sap.patch

DIFF from tilka git

diff --git a/AUTHORS b/AUTHORS
index c1d2df2..a26ef43 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -28,6 +28,10 @@ N: Peter Partin
 E: peter DOT martin AT tripleplay DASH servies DOT com
 D: ATSC, MRTG, PID remap
 
+N: Simon Lockhart
+E: simon AT slimey DOT org
+D: Deltacast ASI card support
+
 N: Christophe Massiot
 E: massiot AT via DOT ecp DOT fr
 C: massiot
@@ -38,6 +42,7 @@ E: jpsaman AT videolan DOT org
 C: jpsaman
 D: DVB-S2 bug fixes, syslog support
 
-N: Simon Lockhart
-E: simon AT slimey DOT org
-D: Deltacast ASI card support
+N: Selfnet e.V. (Tillmann Karras, Markus Wick, Dirk Braunschweiger)
+E: admin AT selfnet DOT de
+W: www.selfnet.de
+D: SAP support
diff --git a/Makefile b/Makefile
index 3b6775c..73b7261 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ endif
 
 LDLIBS_DVBLAST += -lpthread
 
-OBJ_DVBLAST = dvblast.o util.o dvb.o udp.o asi.o demux.o output.o en50221.o comm.o mrtg-cnt.o asi-deltacast.o
+OBJ_DVBLAST = dvblast.o util.o dvb.o udp.o asi.o demux.o output.o en50221.o comm.o mrtg-cnt.o asi-deltacast.o sap.o
 OBJ_DVBLASTCTL = util.o dvblastctl.o
 
 ifndef V
@@ -49,7 +49,7 @@ all: dvblast dvblastctl
 
 .PHONY: clean install uninstall dist
 
-%.o: %.c Makefile config.h dvblast.h en50221.h comm.h asi.h mrtg-cnt.h asi-deltacast.h
+%.o: %.c Makefile config.h dvblast.h en50221.h comm.h asi.h mrtg-cnt.h asi-deltacast.h sap.h
 	@echo "CC      $<"
 	$(Q)$(CROSS)$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
 
diff --git a/NEWS b/NEWS
index 76a6d5f..282cf0e 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@ Changes between 2.2 and 2.3:
   * Added support for multi-delivery system frontends.
   * Added support for multistream that appeared in Linux 3.6
   * Added support for Deltacast ASI cards
+  * Added support for SAP announcements generated from SDT.
 
 Changes between 2.1 and 2.2:
 ----------------------------
diff --git a/bitstream_patch.h b/bitstream_patch.h
new file mode 100644
index 0000000..9446690
--- /dev/null
+++ b/bitstream_patch.h
@@ -0,0 +1,4 @@
+static inline void psi_copy(uint8_t *pp_dest, uint8_t *pp_src)
+{
+     memcpy(pp_dest, pp_src, (PSI_MAX_SIZE + PSI_HEADER_SIZE) * sizeof(uint8_t));
+}
diff --git a/demux.c b/demux.c
index b786515..a349d34 100644
--- a/demux.c
+++ b/demux.c
@@ -47,6 +47,7 @@
 #include <bitstream/dvb/si.h>
 #include <bitstream/dvb/si_print.h>
 #include <bitstream/mpeg/psi_print.h>
+#include "bitstream_patch.h"
 
 extern bool b_enable_emm;
 extern bool b_enable_ecm;
@@ -1174,6 +1175,19 @@ static void SendEIT( sid_t *p_sid, mtime_t i_dts, uint8_t *p_eit )
 
             psi_set_crc( p_eit );
 
+            int j = 0;
+            uint8_t *p_eit_n;
+            while(( p_eit_n = eit_get_event(p_eit,j++)) != NULL )
+            {
+                if ( eitn_get_running( p_eit_n ) == 4 )
+                {
+                    free( p_output->p_eit_epg_section );
+                    p_output->p_eit_epg_section = psi_allocate();
+                    psi_copy( p_output->p_eit_epg_section, p_eit );
+                    break;
+                }
+            }
+
             OutputPSISection( p_output, p_eit, EIT_PID, &p_output->i_eit_cc,
                               i_dts, &p_output->p_eit_ts_buffer,
                               &p_output->i_eit_ts_buffer_offset );
diff --git a/dvblast.1 b/dvblast.1
index 6dbb0f7..33b741d 100644
--- a/dvblast.1
+++ b/dvblast.1
@@ -178,6 +178,18 @@ Symbole rate
 \fB\-S\fR, \fB\-\-diseqc\fR <diseqc>
 Satellite number for diseqc (0: no diseqc, 1\-4, A or B)
 .TP
+\fB--sap\fR
+Announce streams via SAP/SDP
+.TP
+\fB--sap-ip4 <ip>\fB
+Multicast IPv4 address for SAP announcements (default: 239.195.255.255)
+.TP
+\fB--sap-ip6 <ip>\fB
+Multicast IPv6 address for SAP announcements (default: ff08::2:7ffe)
+.TP
+\fB--sap-interval <secs>\fB
+Time interval between announcements per stream (default: 1)
+.TP
 \fB\-t\fR, \fB\-\-ttl\fR <ttl>
 Time-To-Live of the multicast stream
 .TP
diff --git a/dvblast.c b/dvblast.c
index ebd4992..36f631b 100644
--- a/dvblast.c
+++ b/dvblast.c
@@ -48,6 +48,7 @@
 #include <bitstream/ietf/rtp.h>
 
 #include "mrtg-cnt.h"
+#include "sap.h"
 
 /*****************************************************************************
  * Local declarations
@@ -104,6 +105,8 @@ int i_verbose = DEFAULT_VERBOSITY;
 int i_syslog = 0;
 char *psz_syslog_ident = NULL;
 
+int b_enable_sap = 0;
+
 bool b_enable_emm = false;
 bool b_enable_ecm = false;
 
@@ -572,6 +575,10 @@ void usage()
     msg_Raw( NULL, "  -q --quiet            be quiet (less verbosity, repeat or use number for even quieter)" );
     msg_Raw( NULL, "  -Q --quit-timeout     when locked, quit after this delay (in ms), or after the first lock timeout" );
     msg_Raw( NULL, "  -r --remote-socket <remote socket>" );
+    msg_Raw( NULL, "     --sap              announce streams via SAP/SDP");
+    msg_Raw( NULL, "     --sap-ip4 <ip4>    multicast IPv4 address for SAP announcements (default: %s)", SAP_DEFAULT_IP4_ADDR);
+    msg_Raw( NULL, "     --sap-ip6 <ip6>    multicast IPv6 address for SAP announcements (default: %s)", SAP_DEFAULT_IP6_ADDR);
+    msg_Raw( NULL, "     --sap-interval <secs> time interval between announcements per stream (default 1)");
     msg_Raw( NULL, "  -V --version          only display the version" );
     msg_Raw( NULL, "  -Z --mrtg-file <file> Log input packets and errors into mrtg-file" );
     exit(1);
@@ -657,10 +664,15 @@ int main( int i_argc, char **pp_argv )
         { "ca-number",       required_argument, NULL, 'y' },
         { "pidmap",          required_argument, NULL, '0' },
         { "dvr-buf-size",    required_argument, NULL, '2' },
+        { "sap",             no_argument,       &b_enable_sap, 1 },
+        { "sap-ip4",         required_argument, NULL,  1001 },
+        { "sap-ip6",         required_argument, NULL,  1002 },
+        { "sap-interval",    required_argument, NULL,  1003 },
         { 0, 0, 0, 0 }
     };
 
-    while ( (c = getopt_long(i_argc, pp_argv, "q::c:r:t:o:i:a:n:5:f:F:R:s:S:k:v:pb:I:m:P:K:G:H:X:O:uwUTL:E:d:D:A:lg:zCWYeM:N:j:J:B:x:Q:hVZ:y:0:1:2:", long_options, NULL)) != -1 )
+    int option_index = 0;
+    while ( (c = getopt_long(i_argc, pp_argv, "q::c:r:t:o:i:a:n:5:f:F:R:s:S:k:v:pb:I:m:P:K:G:H:X:O:uwUTL:E:d:D:A:lg:zCWYeM:N:j:J:B:x:Q:hVZ:y:0:1:2:", long_options, &option_index)) != -1 )
     {
         switch ( c )
         {
@@ -902,7 +914,7 @@ int main( int i_argc, char **pp_argv )
         case 'Y':
             b_enable_ecm = true;
             break;
- 
+
         case 'e':
             b_epg_global = true;
             break;
@@ -1000,9 +1012,40 @@ int main( int i_argc, char **pp_argv )
             i_dvr_buffer_size *= TS_SIZE;
             break;
 #endif
+
+        case 1001: // sap-ip4
+            if ( inet_pton(AF_INET, optarg, &g_sap_ip4_dest) != 1 )
+            {
+                msg_Err( NULL, "Invalid SAP IPv4 address" );
+                exit(EXIT_FAILURE);
+            }
+            if ( !IN_MULTICAST(ntohl(g_sap_ip4_dest)) )
+                msg_Warn( NULL, "SAP IPv4 address is not a multicast address (using it anyway)" );
+            break;
+
+        case 1002: // sap-ip6
+            if ( inet_pton(AF_INET6, optarg, &g_sap_ip6_dest) != 1 )
+            {
+                msg_Err( NULL, "Invalid SAP IPv6 address" );
+                exit(EXIT_FAILURE);
+            }
+            if ( !IN6_IS_ADDR_MULTICAST( &g_sap_ip6_dest ) )
+                msg_Warn( NULL, "SAP IPv6 address is not a multicast address (using it anyway)" );
+            break;
+
+        case 1003: // sap-interval
+            g_sap_interval = atoi(optarg);
+            if ( g_sap_interval < 1 )
+                g_sap_interval = 1;
+            break;
+
         case 'h':
-        default:
             usage();
+            break;
+
+        default:
+            if ( !option_index )
+                usage();
         }
     }
     if ( optind < i_argc || pf_Open == NULL )
@@ -1015,7 +1058,7 @@ int main( int i_argc, char **pp_argv )
         DisplayVersion();
 
     msg_Warn( NULL, "restarting" );
-    switch (i_print_type) 
+    switch (i_print_type)
     {
         case PRINT_XML:
             printf("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
@@ -1123,6 +1166,9 @@ int main( int i_argc, char **pp_argv )
 
     config_ReadFile( psz_conf_file );
 
+    if ( b_enable_sap )
+        sap_Init();
+
     if ( psz_srv_socket != NULL )
         comm_Open();
 
@@ -1143,6 +1189,9 @@ int main( int i_argc, char **pp_argv )
             config_ReadFile( psz_conf_file );
         }
 
+        if ( b_enable_sap )
+            sap_Announce();
+
         if ( i_quit_timeout && i_quit_timeout <= i_wallclock )
         {
             switch (i_print_type)
@@ -1172,6 +1221,9 @@ int main( int i_argc, char **pp_argv )
     demux_Close();
     free( p_network_name );
 
+    if ( b_enable_sap )
+        sap_Close();
+
     if ( b_enable_syslog )
         msg_Disconnect();
 
diff --git a/dvblast.h b/dvblast.h
index 7cd981d..088cc8e 100644
--- a/dvblast.h
+++ b/dvblast.h
@@ -162,6 +162,7 @@ typedef struct output_t
     uint8_t i_nit_version, i_nit_cc;
     uint8_t *p_sdt_section;
     uint8_t i_sdt_version, i_sdt_cc;
+    uint8_t *p_eit_epg_section;
     block_t *p_eit_ts_buffer;
     uint8_t i_eit_ts_buffer_offset, i_eit_cc;
     uint16_t i_tsid;
diff --git a/output.c b/output.c
index 1605425..4fcaa62 100644
--- a/output.c
+++ b/output.c
@@ -185,6 +185,7 @@ int output_Init( output_t *p_output, const output_config_t *p_config )
     p_output->p_pmt_section = NULL;
     p_output->p_nit_section = NULL;
     p_output->p_sdt_section = NULL;
+    p_output->p_eit_epg_section = NULL;
     p_output->p_eit_ts_buffer = NULL;
     if ( b_random_tsid )
         p_output->i_tsid = rand() & 0xffff;
@@ -216,9 +217,9 @@ int output_Init( output_t *p_output, const output_config_t *p_config )
     int ret = 0;
     if ( p_config->bind_addr.ss_family != AF_UNSPEC )
     {
-        if ( bind( p_output->i_handle, (struct sockaddr *)&p_config->bind_addr,
-                   i_sockaddr_len ) < 0 )
-            msg_Warn( NULL, "couldn't bind socket (%s)", strerror(errno) );
+//        if ( bind( p_output->i_handle, (struct sockaddr *)&p_config->bind_addr,
+//                   i_sockaddr_len ) < 0 )
+//            msg_Warn( NULL, "couldn't bind socket (%s)", strerror(errno) );
 
         if ( p_config->i_family == AF_INET )
         {
@@ -301,6 +302,7 @@ void output_Close( output_t *p_output )
     free( p_output->p_pmt_section );
     free( p_output->p_nit_section );
     free( p_output->p_sdt_section );
+    free( p_output->p_eit_epg_section );
     free( p_output->p_eit_ts_buffer );
     p_output->config.i_config &= ~OUTPUT_VALID;
 
diff --git a/sap.c b/sap.c
new file mode 100644
index 0000000..9fbe4d4
--- /dev/null
+++ b/sap.c
@@ -0,0 +1,407 @@
+/*****************************************************************************
+ * sap.c SAP Announcements generated from SDT
+ *****************************************************************************
+ * Copyright (C) 2012 VideoLAN
+ *
+ * Author:  Dirk Braunschweiger <dirkmb@selfnet.de>
+ *          Markus Wick         <markus@selfnet.de>
+ *          Tillmann Karras     <tillmann@selfnet.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "config.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include <unistd.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <locale.h>
+#include <errno.h>
+
+#include <bitstream/dvb/si/sdt.h>
+#include <bitstream/dvb/si/eit.h>
+#include <bitstream/dvb/si/desc_48.h>
+#include <bitstream/dvb/si/desc_4d.h>
+
+#ifdef HAVE_ICONV
+#include <iconv.h>
+#endif
+
+#include "dvblast.h"
+#include "sap.h"
+
+/* SAP config */
+unsigned int g_sap_interval = 1;
+in_addr_t  g_sap_ip4_dest = -1;
+struct in6_addr g_sap_ip6_dest = { .s6_addr = { 0 } };
+
+/* Reporting timer */
+static mtime_t sap_time = 0;
+
+static int i_sap_handle;
+static int i_next_output = 0;
+static struct sockaddr_in  addr4;
+static struct sockaddr_in6 addr6;
+
+/* Checks if the UTF-8 character pointed to by chr is a DVB control code
+ * as defined by EN 300 468 Annex A.1. */
+static inline int dvb_is_control_code( char *chr, int length )
+{
+    /* c2 80-9f  or  ee 82 80-9f */
+    return ( length == 2 && chr[0] == '\xc2' && (chr[1] & 0xe0) == 0x80 ) ||
+           ( length == 3 && chr[0] == '\xee' && chr[1] == '\x82' && (chr[2] & 0xe0) == 0x80 );
+}
+
+/* Strips DVB control codes in-place and returns the new length.
+ * Probably not very efficient and only supports UTF-8. */
+static size_t dvb_string_strip_control_codes( char *str, size_t size )
+{
+    char *src = str, *dst = str;
+    size_t remaining = size;
+
+    if ( strcmp( psz_native_charset, "UTF-8" ) != 0 )
+    {
+        return size;
+    }
+
+    while ( remaining )
+    {
+        int char_length = mblen( src, remaining );
+        if ( char_length == 0 )
+            break;
+        if ( char_length == -1 )
+        {
+            msg_Warn( NULL, "Invalid UTF-8 in DVB string\n" );
+            break;
+        }
+        if ( !dvb_is_control_code( src, char_length ) )
+        {
+            // probably more efficient than memmove()
+            switch ( char_length )
+            {
+            case 4:
+                *dst++ = *src++;
+            case 3:
+                *dst++ = *src++;
+            case 2:
+                *dst++ = *src++;
+            case 1:
+                *dst++ = *src++;
+            }
+        } else {
+            src += char_length;
+        }
+        remaining -= char_length;
+    }
+    return dst - str;
+}
+
+/* Converts a DVB string into native encoding and returns its new size. */
+static size_t dvb_string_copy( char *dest, size_t dest_max_len,
+                               const uint8_t *src, size_t src_len )
+{
+    if ( !src_len || !dest_max_len )
+        return 0;
+
+    char *dest_orig = dest;
+#ifdef HAVE_ICONV
+    const char *psz_encoding = dvb_string_get_encoding(&src, &src_len);
+
+    if ( !psz_encoding )
+        psz_encoding = psz_dvb_charset;
+
+    iconv_t p_iconv = iconv_open(psz_native_charset, psz_encoding);
+
+    size_t p_remain[2] = {src_len, dest_max_len};
+    iconv(p_iconv, (char**)&src, p_remain,
+            &dest, p_remain+1);
+
+    iconv_close(p_iconv);
+
+    size_t len = dest - dest_orig;
+#else
+    size_t len = dest_max_len < src_len ? dest_max_len : src_len;
+    memcpy(dest, src, len);
+#endif
+
+    dest_orig[len] = '\0';
+
+    len = dvb_string_strip_control_codes( dest_orig, len );
+
+    return len;
+}
+
+void sap_Init(void)
+{
+    /* required for mblen() */
+    setlocale (LC_ALL, "");
+
+    if ( g_sap_ip4_dest == -1 )
+        inet_pton(AF_INET, SAP_DEFAULT_IP4_ADDR, &g_sap_ip4_dest);
+
+    if ( g_sap_ip6_dest.s6_addr[0] == 0 )
+        inet_pton(AF_INET6, SAP_DEFAULT_IP6_ADDR, &g_sap_ip6_dest);
+
+    /* IPv4 */
+    memset(&addr4, 0, sizeof(addr4));
+    addr4.sin_addr.s_addr = g_sap_ip4_dest;
+    addr4.sin_port = htons(SAP_DPORT);
+    addr4.sin_family = AF_INET;
+
+    /* IPv6 */
+    memset(&addr6, 0, sizeof(addr6));
+    addr6.sin6_addr = g_sap_ip6_dest;
+    addr6.sin6_port = htons(SAP_DPORT);
+    addr6.sin6_family = AF_INET6;
+
+    /* setting starttime */
+    sap_time = i_wallclock;
+}
+
+void sap_Announce(void)
+{
+    /* no output, so no announcements */
+    if ( i_nb_outputs <= 0 ) return;
+
+    /* See if we need to send the announcements */
+    if ( i_wallclock < sap_time ) return;
+
+    /* Set the timer for next time
+     *
+     * Normally we add the interval to the previous time so that if one
+     * dump is a bit late, the next one still occurs at the correct time.
+     * However, if there is a long gap (e.g. because the channel has
+     * stopped for some time), then just rebase the timing to the current
+     * time.  I've chosen SAP_INTERVAL as the long gap - this is arbitary */
+    if ( i_wallclock > sap_time + g_sap_interval * 1000000ll )
+    {
+       msg_Dbg(NULL, "SAP is %ld seconds late - reset timing\n", (i_wallclock - sap_time) / 1000000);
+       sap_time = i_wallclock;
+    }
+    sap_time += g_sap_interval*1000000ll/i_nb_outputs;
+
+    /* switching to the next output stream */
+    if ( ++i_next_output >= i_nb_outputs ) i_next_output = 0;
+    output_t *p_output = pp_outputs[i_next_output];
+
+    char psz_session_addr[INET6_ADDRSTRLEN] = ""; /* IP of session (i.e. not the SAP stream!) */
+    char psz_session_port[6] = "";                /* port of session */
+    int i_mtu = p_output->config.i_mtu;
+    int i_fam = p_output->config.i_family;
+    struct sockaddr_storage local_addr;
+    socklen_t i_local_addr_len = sizeof(local_addr);
+    char psz_fqdn[NI_MAXHOST] = "";
+    struct addrinfo *ai_list, *ai, hints = { .ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM };
+
+    /* Get multicast group address of the DVB stream to be announced */
+    getnameinfo( (struct sockaddr*) &p_output->config.connect_addr, sizeof(struct sockaddr_storage),
+                 psz_session_addr, sizeof(psz_session_addr),
+                 psz_session_port, sizeof(psz_session_port),
+                 NI_NUMERICHOST | NI_NUMERICSERV );
+
+    /* Get local address of the DVB streaming socket */
+    getsockname( p_output->i_handle, (struct sockaddr*) &local_addr, &i_local_addr_len );
+
+    /* Get local FQDN (or IP as string) */
+    gethostname( psz_fqdn, sizeof(psz_fqdn) );
+    getaddrinfo( psz_fqdn, NULL, &hints, &ai_list );
+    for ( ai = ai_list; ai; ai = ai->ai_next )
+    {
+        if ( !getnameinfo( ai->ai_addr, ai->ai_addrlen, psz_fqdn, sizeof(psz_fqdn), NULL, 0, 0 ) )
+        {
+            /* success */
+            break;
+        }
+    }
+    if ( !ai )
+    {
+        msg_Err( NULL, "Are you even connected to a network?" );
+        exit( EXIT_FAILURE );
+    }
+    freeaddrinfo( ai_list );
+
+    uint16_t i_sid = 0;            /* service id of this stream */
+    const uint8_t *p_service = 0;  /* name of service */
+    uint8_t i_service_len = 0;
+    uint8_t i_service_type = 0;    /* type of service (see ETSI EN 300 468 table 86) */
+    const uint8_t *p_event = 0;    /* name of event */
+    uint8_t i_event_len = 0;
+    const uint8_t *p_text = 0;     /* long description of event */
+    uint8_t i_text_len = 0;
+
+    /* Parsing SDT */
+    int j = 0, k = 0;
+    uint8_t *p_sdt = p_output->p_sdt_section;
+    if ( p_sdt )
+    {
+        uint8_t *sdtn;
+        while ( (sdtn = sdt_get_service( p_sdt, k++ )) != NULL )
+        {
+            i_sid = sdtn_get_sid( sdtn );
+
+            /* searching for 0x48 service descriptor */
+            uint8_t *p_desc;
+            while ( (p_desc = descs_get_desc( sdtn_get_descs( sdtn ), j++ )) != NULL )
+            {
+                if ( desc_get_tag( p_desc ) == 0x48 && desc48_validate( p_desc ) )
+                {
+                    p_service = desc48_get_service( p_desc, &i_service_len );
+                    i_service_type = desc48_get_type( p_desc );
+                }
+            }
+        }
+    } else {
+        msg_Dbg( NULL, "not announcing SAP until we get a SDT" );
+        return;
+    }
+
+    /* Parsing EIT_EPG */
+    j = 0, k = 0;
+    uint8_t *p_eit = p_output->p_eit_epg_section;
+    if ( p_eit )
+    {
+        uint8_t *eitn;
+        while ( (eitn = eit_get_event(p_eit, k++)) != NULL )
+        {
+            uint8_t *p_desc;
+            while ( (p_desc = descs_get_desc( eitn_get_descs(eitn), j++ )) != NULL )
+            {
+                if ( desc_get_tag( p_desc ) == 0x4d && desc4d_validate( p_desc ) )
+                {
+                    p_event = desc4d_get_event_name( p_desc, &i_event_len );
+                    p_text = desc4d_get_text( p_desc, &i_text_len );
+                }
+            }
+        }
+    }
+
+    /* constructing the SAP/SDP package */
+    char buffer[i_mtu];
+    char *worker = buffer;
+    char *worker_end = buffer+i_mtu;
+    int addr_len = i_fam == AF_INET6 ? 16 : 4;
+
+    /* create the SAP header
+     *
+     * Byte 0: V version number v1&v2     = 001      (3 bits)
+     *         A address type   IPv4/IPv6 = 0/1      (1 bit)
+     *         R reserved                 = 0        (1 bit)
+     *         T message type   ann/del   = 0/1      (1 bit)
+     *         E encryption     off/on    = 0/1      (1 bit)
+     *         C compressed     off/on    = 0/1      (1 bit)
+     */
+
+    /*            VVVARTEC  (announces only, not encrypted, not compressed) */
+    worker[0] = 0b00100000;
+    worker[0] |= !!(i_fam == AF_INET6) << 4;
+
+    /* Byte 1 : Authentification length - Not supported */
+    worker[1] = 0x00;
+
+    /* Bytes 2-3 : Message Id Hash */
+    worker[2] = (i_sid>>8) & 0xff;
+    worker[3] = i_sid & 0xff;
+    worker += 4;
+
+    /* Bytes 4-7 (or 4-19) byte: Originating source */
+    if ( i_fam == AF_INET6 )
+        memcpy(worker, &((struct sockaddr_in6*) &local_addr)->sin6_addr, addr_len);
+    else
+        memcpy(worker, &((struct sockaddr_in*) &local_addr)->sin_addr, addr_len);
+    worker += addr_len;
+
+    /* finally MIME type */
+    worker += snprintf(worker, worker_end-worker, "application/sdp");
+    worker[0] = 0;
+    worker++;
+
+    /* and the SDP payload */
+    worker += snprintf(worker, worker_end-worker,
+                       "v=0\r\n"
+                       "o=- %d 1 IN %s %s\r\n"
+                       "s=", i_sid, i_fam == AF_INET6 ? "IP6" : "IP4", psz_fqdn);
+    worker += dvb_string_copy(worker, worker_end-worker, p_service, i_service_len);
+    if ( i_event_len )
+    {
+        worker += snprintf(worker, worker_end-worker, " [");
+        worker += dvb_string_copy(worker, worker_end-worker, p_event, i_event_len);
+        worker += snprintf(worker, worker_end-worker, "]");
+    }
+    worker += snprintf(worker, worker_end-worker,
+                       "\r\n"
+                       "i=");
+    worker += dvb_string_copy(worker, worker_end-worker, p_text, i_text_len);
+    worker += snprintf(worker, worker_end-worker,
+                       "\r\n"
+                       "u=http://www.videolan.org/projects/dvblast.html\r\n");
+    if ( i_fam == AF_INET6 )
+    {
+        worker += snprintf(worker, worker_end-worker,
+                       "c=IN IP6 %s\r\n",
+                       psz_session_addr);
+    }
+    else
+    {
+        worker += snprintf(worker, worker_end-worker,
+                       "c=IN IP4 %s/%d\r\n",
+                       psz_session_addr, p_output->config.i_ttl);
+    }
+    const char *service_type;
+    switch (i_service_type)
+    {
+    case 1:  service_type = "Television"; break;
+    case 2:  service_type = "Radio";      break;
+    default: service_type = "Unknown";    break;
+    }
+    worker += snprintf(worker, worker_end-worker,
+                       "t=0 0\r\n"
+                       "a=tool:dvblast %s (%s)\r\n"
+                       "a=type:broadcast\r\n" /* implies a=recvonly */
+                       "a=charset:%s\r\n"
+                       /* now the media-level: */
+                       "m=video %s RTP/AVP 33\r\n" /* FIXME: other parts of dvblast also support sending raw UDP */
+//                       "i=Media Title\r\n" // maybe put the description here?
+                       "a=cat:%s\r\n"
+//                       "a=rtpmap:33 MP2T/90000\r\n" // we don't need this because 33 is a standardized RTP type
+//                       "a=lang:de\r\n"
+                       , VERSION, VERSION_EXTRA, psz_native_charset, psz_session_port, service_type);
+
+    /* sending this announcement */
+    if ( (i_fam == AF_INET  && sendto( p_output->i_handle, buffer, worker-buffer, 0,
+                (struct sockaddr*) &addr4, sizeof(addr4)) < 0) ||
+         (i_fam == AF_INET6 && sendto( p_output->i_handle, buffer, worker-buffer, 0,
+                (struct sockaddr*) &addr6, sizeof(addr6)) < 0 ))
+    {
+        msg_Err( NULL, "couldn't send to %d (%s)",
+                 i_sap_handle, strerror(errno) );
+    }
+}
+
+void sap_Close(void)
+{
+    if ( i_sap_handle >= 0 )
+	close( i_sap_handle );
+}
diff --git a/sap.h b/sap.h
new file mode 100644
index 0000000..0251fc1
--- /dev/null
+++ b/sap.h
@@ -0,0 +1,48 @@
+/*****************************************************************************
+ * sap.h SAP Announcements generated from SDT
+ *****************************************************************************
+ * Copyright (C) 2012 VideoLAN
+ *
+ * Author:  Dirk Braunschweiger <dirkmb@selfnet.de>
+ *          Markus Wick         <markus@selfnet.de>
+ *          Tillmann Karras     <tillmann@selfnet.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef SAP_H
+#define SAP_H
+
+// Define the dump period in seconds
+extern unsigned int g_sap_interval;
+
+/* The IP multicast addresses to be used for SAP announcements.
+ * See RFC 2974 section 3 and RFC 2365 sections 6-7.
+ *
+ * IPv4: always the highest address of the admin scope
+ * IPv6: always ff0x::2:7ffe where x denotes the admin scope
+ */
+extern in_addr_t g_sap_ip4_dest;
+extern struct in6_addr g_sap_ip6_dest;
+
+#define SAP_DEFAULT_IP4_ADDR "239.195.255.255"
+#define SAP_DEFAULT_IP6_ADDR "ff08::2:7ffe"
+#define SAP_DPORT 9875
+
+void sap_Init(void);
+void sap_Announce(void);
+void sap_Close(void);
+
+#endif