netsync.c 10 KB
Newer Older
1 2 3
/*****************************************************************************
 * netsync.c: synchronisation between several network clients.
 *****************************************************************************
4
 * Copyright (C) 2004 the VideoLAN team
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
 * $Id$
 *
 * 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
Antoine Cellerier's avatar
Antoine Cellerier committed
21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 23 24 25 26 27 28 29
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>
#include <vlc/vlc.h>
#include <vlc/intf.h>
30
#include <vlc/input.h>
31 32 33 34 35 36 37

#ifdef HAVE_UNISTD_H
#    include <unistd.h>
#endif
#ifdef HAVE_SYS_TIME_H
#    include <sys/time.h>
#endif
38 39
#ifdef HAVE_SYS_TYPES_H
#   include <sys/types.h>
40 41 42 43
#endif

#include "network.h"

44
#define NETSYNC_PORT 9875
45 46 47 48 49 50 51 52 53 54 55 56 57 58

/* Needed for Solaris */
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Activate( vlc_object_t * );
static void Close   ( vlc_object_t * );

static mtime_t GetClockRef( intf_thread_t *, mtime_t );

Clément Stenac's avatar
Clément Stenac committed
59
/// \bug [String] This string is BAD.
60 61 62
#define NETSYNC_TEXT N_( "Act as master" )
#define NETSYNC_LONGTEXT N_( "Should " \
  "act as the master client for the network synchronisation?" )
63

Clément Stenac's avatar
Clément Stenac committed
64
/// \bug [String] This string is BAD.
65
#define MIP_TEXT N_( "Master client ip address" )
66
#define MIP_LONGTEXT N_( "IP address of " \
67 68 69
  "the master client used for the network synchronisation." )

vlc_module_begin();
70
    set_shortname( _("Network Sync"));
71
    set_description( _("Network synchronisation") );
72 73
    set_category( CAT_ADVANCED );
    set_subcategory( SUBCAT_ADVANCED_MISC );
74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131

    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;

    p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
    if( !p_intf->p_sys )
    {
        msg_Err( p_intf, "no memory" );
        return VLC_ENOMEM;
    }

    p_intf->p_sys->p_input = NULL;

    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" );
132
    char *psz_master = NULL;
133 134 135 136 137 138 139 140 141 142 143 144 145
    char p_data[MAX_MSG_LENGTH];
    int i_socket;

    if( !b_master )
    {
        psz_master = config_GetPsz( p_intf, "netsync-master-ip" );
        if( psz_master == NULL )
        {
            msg_Err( p_intf, "master address not specified" );
            return;
        }
    }

146
    if( b_master )
147
        i_socket = net_ListenUDP1( p_intf, NULL, NETSYNC_PORT );
148 149
    else
        i_socket = net_ConnectUDP( p_intf, psz_master, NETSYNC_PORT, 0 );
150 151

    if( psz_master ) free( psz_master );
152 153 154

    if( i_socket < 0 )
    {
155
        msg_Err( p_intf, "failed opening UDP socket" ); /* str review: is this good enough? */
156 157 158 159 160 161
        return;
    }

    /* High priority thread */
    vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT );

162
    while( !intf_ShouldDie( p_intf ) )
163
    {
164
        struct timeval timeout;
165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215
        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_storage 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( from );
            i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0,
216
                               (struct sockaddr*)&from,
217
                               (unsigned int *)&i_struct_size );
218 219 220 221 222 223 224 225 226 227 228 229 230

            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, i_struct_size );

231
#if 0
232 233 234 235 236
            msg_Dbg( p_intf, "Master clockref: "I64Fd" -> "I64Fd", from %s "
                     "(date: "I64Fd")", i_clockref, i_master_clockref,
                     from.ss_family == AF_INET
                     ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
                     : "non-IPv4", i_date );
237
#endif
238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294
        }
        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 = send( i_socket, p_data, sizeof(int64_t), 0 );
            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;
            }

295
#if 0
296 297
            msg_Dbg( p_intf, "Slave clockref: "I64Fd" -> "I64Fd" -> "I64Fd", "
                     "clock diff: "I64Fd" drift: "I64Fd,
298
                     i_clockref, i_master_clockref,
299
                     i_client_clockref, i_diff_date, i_drift );
300
#endif
301 302 303 304 305 306 307 308 309 310 311 312 313

            /* 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;
314
    mtime_t i_ts;
315

316
    if( !p_input || !p_input->p_es_out ) return 0;
317

318 319 320 321 322
    if( es_out_Control( p_input->p_es_out, ES_OUT_GET_TS, i_pts, &i_ts ) ==
        VLC_SUCCESS )
    {
        return i_ts;
    }
323 324 325

    return 0;
}