gstreamer/gst/rtp/gstrtptheoradepay.c
2013-03-31 19:14:04 +02:00

655 lines
21 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/tag/tag.h>
#include <gst/rtp/gstrtpbuffer.h>
#include <string.h>
#include "gstrtptheoradepay.h"
GST_DEBUG_CATEGORY_STATIC (rtptheoradepay_debug);
#define GST_CAT_DEFAULT (rtptheoradepay_debug)
static GstStaticPadTemplate gst_rtp_theora_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) \"THEORA\""
/* All required parameters
*
* "sampling = (string) { "YCbCr-4:2:0", "YCbCr-4:2:2", "YCbCr-4:4:4" } "
* "width = (string) [1, 1048561] (multiples of 16) "
* "height = (string) [1, 1048561] (multiples of 16) "
* "delivery-method = (string) { inline, in_band, out_band/<specific_name> } "
* "configuration = (string) ANY"
*/
/* All optional parameters
*
* "configuration-uri ="
*/
)
);
static GstStaticPadTemplate gst_rtp_theora_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-theora")
);
#define gst_rtp_theora_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpTheoraDepay, gst_rtp_theora_depay,
GST_TYPE_RTP_BASE_DEPAYLOAD);
static gboolean gst_rtp_theora_depay_setcaps (GstRTPBaseDepayload * depayload,
GstCaps * caps);
static GstBuffer *gst_rtp_theora_depay_process (GstRTPBaseDepayload * depayload,
GstBuffer * buf);
static gboolean gst_rtp_theora_depay_packet_lost (GstRTPBaseDepayload *
depayload, GstEvent * event);
static void gst_rtp_theora_depay_finalize (GObject * object);
static void
gst_rtp_theora_depay_class_init (GstRtpTheoraDepayClass * 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_theora_depay_finalize;
gstrtpbasedepayload_class->process = gst_rtp_theora_depay_process;
gstrtpbasedepayload_class->set_caps = gst_rtp_theora_depay_setcaps;
gstrtpbasedepayload_class->packet_lost = gst_rtp_theora_depay_packet_lost;
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_theora_depay_sink_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_theora_depay_src_template));
gst_element_class_set_static_metadata (gstelement_class,
"RTP Theora depayloader", "Codec/Depayloader/Network/RTP",
"Extracts Theora video from RTP packets (draft-01 of RFC XXXX)",
"Wim Taymans <wim.taymans@gmail.com>");
GST_DEBUG_CATEGORY_INIT (rtptheoradepay_debug, "rtptheoradepay", 0,
"Theora RTP Depayloader");
}
static void
gst_rtp_theora_depay_init (GstRtpTheoraDepay * rtptheoradepay)
{
rtptheoradepay->adapter = gst_adapter_new ();
}
static void
gst_rtp_theora_depay_finalize (GObject * object)
{
GstRtpTheoraDepay *rtptheoradepay = GST_RTP_THEORA_DEPAY (object);
g_object_unref (rtptheoradepay->adapter);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static gboolean
gst_rtp_theora_depay_parse_configuration (GstRtpTheoraDepay * rtptheoradepay,
GstBuffer * confbuf)
{
GstBuffer *buf;
guint32 num_headers;
GstMapInfo map;
guint8 *data;
gsize size;
gint i, j;
gst_buffer_map (confbuf, &map, GST_MAP_READ);
data = map.data;
size = map.size;
GST_DEBUG_OBJECT (rtptheoradepay, "config size %" G_GSIZE_FORMAT, size);
/* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Number of packed headers |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Packed header |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Packed header |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | .... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
if (size < 4)
goto too_small;
num_headers = GST_READ_UINT32_BE (data);
size -= 4;
data += 4;
GST_DEBUG_OBJECT (rtptheoradepay, "have %u headers", num_headers);
/* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Ident | length ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. | n. of headers | length1 | length2 ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. | Identification Header ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .................................................................
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. | Comment Header ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .................................................................
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. Comment Header |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Setup Header ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .................................................................
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. Setup Header |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
for (i = 0; i < num_headers; i++) {
guint32 ident;
guint16 length;
guint8 n_headers, b;
GstRtpTheoraConfig *conf;
guint *h_sizes;
guint extra = 1;
if (size < 6)
goto too_small;
ident = (data[0] << 16) | (data[1] << 8) | data[2];
length = (data[3] << 8) | data[4];
n_headers = data[5];
size -= 6;
data += 6;
GST_DEBUG_OBJECT (rtptheoradepay,
"header %d, ident 0x%08x, length %u, left %" G_GSIZE_FORMAT, i, ident,
length, size);
/* FIXME check if we already got this ident */
/* length might also include count of following size fields */
if (size < length && size + 1 != length)
goto too_small;
/* read header sizes we read 2 sizes, the third size (for which we allocate
* space) must be derived from the total packed header length. */
h_sizes = g_newa (guint, n_headers + 1);
for (j = 0; j < n_headers; j++) {
guint h_size;
h_size = 0;
do {
if (size < 1)
goto too_small;
b = *data++;
size--;
extra++;
h_size = (h_size << 7) | (b & 0x7f);
} while (b & 0x80);
GST_DEBUG_OBJECT (rtptheoradepay, "headers %d: size: %u", j, h_size);
h_sizes[j] = h_size;
length -= h_size;
}
/* last header length is the remaining space */
GST_DEBUG_OBJECT (rtptheoradepay, "last header size: %u", length);
h_sizes[j] = length;
GST_DEBUG_OBJECT (rtptheoradepay, "preparing headers");
conf = g_new0 (GstRtpTheoraConfig, 1);
conf->ident = ident;
for (j = 0; j <= n_headers; j++) {
guint h_size;
h_size = h_sizes[j];
if (size < h_size) {
if (j != n_headers || size + extra != h_size) {
goto too_small;
} else {
/* otherwise means that overall length field contained total length,
* including extra fields */
h_size -= extra;
}
}
GST_DEBUG_OBJECT (rtptheoradepay, "reading header %d, size %u", j,
h_size);
buf = gst_buffer_new_and_alloc (h_size);
gst_buffer_fill (buf, 0, data, h_size);
conf->headers = g_list_append (conf->headers, buf);
data += h_size;
size -= h_size;
}
rtptheoradepay->configs = g_list_append (rtptheoradepay->configs, conf);
}
gst_buffer_unmap (confbuf, &map);
return TRUE;
/* ERRORS */
too_small:
{
GST_DEBUG_OBJECT (rtptheoradepay, "configuration too small");
gst_buffer_unmap (confbuf, &map);
return FALSE;
}
}
static gboolean
gst_rtp_theora_depay_parse_inband_configuration (GstRtpTheoraDepay *
rtptheoradepay, guint ident, guint8 * configuration, guint size,
guint length)
{
GstBuffer *confbuf;
GstMapInfo map;
if (G_UNLIKELY (size < 4))
return FALSE;
/* transform inline to out-of-band and parse that one */
confbuf = gst_buffer_new_and_alloc (size + 9);
gst_buffer_map (confbuf, &map, GST_MAP_WRITE);
/* 1 header */
GST_WRITE_UINT32_BE (map.data, 1);
/* write Ident */
GST_WRITE_UINT24_BE (map.data + 4, ident);
/* write sort-of-length */
GST_WRITE_UINT16_BE (map.data + 7, length);
/* copy remainder */
memcpy (map.data + 9, configuration, size);
gst_buffer_unmap (confbuf, &map);
return gst_rtp_theora_depay_parse_configuration (rtptheoradepay, confbuf);
}
static gboolean
gst_rtp_theora_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstStructure *structure;
GstRtpTheoraDepay *rtptheoradepay;
GstCaps *srccaps;
const gchar *configuration;
gboolean res;
rtptheoradepay = GST_RTP_THEORA_DEPAY (depayload);
rtptheoradepay->needs_keyframe = FALSE;
structure = gst_caps_get_structure (caps, 0);
/* read and parse configuration string */
configuration = gst_structure_get_string (structure, "configuration");
if (configuration) {
GstBuffer *confbuf;
guint8 *data;
gsize size;
/* deserialize base64 to buffer */
data = g_base64_decode (configuration, &size);
confbuf = gst_buffer_new ();
gst_buffer_append_memory (confbuf,
gst_memory_new_wrapped (0, data, size, 0, size, data, g_free));
if (!gst_rtp_theora_depay_parse_configuration (rtptheoradepay, confbuf))
goto invalid_configuration;
}
/* set caps on pad and on header */
srccaps = gst_caps_new_empty_simple ("video/x-theora");
res = gst_pad_set_caps (depayload->srcpad, srccaps);
gst_caps_unref (srccaps);
/* Clock rate is always 90000 according to draft-barbato-avt-rtp-theora-01 */
depayload->clock_rate = 90000;
return res;
/* ERRORS */
invalid_configuration:
{
GST_ERROR_OBJECT (rtptheoradepay, "invalid configuration specified");
return FALSE;
}
}
static gboolean
gst_rtp_theora_depay_switch_codebook (GstRtpTheoraDepay * rtptheoradepay,
guint32 ident)
{
GList *walk;
gboolean res = FALSE;
for (walk = rtptheoradepay->configs; walk; walk = g_list_next (walk)) {
GstRtpTheoraConfig *conf = (GstRtpTheoraConfig *) walk->data;
if (conf->ident == ident) {
GList *headers;
/* FIXME, remove pads, create new pad.. */
/* push out all the headers */
for (headers = conf->headers; headers; headers = g_list_next (headers)) {
GstBuffer *header = GST_BUFFER_CAST (headers->data);
gst_buffer_ref (header);
gst_rtp_base_depayload_push (GST_RTP_BASE_DEPAYLOAD (rtptheoradepay),
header);
}
/* remember the current config */
rtptheoradepay->config = conf;
res = TRUE;
}
}
if (!res) {
/* we don't know about the headers, figure out an alternative method for
* getting the codebooks. FIXME, fail for now. */
}
return res;
}
static GstBuffer *
gst_rtp_theora_depay_process (GstRTPBaseDepayload * depayload, GstBuffer * buf)
{
GstRtpTheoraDepay *rtptheoradepay;
GstBuffer *outbuf;
GstFlowReturn ret;
gint payload_len;
guint8 *payload, *to_free = NULL;
guint32 header, ident;
guint8 F, TDT, packets;
GstRTPBuffer rtp = { NULL };
rtptheoradepay = GST_RTP_THEORA_DEPAY (depayload);
gst_rtp_buffer_map (buf, GST_MAP_READ, &rtp);
payload_len = gst_rtp_buffer_get_payload_len (&rtp);
GST_DEBUG_OBJECT (depayload, "got RTP packet of size %d", payload_len);
/* we need at least 4 bytes for the packet header */
if (G_UNLIKELY (payload_len < 4))
goto packet_short;
payload = gst_rtp_buffer_get_payload (&rtp);
header = GST_READ_UINT32_BE (payload);
/*
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Ident | F |TDT|# pkts.|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* F: Fragment type (0=none, 1=start, 2=cont, 3=end)
* TDT: Theora data type (0=theora, 1=config, 2=comment, 3=reserved)
* pkts: number of packets.
*/
TDT = (header & 0x30) >> 4;
if (G_UNLIKELY (TDT == 3))
goto ignore_reserved;
ident = (header >> 8) & 0xffffff;
F = (header & 0xc0) >> 6;
packets = (header & 0xf);
GST_DEBUG_OBJECT (depayload, "ident: 0x%08x, F: %d, TDT: %d, packets: %d",
ident, F, TDT, packets);
if (TDT == 0) {
gboolean do_switch = FALSE;
/* we have a raw payload, find the codebook for the ident */
if (!rtptheoradepay->config) {
/* we don't have an active codebook, find the codebook and
* activate it */
do_switch = TRUE;
} else if (rtptheoradepay->config->ident != ident) {
/* codebook changed */
do_switch = TRUE;
}
if (do_switch) {
if (!gst_rtp_theora_depay_switch_codebook (rtptheoradepay, ident))
goto switch_failed;
}
}
/* skip header */
payload += 4;
payload_len -= 4;
/* fragmented packets, assemble */
if (F != 0) {
GstBuffer *vdata;
guint headerskip;
if (F == 1) {
/* if we start a packet, clear adapter and start assembling. */
gst_adapter_clear (rtptheoradepay->adapter);
GST_DEBUG_OBJECT (depayload, "start assemble");
rtptheoradepay->assembling = TRUE;
}
if (!rtptheoradepay->assembling)
goto no_output;
/* first assembled packet, reuse 2 bytes to store the length */
headerskip = (F == 1 ? 4 : 6);
/* skip header and length. */
vdata = gst_rtp_buffer_get_payload_subbuffer (&rtp, headerskip, -1);
GST_DEBUG_OBJECT (depayload, "assemble theora packet");
gst_adapter_push (rtptheoradepay->adapter, vdata);
/* packet is not complete, we are done */
if (F != 3)
goto no_output;
/* construct assembled buffer */
payload_len = gst_adapter_available (rtptheoradepay->adapter);
payload = gst_adapter_take (rtptheoradepay->adapter, payload_len);
/* fix the length */
payload[0] = ((payload_len - 2) >> 8) & 0xff;
payload[1] = (payload_len - 2) & 0xff;
to_free = payload;
}
GST_DEBUG_OBJECT (depayload, "assemble done, payload_len %d", payload_len);
/* we not assembling anymore now */
rtptheoradepay->assembling = FALSE;
gst_adapter_clear (rtptheoradepay->adapter);
/* payload now points to a length with that many theora data bytes.
* Iterate over the packets and send them out.
*
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | length | theora data ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. theora data |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | length | next theora packet data ..
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* .. theora data |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*
*/
while (payload_len >= 2) {
guint16 length;
length = GST_READ_UINT16_BE (payload);
payload += 2;
payload_len -= 2;
GST_DEBUG_OBJECT (depayload, "read length %u, avail: %d", length,
payload_len);
/* skip packet if something odd happens */
if (G_UNLIKELY (length > payload_len))
goto length_short;
/* handle in-band configuration */
if (G_UNLIKELY (TDT == 1)) {
GST_DEBUG_OBJECT (rtptheoradepay, "in-band configuration");
if (!gst_rtp_theora_depay_parse_inband_configuration (rtptheoradepay,
ident, payload, payload_len, length))
goto invalid_configuration;
goto no_output;
}
/* create buffer for packet */
if (G_UNLIKELY (to_free)) {
outbuf =
gst_buffer_new_wrapped_full (0, to_free, (payload - to_free) + length,
payload - to_free, length, to_free, g_free);
to_free = NULL;
} else {
outbuf = gst_buffer_new_and_alloc (length);
gst_buffer_fill (outbuf, 0, payload, length);
}
if (payload_len > 0 && (payload[0] & 0xC0) == 0x0) {
rtptheoradepay->needs_keyframe = FALSE;
} else {
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
}
payload += length;
payload_len -= length;
ret = gst_rtp_base_depayload_push (depayload, outbuf);
if (ret != GST_FLOW_OK)
break;
}
g_free (to_free);
if (rtptheoradepay->needs_keyframe)
goto request_keyframe;
gst_rtp_buffer_unmap (&rtp);
return NULL;
no_output:
{
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
/* ERORRS */
switch_failed:
{
GST_ELEMENT_WARNING (rtptheoradepay, STREAM, DECODE,
(NULL), ("Could not switch codebooks"));
goto request_config;
}
packet_short:
{
GST_ELEMENT_WARNING (rtptheoradepay, STREAM, DECODE,
(NULL), ("Packet was too short (%d < 4)", payload_len));
goto request_keyframe;
}
ignore_reserved:
{
GST_WARNING_OBJECT (rtptheoradepay, "reserved TDT ignored");
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
length_short:
{
GST_ELEMENT_WARNING (rtptheoradepay, STREAM, DECODE,
(NULL), ("Packet contains invalid data"));
goto request_keyframe;
}
invalid_configuration:
{
/* fatal, as we otherwise risk carrying on without output */
GST_ELEMENT_ERROR (rtptheoradepay, STREAM, DECODE,
(NULL), ("Packet contains invalid configuration"));
goto request_config;
}
request_config:
{
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_rtp_buffer_unmap (&rtp);
return NULL;
}
request_keyframe:
{
rtptheoradepay->needs_keyframe = TRUE;
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (depayload),
gst_event_new_custom (GST_EVENT_CUSTOM_UPSTREAM,
gst_structure_new_empty ("GstForceKeyUnit")));
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
}
gboolean
gst_rtp_theora_depay_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtptheoradepay",
GST_RANK_SECONDARY, GST_TYPE_RTP_THEORA_DEPAY);
}
static gboolean
gst_rtp_theora_depay_packet_lost (GstRTPBaseDepayload * depayload,
GstEvent * event)
{
GstRtpTheoraDepay *rtptheoradepay = GST_RTP_THEORA_DEPAY (depayload);
guint seqnum = 0;
gst_structure_get_uint (gst_event_get_structure (event), "seqnum", &seqnum);
GST_LOG_OBJECT (depayload, "Requested keyframe because frame with seqnum %u"
" is missing", seqnum);
rtptheoradepay->needs_keyframe = TRUE;
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (depayload),
gst_event_new_custom (GST_EVENT_CUSTOM_UPSTREAM,
gst_structure_new_empty ("GstForceKeyUnit")));
return TRUE;
}