_offset;
ret = gst_pad_push (mux->priv->srcpad, buffer);
return ret;
no_vfunc:
{
GST_ERROR_OBJECT (mux, "Subclass does not implement "
"render_end_tag vfunc!");
return GST_FLOW_ERROR;
}
}
static GstEvent *
gst_tag_mux_adjust_event_offsets (GstTagMux * mux,
const GstEvent * newsegment_event)
{
GstSegment segment;
gst_event_copy_segment ((GstEvent *) newsegment_event, &segment);
g_assert (segment.format == GST_FORMAT_BYTES);
if (segment.start != -1)
segment.start += mux->priv->start_tag_size;
if (segment.stop != -1)
segment.stop += mux->priv->start_tag_size;
if (segment.time != -1)
segment.time += mux->priv->start_tag_size;
GST_DEBUG_OBJECT (mux, "adjusting newsegment event offsets to start=%"
G_GINT64_FORMAT ", stop=%" G_GINT64_FORMAT ", cur=%" G_GINT64_FORMAT
" (delta = +%" G_GSIZE_FORMAT ")", segment.start, segment.stop,
segment.time, mux->priv->start_tag_size);
return gst_event_new_segment (&segment);
}
static GstFlowReturn
gst_tag_mux_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstTagMux *mux = GST_TAG_MUX (parent);
GstFlowReturn ret;
int length;
if (mux->priv->render_start_tag) {
GST_INFO_OBJECT (mux, "Adding tags to stream");
ret = gst_tag_mux_render_start_tag (mux);
if (ret != GST_FLOW_OK) {
GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
gst_buffer_unref (buffer);
return ret;
}
/* Now send the cached newsegment event that we got from upstream */
if (mux->priv->newsegment_ev) {
GstEvent *newseg;
GstSegment segment;
GST_DEBUG_OBJECT (mux, "sending cached newsegment event");
newseg = gst_tag_mux_adjust_event_offsets (mux, mux->priv->newsegment_ev);
gst_event_unref (mux->priv->newsegment_ev);
mux->priv->newsegment_ev = NULL;
gst_event_copy_segment (newseg, &segment);
gst_pad_push_event (mux->priv->srcpad, newseg);
mux->priv->current_offset = segment.start;
mux->priv->max_offset =
MAX (mux->priv->max_offset, mux->priv->current_offset);
} else {
/* upstream sent no newsegment event or only one in a non-BYTE format */
}
mux->priv->render_start_tag = FALSE;
}
buffer = gst_buffer_make_writable (buffer);
if (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE) {
GST_LOG_OBJECT (mux, "Adjusting buffer offset from %" G_GINT64_FORMAT
" to %" G_GINT64_FORMAT, GST_BUFFER_OFFSET (buffer),
GST_BUFFER_OFFSET (buffer) + mux->priv->start_tag_size);
GST_BUFFER_OFFSET (buffer) += mux->priv->start_tag_size;
}
length = gst_buffer_get_size (buffer);
ret = gst_pad_push (mux->priv->srcpad, buffer);
mux->priv->current_offset += length;
mux->priv->max_offset =
MAX (mux->priv->max_offset, mux->priv->current_offset);
return ret;
}
static gboolean
gst_tag_mux_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstTagMux *mux;
gboolean result;
mux = GST_TAG_MUX (parent);
result = FALSE;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_TAG:{
GstTagList *tags;
gst_event_parse_tag (event, &tags);
GST_INFO_OBJECT (mux, "Got tag event: %" GST_PTR_FORMAT, tags);
if (mux->priv->event_tags != NULL) {
gst_tag_list_insert (mux->priv->event_tags, tags,
GST_TAG_MERGE_REPLACE);
} else {
mux->priv->event_tags = gst_tag_list_copy (tags);
}
GST_INFO_OBJECT (mux, "Event tags are now: %" GST_PTR_FORMAT,
mux->priv->event_tags);
/* just drop the event, we'll push a new tag event in render_start_tag */
gst_event_unref (event);
result = TRUE;
break;
}
case GST_EVENT_SEGMENT:
{
GstSegment segment;
gst_event_copy_segment (event, &segment);
if (segment.format != GST_FORMAT_BYTES) {
GST_WARNING_OBJECT (mux, "dropping newsegment event in %s format",
gst_format_get_name (segment.format));
gst_event_unref (event);
/* drop it quietly, so it is not seen as a failure to push event,
* which will turn into failure to push data as it is sticky */
result = TRUE;
break;
}
if (mux->priv->render_start_tag) {
/* we have not rendered the tag yet, which means that we don't know
* how large it is going to be yet, so we can't adjust the offsets
* here at this point and need to cache the newsegment event for now
* (also, there could be tag events coming after this newsegment event
* and before the first buffer). */
if (mux->priv->newsegment_ev) {
GST_WARNING_OBJECT (mux, "discarding old cached newsegment event");
gst_event_unref (mux->priv->newsegment_ev);
}
GST_LOG_OBJECT (mux, "caching newsegment event for later");
mux->priv->newsegment_ev = event;
} else {
GST_DEBUG_OBJECT (mux, "got newsegment event, adjusting offsets");
gst_pad_push_event (mux->priv->srcpad,
gst_tag_mux_adjust_event_offsets (mux, event));
gst_event_unref (event);
mux->priv->current_offset = segment.start;
mux->priv->max_offset =
MAX (mux->priv->max_offset, mux->priv->current_offset);
}
event = NULL;
result = TRUE;
break;
}
case GST_EVENT_EOS:{
if (mux->priv->render_end_tag) {
GstFlowReturn ret;
GST_INFO_OBJECT (mux, "Adding tags to stream");
ret = gst_tag_mux_render_end_tag (mux);
if (ret != GST_FLOW_OK) {
GST_DEBUG_OBJECT (mux, "flow: %s", gst_flow_get_name (ret));
return ret;
}
mux->priv->render_end_tag = FALSE;
}
/* Now forward EOS */
result = gst_pad_event_default (pad, parent, event);
break;
}
default:
result = gst_pad_event_default (pad, parent, event);
break;
}
return result;
}
static GstStateChangeReturn
gst_tag_mux_change_state (GstElement * element, GstStateChange transition)
{
GstTagMux *mux;
GstStateChangeReturn result;
mux = GST_TAG_MUX (element);
result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (result != GST_STATE_CHANGE_SUCCESS) {
return result;
}
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:{
if (mux->priv->newsegment_ev) {
gst_event_unref (mux->priv->newsegment_ev);
mux->priv->newsegment_ev = NULL;
}
if (mux->priv->event_tags) {
gst_tag_list_unref (mux->priv->event_tags);
mux->priv->event_tags = NULL;
}
if (mux->priv->final_tags) {
gst_tag_list_unref (mux->priv->final_tags);
mux->priv->final_tags = NULL;
}
mux->priv->start_tag_size = 0;
mux->priv->end_tag_size = 0;
mux->priv->render_start_tag = TRUE;
mux->priv->render_end_tag = TRUE;
mux->priv->current_offset = 0;
mux->priv->max_offset = 0;
break;
}
default:
break;
}
return result;
}