common/netjack.c

   1
   2 /* -*- mode: c; c-file-style: "linux"; -*- */
   3 /*
   4 NetJack Abstraction.
   5
   6 Copyright (C) 2008 Pieter Palmers <pieterpalmers@users.sourceforge.net>
   7 Copyright (C) 2006 Torben Hohn <torbenh@gmx.de>
   8 Copyright (C) 2003 Robert Ham <rah@bash.sh>
   9 Copyright (C) 2001 Paul Davis
  10
  11 This program is free software; you can redistribute it and/or modify
  12 it under the terms of the GNU General Public License as published by
  13 the Free Software Foundation; either version 2 of the License, or
  14 (at your option) any later version.
  15
  16 This program is distributed in the hope that it will be useful,
  17 but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 GNU General Public License for more details.
  20
  21 You should have received a copy of the GNU General Public License
  22 along with this program; if not, write to the Free Software
  23 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 $Id: net_driver.c,v 1.17 2006/04/16 20:16:10 torbenh Exp $
  26 */
  27
  28
  29 #include <math.h>
  30 #include <stdio.h>
  31 #include <memory.h>
  32 #include <unistd.h>
  33 #include <stdlib.h>
  34 #include <errno.h>
  35 #include <stdarg.h>
  36
  37 #include <jack/types.h>
  38 #include "jack/jslist.h"
  39
  40 #include <sys/types.h>
  41
  42 #ifdef WIN32
  43 #include <winsock.h>
  44 #include <malloc.h>
  45 #else
  46 #include <sys/socket.h>
  47 #include <netinet/in.h>
  48 #endif
  49
  50 #include "netjack.h"
  51
  52 //#include "config.h"
  53
  54 #if HAVE_SAMPLERATE
  55 #include <samplerate.h>
  56 #endif
  57
  58 #if HAVE_CELT
  59 #include <celt/celt.h>
  60 #endif
  61
  62 #include "netjack.h"
  63 #include "netjack_packet.h"
  64
  65 // JACK2
  66 #include "jack/control.h"
  67
  68 #define MIN(x,y) ((x)<(y) ? (x) : (y))
  69
  70 static int sync_state = 1;
  71 static jack_transport_state_t last_transport_state;
  72
  73 static int
  74 net_driver_sync_cb(jack_transport_state_t state, jack_position_t *pos, void *data)
  75 {
  76     int retval = sync_state;
  77
  78     if (state == JackTransportStarting && last_transport_state != JackTransportStarting) {
  79         retval = 0;
  80     }
  81 //    if (state == JackTransportStarting)
  82 //              jack_info("Starting sync_state = %d", sync_state);
  83     last_transport_state = state;
  84     return retval;
  85 }
  86
  87 int netjack_wait( netjack_driver_state_t *netj )
  88 {
  89     int we_have_the_expected_frame = 0;
  90     jack_nframes_t next_frame_avail;
  91     jack_time_t packet_recv_time_stamp;
  92     jacknet_packet_header *pkthdr;
  93
  94     if( !netj->next_deadline_valid ) {
  95             netj->next_deadline = jack_get_time() + netj->deadline_offset;
  96             netj->next_deadline_valid = 1;
  97     }
  98
  99     // Increment expected frame here.
 100
 101     if( netj->expected_framecnt_valid ) {
 102         netj->expected_framecnt += 1;
 103     } else {
 104         // starting up.... lets look into the packetcache, and fetch the highest packet.
 105         packet_cache_drain_socket( global_packcache, netj->sockfd );
 106         if( packet_cache_get_highest_available_framecnt( global_packcache, &next_frame_avail ) ) {
 107             netj->expected_framecnt = next_frame_avail;
 108             netj->expected_framecnt_valid = 1;
 109         } else {
 110             // no packets there... start normally.
 111             netj->expected_framecnt = 0;
 112             netj->expected_framecnt_valid = 1;
 113         }
 114
 115     }
 116
 117     //jack_log( "expect %d", netj->expected_framecnt );
 118     // Now check if required packet is already in the cache.
 119     // then poll (have deadline calculated)
 120     // then drain socket, rinse and repeat.
 121     while(1) {
 122         if( packet_cache_get_next_available_framecnt( global_packcache, netj->expected_framecnt, &next_frame_avail) ) {
 123             if( next_frame_avail == netj->expected_framecnt ) {
 124                 we_have_the_expected_frame = 1;
 125                 if( !netj->always_deadline )
 126                         break;
 127             }
 128         }
 129         if( ! netjack_poll_deadline( netj->sockfd, netj->next_deadline ) ) {
 130             break;
 131         }
 132
 133         packet_cache_drain_socket( global_packcache, netj->sockfd );
 134     }
 135
 136     // check if we know who to send our packets too.
 137     if (!netj->srcaddress_valid)
 138         if( global_packcache->master_address_valid ) {
 139             memcpy (&(netj->syncsource_address), &(global_packcache->master_address), sizeof( struct sockaddr_in ) );
 140             netj->srcaddress_valid = 1;
 141         }
 142
 143     // XXX: switching mode unconditionally is stupid.
 144     //      if we were running free perhaps we like to behave differently
 145     //      ie. fastforward one packet etc.
 146     //      well... this is the first packet we see. hmm.... dunno ;S
 147     //      it works... so...
 148     netj->running_free = 0;
 149
 150     //if( !we_have_the_expected_frame )
 151     //    jack_error( "netxrun... %d", netj->expected_framecnt );
 152
 153     if( we_have_the_expected_frame ) {
 154         netj->time_to_deadline = netj->next_deadline - jack_get_time() - netj->period_usecs;
 155         packet_cache_retreive_packet_pointer( global_packcache, netj->expected_framecnt, (char **) &(netj->rx_buf), netj->rx_bufsize , &packet_recv_time_stamp);
 156         pkthdr = (jacknet_packet_header *) netj->rx_buf;
 157         packet_header_ntoh(pkthdr);
 158         netj->deadline_goodness = (int)pkthdr->sync_state;
 159         netj->packet_data_valid = 1;
 160
 161         if( netj->deadline_goodness != MASTER_FREEWHEELS ) {
 162                 if( netj->deadline_goodness < (netj->period_usecs/4+10*(int)netj->period_usecs*netj->latency/100) ) {
 163                         netj->deadline_offset -= netj->period_usecs/100;
 164                         //jack_log( "goodness: %d, Adjust deadline: --- %d\n", netj->deadline_goodness, (int) netj->period_usecs*netj->latency/100 );
 165                 }
 166                 if( netj->deadline_goodness > (netj->period_usecs/4+10*(int)netj->period_usecs*netj->latency/100) ) {
 167                         netj->deadline_offset += netj->period_usecs/100;
 168                         //jack_log( "goodness: %d, Adjust deadline: +++ %d\n", netj->deadline_goodness, (int) netj->period_usecs*netj->latency/100 );
 169                 }
 170         }
 171         if( netj->deadline_offset < (netj->period_usecs*70/100) ) {
 172                 jack_error( "master is forcing deadline_offset to below 70%% of period_usecs... increase latency setting on master" );
 173                 netj->deadline_offset = (netj->period_usecs*90/100);
 174         }
 175
 176         netj->next_deadline = jack_get_time() + netj->deadline_offset;
 177     } else {
 178         netj->time_to_deadline = 0;
 179         netj->next_deadline = jack_get_time() + netj->deadline_offset;
 180         // bah... the packet is not there.
 181         // either
 182         // - it got lost.
 183         // - its late
 184         // - sync source is not sending anymore.
 185
 186         // lets check if we have the next packets, we will just run a cycle without data.
 187         // in that case.
 188
 189         if( packet_cache_get_next_available_framecnt( global_packcache, netj->expected_framecnt, &next_frame_avail) )
 190         {
 191             jack_nframes_t offset = next_frame_avail - netj->expected_framecnt;
 192
 193             //XXX: hmm... i need to remember why resync_threshold wasnt right.
 194             //if( offset < netj->resync_threshold )
 195             if( offset < 10 ) {
 196                 // ok. dont do nothing. we will run without data.
 197                 // this seems to be one or 2 lost packets.
 198                 //
 199                 // this can also be reordered packet jitter.
 200                 // (maybe this is not happening in real live)
 201                 //  but it happens in netem.
 202
 203                 netj->packet_data_valid = 0;
 204
 205                 // I also found this happening, when the packet queue, is too full.
 206                 // but wtf ? use a smaller latency. this link can handle that ;S
 207                 if( packet_cache_get_fill( global_packcache, netj->expected_framecnt ) > 80.0 )
 208                     netj->next_deadline -= netj->period_usecs/2;
 209
 210
 211             } else {
 212                 // the diff is too high. but we have a packet in the future.
 213                 // lets resync.
 214                 netj->expected_framecnt = next_frame_avail;
 215                 packet_cache_retreive_packet_pointer( global_packcache, netj->expected_framecnt, (char **) &(netj->rx_buf), netj->rx_bufsize, NULL );
 216                 pkthdr = (jacknet_packet_header *) netj->rx_buf;
 217                 packet_header_ntoh(pkthdr);
 218                 //netj->deadline_goodness = 0;
 219                 netj->deadline_goodness = (int)pkthdr->sync_state - (int)netj->period_usecs * offset;
 220                 netj->next_deadline_valid = 0;
 221                 netj->packet_data_valid = 1;
 222             }
 223
 224         } else {
 225             // no packets in buffer.
 226             netj->packet_data_valid = 0;
 227
 228             //printf( "frame %d No Packet in queue. num_lost_packets = %d \n", netj->expected_framecnt, netj->num_lost_packets );
 229             if( netj->num_lost_packets < 5 ) {
 230                 // ok. No Packet in queue. The packet was either lost,
 231                 // or we are running too fast.
 232                 //
 233                 // Adjusting the deadline unconditionally resulted in
 234                 // too many xruns on master.
 235                 // But we need to adjust for the case we are running too fast.
 236                 // So lets check if the last packet is there now.
 237                 //
 238                 // It would not be in the queue anymore, if it had been
 239                 // retrieved. This might break for redundancy, but
 240                 // i will make the packet cache drop redundant packets,
 241                 // that have already been retreived.
 242                 //
 243                 if( packet_cache_get_highest_available_framecnt( global_packcache, &next_frame_avail) ) {
 244                     if( next_frame_avail == (netj->expected_framecnt - 1) ) {
 245                         // Ok. the last packet is there now.
 246                         // and it had not been retrieved.
 247                         //
 248                         // TODO: We are still dropping 2 packets.
 249                         //       perhaps we can adjust the deadline
 250                         //       when (num_packets lost == 0)
 251
 252                         // This might still be too much.
 253                         netj->next_deadline += netj->period_usecs;
 254                     }
 255                 }
 256             } else if( (netj->num_lost_packets <= 100) ) {
 257                 // lets try adjusting the deadline harder, for some packets, we might have just ran 2 fast.
 258                 netj->next_deadline += netj->period_usecs*netj->latency/8;
 259             } else {
 260
 261                 // But now we can check for any new frame available.
 262                 //
 263                 if( packet_cache_get_highest_available_framecnt( global_packcache, &next_frame_avail) ) {
 264                     netj->expected_framecnt = next_frame_avail;
 265                     packet_cache_retreive_packet_pointer( global_packcache, netj->expected_framecnt, (char **) &(netj->rx_buf), netj->rx_bufsize, NULL );
 266                     pkthdr = (jacknet_packet_header *) netj->rx_buf;
 267                     packet_header_ntoh(pkthdr);
 268                     netj->deadline_goodness = pkthdr->sync_state;
 269                     netj->next_deadline_valid = 0;
 270                     netj->packet_data_valid = 1;
 271                     netj->running_free = 0;
 272                     jack_info( "resync after freerun... %d\n", netj->expected_framecnt );
 273                 } else {
 274                     if( netj->num_lost_packets == 101 ) {
 275                         jack_info( "master seems gone... entering freerun mode\n", netj->expected_framecnt );
 276                     }
 277
 278                     netj->running_free = 1;
 279
 280                     // when we really dont see packets.
 281                     // reset source address. and open possibility for new master.
 282                     // maybe dsl reconnect. Also restart of netsource without fix
 283                     // reply address changes port.
 284                     if (netj->num_lost_packets > 200 ) {
 285                         netj->srcaddress_valid = 0;
 286                         packet_cache_reset_master_address( global_packcache );
 287                     }
 288                 }
 289             }
 290         }
 291     }
 292
 293     int retval = 0;
 294
 295     if( !netj->packet_data_valid ) {
 296         netj->num_lost_packets += 1;
 297         if( netj->num_lost_packets == 1 )
 298             retval = netj->period_usecs;
 299     } else {
 300         if( (netj->num_lost_packets>1) && !netj->running_free )
 301             retval = (netj->num_lost_packets-1) * netj->period_usecs;
 302
 303         netj->num_lost_packets = 0;
 304     }
 305
 306     return retval;
 307 }
 308
 309 void netjack_send_silence( netjack_driver_state_t *netj, int syncstate )
 310 {
 311     int tx_size = get_sample_size(netj->bitdepth) * netj->playback_channels * netj->net_period_up + sizeof(jacknet_packet_header);
 312     unsigned int *packet_buf, *packet_bufX;
 313
 314     packet_buf = alloca( tx_size);
 315     jacknet_packet_header *tx_pkthdr = (jacknet_packet_header *)packet_buf;
 316     jacknet_packet_header *rx_pkthdr = (jacknet_packet_header *)netj->rx_buf;
 317
 318     //framecnt = rx_pkthdr->framecnt;
 319
 320     netj->reply_port = rx_pkthdr->reply_port;
 321
 322     // offset packet_bufX by the packetheader.
 323     packet_bufX = packet_buf + sizeof(jacknet_packet_header) / sizeof(jack_default_audio_sample_t);
 324
 325     tx_pkthdr->sync_state = syncstate;
 326     tx_pkthdr->framecnt = netj->expected_framecnt;
 327
 328     // memset 0 the payload.
 329     int payload_size = get_sample_size(netj->bitdepth) * netj->playback_channels * netj->net_period_up;
 330     memset(packet_bufX, 0, payload_size);
 331
 332     packet_header_hton(tx_pkthdr);
 333     if (netj->srcaddress_valid)
 334     {
 335         int r;
 336         if (netj->reply_port)
 337             netj->syncsource_address.sin_port = htons(netj->reply_port);
 338
 339         for( r=0; r<netj->redundancy; r++ )
 340             netjack_sendto(netj->outsockfd, (char *)packet_buf, tx_size,
 341                     0, (struct sockaddr*)&(netj->syncsource_address), sizeof(struct sockaddr_in), netj->mtu);
 342     }
 343 }
 344
 345
 346 void netjack_attach( netjack_driver_state_t *netj )
 347 {
 348     //puts ("net_driver_attach");
 349     jack_port_t * port;
 350     char buf[32];
 351     unsigned int chn;
 352     int port_flags;
 353
 354
 355     if (netj->handle_transport_sync)
 356         jack_set_sync_callback(netj->client, (JackSyncCallback) net_driver_sync_cb, NULL);
 357
 358     port_flags = JackPortIsOutput | JackPortIsPhysical | JackPortIsTerminal;
 359
 360     for (chn = 0; chn < netj->capture_channels_audio; chn++) {
 361         snprintf (buf, sizeof(buf) - 1, "capture_%u", chn + 1);
 362
 363         port = jack_port_register (netj->client, buf,
 364                                    JACK_DEFAULT_AUDIO_TYPE,
 365                                    port_flags, 0);
 366         if (!port) {
 367             jack_error ("NET: cannot register port for %s", buf);
 368             break;
 369         }
 370
 371         netj->capture_ports =
 372             jack_slist_append (netj->capture_ports, port);
 373
 374         if( netj->bitdepth == CELT_MODE ) {
 375 #if HAVE_CELT
 376 #if HAVE_CELT_API_0_7
 377             celt_int32 lookahead;
 378             CELTMode *celt_mode = celt_mode_create( netj->sample_rate, netj->period_size, NULL );
 379             netj->capture_srcs = jack_slist_append(netj->capture_srcs, celt_decoder_create( celt_mode, 1, NULL ) );
 380 #else
 381             celt_int32_t lookahead;
 382             CELTMode *celt_mode = celt_mode_create( netj->sample_rate, 1, netj->period_size, NULL );
 383             netj->capture_srcs = jack_slist_append(netj->capture_srcs, celt_decoder_create( celt_mode ) );
 384 #endif
 385             celt_mode_info( celt_mode, CELT_GET_LOOKAHEAD, &lookahead );
 386             netj->codec_latency = 2*lookahead;
 387 #endif
 388         } else {
 389 #if HAVE_SAMPLERATE
 390             netj->capture_srcs = jack_slist_append(netj->capture_srcs, src_new(SRC_LINEAR, 1, NULL));
 391 #endif
 392         }
 393     }
 394     for (chn = netj->capture_channels_audio; chn < netj->capture_channels; chn++) {
 395         snprintf (buf, sizeof(buf) - 1, "capture_%u", chn + 1);
 396
 397         port = jack_port_register (netj->client, buf,
 398                                    JACK_DEFAULT_MIDI_TYPE,
 399                                    port_flags, 0);
 400         if (!port) {
 401             jack_error ("NET: cannot register port for %s", buf);
 402             break;
 403         }
 404
 405         netj->capture_ports =
 406             jack_slist_append (netj->capture_ports, port);
 407     }
 408
 409     port_flags = JackPortIsInput | JackPortIsPhysical | JackPortIsTerminal;
 410
 411     for (chn = 0; chn < netj->playback_channels_audio; chn++) {
 412         snprintf (buf, sizeof(buf) - 1, "playback_%u", chn + 1);
 413
 414         port = jack_port_register (netj->client, buf,
 415                                    JACK_DEFAULT_AUDIO_TYPE,
 416                                    port_flags, 0);
 417
 418         if (!port) {
 419             jack_error ("NET: cannot register port for %s", buf);
 420             break;
 421         }
 422
 423         netj->playback_ports =
 424             jack_slist_append (netj->playback_ports, port);
 425         if( netj->bitdepth == CELT_MODE ) {
 426 #if HAVE_CELT
 427 #if HAVE_CELT_API_0_7
 428             CELTMode *celt_mode = celt_mode_create( netj->sample_rate, netj->period_size, NULL );
 429             netj->playback_srcs = jack_slist_append(netj->playback_srcs, celt_encoder_create( celt_mode, 1, NULL ) );
 430 #else
 431             CELTMode *celt_mode = celt_mode_create( netj->sample_rate, 1, netj->period_size, NULL );
 432             netj->playback_srcs = jack_slist_append(netj->playback_srcs, celt_encoder_create( celt_mode ) );
 433 #endif
 434 #endif
 435         } else {
 436 #if HAVE_SAMPLERATE
 437             netj->playback_srcs = jack_slist_append(netj->playback_srcs, src_new(SRC_LINEAR, 1, NULL));
 438 #endif
 439         }
 440     }
 441     for (chn = netj->playback_channels_audio; chn < netj->playback_channels; chn++) {
 442         snprintf (buf, sizeof(buf) - 1, "playback_%u", chn + 1);
 443
 444         port = jack_port_register (netj->client, buf,
 445                                    JACK_DEFAULT_MIDI_TYPE,
 446                                    port_flags, 0);
 447
 448         if (!port) {
 449             jack_error ("NET: cannot register port for %s", buf);
 450             break;
 451         }
 452
 453         netj->playback_ports =
 454             jack_slist_append (netj->playback_ports, port);
 455     }
 456
 457     jack_activate (netj->client);
 458 }
 459
 460
 461 void netjack_detach( netjack_driver_state_t *netj )
 462 {
 463     JSList * node;
 464
 465
 466     for (node = netj->capture_ports; node; node = jack_slist_next (node))
 467         jack_port_unregister (netj->client,
 468                               ((jack_port_t *) node->data));
 469
 470     jack_slist_free (netj->capture_ports);
 471     netj->capture_ports = NULL;
 472
 473     for (node = netj->playback_ports; node; node = jack_slist_next (node))
 474         jack_port_unregister (netj->client,
 475                               ((jack_port_t *) node->data));
 476
 477     jack_slist_free (netj->playback_ports);
 478     netj->playback_ports = NULL;
 479 }
 480
 481
 482 netjack_driver_state_t *netjack_init (netjack_driver_state_t *netj,
 483                 jack_client_t * client,
 484                 const char *name,
 485                 unsigned int capture_ports,
 486                 unsigned int playback_ports,
 487                 unsigned int capture_ports_midi,
 488                 unsigned int playback_ports_midi,
 489                 jack_nframes_t sample_rate,
 490                 jack_nframes_t period_size,
 491                 unsigned int listen_port,
 492                 unsigned int transport_sync,
 493                 unsigned int resample_factor,
 494                 unsigned int resample_factor_up,
 495                 unsigned int bitdepth,
 496                 unsigned int use_autoconfig,
 497                 unsigned int latency,
 498                 unsigned int redundancy,
 499                 int dont_htonl_floats,
 500                 int always_deadline)
 501 {
 502
 503     // Fill in netj values.
 504     // might be subject to autoconfig...
 505     // so dont calculate anything with them...
 506
 507
 508     netj->sample_rate = sample_rate;
 509     netj->period_size = period_size;
 510     netj->dont_htonl_floats = dont_htonl_floats;
 511
 512     netj->listen_port   = listen_port;
 513
 514     netj->capture_channels  = capture_ports + capture_ports_midi;
 515     netj->capture_channels_audio  = capture_ports;
 516     netj->capture_channels_midi   = capture_ports_midi;
 517     netj->capture_ports     = NULL;
 518     netj->playback_channels = playback_ports + playback_ports_midi;
 519     netj->playback_channels_audio = playback_ports;
 520     netj->playback_channels_midi = playback_ports_midi;
 521     netj->playback_ports    = NULL;
 522     netj->codec_latency = 0;
 523
 524     netj->handle_transport_sync = transport_sync;
 525     netj->mtu = 1400;
 526     netj->latency = latency;
 527     netj->redundancy = redundancy;
 528     netj->use_autoconfig = use_autoconfig;
 529     netj->always_deadline = always_deadline;
 530
 531
 532     netj->client = client;
 533
 534
 535     if ((bitdepth != 0) && (bitdepth != 8) && (bitdepth != 16) && (bitdepth != CELT_MODE))
 536     {
 537         jack_info ("Invalid bitdepth: %d (8, 16 or 0 for float) !!!", bitdepth);
 538         return NULL;
 539     }
 540     netj->bitdepth = bitdepth;
 541
 542
 543     if (resample_factor_up == 0)
 544         resample_factor_up = resample_factor;
 545
 546     netj->resample_factor = resample_factor;
 547     netj->resample_factor_up = resample_factor_up;
 548
 549
 550     return netj;
 551 }
 552
 553 void netjack_release( netjack_driver_state_t *netj )
 554 {
 555     close( netj->sockfd );
 556     close( netj->outsockfd );
 557
 558     packet_cache_free( global_packcache );
 559     global_packcache = NULL;
 560 }
 561
 562 int
 563 netjack_startup( netjack_driver_state_t *netj )
 564 {
 565     int first_pack_len;
 566     struct sockaddr_in address;
 567     // Now open the socket, and wait for the first packet to arrive...
 568     netj->sockfd = socket (AF_INET, SOCK_DGRAM, 0);
 569 #ifdef WIN32
 570     if (netj->sockfd == INVALID_SOCKET)
 571 #else
 572     if (netj->sockfd == -1)
 573 #endif
 574     {
 575         jack_info ("socket error");
 576         return -1;
 577     }
 578     address.sin_family = AF_INET;
 579     address.sin_port = htons(netj->listen_port);
 580     address.sin_addr.s_addr = htonl(INADDR_ANY);
 581     if (bind (netj->sockfd, (struct sockaddr *) &address, sizeof (address)) < 0)
 582     {
 583         jack_info("bind error");
 584         return -1;
 585     }
 586
 587     netj->outsockfd = socket (AF_INET, SOCK_DGRAM, 0);
 588 #ifdef WIN32
 589     if (netj->outsockfd == INVALID_SOCKET)
 590 #else
 591     if (netj->outsockfd == -1)
 592 #endif
 593     {
 594         jack_info ("socket error");
 595         return -1;
 596     }
 597     netj->srcaddress_valid = 0;
 598     if (netj->use_autoconfig)
 599     {
 600         jacknet_packet_header *first_packet = alloca (sizeof (jacknet_packet_header));
 601 #ifdef WIN32
 602     int address_size = sizeof( struct sockaddr_in );
 603 #else
 604         socklen_t address_size = sizeof (struct sockaddr_in);
 605 #endif
 606         //jack_info ("Waiting for an incoming packet !!!");
 607         //jack_info ("*** IMPORTANT *** Dont connect a client to jackd until the driver is attached to a clock source !!!");
 608
 609     while(1) {
 610     first_pack_len = recvfrom (netj->sockfd, (char *)first_packet, sizeof (jacknet_packet_header), 0, (struct sockaddr*) & netj->syncsource_address, &address_size);
 611 #ifdef WIN32
 612         if( first_pack_len == -1 ) {
 613             first_pack_len = sizeof(jacknet_packet_header);
 614             break;
 615         }
 616 #else
 617         if (first_pack_len == sizeof (jacknet_packet_header))
 618             break;
 619 #endif
 620     }
 621         netj->srcaddress_valid = 1;
 622
 623         if (first_pack_len == sizeof (jacknet_packet_header))
 624         {
 625             packet_header_ntoh (first_packet);
 626
 627             jack_info ("AutoConfig Override !!!");
 628             if (netj->sample_rate != first_packet->sample_rate)
 629             {
 630                 jack_info ("AutoConfig Override: Master JACK sample rate = %d", first_packet->sample_rate);
 631                 netj->sample_rate = first_packet->sample_rate;
 632             }
 633
 634             if (netj->period_size != first_packet->period_size)
 635             {
 636                 jack_info ("AutoConfig Override: Master JACK period size is %d", first_packet->period_size);
 637                 netj->period_size = first_packet->period_size;
 638             }
 639             if (netj->capture_channels_audio != first_packet->capture_channels_audio)
 640             {
 641                 jack_info ("AutoConfig Override: capture_channels_audio = %d", first_packet->capture_channels_audio);
 642                 netj->capture_channels_audio = first_packet->capture_channels_audio;
 643             }
 644             if (netj->capture_channels_midi != first_packet->capture_channels_midi)
 645             {
 646                 jack_info ("AutoConfig Override: capture_channels_midi = %d", first_packet->capture_channels_midi);
 647                 netj->capture_channels_midi = first_packet->capture_channels_midi;
 648             }
 649             if (netj->playback_channels_audio != first_packet->playback_channels_audio)
 650             {
 651                 jack_info ("AutoConfig Override: playback_channels_audio = %d", first_packet->playback_channels_audio);
 652                 netj->playback_channels_audio = first_packet->playback_channels_audio;
 653             }
 654             if (netj->playback_channels_midi != first_packet->playback_channels_midi)
 655             {
 656                 jack_info ("AutoConfig Override: playback_channels_midi = %d", first_packet->playback_channels_midi);
 657                 netj->playback_channels_midi = first_packet->playback_channels_midi;
 658             }
 659
 660             netj->mtu = first_packet->mtu;
 661             jack_info ("MTU is set to %d bytes", first_packet->mtu);
 662             netj->latency = first_packet->latency;
 663         }
 664     }
 665     netj->capture_channels  = netj->capture_channels_audio + netj->capture_channels_midi;
 666     netj->playback_channels = netj->playback_channels_audio + netj->playback_channels_midi;
 667
 668     // After possible Autoconfig: do all calculations...
 669     netj->period_usecs =
 670         (jack_time_t) floor ((((float) netj->period_size) / (float)netj->sample_rate)
 671                              * 1000000.0f);
 672
 673     if( netj->latency == 0 )
 674         netj->deadline_offset = 50*netj->period_usecs;
 675     else
 676         netj->deadline_offset = netj->period_usecs + 10*netj->latency*netj->period_usecs/100;
 677
 678     if( netj->bitdepth == CELT_MODE ) {
 679         // celt mode.
 680         // TODO: this is a hack. But i dont want to change the packet header.
 681         netj->net_period_down = netj->resample_factor;
 682         netj->net_period_up = netj->resample_factor_up;
 683     } else {
 684         netj->net_period_down = (float) netj->period_size / (float) netj->resample_factor;
 685         netj->net_period_up = (float) netj->period_size / (float) netj->resample_factor_up;
 686     }
 687
 688     netj->rx_bufsize = sizeof (jacknet_packet_header) + netj->net_period_down * netj->capture_channels * get_sample_size (netj->bitdepth);
 689     netj->pkt_buf = malloc (netj->rx_bufsize);
 690     global_packcache = packet_cache_new (netj->latency + 50, netj->rx_bufsize, netj->mtu);
 691
 692     netj->expected_framecnt_valid = 0;
 693     netj->num_lost_packets = 0;
 694     netj->next_deadline_valid = 0;
 695     netj->deadline_goodness = 0;
 696     netj->time_to_deadline = 0;
 697
 698     // Special handling for latency=0
 699     if( netj->latency == 0 )
 700         netj->resync_threshold = 0;
 701     else
 702         netj->resync_threshold = MIN( 15, netj->latency-1 );
 703
 704     netj->running_free = 0;
 705
 706     return 0;
 707 }