gstreamer/gst/rtp/gstrtph264depay.c
Matthew Waters ea61714c70 rtph26*depay: drop FU's without a corresponding start bit
If we have not received a FU with a start bit set, any subsequent FU
data is not useful at all and would result in an invalid stream.

This case is constructed from multiple requirements in
RFC 3984 Section 5.8 and RFC 7798 Section 4.4.3.  Following are excerpts
from RFC 3984 but RFC 7798 contains similar language.

The FU in a single FU case is forbidden:

   A fragmented NAL unit MUST NOT be transmitted in one FU; i.e., the
   Start bit and End bit MUST NOT both be set to one in the same FU
   header.

and dropping is possible:

   If a fragmentation unit is lost, the receiver SHOULD discard all
   following fragmentation units in transmission order corresponding to
   the same fragmented NAL unit.

The jump in seqnum case is supported by this from the specification
instead of implementing the forbidden_zero_bit mangling:

   If a fragmentation unit is lost, the receiver SHOULD discard all
   following fragmentation units in transmission order corresponding to
   the same fragmented NAL unit.

   A receiver in an endpoint or in a MANE MAY aggregate the first n-1
   fragments of a NAL unit to an (incomplete) NAL unit, even if fragment
   n of that NAL unit is not received.  In this case, the
   forbidden_zero_bit of the NAL unit MUST be set to one to indicate a
   syntax violation.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/730>
2020-09-21 08:08:38 +00:00

1388 lines
42 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 <stdio.h>
#include <string.h>
#include <gst/base/gstbitreader.h>
#include <gst/rtp/gstrtpbuffer.h>
#include <gst/pbutils/pbutils.h>
#include <gst/video/video.h>
#include "gstrtph264depay.h"
#include "gstrtputils.h"
GST_DEBUG_CATEGORY_STATIC (rtph264depay_debug);
#define GST_CAT_DEFAULT (rtph264depay_debug)
/* This is what we'll default to when downstream hasn't
* expressed a restriction or preference via caps */
#define DEFAULT_BYTE_STREAM TRUE
#define DEFAULT_ACCESS_UNIT FALSE
/* 3 zero bytes syncword */
static const guint8 sync_bytes[] = { 0, 0, 0, 1 };
static GstStaticPadTemplate gst_rtp_h264_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-h264, "
"stream-format = (string) avc, alignment = (string) au; "
"video/x-h264, "
"stream-format = (string) byte-stream, alignment = (string) { nal, au }")
);
static GstStaticPadTemplate gst_rtp_h264_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) \"H264\"")
/* optional parameters */
/* "profile-level-id = (string) ANY, " */
/* "max-mbps = (string) ANY, " */
/* "max-fs = (string) ANY, " */
/* "max-cpb = (string) ANY, " */
/* "max-dpb = (string) ANY, " */
/* "max-br = (string) ANY, " */
/* "redundant-pic-cap = (string) { \"0\", \"1\" }, " */
/* "sprop-parameter-sets = (string) ANY, " */
/* "parameter-add = (string) { \"0\", \"1\" }, " */
/* "packetization-mode = (string) { \"0\", \"1\", \"2\" }, " */
/* "sprop-interleaving-depth = (string) ANY, " */
/* "sprop-deint-buf-req = (string) ANY, " */
/* "deint-buf-cap = (string) ANY, " */
/* "sprop-init-buf-time = (string) ANY, " */
/* "sprop-max-don-diff = (string) ANY, " */
/* "max-rcmd-nalu-size = (string) ANY " */
);
#define gst_rtp_h264_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpH264Depay, gst_rtp_h264_depay,
GST_TYPE_RTP_BASE_DEPAYLOAD);
static void gst_rtp_h264_depay_finalize (GObject * object);
static GstStateChangeReturn gst_rtp_h264_depay_change_state (GstElement *
element, GstStateChange transition);
static GstBuffer *gst_rtp_h264_depay_process (GstRTPBaseDepayload * depayload,
GstRTPBuffer * rtp);
static gboolean gst_rtp_h264_depay_setcaps (GstRTPBaseDepayload * filter,
GstCaps * caps);
static gboolean gst_rtp_h264_depay_handle_event (GstRTPBaseDepayload * depay,
GstEvent * event);
static GstBuffer *gst_rtp_h264_complete_au (GstRtpH264Depay * rtph264depay,
GstClockTime * out_timestamp, gboolean * out_keyframe);
static void gst_rtp_h264_depay_push (GstRtpH264Depay * rtph264depay,
GstBuffer * outbuf, gboolean keyframe, GstClockTime timestamp,
gboolean marker);
static void
gst_rtp_h264_depay_class_init (GstRtpH264DepayClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gobject_class->finalize = gst_rtp_h264_depay_finalize;
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_h264_depay_src_template);
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_h264_depay_sink_template);
gst_element_class_set_static_metadata (gstelement_class,
"RTP H264 depayloader", "Codec/Depayloader/Network/RTP",
"Extracts H264 video from RTP packets (RFC 3984)",
"Wim Taymans <wim.taymans@gmail.com>");
gstelement_class->change_state = gst_rtp_h264_depay_change_state;
gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_h264_depay_process;
gstrtpbasedepayload_class->set_caps = gst_rtp_h264_depay_setcaps;
gstrtpbasedepayload_class->handle_event = gst_rtp_h264_depay_handle_event;
}
static void
gst_rtp_h264_depay_init (GstRtpH264Depay * rtph264depay)
{
rtph264depay->adapter = gst_adapter_new ();
rtph264depay->picture_adapter = gst_adapter_new ();
rtph264depay->byte_stream = DEFAULT_BYTE_STREAM;
rtph264depay->merge = DEFAULT_ACCESS_UNIT;
rtph264depay->sps = g_ptr_array_new_with_free_func (
(GDestroyNotify) gst_buffer_unref);
rtph264depay->pps = g_ptr_array_new_with_free_func (
(GDestroyNotify) gst_buffer_unref);
}
static void
gst_rtp_h264_depay_reset (GstRtpH264Depay * rtph264depay, gboolean hard)
{
gst_adapter_clear (rtph264depay->adapter);
rtph264depay->wait_start = TRUE;
gst_adapter_clear (rtph264depay->picture_adapter);
rtph264depay->picture_start = FALSE;
rtph264depay->last_keyframe = FALSE;
rtph264depay->last_ts = 0;
rtph264depay->current_fu_type = 0;
rtph264depay->new_codec_data = FALSE;
g_ptr_array_set_size (rtph264depay->sps, 0);
g_ptr_array_set_size (rtph264depay->pps, 0);
if (hard) {
if (rtph264depay->allocator != NULL) {
gst_object_unref (rtph264depay->allocator);
rtph264depay->allocator = NULL;
}
gst_allocation_params_init (&rtph264depay->params);
}
}
static void
gst_rtp_h264_depay_drain (GstRtpH264Depay * rtph264depay)
{
GstClockTime timestamp;
gboolean keyframe;
GstBuffer *outbuf;
if (!rtph264depay->picture_start)
return;
outbuf = gst_rtp_h264_complete_au (rtph264depay, &timestamp, &keyframe);
if (outbuf)
gst_rtp_h264_depay_push (rtph264depay, outbuf, keyframe, timestamp, FALSE);
}
static void
gst_rtp_h264_depay_finalize (GObject * object)
{
GstRtpH264Depay *rtph264depay;
rtph264depay = GST_RTP_H264_DEPAY (object);
if (rtph264depay->codec_data)
gst_buffer_unref (rtph264depay->codec_data);
g_object_unref (rtph264depay->adapter);
g_object_unref (rtph264depay->picture_adapter);
g_ptr_array_free (rtph264depay->sps, TRUE);
g_ptr_array_free (rtph264depay->pps, TRUE);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_rtp_h264_depay_negotiate (GstRtpH264Depay * rtph264depay)
{
GstCaps *caps;
gint byte_stream = -1;
gint merge = -1;
caps =
gst_pad_get_allowed_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay));
GST_DEBUG_OBJECT (rtph264depay, "allowed caps: %" GST_PTR_FORMAT, caps);
if (caps) {
if (gst_caps_get_size (caps) > 0) {
GstStructure *s = gst_caps_get_structure (caps, 0);
const gchar *str = NULL;
if ((str = gst_structure_get_string (s, "stream-format"))) {
if (strcmp (str, "avc") == 0) {
byte_stream = FALSE;
} else if (strcmp (str, "byte-stream") == 0) {
byte_stream = TRUE;
} else {
GST_DEBUG_OBJECT (rtph264depay, "unknown stream-format: %s", str);
}
}
if ((str = gst_structure_get_string (s, "alignment"))) {
if (strcmp (str, "au") == 0) {
merge = TRUE;
} else if (strcmp (str, "nal") == 0) {
merge = FALSE;
} else {
GST_DEBUG_OBJECT (rtph264depay, "unknown alignment: %s", str);
}
}
}
gst_caps_unref (caps);
}
if (byte_stream != -1) {
GST_DEBUG_OBJECT (rtph264depay, "downstream requires byte-stream %d",
byte_stream);
rtph264depay->byte_stream = byte_stream;
} else {
GST_DEBUG_OBJECT (rtph264depay, "defaulting to byte-stream %d",
DEFAULT_BYTE_STREAM);
rtph264depay->byte_stream = DEFAULT_BYTE_STREAM;
}
if (merge != -1) {
GST_DEBUG_OBJECT (rtph264depay, "downstream requires merge %d", merge);
rtph264depay->merge = merge;
} else {
GST_DEBUG_OBJECT (rtph264depay, "defaulting to merge %d",
DEFAULT_ACCESS_UNIT);
rtph264depay->merge = DEFAULT_ACCESS_UNIT;
}
}
static gboolean
parse_sps (GstMapInfo * map, guint32 * sps_id)
{
GstBitReader br = GST_BIT_READER_INIT (map->data + 4,
map->size - 4);
if (map->size < 5)
return FALSE;
if (!gst_rtp_read_golomb (&br, sps_id))
return FALSE;
return TRUE;
}
static gboolean
parse_pps (GstMapInfo * map, guint32 * sps_id, guint32 * pps_id)
{
GstBitReader br = GST_BIT_READER_INIT (map->data + 1,
map->size - 1);
if (map->size < 2)
return FALSE;
if (!gst_rtp_read_golomb (&br, pps_id))
return FALSE;
if (!gst_rtp_read_golomb (&br, sps_id))
return FALSE;
return TRUE;
}
static gboolean
gst_rtp_h264_depay_set_output_caps (GstRtpH264Depay * rtph264depay,
GstCaps * caps)
{
GstAllocationParams params;
GstAllocator *allocator = NULL;
GstPad *srcpad;
gboolean res;
gst_allocation_params_init (&params);
srcpad = GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay);
res = gst_pad_set_caps (srcpad, caps);
if (res) {
GstQuery *query;
query = gst_query_new_allocation (caps, TRUE);
if (!gst_pad_peer_query (srcpad, query)) {
GST_DEBUG_OBJECT (rtph264depay, "downstream ALLOCATION query failed");
}
if (gst_query_get_n_allocation_params (query) > 0) {
gst_query_parse_nth_allocation_param (query, 0, &allocator, &params);
}
gst_query_unref (query);
}
if (rtph264depay->allocator)
gst_object_unref (rtph264depay->allocator);
rtph264depay->allocator = allocator;
rtph264depay->params = params;
return res;
}
static gboolean
gst_rtp_h264_set_src_caps (GstRtpH264Depay * rtph264depay)
{
gboolean res = TRUE;
GstCaps *srccaps;
GstCaps *old_caps;
GstPad *srcpad;
if (!rtph264depay->byte_stream &&
(!rtph264depay->new_codec_data ||
rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0))
return TRUE;
srccaps = gst_caps_new_simple ("video/x-h264",
"stream-format", G_TYPE_STRING,
rtph264depay->byte_stream ? "byte-stream" : "avc",
"alignment", G_TYPE_STRING, rtph264depay->merge ? "au" : "nal", NULL);
if (!rtph264depay->byte_stream) {
GstBuffer *codec_data;
GstMapInfo map;
GstMapInfo nalmap;
guint8 *data;
guint len;
guint new_size;
guint i;
guchar level = 0;
guchar profile_compat = G_MAXUINT8;
/* start with 7 bytes header */
len = 7;
/* count sps & pps */
for (i = 0; i < rtph264depay->sps->len; i++)
len += 2 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->sps, i));
for (i = 0; i < rtph264depay->pps->len; i++)
len += 2 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->pps, i));
codec_data = gst_buffer_new_and_alloc (len);
gst_buffer_map (codec_data, &map, GST_MAP_READWRITE);
data = map.data;
/* 8 bits version == 1 */
*data++ = 1;
/* According to: ISO/IEC 14496-15:2004(E) section 5.2.4.1
* The level is the max level of all SPSes
* A profile compat bit can only be set if all SPSes include that bit
*/
for (i = 0; i < rtph264depay->sps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, i), &nalmap,
GST_MAP_READ);
profile_compat &= nalmap.data[2];
level = MAX (level, nalmap.data[3]);
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, i), &nalmap);
}
/* Assume all SPSes use the same profile, so extract from the first SPS */
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, 0), &nalmap,
GST_MAP_READ);
*data++ = nalmap.data[1];
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, 0), &nalmap);
*data++ = profile_compat;
*data++ = level;
/* 6 bits reserved | 2 bits lengthSizeMinusOn */
*data++ = 0xff;
/* 3 bits reserved | 5 bits numOfSequenceParameterSets */
*data++ = 0xe0 | (rtph264depay->sps->len & 0x1f);
/* copy all SPS */
for (i = 0; i < rtph264depay->sps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, i), &nalmap,
GST_MAP_READ);
GST_DEBUG_OBJECT (rtph264depay, "copy SPS %d of length %u", i,
(guint) nalmap.size);
GST_WRITE_UINT16_BE (data, nalmap.size);
data += 2;
memcpy (data, nalmap.data, nalmap.size);
data += nalmap.size;
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, i), &nalmap);
}
/* 8 bits numOfPictureParameterSets */
*data++ = rtph264depay->pps->len;
/* copy all PPS */
for (i = 0; i < rtph264depay->pps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->pps, i), &nalmap,
GST_MAP_READ);
GST_DEBUG_OBJECT (rtph264depay, "copy PPS %d of length %u", i,
(guint) nalmap.size);
GST_WRITE_UINT16_BE (data, nalmap.size);
data += 2;
memcpy (data, nalmap.data, nalmap.size);
data += nalmap.size;
gst_buffer_unmap (g_ptr_array_index (rtph264depay->pps, i), &nalmap);
}
new_size = data - map.data;
gst_buffer_unmap (codec_data, &map);
gst_buffer_set_size (codec_data, new_size);
gst_caps_set_simple (srccaps,
"codec_data", GST_TYPE_BUFFER, codec_data, NULL);
gst_buffer_unref (codec_data);
}
/* Set profile a level from SPS */
{
gint i;
GstBuffer *max_level_sps = NULL;
gint level = 0;
GstMapInfo nalmap;
/* Get the SPS with the highest level. We assume
* all SPS have the same profile */
for (i = 0; i < rtph264depay->sps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, i), &nalmap,
GST_MAP_READ);
if (level == 0 || level < nalmap.data[3]) {
max_level_sps = g_ptr_array_index (rtph264depay->sps, i);
level = nalmap.data[3];
}
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, i), &nalmap);
}
if (max_level_sps) {
gst_buffer_map (max_level_sps, &nalmap, GST_MAP_READ);
gst_codec_utils_h264_caps_set_level_and_profile (srccaps, nalmap.data + 1,
nalmap.size - 1);
gst_buffer_unmap (max_level_sps, &nalmap);
}
}
srcpad = GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay);
old_caps = gst_pad_get_current_caps (srcpad);
if (old_caps == NULL || !gst_caps_is_equal (srccaps, old_caps)) {
res = gst_rtp_h264_depay_set_output_caps (rtph264depay, srccaps);
}
gst_clear_caps (&old_caps);
gst_caps_unref (srccaps);
/* Insert SPS and PPS into the stream on next opportunity (if bytestream) */
if (rtph264depay->byte_stream
&& (rtph264depay->sps->len > 0 || rtph264depay->pps->len > 0)) {
gint i;
GstBuffer *codec_data;
GstMapInfo map;
guint8 *data;
guint len = 0;
for (i = 0; i < rtph264depay->sps->len; i++) {
len += 4 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->sps, i));
}
for (i = 0; i < rtph264depay->pps->len; i++) {
len += 4 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->pps, i));
}
codec_data = gst_buffer_new_and_alloc (len);
gst_buffer_map (codec_data, &map, GST_MAP_WRITE);
data = map.data;
for (i = 0; i < rtph264depay->sps->len; i++) {
GstBuffer *sps_buf = g_ptr_array_index (rtph264depay->sps, i);
guint sps_size = gst_buffer_get_size (sps_buf);
if (rtph264depay->byte_stream)
memcpy (data, sync_bytes, sizeof (sync_bytes));
else
GST_WRITE_UINT32_BE (data, sps_size);
gst_buffer_extract (sps_buf, 0, data + 4, -1);
data += 4 + sps_size;
}
for (i = 0; i < rtph264depay->pps->len; i++) {
GstBuffer *pps_buf = g_ptr_array_index (rtph264depay->pps, i);
guint pps_size = gst_buffer_get_size (pps_buf);
if (rtph264depay->byte_stream)
memcpy (data, sync_bytes, sizeof (sync_bytes));
else
GST_WRITE_UINT32_BE (data, pps_size);
gst_buffer_extract (pps_buf, 0, data + 4, -1);
data += 4 + pps_size;
}
gst_buffer_unmap (codec_data, &map);
if (rtph264depay->codec_data)
gst_buffer_unref (rtph264depay->codec_data);
rtph264depay->codec_data = codec_data;
}
if (res)
rtph264depay->new_codec_data = FALSE;
return res;
}
gboolean
gst_rtp_h264_add_sps_pps (GstElement * rtph264, GPtrArray * sps_array,
GPtrArray * pps_array, GstBuffer * nal)
{
GstMapInfo map;
guchar type;
guint i;
gst_buffer_map (nal, &map, GST_MAP_READ);
type = map.data[0] & 0x1f;
if (type == 7) {
guint32 sps_id;
if (!parse_sps (&map, &sps_id)) {
GST_WARNING_OBJECT (rtph264, "Invalid SPS,"
" can't parse seq_parameter_set_id");
goto drop;
}
for (i = 0; i < sps_array->len; i++) {
GstBuffer *sps = g_ptr_array_index (sps_array, i);
GstMapInfo spsmap;
guint32 tmp_sps_id;
gst_buffer_map (sps, &spsmap, GST_MAP_READ);
parse_sps (&spsmap, &tmp_sps_id);
if (sps_id == tmp_sps_id) {
if (map.size == spsmap.size &&
memcmp (map.data, spsmap.data, spsmap.size) == 0) {
GST_LOG_OBJECT (rtph264, "Unchanged SPS %u, not updating", sps_id);
gst_buffer_unmap (sps, &spsmap);
goto drop;
} else {
gst_buffer_unmap (sps, &spsmap);
g_ptr_array_remove_index_fast (sps_array, i);
g_ptr_array_add (sps_array, nal);
GST_LOG_OBJECT (rtph264, "Modified SPS %u, replacing", sps_id);
goto done;
}
}
gst_buffer_unmap (sps, &spsmap);
}
GST_LOG_OBJECT (rtph264, "Adding new SPS %u", sps_id);
g_ptr_array_add (sps_array, nal);
} else if (type == 8) {
guint32 sps_id;
guint32 pps_id;
if (!parse_pps (&map, &sps_id, &pps_id)) {
GST_WARNING_OBJECT (rtph264, "Invalid PPS,"
" can't parse seq_parameter_set_id or pic_parameter_set_id");
goto drop;
}
for (i = 0; i < pps_array->len; i++) {
GstBuffer *pps = g_ptr_array_index (pps_array, i);
GstMapInfo ppsmap;
guint32 tmp_sps_id;
guint32 tmp_pps_id;
gst_buffer_map (pps, &ppsmap, GST_MAP_READ);
parse_pps (&ppsmap, &tmp_sps_id, &tmp_pps_id);
if (pps_id == tmp_pps_id) {
if (map.size == ppsmap.size &&
memcmp (map.data, ppsmap.data, ppsmap.size) == 0) {
GST_LOG_OBJECT (rtph264, "Unchanged PPS %u:%u, not updating", sps_id,
pps_id);
gst_buffer_unmap (pps, &ppsmap);
goto drop;
} else {
gst_buffer_unmap (pps, &ppsmap);
g_ptr_array_remove_index_fast (pps_array, i);
g_ptr_array_add (pps_array, nal);
GST_LOG_OBJECT (rtph264, "Modified PPS %u:%u, replacing",
sps_id, pps_id);
goto done;
}
}
gst_buffer_unmap (pps, &ppsmap);
}
GST_LOG_OBJECT (rtph264, "Adding new PPS %u:%i", sps_id, pps_id);
g_ptr_array_add (pps_array, nal);
} else {
goto drop;
}
done:
gst_buffer_unmap (nal, &map);
return TRUE;
drop:
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return FALSE;
}
static void
gst_rtp_h264_depay_add_sps_pps (GstRtpH264Depay * rtph264depay, GstBuffer * nal)
{
if (gst_rtp_h264_add_sps_pps (GST_ELEMENT (rtph264depay),
rtph264depay->sps, rtph264depay->pps, nal))
rtph264depay->new_codec_data = TRUE;
}
static gboolean
gst_rtp_h264_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
gint clock_rate;
GstStructure *structure = gst_caps_get_structure (caps, 0);
GstRtpH264Depay *rtph264depay;
const gchar *ps;
GstBuffer *codec_data;
GstMapInfo map;
guint8 *ptr;
rtph264depay = GST_RTP_H264_DEPAY (depayload);
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000;
depayload->clock_rate = clock_rate;
/* Base64 encoded, comma separated config NALs */
ps = gst_structure_get_string (structure, "sprop-parameter-sets");
/* negotiate with downstream w.r.t. output format and alignment */
gst_rtp_h264_depay_negotiate (rtph264depay);
if (rtph264depay->byte_stream && ps != NULL) {
/* for bytestream we only need the parameter sets but we don't error out
* when they are not there, we assume they are in the stream. */
gchar **params;
guint len, total;
gint i;
params = g_strsplit (ps, ",", 0);
/* count total number of bytes in base64. Also include the sync bytes in
* front of the params. */
len = 0;
for (i = 0; params[i]; i++) {
len += strlen (params[i]);
len += sizeof (sync_bytes);
}
/* we seriously overshoot the length, but it's fine. */
codec_data = gst_buffer_new_and_alloc (len);
gst_buffer_map (codec_data, &map, GST_MAP_WRITE);
ptr = map.data;
total = 0;
for (i = 0; params[i]; i++) {
guint save = 0;
gint state = 0;
GST_DEBUG_OBJECT (depayload, "decoding param %d (%s)", i, params[i]);
memcpy (ptr, sync_bytes, sizeof (sync_bytes));
ptr += sizeof (sync_bytes);
len =
g_base64_decode_step (params[i], strlen (params[i]), ptr, &state,
&save);
GST_DEBUG_OBJECT (depayload, "decoded %d bytes", len);
total += len + sizeof (sync_bytes);
ptr += len;
}
gst_buffer_unmap (codec_data, &map);
gst_buffer_resize (codec_data, 0, total);
g_strfreev (params);
/* keep the codec_data, we need to send it as the first buffer. We cannot
* push it in the adapter because the adapter might be flushed on discont.
*/
if (rtph264depay->codec_data)
gst_buffer_unref (rtph264depay->codec_data);
rtph264depay->codec_data = codec_data;
} else if (!rtph264depay->byte_stream) {
gchar **params;
gint i;
if (ps == NULL)
goto incomplete_caps;
params = g_strsplit (ps, ",", 0);
GST_DEBUG_OBJECT (depayload, "we have %d params", g_strv_length (params));
/* start with 7 bytes header */
for (i = 0; params[i]; i++) {
GstBuffer *nal;
GstMapInfo nalmap;
gsize nal_len;
guint save = 0;
gint state = 0;
nal_len = strlen (params[i]);
if (nal_len == 0) {
GST_WARNING_OBJECT (depayload, "empty param '%s' (#%d)", params[i], i);
continue;
}
nal = gst_buffer_new_and_alloc (nal_len);
gst_buffer_map (nal, &nalmap, GST_MAP_READWRITE);
nal_len =
g_base64_decode_step (params[i], nal_len, nalmap.data, &state, &save);
GST_DEBUG_OBJECT (depayload, "adding param %d as %s", i,
((nalmap.data[0] & 0x1f) == 7) ? "SPS" : "PPS");
gst_buffer_unmap (nal, &nalmap);
gst_buffer_set_size (nal, nal_len);
gst_rtp_h264_depay_add_sps_pps (rtph264depay, nal);
}
g_strfreev (params);
if (rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0)
goto incomplete_caps;
}
return gst_rtp_h264_set_src_caps (rtph264depay);
/* ERRORS */
incomplete_caps:
{
GST_DEBUG_OBJECT (depayload, "we have incomplete caps,"
" doing setcaps later");
return TRUE;
}
}
static GstBuffer *
gst_rtp_h264_depay_allocate_output_buffer (GstRtpH264Depay * depay, gsize size)
{
GstBuffer *buffer = NULL;
g_return_val_if_fail (size > 0, NULL);
GST_LOG_OBJECT (depay, "want output buffer of %u bytes", (guint) size);
buffer = gst_buffer_new_allocate (depay->allocator, size, &depay->params);
if (buffer == NULL) {
GST_INFO_OBJECT (depay, "couldn't allocate output buffer");
buffer = gst_buffer_new_allocate (NULL, size, NULL);
}
return buffer;
}
static GstBuffer *
gst_rtp_h264_complete_au (GstRtpH264Depay * rtph264depay,
GstClockTime * out_timestamp, gboolean * out_keyframe)
{
GstBufferList *list;
GstMapInfo outmap;
GstBuffer *outbuf;
guint outsize, offset = 0;
gint b, n_bufs, m, n_mem;
/* we had a picture in the adapter and we completed it */
GST_DEBUG_OBJECT (rtph264depay, "taking completed AU");
outsize = gst_adapter_available (rtph264depay->picture_adapter);
outbuf = gst_rtp_h264_depay_allocate_output_buffer (rtph264depay, outsize);
if (outbuf == NULL)
return NULL;
if (!gst_buffer_map (outbuf, &outmap, GST_MAP_WRITE))
return NULL;
list = gst_adapter_take_buffer_list (rtph264depay->picture_adapter, outsize);
n_bufs = gst_buffer_list_length (list);
for (b = 0; b < n_bufs; ++b) {
GstBuffer *buf = gst_buffer_list_get (list, b);
n_mem = gst_buffer_n_memory (buf);
for (m = 0; m < n_mem; ++m) {
GstMemory *mem = gst_buffer_peek_memory (buf, m);
gsize mem_size = gst_memory_get_sizes (mem, NULL, NULL);
GstMapInfo mem_map;
if (gst_memory_map (mem, &mem_map, GST_MAP_READ)) {
memcpy (outmap.data + offset, mem_map.data, mem_size);
gst_memory_unmap (mem, &mem_map);
} else {
memset (outmap.data + offset, 0, mem_size);
}
offset += mem_size;
}
gst_rtp_copy_video_meta (rtph264depay, outbuf, buf);
}
gst_buffer_list_unref (list);
gst_buffer_unmap (outbuf, &outmap);
*out_timestamp = rtph264depay->last_ts;
*out_keyframe = rtph264depay->last_keyframe;
rtph264depay->last_keyframe = FALSE;
rtph264depay->picture_start = FALSE;
return outbuf;
}
static void
gst_rtp_h264_depay_push (GstRtpH264Depay * rtph264depay, GstBuffer * outbuf,
gboolean keyframe, GstClockTime timestamp, gboolean marker)
{
/* prepend codec_data */
if (rtph264depay->codec_data) {
GST_DEBUG_OBJECT (rtph264depay, "prepending codec_data");
gst_rtp_copy_video_meta (rtph264depay, rtph264depay->codec_data, outbuf);
outbuf = gst_buffer_append (rtph264depay->codec_data, outbuf);
rtph264depay->codec_data = NULL;
keyframe = TRUE;
}
outbuf = gst_buffer_make_writable (outbuf);
gst_rtp_drop_non_video_meta (rtph264depay, outbuf);
GST_BUFFER_PTS (outbuf) = timestamp;
if (keyframe)
GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
if (marker)
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_MARKER);
gst_rtp_base_depayload_push (GST_RTP_BASE_DEPAYLOAD (rtph264depay), outbuf);
}
/* SPS/PPS/IDR considered key, all others DELTA;
* so downstream waiting for keyframe can pick up at SPS/PPS/IDR */
#define NAL_TYPE_IS_KEY(nt) (((nt) == 5) || ((nt) == 7) || ((nt) == 8))
static void
gst_rtp_h264_depay_handle_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
GstClockTime in_timestamp, gboolean marker)
{
GstRTPBaseDepayload *depayload = GST_RTP_BASE_DEPAYLOAD (rtph264depay);
gint nal_type;
GstMapInfo map;
GstBuffer *outbuf = NULL;
GstClockTime out_timestamp;
gboolean keyframe, out_keyframe;
gst_buffer_map (nal, &map, GST_MAP_READ);
if (G_UNLIKELY (map.size < 5))
goto short_nal;
nal_type = map.data[4] & 0x1f;
GST_DEBUG_OBJECT (rtph264depay, "handle NAL type %d", nal_type);
keyframe = NAL_TYPE_IS_KEY (nal_type);
out_keyframe = keyframe;
out_timestamp = in_timestamp;
if (!rtph264depay->byte_stream) {
if (nal_type == 7 || nal_type == 8) {
gst_rtp_h264_depay_add_sps_pps (rtph264depay,
gst_buffer_copy_region (nal, GST_BUFFER_COPY_ALL,
4, gst_buffer_get_size (nal) - 4));
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return;
} else if (rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0) {
/* Down push down any buffer in non-bytestream mode if the SPS/PPS haven't
* go through yet
*/
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (depayload),
gst_event_new_custom (GST_EVENT_CUSTOM_UPSTREAM,
gst_structure_new ("GstForceKeyUnit",
"all-headers", G_TYPE_BOOLEAN, TRUE, NULL)));
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return;
}
if (rtph264depay->new_codec_data &&
rtph264depay->sps->len > 0 && rtph264depay->pps->len > 0)
gst_rtp_h264_set_src_caps (rtph264depay);
}
if (rtph264depay->merge) {
gboolean start = FALSE, complete = FALSE;
/* marker bit isn't mandatory so in the following code we try to guess
* an AU boundary by detecting a new picture start */
if (!marker) {
/* consider a coded slices (IDR or not) to start a picture,
* (so ending the previous one) if first_mb_in_slice == 0
* (non-0 is part of previous one) */
/* NOTE this is not entirely according to Access Unit specs in 7.4.1.2.4,
* but in practice it works in sane cases, needs not much parsing,
* and also works with broken frame_num in NAL (where spec-wise would fail) */
/* FIXME: this code isn't correct for interlaced content as AUs should be
* constructed with pairs of fields and the guess here will just push out
* AUs with a single field in it */
if (nal_type == 1 || nal_type == 2 || nal_type == 5) {
/* we have a picture start */
start = TRUE;
if (map.data[5] & 0x80) {
/* first_mb_in_slice == 0 completes a picture */
complete = TRUE;
}
} else if (nal_type >= 6 && nal_type <= 9) {
/* SEI, SPS, PPS, AU terminate picture */
complete = TRUE;
}
GST_DEBUG_OBJECT (depayload, "start %d, complete %d", start, complete);
if (complete && rtph264depay->picture_start)
outbuf = gst_rtp_h264_complete_au (rtph264depay, &out_timestamp,
&out_keyframe);
}
/* add to adapter */
gst_buffer_unmap (nal, &map);
GST_DEBUG_OBJECT (depayload, "adding NAL to picture adapter");
gst_adapter_push (rtph264depay->picture_adapter, nal);
rtph264depay->last_ts = in_timestamp;
rtph264depay->last_keyframe |= keyframe;
rtph264depay->picture_start |= start;
if (marker)
outbuf = gst_rtp_h264_complete_au (rtph264depay, &out_timestamp,
&out_keyframe);
} else {
/* no merge, output is input nal */
GST_DEBUG_OBJECT (depayload, "using NAL as output");
outbuf = nal;
gst_buffer_unmap (nal, &map);
}
if (outbuf) {
gst_rtp_h264_depay_push (rtph264depay, outbuf, out_keyframe, out_timestamp,
marker);
}
return;
/* ERRORS */
short_nal:
{
GST_WARNING_OBJECT (depayload, "dropping short NAL");
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return;
}
}
static void
gst_rtp_h264_finish_fragmentation_unit (GstRtpH264Depay * rtph264depay)
{
guint outsize;
GstMapInfo map;
GstBuffer *outbuf;
outsize = gst_adapter_available (rtph264depay->adapter);
outbuf = gst_adapter_take_buffer (rtph264depay->adapter, outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
GST_DEBUG_OBJECT (rtph264depay, "output %d bytes", outsize);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
outsize -= 4;
map.data[0] = (outsize >> 24);
map.data[1] = (outsize >> 16);
map.data[2] = (outsize >> 8);
map.data[3] = (outsize);
}
gst_buffer_unmap (outbuf, &map);
rtph264depay->current_fu_type = 0;
gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf,
rtph264depay->fu_timestamp, rtph264depay->fu_marker);
}
static GstBuffer *
gst_rtp_h264_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
{
GstRtpH264Depay *rtph264depay;
GstBuffer *outbuf = NULL;
guint8 nal_unit_type;
rtph264depay = GST_RTP_H264_DEPAY (depayload);
/* flush remaining data on discont */
if (GST_BUFFER_IS_DISCONT (rtp->buffer)) {
gst_adapter_clear (rtph264depay->adapter);
rtph264depay->wait_start = TRUE;
rtph264depay->current_fu_type = 0;
rtph264depay->last_fu_seqnum = 0;
}
{
gint payload_len;
guint8 *payload;
guint header_len;
guint8 nal_ref_idc;
GstMapInfo map;
guint outsize, nalu_size;
GstClockTime timestamp;
gboolean marker;
timestamp = GST_BUFFER_PTS (rtp->buffer);
payload_len = gst_rtp_buffer_get_payload_len (rtp);
payload = gst_rtp_buffer_get_payload (rtp);
marker = gst_rtp_buffer_get_marker (rtp);
GST_DEBUG_OBJECT (rtph264depay, "receiving %d bytes", payload_len);
if (payload_len == 0)
goto empty_packet;
/* +---------------+
* |0|1|2|3|4|5|6|7|
* +-+-+-+-+-+-+-+-+
* |F|NRI| Type |
* +---------------+
*
* F must be 0.
*/
nal_ref_idc = (payload[0] & 0x60) >> 5;
nal_unit_type = payload[0] & 0x1f;
/* at least one byte header with type */
header_len = 1;
GST_DEBUG_OBJECT (rtph264depay, "NRI %d, Type %d %s", nal_ref_idc,
nal_unit_type, marker ? "marker" : "");
/* If FU unit was being processed, but the current nal is of a different
* type. Assume that the remote payloader is buggy (didn't set the end bit
* when the FU ended) and send out what we gathered thusfar */
if (G_UNLIKELY (rtph264depay->current_fu_type != 0 &&
nal_unit_type != rtph264depay->current_fu_type))
gst_rtp_h264_finish_fragmentation_unit (rtph264depay);
switch (nal_unit_type) {
case 0:
case 30:
case 31:
/* undefined */
goto undefined_type;
case 25:
/* STAP-B Single-time aggregation packet 5.7.1 */
/* 2 byte extra header for DON */
header_len += 2;
/* fallthrough */
case 24:
{
/* strip headers */
payload += header_len;
payload_len -= header_len;
rtph264depay->wait_start = FALSE;
/* STAP-A Single-time aggregation packet 5.7.1 */
while (payload_len > 2) {
gboolean last = FALSE;
/* 1
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | NALU Size |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
nalu_size = (payload[0] << 8) | payload[1];
/* don't include nalu_size */
if (nalu_size > (payload_len - 2))
nalu_size = payload_len - 2;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
map.data[0] = map.data[1] = 0;
map.data[2] = payload[0];
map.data[3] = payload[1];
}
/* strip NALU size */
payload += 2;
payload_len -= 2;
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
gst_buffer_unmap (outbuf, &map);
gst_rtp_copy_video_meta (rtph264depay, outbuf, rtp->buffer);
if (payload_len - nalu_size <= 2)
last = TRUE;
gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf, timestamp,
marker && last);
payload += nalu_size;
payload_len -= nalu_size;
}
break;
}
case 26:
/* MTAP16 Multi-time aggregation packet 5.7.2 */
// header_len = 5;
/* fallthrough, not implemented */
case 27:
/* MTAP24 Multi-time aggregation packet 5.7.2 */
// header_len = 6;
goto not_implemented;
break;
case 28:
case 29:
{
/* FU-A Fragmentation unit 5.8 */
/* FU-B Fragmentation unit 5.8 */
gboolean S, E;
/* +---------------+
* |0|1|2|3|4|5|6|7|
* +-+-+-+-+-+-+-+-+
* |S|E|R| Type |
* +---------------+
*
* R is reserved and always 0
*/
S = (payload[1] & 0x80) == 0x80;
E = (payload[1] & 0x40) == 0x40;
GST_DEBUG_OBJECT (rtph264depay, "S %d, E %d", S, E);
if (rtph264depay->wait_start && !S)
goto waiting_start;
if (S) {
/* NAL unit starts here */
guint8 nal_header;
/* If a new FU unit started, while still processing an older one.
* Assume that the remote payloader is buggy (doesn't set the end
* bit) and send out what we've gathered thusfar */
if (G_UNLIKELY (rtph264depay->current_fu_type != 0))
gst_rtp_h264_finish_fragmentation_unit (rtph264depay);
rtph264depay->current_fu_type = nal_unit_type;
rtph264depay->fu_timestamp = timestamp;
rtph264depay->last_fu_seqnum = gst_rtp_buffer_get_seq (rtp);
rtph264depay->wait_start = FALSE;
/* reconstruct NAL header */
nal_header = (payload[0] & 0xe0) | (payload[1] & 0x1f);
/* strip type header, keep FU header, we'll reuse it to reconstruct
* the NAL header. */
payload += 1;
payload_len -= 1;
nalu_size = payload_len;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
map.data[sizeof (sync_bytes)] = nal_header;
gst_buffer_unmap (outbuf, &map);
gst_rtp_copy_video_meta (rtph264depay, outbuf, rtp->buffer);
GST_DEBUG_OBJECT (rtph264depay, "queueing %d bytes", outsize);
/* and assemble in the adapter */
gst_adapter_push (rtph264depay->adapter, outbuf);
} else {
if (rtph264depay->current_fu_type == 0) {
/* previous FU packet missing start bit? */
GST_WARNING_OBJECT (rtph264depay, "missing FU start bit on an "
"earlier packet. Dropping.");
gst_adapter_clear (rtph264depay->adapter);
return NULL;
}
if (gst_rtp_buffer_compare_seqnum (rtph264depay->last_fu_seqnum,
gst_rtp_buffer_get_seq (rtp)) != 1) {
/* jump in sequence numbers within an FU is cause for discarding */
GST_WARNING_OBJECT (rtph264depay, "Jump in sequence numbers from "
"%u to %u within Fragmentation Unit. Data was lost, dropping "
"stored.", rtph264depay->last_fu_seqnum,
gst_rtp_buffer_get_seq (rtp));
gst_adapter_clear (rtph264depay->adapter);
return NULL;
}
rtph264depay->last_fu_seqnum = gst_rtp_buffer_get_seq (rtp);
/* strip off FU indicator and FU header bytes */
payload += 2;
payload_len -= 2;
outsize = payload_len;
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_fill (outbuf, 0, payload, outsize);
gst_rtp_copy_video_meta (rtph264depay, outbuf, rtp->buffer);
GST_DEBUG_OBJECT (rtph264depay, "queueing %d bytes", outsize);
/* and assemble in the adapter */
gst_adapter_push (rtph264depay->adapter, outbuf);
}
outbuf = NULL;
rtph264depay->fu_marker = marker;
/* if NAL unit ends, flush the adapter */
if (E)
gst_rtp_h264_finish_fragmentation_unit (rtph264depay);
break;
}
default:
{
rtph264depay->wait_start = FALSE;
/* 1-23 NAL unit Single NAL unit packet per H.264 5.6 */
/* the entire payload is the output buffer */
nalu_size = payload_len;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
map.data[0] = map.data[1] = 0;
map.data[2] = nalu_size >> 8;
map.data[3] = nalu_size & 0xff;
}
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
gst_buffer_unmap (outbuf, &map);
gst_rtp_copy_video_meta (rtph264depay, outbuf, rtp->buffer);
gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf, timestamp, marker);
break;
}
}
}
return NULL;
/* ERRORS */
empty_packet:
{
GST_DEBUG_OBJECT (rtph264depay, "empty packet");
return NULL;
}
undefined_type:
{
GST_ELEMENT_WARNING (rtph264depay, STREAM, DECODE,
(NULL), ("Undefined packet type"));
return NULL;
}
waiting_start:
{
GST_DEBUG_OBJECT (rtph264depay, "waiting for start");
return NULL;
}
not_implemented:
{
GST_ELEMENT_ERROR (rtph264depay, STREAM, FORMAT,
(NULL), ("NAL unit type %d not supported yet", nal_unit_type));
return NULL;
}
}
static gboolean
gst_rtp_h264_depay_handle_event (GstRTPBaseDepayload * depay, GstEvent * event)
{
GstRtpH264Depay *rtph264depay;
rtph264depay = GST_RTP_H264_DEPAY (depay);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_STOP:
gst_rtp_h264_depay_reset (rtph264depay, FALSE);
break;
case GST_EVENT_EOS:
gst_rtp_h264_depay_drain (rtph264depay);
break;
default:
break;
}
return
GST_RTP_BASE_DEPAYLOAD_CLASS (parent_class)->handle_event (depay, event);
}
static GstStateChangeReturn
gst_rtp_h264_depay_change_state (GstElement * element,
GstStateChange transition)
{
GstRtpH264Depay *rtph264depay;
GstStateChangeReturn ret;
rtph264depay = GST_RTP_H264_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_rtp_h264_depay_reset (rtph264depay, TRUE);
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_rtp_h264_depay_reset (rtph264depay, TRUE);
break;
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
return ret;
}
gboolean
gst_rtp_h264_depay_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (rtph264depay_debug, "rtph264depay", 0,
"H264 Video RTP Depayloader");
return gst_element_register (plugin, "rtph264depay",
GST_RANK_SECONDARY, GST_TYPE_RTP_H264_DEPAY);
}