gstreamer/gst/dvdsub/gstdvdsubparse.c
2012-04-10 00:47:44 +01:00

231 lines
6.6 KiB
C

/* GStreamer DVD subtitle parser
* Copyright (C) 2007 Mark Nauwelaerts <mnauw@users.sourceforge.net>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <gst/gst.h>
#include "gstdvdsubparse.h"
GST_DEBUG_CATEGORY_STATIC (dvdsubparse_debug);
#define GST_CAT_DEFAULT dvdsubparse_debug
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-dvd-subpicture, parsed=(boolean)true")
);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-dvd-subpicture")
);
static void gst_dvd_sub_parse_finalize (GObject * object);
static void gst_dvd_sub_parse_reset (GstDvdSubParse * parse);
static gboolean gst_dvd_sub_parse_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static GstFlowReturn gst_dvd_sub_parse_chain (GstPad * pad, GstObject * parent,
GstBuffer * buf);
static GstStateChangeReturn gst_dvd_sub_parse_change_state (GstElement *
element, GstStateChange transition);
#define gst_dvd_sub_parse_parent_class parent_class
G_DEFINE_TYPE (GstDvdSubParse, gst_dvd_sub_parse, GST_TYPE_ELEMENT);
static void
gst_dvd_sub_parse_class_init (GstDvdSubParseClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gobject_class->finalize = gst_dvd_sub_parse_finalize;
GST_DEBUG_CATEGORY_INIT (dvdsubparse_debug, "dvdsubparse", 0,
"DVD subtitle parser");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_dvd_sub_parse_change_state);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&src_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_set_static_metadata (gstelement_class,
"DVD subtitle parser", "Codec/Parser/Subtitle",
"Parses and packetizes DVD subtitle streams",
"Mark Nauwelaerts <mnauw@users.sourceforge.net>");
}
static void
gst_dvd_sub_parse_finalize (GObject * object)
{
GstDvdSubParse *parse = GST_DVD_SUB_PARSE (object);
g_object_unref (parse->adapter);
parse->adapter = NULL;
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_dvd_sub_parse_init (GstDvdSubParse * parse)
{
parse->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (parse->sinkpad,
GST_DEBUG_FUNCPTR (gst_dvd_sub_parse_chain));
gst_pad_set_event_function (parse->sinkpad,
GST_DEBUG_FUNCPTR (gst_dvd_sub_parse_event));
gst_element_add_pad (GST_ELEMENT (parse), parse->sinkpad);
parse->srcpad = gst_pad_new_from_static_template (&src_template, "src");
gst_pad_use_fixed_caps (parse->srcpad);
gst_pad_set_caps (parse->srcpad,
gst_static_pad_template_get_caps (&src_template));
gst_element_add_pad (GST_ELEMENT (parse), parse->srcpad);
/* remainder */
parse->adapter = gst_adapter_new ();
gst_dvd_sub_parse_reset (parse);
}
static void
gst_dvd_sub_parse_reset (GstDvdSubParse * parse)
{
parse->needed = 0;
parse->stamp = GST_CLOCK_TIME_NONE;
gst_adapter_clear (parse->adapter);
}
static gboolean
gst_dvd_sub_parse_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstDvdSubParse *parse;
gboolean ret;
parse = GST_DVD_SUB_PARSE (parent);
switch GST_EVENT_TYPE
(event) {
case GST_EVENT_FLUSH_STOP:
gst_dvd_sub_parse_reset (parse);
/* fall-through */
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
static GstFlowReturn
gst_dvd_sub_parse_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstDvdSubParse *parse = GST_DVD_SUB_PARSE (parent);
GstAdapter *adapter;
GstBuffer *outbuf = NULL;
GstFlowReturn ret = GST_FLOW_OK;
adapter = parse->adapter;
GST_LOG_OBJECT (parse, "%" G_GSIZE_FORMAT " bytes, ts: %" GST_TIME_FORMAT,
gst_buffer_get_size (buf), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)));
gst_adapter_push (adapter, buf);
if (!parse->needed) {
guint8 data[2];
gst_adapter_copy (adapter, data, 0, 2);
parse->needed = GST_READ_UINT16_BE (data);
}
if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) {
if (GST_CLOCK_TIME_IS_VALID (parse->stamp))
/* normally, we expect only the first fragment to carry a timestamp */
GST_WARNING_OBJECT (parse, "Received more timestamps than expected.");
else
parse->stamp = GST_BUFFER_TIMESTAMP (buf);
}
if (parse->needed) {
guint av;
av = gst_adapter_available (adapter);
if (av >= parse->needed) {
if (av > parse->needed) {
/* normally, we expect several fragment, boundary aligned */
GST_WARNING_OBJECT (parse, "Unexpected: needed %d, "
"but more (%d) is available.", parse->needed, av);
}
outbuf = gst_adapter_take_buffer (adapter, parse->needed);
/* decorate buffer */
GST_BUFFER_TIMESTAMP (outbuf) = parse->stamp;
/* reset state */
parse->stamp = GST_CLOCK_TIME_NONE;
parse->needed = 0;
/* and send along */
ret = gst_pad_push (parse->srcpad, outbuf);
}
}
return ret;
}
static GstStateChangeReturn
gst_dvd_sub_parse_change_state (GstElement * element, GstStateChange transition)
{
GstDvdSubParse *parse = GST_DVD_SUB_PARSE (element);
GstStateChangeReturn ret;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
case GST_STATE_CHANGE_READY_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (ret != GST_STATE_CHANGE_SUCCESS)
return ret;
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_dvd_sub_parse_reset (parse);
break;
default:
break;
}
return GST_STATE_CHANGE_SUCCESS;
}