gstreamer/gst/rtp/gstrtpmpvdepay.c
2021-03-29 12:45:22 +02:00

194 lines
6 KiB
C

/* GStreamer
* Copyright (C) <2006> Wim Taymans <wim.taymans@gmail.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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <gst/rtp/gstrtpbuffer.h>
#include <gst/video/video.h>
#include <string.h>
#include "gstrtpelements.h"
#include "gstrtpmpvdepay.h"
#include "gstrtputils.h"
GST_DEBUG_CATEGORY_STATIC (rtpmpvdepay_debug);
#define GST_CAT_DEFAULT (rtpmpvdepay_debug)
/* FIXME, we set the mpeg version to 2, we should ideally be looking at contents
* of the stream to figure out the version */
static GstStaticPadTemplate gst_rtp_mpv_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS
("video/mpeg, mpegversion = (int) 2, systemstream = (boolean) FALSE")
);
static GstStaticPadTemplate gst_rtp_mpv_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"video\", "
"clock-rate = (int) 90000, " "encoding-name = (string) \"MPV\";"
"application/x-rtp, "
"media = (string) \"video\", "
"payload = (int) " GST_RTP_PAYLOAD_MPV_STRING ", "
"clock-rate = (int) 90000")
);
G_DEFINE_TYPE (GstRtpMPVDepay, gst_rtp_mpv_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpmpvdepay, "rtpmpvdepay",
GST_RANK_SECONDARY, GST_TYPE_RTP_MPV_DEPAY, rtp_element_init (plugin));
static gboolean gst_rtp_mpv_depay_setcaps (GstRTPBaseDepayload * depayload,
GstCaps * caps);
static GstBuffer *gst_rtp_mpv_depay_process (GstRTPBaseDepayload * depayload,
GstRTPBuffer * rtp);
static void
gst_rtp_mpv_depay_class_init (GstRtpMPVDepayClass * klass)
{
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_mpv_depay_src_template);
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_mpv_depay_sink_template);
gst_element_class_set_static_metadata (gstelement_class,
"RTP MPEG video depayloader", "Codec/Depayloader/Network/RTP",
"Extracts MPEG video from RTP packets (RFC 2250)",
"Wim Taymans <wim.taymans@gmail.com>");
gstrtpbasedepayload_class->set_caps = gst_rtp_mpv_depay_setcaps;
gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_mpv_depay_process;
GST_DEBUG_CATEGORY_INIT (rtpmpvdepay_debug, "rtpmpvdepay", 0,
"MPEG Video RTP Depayloader");
}
static void
gst_rtp_mpv_depay_init (GstRtpMPVDepay * rtpmpvdepay)
{
}
static gboolean
gst_rtp_mpv_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstStructure *structure;
gint clock_rate;
GstCaps *outcaps;
gboolean res;
structure = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000; /* default */
depayload->clock_rate = clock_rate;
outcaps = gst_caps_new_simple ("video/mpeg",
"mpegversion", G_TYPE_INT, 2,
"systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
res = gst_pad_set_caps (depayload->srcpad, outcaps);
gst_caps_unref (outcaps);
return res;
}
static GstBuffer *
gst_rtp_mpv_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
{
GstRtpMPVDepay *rtpmpvdepay;
GstBuffer *outbuf = NULL;
rtpmpvdepay = GST_RTP_MPV_DEPAY (depayload);
{
gint payload_len, payload_header;
guint8 *payload;
guint8 T;
payload_len = gst_rtp_buffer_get_payload_len (rtp);
payload = gst_rtp_buffer_get_payload (rtp);
payload_header = 0;
if (payload_len <= 4)
goto empty_packet;
/* 3.4 MPEG Video-specific header
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | MBZ |T| TR | |N|S|B|E| P | | BFC | | FFC |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* AN FBV FFV
*/
T = (payload[0] & 0x04);
payload_len -= 4;
payload_header += 4;
payload += 4;
if (T) {
/*
* 3.4.1 MPEG-2 Video-specific header extension
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |X|E|f_[0,0]|f_[0,1]|f_[1,0]|f_[1,1]| DC| PS|T|P|C|Q|V|A|R|H|G|D|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
if (payload_len <= 4)
goto empty_packet;
payload_len -= 4;
payload_header += 4;
payload += 4;
}
outbuf = gst_rtp_buffer_get_payload_subbuffer (rtp, payload_header, -1);
if (outbuf) {
GST_DEBUG_OBJECT (rtpmpvdepay,
"gst_rtp_mpv_depay_chain: pushing buffer of size %" G_GSIZE_FORMAT,
gst_buffer_get_size (outbuf));
gst_rtp_drop_non_video_meta (rtpmpvdepay, outbuf);
}
}
return outbuf;
/* ERRORS */
empty_packet:
{
GST_ELEMENT_WARNING (rtpmpvdepay, STREAM, DECODE,
(NULL), ("Empty payload."));
return NULL;
}
}