gstreamer/gst/pcapparse/gstirtspparse.c
2012-11-04 00:09:59 +00:00

251 lines
7.3 KiB
C

/* GStreamer Interleaved RTSP parser
* Copyright (C) 2011 Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>
* Copyright (C) 2011 Nokia Corporation. All rights reserved.
* Contact: Stefan Kost <stefan.kost@nokia.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:element-irtspparse
* @short_description: Interleaved RTSP parser
* @see_also: #GstPcapParse
*
* This is an interleaved RTSP parser that allows extracting specific
* so-called "channels" from received interleaved (TCP) RTSP data
* (typically extracted from some network capture).
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch-0.10 filesrc location=h264crasher.pcap ! pcapparse ! irtspparse
* ! rtph264depay ! ffdec_h264 ! fakesink
* ]| Read from a pcap dump file using filesrc, extract the raw TCP packets,
* depayload and decode them.
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstirtspparse.h"
#include <gst/base/gstbytereader.h>
GST_DEBUG_CATEGORY_STATIC (irtsp_parse_debug);
#define GST_CAT_DEFAULT irtsp_parse_debug
enum
{
PROP_0,
PROP_CHANNEL_ID
};
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp ; application/x-rtcp"));
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void gst_irtsp_parse_finalize (GObject * object);
static gboolean gst_irtsp_parse_start (GstBaseParse * parse);
static gboolean gst_irtsp_parse_stop (GstBaseParse * parse);
static GstFlowReturn gst_irtsp_parse_handle_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, gint * skipsize);
static void gst_irtsp_parse_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_irtsp_parse_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
#define parent_class gst_irtsp_parse_parent_class
G_DEFINE_TYPE (GstIRTSPParse, gst_irtsp_parse, GST_TYPE_BASE_PARSE);
static void
gst_irtsp_parse_class_init (GstIRTSPParseClass * klass)
{
GstBaseParseClass *parse_class = GST_BASE_PARSE_CLASS (klass);
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GST_DEBUG_CATEGORY_INIT (irtsp_parse_debug, "irtspparse", 0,
"Interleaved RTSP stream parser");
object_class->finalize = gst_irtsp_parse_finalize;
object_class->set_property = gst_irtsp_parse_set_property;
object_class->get_property = gst_irtsp_parse_get_property;
g_object_class_install_property (object_class, PROP_CHANNEL_ID,
g_param_spec_int ("channel-id", "channel-id",
"Channel Identifier", 0, 255,
0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
parse_class->start = GST_DEBUG_FUNCPTR (gst_irtsp_parse_start);
parse_class->stop = GST_DEBUG_FUNCPTR (gst_irtsp_parse_stop);
parse_class->handle_frame = GST_DEBUG_FUNCPTR (gst_irtsp_parse_handle_frame);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_template));
gst_element_class_set_static_metadata (element_class, "IRTSPParse",
"Raw/Parser",
"Parses a raw interleaved RTSP stream",
"Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>");
}
static void
gst_irtsp_parse_reset (GstIRTSPParse * IRTSPParse)
{
}
static void
gst_irtsp_parse_init (GstIRTSPParse * IRTSPParse)
{
gst_base_parse_set_min_frame_size (GST_BASE_PARSE (IRTSPParse), 4);
gst_irtsp_parse_reset (IRTSPParse);
}
static void
gst_irtsp_parse_finalize (GObject * object)
{
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static gboolean
gst_irtsp_parse_start (GstBaseParse * parse)
{
GstIRTSPParse *IRTSPParse = GST_IRTSP_PARSE (parse);
GST_DEBUG_OBJECT (parse, "starting");
gst_irtsp_parse_reset (IRTSPParse);
return TRUE;
}
static gboolean
gst_irtsp_parse_stop (GstBaseParse * parse)
{
GST_DEBUG_OBJECT (parse, "stopping");
return TRUE;
}
static GstFlowReturn
gst_irtsp_parse_handle_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, gint * skipsize)
{
GstIRTSPParse *IRTSPParse = GST_IRTSP_PARSE (parse);
GstBuffer *buf = frame->buffer;
GstByteReader reader;
gint off;
GstMapInfo map;
gboolean ret = FALSE;
guint framesize;
gst_buffer_map (buf, &map, GST_MAP_READ);
if (G_UNLIKELY (map.size < 4))
goto exit;
gst_byte_reader_init (&reader, map.data, map.size);
off = gst_byte_reader_masked_scan_uint32 (&reader, 0xffff0000,
0x24000000 + (IRTSPParse->channel_id << 16), 0, map.size);
GST_LOG_OBJECT (parse, "possible sync at buffer offset %d", off);
/* didn't find anything that looks like a sync word, skip */
if (off < 0) {
*skipsize = map.size - 3;
goto exit;
}
/* possible frame header, but not at offset 0? skip bytes before sync */
if (off > 0) {
*skipsize = off;
goto exit;
}
framesize = GST_READ_UINT16_BE (map.data + 2) + 4;
GST_LOG_OBJECT (parse, "got frame size %d", framesize);
ret = TRUE;
if (!gst_pad_has_current_caps (GST_BASE_PARSE_SRC_PAD (parse))) {
GstCaps *caps;
caps = gst_caps_new_empty_simple ("application/x-rtp");
gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps);
gst_caps_unref (caps);
}
exit:
gst_buffer_unmap (buf, &map);
if (ret && framesize <= map.size) {
/* HACK HACK skip header.
* could also ask baseparse to skip this,
* but that would give us a discontinuity for free
* which is a bit too much to have on all our packets */
frame->out_buffer = gst_buffer_copy (frame->buffer);
gst_buffer_resize (frame->out_buffer, 4, -1);
GST_BUFFER_FLAG_UNSET (frame->out_buffer, GST_BUFFER_FLAG_DISCONT);
return gst_base_parse_finish_frame (parse, frame, framesize);
}
return GST_FLOW_OK;
}
static void
gst_irtsp_parse_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstIRTSPParse *IRTSPParse = GST_IRTSP_PARSE (object);
switch (prop_id) {
case PROP_CHANNEL_ID:
IRTSPParse->channel_id = g_value_get_int (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_irtsp_parse_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstIRTSPParse *IRTSPParse = GST_IRTSP_PARSE (object);
switch (prop_id) {
case PROP_CHANNEL_ID:
g_value_set_int (value, IRTSPParse->channel_id);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}