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/*
* gstrtpvp8depay.c - Source for GstRtpVP8Depay
* Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
* Copyright (C) 2011 Collabora Ltd.
* Contact: Youness Alaoui <youness.alaoui@collabora.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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 "gstrtpvp8depay.h"
GST_DEBUG_CATEGORY_STATIC (gst_rtp_vp8_depay_debug);
#define GST_CAT_DEFAULT gst_rtp_vp8_depay_debug
G_DEFINE_TYPE (GstRtpVP8Depay, gst_rtp_vp8_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
static GstStaticPadTemplate gst_rtp_vp8_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-vp8"));
static GstStaticPadTemplate gst_rtp_vp8_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ","
"clock-rate = (int) 90000,"
"media = (string) \"video\","
"encoding-name = (string) \"VP8-DRAFT-IETF-01\""));
static void
gst_rtp_vp8_depay_init (GstRtpVP8Depay * self)
{
self->adapter = gst_adapter_new ();
self->started = FALSE;
}
static void gst_rtp_vp8_depay_dispose (GObject * object);
static GstBuffer *gst_rtp_vp8_depay_process (GstRTPBaseDepayload * depayload,
GstBuffer * buf);
static gboolean gst_rtp_vp8_depay_set_caps (GstRTPBaseDepayload * depayload,
GstCaps * caps);
static void
gst_rtp_vp8_depay_class_init (GstRtpVP8DepayClass * gst_rtp_vp8_depay_class)
{
GObjectClass *object_class = G_OBJECT_CLASS (gst_rtp_vp8_depay_class);
GstElementClass *element_class = GST_ELEMENT_CLASS (gst_rtp_vp8_depay_class);
GstRTPBaseDepayloadClass *depay_class =
(GstRTPBaseDepayloadClass *) (gst_rtp_vp8_depay_class);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_rtp_vp8_depay_sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_rtp_vp8_depay_src_template));
gst_element_class_set_static_metadata (element_class, "RTP VP8 depayloader",
"Codec/Depayloader/Network/RTP",
"Extracts VP8 video from RTP packets)",
"Sjoerd Simons <sjoerd@luon.net>");
object_class->dispose = gst_rtp_vp8_depay_dispose;
depay_class->process = gst_rtp_vp8_depay_process;
depay_class->set_caps = gst_rtp_vp8_depay_set_caps;
GST_DEBUG_CATEGORY_INIT (gst_rtp_vp8_depay_debug, "rtpvp8depay", 0,
"VP8 Video RTP Depayloader");
}
static void
gst_rtp_vp8_depay_dispose (GObject * object)
{
GstRtpVP8Depay *self = GST_RTP_VP8_DEPAY (object);
if (self->adapter != NULL)
g_object_unref (self->adapter);
self->adapter = NULL;
/* release any references held by the object here */
if (G_OBJECT_CLASS (gst_rtp_vp8_depay_parent_class)->dispose)
G_OBJECT_CLASS (gst_rtp_vp8_depay_parent_class)->dispose (object);
}
static GstBuffer *
gst_rtp_vp8_depay_process (GstRTPBaseDepayload * depay, GstBuffer * buf)
{
GstRtpVP8Depay *self = GST_RTP_VP8_DEPAY (depay);
GstBuffer *payload;
guint8 *data;
guint offset;
guint size;
GstRTPBuffer rtpbuffer = GST_RTP_BUFFER_INIT;
if (G_UNLIKELY (GST_BUFFER_IS_DISCONT (buf))) {
GST_LOG_OBJECT (self, "Discontinuity, flushing adapter");
gst_adapter_clear (self->adapter);
self->started = FALSE;
}
gst_rtp_buffer_map (buf, GST_MAP_READ, &rtpbuffer);
size = gst_rtp_buffer_get_payload_len (&rtpbuffer);
/* At least one header and one vp8 byte */
if (G_UNLIKELY (size < 2))
goto too_small;
data = gst_rtp_buffer_get_payload (&rtpbuffer);
if (G_UNLIKELY (!self->started)) {
/* Check if this is the start of a VP8 frame, otherwise bail */
/* S=1 and PartID= 0 */
if ((data[0] & 0x1F) != 0x10)
goto done;
self->started = TRUE;
}
offset = 1;
/* Check X optional header */
if ((data[0] & 0x80) != 0) {
offset++;
/* Check I optional header */
if ((data[1] & 0x80) != 0) {
offset++;
if (G_UNLIKELY (offset + 2 >= size))
goto too_small;
/* Check for 16 bits PictureID */
if ((data[2] & 0x80) != 0)
offset++;
}
/* Check L optional header */
if ((data[1] & 0x40) != 0)
offset++;
/* Check T or K optional headers */
if ((data[1] & 0x20) != 0 || (data[1] & 0x10) != 0)
offset++;
}
if (G_UNLIKELY (offset >= size))
goto too_small;
payload = gst_rtp_buffer_get_payload_subbuffer (&rtpbuffer, offset, -1);
gst_adapter_push (self->adapter, payload);
/* Marker indicates that it was the last rtp packet for this frame */
if (gst_rtp_buffer_get_marker (&rtpbuffer)) {
GstBuffer *out;
guint8 flag0;
gst_adapter_copy (self->adapter, &flag0, 0, 1);
out = gst_adapter_take_buffer (self->adapter,
gst_adapter_available (self->adapter));
self->started = FALSE;
gst_rtp_buffer_unmap (&rtpbuffer);
/* mark keyframes */
out = gst_buffer_make_writable (out);
if ((flag0 & 0x01))
GST_BUFFER_FLAG_SET (out, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_UNSET (out, GST_BUFFER_FLAG_DELTA_UNIT);
return out;
}
done:
gst_rtp_buffer_unmap (&rtpbuffer);
return NULL;
too_small:
GST_LOG_OBJECT (self, "Invalid rtp packet (too small), ignoring");
gst_adapter_clear (self->adapter);
self->started = FALSE;
goto done;
}
static gboolean
gst_rtp_vp8_depay_set_caps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstCaps *srccaps = gst_caps_new_simple ("video/x-vp8",
"framerate", GST_TYPE_FRACTION, 0, 1,
NULL);
gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload), srccaps);
gst_caps_unref (srccaps);
return TRUE;
}
gboolean
gst_rtp_vp8_depay_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtpvp8depay",
GST_RANK_MARGINAL, GST_TYPE_RTP_VP8_DEPAY);
}
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