/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */ /* * Copyright (c) Xerox Corporation 1997. All rights reserved. * * 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 St, Fifth Floor, Boston, MA 02110-1301 USA * * Linking this file statically or dynamically with other modules is making * a combined work based on this file. Thus, the terms and conditions of * the GNU General Public License cover the whole combination. * * In addition, as a special exception, the copyright holders of this file * give you permission to combine this file with free software programs or * libraries that are released under the GNU LGPL and with code included in * the standard release of ns-2 under the Apache 2.0 license or under * otherwise-compatible licenses with advertising requirements (or modified * versions of such code, with unchanged license). You may copy and * distribute such a system following the terms of the GNU GPL for this * file and the licenses of the other code concerned, provided that you * include the source code of that other code when and as the GNU GPL * requires distribution of source code. * * Note that people who make modified versions of this file are not * obligated to grant this special exception for their modified versions; * it is their choice whether to do so. The GNU General Public License * gives permission to release a modified version without this exception; * this exception also makes it possible to release a modified version * which carries forward this exception. */ /* * Copyright (c) 1995 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the Network Research * Group at Lawrence Berkeley National Laboratory. * 4. Neither the name of the University nor of the Laboratory may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE */ #ifndef lint static const char rcsid[] = "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/apps/vatrcvr.cc,v 1.7 2005/08/26 05:05:28 tomh Exp $"; #endif #ifndef WIN32 #include #endif #include "agent.h" #include "rtp.h" #include "adaptive-receiver.h" #include "vat.h" //Most of this code is taken from the decoder.cc file of the publicly available //vat code with some minor midifications. class VatRcvr : public AdaptiveRcvr { public: VatRcvr(); protected: int adapt(Packet *pkt, u_int32_t time); void count(int statno); u_int32_t hostoffset_; int32_t var_; //variance in this host's interarrival time u_int32_t playout_; // playout delay (in media units) int maxdel_; int block_size_; int lecture_mode_; u_int32_t lastrecv_; u_int32_t predicted_drop_; int delvar_; /*XXX*/ #define MAXSTAT 16 struct statcntr { const char* name; u_int cnt; } stat_[MAXSTAT]; int nstat_; }; inline void VatRcvr::count(int statno) { ++stat_[statno].cnt; } inline int absdiff(int x, int y) { register int r = y - x; return (r < 0? -r : r); } static inline int newoffset( int nvar, int playout, int maxdel, int mindel, int lecture) { register int offset = nvar; if (offset > maxdel) offset = maxdel; register int diff = playout - offset; if (diff > 0) { // offset going down: in LectureMode, drop at most // one frametime per talkspurt. In ConferenceMode, // drop at most 1/2 of difference. if (lecture) { if (diff > FRAMESIZE) { if (playout > (maxdel * 3) / 4 && diff > 10 * FRAMESIZE) diff = 5 * FRAMESIZE; else diff = FRAMESIZE; } } else diff >>= 1; offset = playout - diff; } else if (-diff > maxdel) { // offset going way up: only allow 3/4 of max. offset = (maxdel * 3) / 4; } if (offset > (maxdel * 7) / 8) offset = (maxdel * 7) / 8; else if (offset < mindel) offset = mindel; return (offset); } int VatRcvr::adapt(Packet *pkt, u_int32_t local_clock) { hdr_cmn* ch = hdr_cmn::access(pkt); register u_int32_t tstamp = (int)ch->timestamp(); register int hoff = (int)hostoffset_; register int offset = (tstamp + hoff - local_clock) &~ 3; hdr_rtp *rh = hdr_rtp::access(pkt); int new_ts = rh->flags() & RTP_M ; //struct timeval tv; //static long int last; /* printf("%1d %10d %10d\n", new_ts ? 1: 0, tstamp, local_clock);*/ /* printf("%u\n", tstamp); */ //gettimeofday(&tv, NULL); //last = tv.tv_usec - last; //if (last < 0) // last += 1000000; /* printf("%u %u %u ==> %d\n", tstamp, hoff, local_clock, offset); printf("%u %d\n", tv.tv_usec, last); */ //last = tv.tv_usec; /* printf("%u ==> %d\n", local_clock, offset); */ if (hoff == 0 || new_ts) { /* if (hoff == 0) { */ /* printf("TS: var = %d playback = %d", var_ >> (VAR_FILTER + 3), playout_ >> (PLAYO_FILTER + 3)); */ /* * start of new talk spurt -- * use accumulated variance to compute new offset if * this would make a significant change. We change if * - the variance is currently 'small', or * - the change would be a least a packet time */ register int nvar = var_ >> (VAR_FILTER - VAR_MULT); offset = playout_ >> PLAYO_FILTER; if (nvar < 3*FRAMESIZE || absdiff(nvar, offset) >= FRAMESIZE) { offset = newoffset(nvar, offset, maxdel_, block_size_, lecture_mode_); /* * assume that a talk spurt starts with TALK_LEAD * samples of history & subtract them off if possible. */ /* CHANGED THIS PART OF VAT CODE AS WELL */ if (new_ts) { offset -= 4 * FRAMESIZE; if (offset < block_size_) offset = block_size_; } } hostoffset_ = local_clock - tstamp + offset; /* printf(" new playback = %d\n", offset >> 3); */ } else if (offset < 0 || offset > maxdel_) { /* printf("LP: late by %d var = %d playback = %d", (0 - (offset >> 3)), var_ >> (VAR_FILTER + 3), playout_ >> (PLAYO_FILTER + 3)); */ /* * packet out of range -- if last packet also out of * range or if the delay would increase, resync. */ if (offset < 0 || predicted_drop_ == tstamp) { offset = newoffset(var_ >> (VAR_FILTER - VAR_MULT), playout_ >> PLAYO_FILTER, maxdel_, block_size_, lecture_mode_); hostoffset_ = local_clock - tstamp + offset; } else { /* printf("late packet\n"); */ predicted_drop_ = tstamp + block_size_; lastrecv_ = tstamp - local_clock; count(STAT_LATE); return (-1); } /* printf(" new playback = %d\n", offset >> 3); */ } else { // packet in range, update interarrival var. est. register int nvar = var_; register int off = tstamp - local_clock - lastrecv_; /* printf("offset = %3d", off >> 3); */ if (off < 0) off = -off; off -= (nvar >> VAR_FILTER); var_ = nvar + off; /* printf(" var = %3d", var_ >> 8); */ } lastrecv_ = tstamp - local_clock; register u_int avgplay = playout_; playout_ = avgplay + (offset - (avgplay >> PLAYO_FILTER)); /* printf(" offset = %3d avg playout = %3d", offset >> 3, playout_ >> 8); */ offset &= ~3; delvar_ = var_ >> VAR_FILTER; /* printf("\n"); */ return (offset); } static class VatRcvrClass : public TclClass { public: VatRcvrClass() : TclClass("Agent/VatRcvr") {} TclObject* create(int, const char*const*) { return (new VatRcvr()); } } class_vat_rcvr; VatRcvr::VatRcvr() : hostoffset_(0), var_(INITIAL_OFFSET << (VAR_FILTER - VAR_MULT)), playout_(INITIAL_OFFSET << PLAYO_FILTER), maxdel_(8000*6), block_size_(FRAMESIZE), lecture_mode_(0), lastrecv_(0), predicted_drop_(~0), nstat_(0) { for (int i = 0; i < MAXSTAT; ++i) { stat_[i].name = 0; stat_[i].cnt = 0; } stat_[STAT_LATE].name = "Late-Pkts"; nstat_ = 1; }