Commit 31067bdd authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

Bring back the lightweight RTCP sender

parent c9d3f473
......@@ -6,7 +6,7 @@ SOURCES_stream_out_duplicate = duplicate.c
SOURCES_stream_out_es = es.c
SOURCES_stream_out_display = display.c
SOURCES_stream_out_gather = gather.c
SOURCES_stream_out_rtp = rtp.c rtp.h rtsp.c
SOURCES_stream_out_rtp = rtp.h rtp.c rtcp.c rtsp.c
SOURCES_stream_out_switcher = switcher.c
SOURCES_stream_out_bridge = bridge.c
SOURCES_stream_out_mosaic_bridge = mosaic_bridge.c
......
/*****************************************************************************
* rtcp.c: RTCP stream output support
*****************************************************************************
* Copyright © 2007 Rémi Denis-Courmont
* $Id$
*
* 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
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <vlc/vlc.h>
#include <vlc_block.h>
#include <vlc_network.h>
#include <vlc_url.h>
#include <vlc_sout.h>
#include "rtp.h"
/*
* NOTE on RTCP implementation:
* - there is a single sender (us), no conferencing here! => n = sender = 1,
* - as such we need not bother to include Receiver Reports,
* - in unicast case, there is a single receiver => members = 1 + 1 = 2,
* and obviously n > 25% of members,
* - in multicast case, we do not want to maintain the number of receivers
* and we assume it is big (i.e. than 3) because that's what broadcasting is
* all about,
* - it is assumed we_sent = true (could be wrong), since we are THE sender,
* - we always send SR + SDES, while running,
* - FIXME: we do not implement separate rate limiting for SDES,
* - we do not implement any profile-specific extensions for the time being.
*/
struct rtcp_sender_t
{
size_t length; /* RTCP packet length */
uint8_t payload[28 + 8 + (2 * 257)];
int handle; /* RTCP socket handler */
uint32_t packets; /* RTP packets sent */
uint32_t bytes; /* RTP bytes sent */
unsigned counter; /* RTP packets sent since last RTCP packet */
};
rtcp_sender_t *OpenRTCP (vlc_object_t *obj, int rtp_fd,
int proto, uint16_t dport)
{
rtcp_sender_t *rtcp;
uint8_t *ptr;
char src[NI_MAXNUMERICHOST], dst[NI_MAXNUMERICHOST];
int sport;
int fd;
if (net_GetSockAddress (rtp_fd, src, &sport)
|| net_GetPeerAddress (rtp_fd, dst, NULL))
return NULL;
sport++;
fd = net_OpenDgram (obj, src, sport, dst, dport, AF_UNSPEC, proto);
if (fd == -1)
return NULL;
rtcp = malloc (sizeof (*rtcp));
if (rtcp == NULL)
{
net_Close (fd);
return NULL;
}
rtcp->handle = fd;
rtcp->bytes = rtcp->packets = rtcp->counter = 0;
ptr = (uint8_t *)strchr (src, '%');
if (ptr != NULL)
*ptr = '\0'; /* remove scope ID frop IPv6 addresses */
ptr = rtcp->payload;
/* Sender report */
ptr[0] = 2 << 6; /* V = 2, P = RC = 0 */
ptr[1] = 200; /* payload type: Sender Report */
SetWBE (ptr + 2, 6); /* length = 6 (7 double words) */
memset (ptr + 4, 0, 4); /* SSRC unknown yet */
SetQWBE (ptr + 8, NTPtime64 ());
memset (ptr + 16, 0, 12); /* timestamp and counters */
ptr += 28;
/* Source description */
uint8_t *sdes = ptr;
ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
ptr[1] = 202; /* payload type: Source Description */
uint8_t *lenptr = ptr + 2;
memset (ptr + 4, 0, 4); /* SSRC unknown yet */
ptr += 8;
ptr[0] = 1; /* CNAME - mandatory */
assert (NI_MAXNUMERICHOST <= 256);
ptr[1] = strlen (src);
memcpy (ptr + 2, src, ptr[1]);
ptr += ptr[1] + 2;
static const char tool[] = PACKAGE_STRING;
ptr[0] = 6; /* TOOL */
ptr[1] = (sizeof (tool) > 256) ? 255 : (sizeof (tool) - 1);
memcpy (ptr + 2, tool, ptr[1]);
ptr += ptr[1] + 2;
while ((ptr - sdes) & 3) /* 32-bits padding */
*ptr++ = 0;
SetWBE (lenptr, ptr - sdes);
rtcp->length = ptr - rtcp->payload;
return VLC_SUCCESS;
}
void CloseRTCP (rtcp_sender_t *rtcp)
{
if (rtcp == NULL)
return;
uint8_t *ptr = rtcp->payload;
/* Bye */
ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
ptr[1] = 203; /* payload type: Bye */
SetWBE (ptr + 2, 1);
/* SSRC is already there :) */
/* We are THE sender, so we are more important than anybody else, so
* we can afford not to check bandwidth constraints here. */
send (rtcp->handle, rtcp->payload, 8, 0);
net_Close (rtcp->handle);
}
void SendRTCP (rtcp_sender_t *restrict rtcp, const block_t *rtp)
{
if ((rtcp == NULL) /* RTCP sender off */
|| (rtp->i_buffer < 12)) /* too short RTP packet */
return;
/* Updates statistics */
rtcp->packets++;
rtcp->bytes += rtp->i_buffer;
rtcp->counter += rtp->i_buffer;
/* 1.25% rate limit */
if ((rtcp->counter / 80) < rtcp->length)
return;
uint8_t *ptr = rtcp->payload;
uint32_t last = GetDWBE (ptr + 8); // last RTCP SR send time
uint64_t now64 = NTPtime64 ();
if ((now64 >> 32) < (last + 5))
return; // no more than one SR every 5 seconds
memcpy (ptr + 4, rtp->p_buffer + 8, 4); /* SR SSRC */
SetQWBE (ptr + 8, now64);
memcpy (ptr + 16, rtp->p_buffer + 4, 4); /* RTP timestamp */
SetDWBE (ptr + 20, rtcp->packets);
SetDWBE (ptr + 24, rtcp->bytes);
memcpy (ptr + 28 + 4, rtp->p_buffer + 8, 4); /* SDES SSRC */
if (send (rtcp->handle, ptr, rtcp->length, 0) == (ssize_t)rtcp->length)
rtcp->counter = 0;
}
......@@ -39,3 +39,9 @@ char *SDPGenerate( const sout_stream_t *p_stream, const char *rtsp_url );
int rtp_add_sink( sout_stream_id_t *id, int fd );
void rtp_del_sink( sout_stream_id_t *id, int fd );
/* RTCP */
typedef struct rtcp_sender_t rtcp_sender_t;
rtcp_sender_t *OpenRTCP (vlc_object_t *obj, int rtp_fd,
int proto, uint16_t dport);
void CloseRTCP (rtcp_sender_t *rtcp);
void SendRTCP (rtcp_sender_t *restrict rtcp, const block_t *rtp);
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