gstreamer/gst/h264parse/gsth264parse.c

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/* GStreamer h264 parser
* Copyright (C) 2005 Michal Benes <michal.benes@itonis.tv>
*
* gsth264parse.c:
*
* 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.
*/
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gsth264parse.h"
static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-h264"));
static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-h264"));
GST_DEBUG_CATEGORY_STATIC (h264_parse_debug);
#define GST_CAT_DEFAULT h264_parse_debug
static const GstElementDetails gst_h264_parse_details =
GST_ELEMENT_DETAILS ("H264Parse",
"Codec/Parser",
"Parses raw h264 stream",
"Michal Benes <michal.benes@itonis.tv>");
GST_BOILERPLATE (GstH264Parse, gst_h264_parse, GstElement, GST_TYPE_ELEMENT);
static void gst_h264_parse_finalize (GObject * object);
static GstFlowReturn gst_h264_parse_chain (GstPad * pad, GstBuffer * buf);
static gboolean gst_h264_parse_handle_event (GstPad * pad, GstEvent * event);
static void
gst_h264_parse_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&srctemplate));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sinktemplate));
gst_element_class_set_details (gstelement_class, &gst_h264_parse_details);
GST_DEBUG_CATEGORY_INIT (h264_parse_debug, "h264parse", 0, "h264 parser");
}
static void
gst_h264_parse_finalize (GObject * object)
{
GstH264Parse *h264parse;
h264parse = GST_H264PARSE (object);
g_object_unref (h264parse->adapter);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_h264_parse_class_init (GstH264ParseClass * klass)
{
GObjectClass *gobject_class;
gobject_class = G_OBJECT_CLASS (klass);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_h264_parse_finalize);
}
static void
gst_h264_parse_init (GstH264Parse * h264parse, GstH264ParseClass * g_class)
{
h264parse->sink = gst_pad_new_from_static_template (&sinktemplate, "sink");
gst_pad_set_chain_function (h264parse->sink,
GST_DEBUG_FUNCPTR (gst_h264_parse_chain));
gst_pad_set_event_function (h264parse->sink,
GST_DEBUG_FUNCPTR (gst_h264_parse_handle_event));
gst_element_add_pad (GST_ELEMENT (h264parse), h264parse->sink);
h264parse->src = gst_pad_new_from_static_template (&srctemplate, "src");
gst_element_add_pad (GST_ELEMENT (h264parse), h264parse->src);
h264parse->adapter = gst_adapter_new ();
}
static GstFlowReturn
gst_h264_parse_chain (GstPad * pad, GstBuffer * buffer)
{
GstFlowReturn res = GST_FLOW_OK;
GstH264Parse *h264parse;
h264parse = GST_H264PARSE (GST_PAD_PARENT (pad));
if (!GST_PAD_CAPS (h264parse->src)) {
GstCaps *caps;
/* Forward sink caps if possible */
caps = GST_PAD_CAPS (h264parse->sink);
if (caps)
gst_caps_ref (caps);
/* Set default caps if the sink caps were not negotiated */
if (!caps)
caps = gst_caps_new_simple ("video/x-h264", NULL);
/* Set source caps */
if (!gst_pad_set_caps (h264parse->src, caps)) {
GST_ELEMENT_ERROR (GST_ELEMENT (h264parse),
CORE, NEGOTIATION, (NULL), ("failed to set caps"));
gst_caps_unref (caps);
return GST_FLOW_ERROR;
}
gst_caps_unref (caps);
}
gst_adapter_push (h264parse->adapter, buffer);
while (res == GST_FLOW_OK) {
gint i;
gint next_nalu_pos = -1;
guint32 nalu_size;
gint avail;
const guint8 *data;
avail = gst_adapter_available (h264parse->adapter);
if (avail < 5)
break;
data = gst_adapter_peek (h264parse->adapter, avail);
nalu_size = (data[0] << 24)
+ (data[1] << 16) + (data[2] << 8) + data[3];
if (nalu_size == 1) {
/* Bytestream format */
/* Find next NALU header */
for (i = 1; i < avail - 4; ++i) {
if (data[i + 0] == 0 && data[i + 1] == 0 && data[i + 2] == 0
&& data[i + 3] == 1) {
next_nalu_pos = i;
break;
}
}
} else {
/* Packetized format */
if (nalu_size + 4 <= avail)
next_nalu_pos = nalu_size + 4;
}
/* Send packet */
if (next_nalu_pos > 0) {
GstBuffer *outbuf;
outbuf = gst_buffer_new_and_alloc (next_nalu_pos);
memcpy (GST_BUFFER_DATA (outbuf), data, next_nalu_pos);
gst_adapter_flush (h264parse->adapter, next_nalu_pos);
gst_buffer_set_caps (outbuf, GST_PAD_CAPS (h264parse->src));
GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
res = gst_pad_push (h264parse->src, outbuf);
} else {
break; /* NALU can not be parsed yet */
}
}
return res;
}
static gboolean
gst_h264_parse_handle_event (GstPad * pad, GstEvent * event)
{
GstH264Parse *h264parse;
gboolean res;
h264parse = GST_H264PARSE (gst_pad_get_parent (pad));
res = gst_pad_event_default (pad, event);
gst_object_unref (h264parse);
return res;
}
static gboolean
plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "h264parse",
GST_RANK_NONE, GST_TYPE_H264PARSE);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"h264parse",
"Element parsing raw h264 streams",
plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)