* modules/control/netsync.c: Experimental network synchronisation module.

configure.ac

@@ -883,7 +883,7 @@ test "${enable_cprof}" != "yes" && enable_cprof="no"
 dnl
 dnl  default modules
 dnl
-AX_ADD_PLUGINS([dummy rc telnet logger gestures memcpy hotkeys])
+AX_ADD_PLUGINS([dummy rc telnet logger gestures memcpy hotkeys netsync])
 AX_ADD_PLUGINS([mpgv mpga m4v h264 mpeg_system ps ps2 pva ts avi asf aac mp4 rawdv demux2 nsv real aiff mjpeg])
 AX_ADD_PLUGINS([cvdsub svcdsub spudec dvbsub mpeg_audio lpcm a52 dts cinepak])
 AX_ADD_PLUGINS([deinterlace invert adjust wall transform distort clone crop motionblur])

modules/control/Modules.am

 SOURCES_gestures = gestures.c
 SOURCES_http = http.c
 SOURCES_telnet = telnet.c
+SOURCES_netsync = netsync.c
 SOURCES_ntservice = ntservice.c
 SOURCES_joystick = joystick.c
 SOURCES_hotkeys = hotkeys.c

modules/control/netsync.c

+/*****************************************************************************
+ * netsync.c: synchronisation between several network clients.
+ *****************************************************************************
+ * Copyright (C) 2004 VideoLAN
+ * $Id: ntservice.c 6963 2004-03-05 19:24:14Z murray $
+ *
+ * Authors: Gildas Bazin <gbazin@videolan.org>
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <stdlib.h>
+#include <vlc/vlc.h>
+#include <vlc/intf.h>
+
+#ifdef HAVE_UNISTD_H
+#    include <unistd.h>
+#endif
+
+#ifdef HAVE_SYS_TIME_H
+#    include <sys/time.h>
+#endif
+#include <sys/types.h>
+
+#ifdef WIN32
+#   include <winsock2.h>
+#   include <ws2tcpip.h>
+#   ifndef IN_MULTICAST
+#       define IN_MULTICAST(a) IN_CLASSD(a)
+#   endif
+#else
+#   include <sys/socket.h>
+#   include <netinet/in.h>
+#   if HAVE_ARPA_INET_H
+#      include <arpa/inet.h>
+#   elif defined( SYS_BEOS )
+#      include <net/netdb.h>
+#   endif
+#endif
+
+#ifdef UNDER_CE
+#   define close(a) CloseHandle(a);
+#elif defined( WIN32 )
+#   define close(a) closesocket(a);
+#endif
+
+#include "network.h"
+#include "input_ext-plugins.h"
+
+#define NETSYNC_PORT_MASTER 9875
+#define NETSYNC_PORT_SLAVE  9876
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+static int  Activate( vlc_object_t * );
+static void Close   ( vlc_object_t * );
+
+static mtime_t GetClockRef( intf_thread_t *, mtime_t );
+
+#define NETSYNC_TEXT N_( "Act as master for network synchronisation" )
+#define NETSYNC_LONGTEXT N_( "Allows you to specify if this client should " \
+  "act as the master client for the network synchronisation." )
+
+#define MIP_TEXT N_( "Master client ip address" )
+#define MIP_LONGTEXT N_( "Allows you to specify the ip address of " \
+  "the master client used for the network synchronisation." )
+
+vlc_module_begin();
+    set_description( _("Network synchronisation") );
+
+    add_bool( "netsync-master", 0, NULL,
+              NETSYNC_TEXT, NETSYNC_LONGTEXT, VLC_TRUE );
+    add_string( "netsync-master-ip", NULL, NULL, MIP_TEXT, MIP_LONGTEXT,
+                VLC_TRUE );
+
+    set_capability( "interface", 0 );
+    set_callbacks( Activate, Close );
+vlc_module_end();
+
+struct intf_sys_t
+{
+    input_thread_t *p_input;
+};
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static void Run( intf_thread_t *p_intf );
+
+/*****************************************************************************
+ * Activate: initialize and create stuff
+ *****************************************************************************/
+static int Activate( vlc_object_t *p_this )
+{
+    intf_thread_t *p_intf = (intf_thread_t*)p_this;
+
+    msg_Info( p_intf, "Using the netsync interface module..." );
+
+    p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
+
+    p_intf->pf_run = Run;
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Close: destroy interface
+ *****************************************************************************/
+void Close( vlc_object_t *p_this )
+{
+    intf_thread_t *p_intf = (intf_thread_t*)p_this;
+
+    free( p_intf->p_sys );
+}
+
+/*****************************************************************************
+ * Run: interface thread
+ *****************************************************************************/
+static void Run( intf_thread_t *p_intf )
+{
+#define MAX_MSG_LENGTH (2 * sizeof(int64_t))
+
+    vlc_bool_t b_master = config_GetInt( p_intf, "netsync-master" );
+    char *psz_master = config_GetPsz( p_intf, "netsync-master-ip" );
+    struct sockaddr_in master_addr;
+    char p_data[MAX_MSG_LENGTH];
+    int i_socket;
+
+    if( !psz_master || inet_addr( psz_master ) == INADDR_NONE )
+    {
+        if( psz_master ) free( psz_master );
+        msg_Err( p_intf, "invalid master address." );
+        return;
+    }
+
+    memset( &master_addr, 0, sizeof( struct sockaddr_in ) );
+    master_addr.sin_family = AF_INET;
+    master_addr.sin_port = htons( (uint16_t)NETSYNC_PORT_MASTER );
+    master_addr.sin_addr.s_addr = inet_addr( psz_master );
+    free( psz_master );
+
+    i_socket = net_OpenUDP( p_intf, NULL, b_master ? NETSYNC_PORT_MASTER :
+                            NETSYNC_PORT_SLAVE, NULL, 0 );
+    if( i_socket < 0 )
+    {
+        msg_Err( p_intf, "failed opening UDP socket." );
+        return;
+    }
+
+    /* High priority thread */
+    vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT );
+
+    while( !p_intf->b_die )
+    {
+        struct timeval  timeout;
+        fd_set fds_r;
+
+        /* Update the input */
+        if( p_intf->p_sys->p_input == NULL )
+        {
+            p_intf->p_sys->p_input =
+                (input_thread_t *)vlc_object_find( p_intf, VLC_OBJECT_INPUT,
+                                                   FIND_ANYWHERE );
+        }
+        else if( p_intf->p_sys->p_input->b_dead )
+        {
+            vlc_object_release( p_intf->p_sys->p_input );
+            p_intf->p_sys->p_input = NULL;
+        }
+
+        if( p_intf->p_sys->p_input == NULL )
+        {
+            /* Wait a bit */
+            msleep( INTF_IDLE_SLEEP );
+            continue;
+        }
+
+        /*
+         * We now have an input
+         */
+
+        /* Initialize file descriptor set and timeout (0.5s) */
+        FD_ZERO( &fds_r );
+        FD_SET( i_socket, &fds_r );
+        timeout.tv_sec = 0;
+        timeout.tv_usec = 500000;
+
+        if( b_master )
+        {
+            struct sockaddr_in from;
+            mtime_t i_date, i_clockref, i_master_clockref;
+            int i_struct_size, i_read, i_ret;
+
+            /* Don't block */
+            i_ret = select( i_socket + 1, &fds_r, 0, 0, &timeout );
+            if( i_ret == 0 ) continue;
+            if( i_ret < 0 )
+            {
+                /* Wait a bit */
+                msleep( INTF_IDLE_SLEEP );
+                continue;
+            }
+
+            /* We received something */
+            i_struct_size = sizeof(struct sockaddr_in);
+            i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0,
+                               (struct sockaddr*)&from, &i_struct_size );
+
+            from.sin_port = htons( (uint16_t)NETSYNC_PORT_SLAVE );
+
+            i_clockref = ntoh64(*(int64_t *)p_data);
+
+            i_date = mdate();
+            *(int64_t *)p_data = hton64( i_date );
+
+            i_master_clockref = GetClockRef( p_intf, i_clockref );
+            *(((int64_t *)p_data)+1) = hton64( i_master_clockref );
+
+            /* Reply to the sender */
+            sendto( i_socket, p_data, 2 * sizeof(int64_t), 0,
+                    (struct sockaddr *)&from, sizeof(struct sockaddr_in) );
+
+            msg_Dbg( p_intf, "Master clockref: "I64Fd" -> "I64Fd", from %s "
+                     "(date: "I64Fd")", i_clockref, i_master_clockref, 
+                     inet_ntoa(from.sin_addr), i_date );
+        }
+        else
+        {
+            mtime_t i_send_date, i_receive_date, i_master_date, i_diff_date;
+            mtime_t i_master_clockref, i_client_clockref, i_drift;
+            mtime_t i_clockref = 0;
+            int i_sent, i_read, i_ret;
+
+            /* Send clock request to the master */
+            *(int64_t *)p_data = hton64( i_clockref );
+            i_send_date = mdate();
+
+            i_sent = sendto( i_socket, p_data, sizeof(int64_t), 0,
+                             (struct sockaddr *)&master_addr,
+                             sizeof(struct sockaddr_in) );
+            if( i_sent <= 0 )
+            {
+                /* Wait a bit */
+                msleep( INTF_IDLE_SLEEP );
+                continue;
+            }
+
+            /* Don't block */
+            i_ret = select(i_socket + 1, &fds_r, 0, 0, &timeout);
+            if( i_ret == 0 ) continue;
+            if( i_ret < 0 )
+            {
+                /* Wait a bit */
+                msleep( INTF_IDLE_SLEEP );
+                continue;
+            }
+
+            i_receive_date = mdate();
+
+            i_read = recv( i_socket, p_data, MAX_MSG_LENGTH, 0 );
+            if( i_read <= 0 )
+            {
+                /* Wait a bit */
+                msleep( INTF_IDLE_SLEEP );
+                continue;
+            }
+
+            i_master_date = ntoh64(*(int64_t *)p_data);
+            i_master_clockref = ntoh64(*(((int64_t *)p_data)+1));
+
+            i_diff_date = i_receive_date -
+                          ((i_receive_date - i_send_date) / 2 + i_master_date);
+
+            i_client_clockref = i_drift = 0;
+            if( p_intf->p_sys->p_input && i_master_clockref )
+            {
+                i_client_clockref = GetClockRef( p_intf, i_clockref );
+                i_drift = i_client_clockref - i_master_clockref - i_diff_date;
+
+                /* Update our clock to match the master's one */
+                if( i_client_clockref )
+                    p_intf->p_sys->p_input->i_pts_delay -= i_drift;
+            }
+
+            msg_Dbg( p_intf, "Slave clockref: "I64Fd" -> "I64Fd" -> "I64Fd", "
+                     "clock diff: "I64Fd" drift: "I64Fd,
+                     i_clockref, i_master_clockref, 
+                     i_client_clockref, i_diff_date, i_drift );
+
+            /* Wait a bit */
+            msleep( INTF_IDLE_SLEEP );
+        }
+    }
+
+    if( p_intf->p_sys->p_input ) vlc_object_release( p_intf->p_sys->p_input );
+    net_Close( i_socket );
+}
+
+static mtime_t GetClockRef( intf_thread_t *p_intf, mtime_t i_pts )
+{
+    input_thread_t *p_input = p_intf->p_sys->p_input;
+    pgrm_descriptor_t *p_pgrm;
+
+    if( !p_input ) return 0;
+
+    p_pgrm = p_input->stream.p_selected_program;
+    if( p_pgrm ) return input_ClockGetTS( p_input, p_pgrm, i_pts );
+
+    return 0;
+}