root/branches/streaming-rework/src/libstreaming/MotuStreamProcessor.cpp

/* $Id$ */

/*
 *   FreeBob Streaming API
 *   FreeBob = Firewire (pro-)audio for linux
 *
 *   http://freebob.sf.net
 *
 *   Copyright (C) 2005,2006 Pieter Palmers <pieterpalmers@users.sourceforge.net>
 *   Copyright (C) 2006 Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
 *
 *   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * 
 *
 */
#include "MotuStreamProcessor.h"
#include "Port.h"
#include "MotuPort.h"

#include <math.h>

#include <netinet/in.h>

#include "cycletimer.h"

// in ticks
#define TRANSMIT_TRANSFER_DELAY 6000U
// the number of cycles to send a packet in advance of it's timestamp
#define TRANSMIT_ADVANCE_CYCLES 1U

namespace FreebobStreaming {

IMPL_DEBUG_MODULE( MotuTransmitStreamProcessor, MotuTransmitStreamProcessor, DEBUG_LEVEL_NORMAL );
IMPL_DEBUG_MODULE( MotuReceiveStreamProcessor, MotuReceiveStreamProcessor, DEBUG_LEVEL_NORMAL );

// Set to 1 to enable the generation of a 1 kHz test tone in analog output 1
#define TESTTONE 1

// A macro to extract specific bits from a native endian quadlet
#define get_bits(_d,_start,_len) (((_d)>>((_start)-(_len)+1)) & ((1<<(_len))-1))

/* transmit */
MotuTransmitStreamProcessor::MotuTransmitStreamProcessor(int port, int framerate,
                unsigned int event_size)
        : TransmitStreamProcessor(port, framerate), m_event_size(event_size),
        m_tx_dbc(0),
        m_closedown_count(-1), m_streaming_active(0) {
}

MotuTransmitStreamProcessor::~MotuTransmitStreamProcessor() {

}

bool MotuTransmitStreamProcessor::init() {

        debugOutput( DEBUG_LEVEL_VERBOSE, "Initializing (%p)...\n");
        // call the parent init
        // this has to be done before allocating the buffers, 
        // because this sets the buffersizes from the processormanager
        if(!TransmitStreamProcessor::init()) {
                debugFatal("Could not do base class init (%p)\n",this);
                return false;
        }

        return true;
}

void MotuTransmitStreamProcessor::setVerboseLevel(int l) {
        setDebugLevel(l); // sets the debug level of the current object
        TransmitStreamProcessor::setVerboseLevel(l); // also set the level of the base class
}


enum raw1394_iso_disposition
MotuTransmitStreamProcessor::getPacket(unsigned char *data, unsigned int *length,
                      unsigned char *tag, unsigned char *sy,
                      int cycle, unsigned int dropped, unsigned int max_length) {

// FIXME: the actual delays in the system need to be worked out so
// we can get this thing synchronised.  For now this seems to work.
    uint64_t ts_head, fc;

        quadlet_t *quadlet = (quadlet_t *)data;
        signed int i;
        
    m_last_cycle=cycle;
    
    // determine if we want to send a packet or not
    // note that we can't use getCycleTimer directly here,
    // because packets are queued in advance. This means that
    // we the packet we are constructing will be sent out 
    // on 'cycle', not 'now'.
    unsigned int ctr=m_handler->getCycleTimer();
    int now_cycles = (int)CYCLE_TIMER_GET_CYCLES(ctr);
    
    // the difference between the cycle this
    // packet is intended for and 'now'
    int cycle_diff = substractCycles(cycle, now_cycles);
    
        // Signal that streaming is still active
        m_streaming_active = 1;

    // as long as the cycle parameter is not in sync with
    // the current time, the stream is considered not
    // to be 'running'
    // NOTE: this works only at startup
    if (!m_running && cycle_diff >= 0 && cycle != -1) {
            debugOutput(DEBUG_LEVEL_VERBOSE, "Xmit StreamProcessor %p started running at cycle %d\n",this, cycle);
            m_running=true;
    }

    if (!m_disabled && m_is_disabled) {
        // this means that we are trying to enable
        if ((unsigned int)cycle == m_cycle_to_enable_at) {
            m_is_disabled=false;
            
            debugOutput(DEBUG_LEVEL_VERBOSE,"Enabling StreamProcessor %p at %u\n", this, cycle);
            
            // initialize the buffer head & tail
            m_SyncSource->m_data_buffer->getBufferHeadTimestamp(&ts_head, &fc); // thread safe
            
            // the number of cycles the sync source lags (> 0)
            // or leads (< 0)
            int sync_lag_cycles=substractCycles(cycle, m_SyncSource->getLastCycle());
            
            // account for the cycle lag between sync SP and this SP
            // the last update of the sync source's timestamps was sync_lag_cycles
            // cycles before the cycle we are calculating the timestamp for.
            // if we were to use one-frame buffers, you would expect the 
            // frame that is sent on cycle CT to have a timestamp T1.
            // ts_head however is for cycle CT-sync_lag_cycles, and lies
            // therefore sync_lag_cycles * TICKS_PER_CYCLE earlier than
            // T1.
            ts_head = addTicks(ts_head, sync_lag_cycles * TICKS_PER_CYCLE);
            
            m_data_buffer->setBufferTailTimestamp(ts_head);
            
            #ifdef DEBUG
            if ((unsigned int)m_data_buffer->getFrameCounter() != m_data_buffer->getBufferSize()) {
                debugWarning("m_data_buffer->getFrameCounter() != m_data_buffer->getBufferSize()\n");
            }
            #endif
            debugOutput(DEBUG_LEVEL_VERBOSE,"XMIT TS SET: TS=%10lld, LAG=%03d, FC=%4d\n",
                            ts_head, sync_lag_cycles, m_data_buffer->getFrameCounter());
        } else {
            debugOutput(DEBUG_LEVEL_VERY_VERBOSE,
                        "will enable StreamProcessor %p at %u, now is %d\n",
                        this, m_cycle_to_enable_at, cycle);
        }
    } else if (m_disabled && !m_is_disabled) {
        // trying to disable
        debugOutput(DEBUG_LEVEL_VERBOSE,"disabling StreamProcessor %p at %u\n", 
                    this, cycle);
        m_is_disabled=true;
    }

        // Do housekeeping expected for all packets sent to the MOTU, even
        // for packets containing no audio data.
        *sy = 0x00;
        *tag = 1;      // All MOTU packets have a CIP-like header


    // the base timestamp is the one of the next sample in the buffer
    m_data_buffer->getBufferHeadTimestamp(&ts_head, &fc); // thread safe
    
    int64_t timestamp = ts_head;

    // we send a packet some cycles in advance, to avoid the
    // following situation:
    // suppose we are only a few ticks away from 
    // the moment to send this packet. therefore we decide
    // not to send the packet, but send it in the next cycle.
    // This means that the next time point will be 3072 ticks
    // later, making that the timestamp will be expired when the 
    // packet is sent, unless TRANSFER_DELAY > 3072.
    // this means that we need at least one cycle of extra buffering.
    uint64_t ticks_to_advance = TICKS_PER_CYCLE * TRANSMIT_ADVANCE_CYCLES;
    
    // if cycle lies cycle_diff cycles in the future, we should
    // queue this packet cycle_diff * TICKS_PER_CYCLE earlier than
    // we would if it were to be sent immediately.
    ticks_to_advance += cycle_diff * TICKS_PER_CYCLE;

    // determine the 'now' time in ticks
    uint64_t cycle_timer=CYCLE_TIMER_TO_TICKS(ctr);
    
    // time until the packet is to be sent (if > 0: send packet)
    int64_t until_next=substractTicks(timestamp, cycle_timer + ticks_to_advance);
    
        // Size of a single data frame in quadlets
        unsigned dbs = m_event_size / 4;
        
    // don't process the stream when it is not enabled, not running
    // or when the next sample is not due yet.
    if((until_next>0) || m_is_disabled || !m_running) {
        // send dummy packet
        
        // construct the packet CIP-like header.  Even if this is a data-less 
        // packet the dbs field is still set as if there were data blocks 
        // present.  For data-less packets the dbc is the same as the previously
        // transmitted block.
        *quadlet = htonl(0x00000400 | ((getNodeId()&0x3f)<<24) | m_tx_dbc | (dbs<<16));
        quadlet++;
        *quadlet = htonl(0x8222ffff);
        quadlet++;
        *length = 8;
        
        #warning high-pitched sound protection removed!
        // In the disabled state simply zero all data sent to the MOTU.  If
        // a stream of empty packets are sent once iso streaming is enabled
        // the MOTU tends to emit high-pitched audio (approx 10 kHz) for
        // some reason.  This is not completely sufficient, however (zeroed
        // packets must also be sent on iso closedown).
    
        // FIXME: Currently we simply send empty packets to the MOTU when
        // the stream is disabled so the "m_disabled == 0" code is never
        // executed.  However, this may change in future so it's left in 
        // for the moment for reference.
        // FIXME: Currently we don't read the buffer at all during closedown.
        // We could (and silently junk the contents) if it turned out to be
        // more helpful.
        
        return RAW1394_ISO_DEFER;
    }

        // The number of events expected by the MOTU is solely dependent on
        // the current sample rate.  An 'event' is one sample from all channels
        // plus possibly other midi and control data.
        signed n_events = m_framerate<=48000?8:(m_framerate<=96000?16:32);

    // add the transmit transfer delay to construct the playout time
    uint64_t ts=addTicks(timestamp, TRANSMIT_TRANSFER_DELAY);
    
    if (m_data_buffer->readFrames(n_events, (char *)(data + 8))) {
    
        // Increment the dbc (data block count).  This is only done if the
        // packet will contain events - that is, we are due to send some
        // data.  Otherwise a pad packet is sent which contains the DBC of
        // the previously sent packet.  This regime also means that the very
        // first packet containing data will have a DBC of n_events, which
        // matches what is observed from other systems.
        m_tx_dbc += n_events;
        if (m_tx_dbc > 0xff)
            m_tx_dbc -= 0x100;
    
        // construct the packet CIP-like header.  Even if this is a data-less 
        // packet the dbs field is still set as if there were data blocks 
        // present.  For data-less packets the dbc is the same as the previously
        // transmitted block.
        *quadlet = htonl(0x00000400 | ((getNodeId()&0x3f)<<24) | m_tx_dbc | (dbs<<16));
        quadlet++;
        *quadlet = htonl(0x8222ffff);
        quadlet++;

        *length = n_events*m_event_size + 8;

        // convert the timestamp to Motu format
        // I assume that it is in ticks, and wraps as the cycle timer
        #warning syt conversion to be done
        
                // FIXME: if we choose to read the buffer even during closedown,
                // here is where the data is silenced.
                //   if (m_closedown_count >= 0)
                //     memset(data+8, 0, read_size);
                if (m_closedown_count > 0)
                        m_closedown_count--;

                // Set up each frames's SPH.  Note that the (int) typecast
                // appears to do rounding.

float ticks_per_frame = m_SyncSource->m_data_buffer->getRate();
                for (i=0; i<n_events; i++, quadlet += dbs) {
                        unsigned int ts_frame = ts;
                        ts_frame += (unsigned int)((float)i * ticks_per_frame);
                        *quadlet = htonl( TICKS_TO_CYCLE_TIMER(ts_frame) );
                }

                // Process all ports that should be handled on a per-packet base
                // this is MIDI for AMDTP (due to the need of DBC, which is lost 
                // when putting the events in the ringbuffer)
                // for motu this might also be control data, however as control
                // data isn't time specific I would also include it in the period
                // based processing
        
                // FIXME: m_tx_dbc probably needs to be initialised to a non-zero
                // value somehow so MIDI sync is possible.  For now we ignore
                // this issue.
                if (!encodePacketPorts((quadlet_t *)(data+8), n_events, m_tx_dbc)) {
                        debugWarning("Problem encoding Packet Ports\n");
                }

        return RAW1394_ISO_OK;
        
    } else if (now_cycles<cycle) {
        // we can still postpone the queueing of the packets
        return RAW1394_ISO_AGAIN;
    } else { // there is no more data in the ringbuffer

        debugWarning("Transmit buffer underrun (now %d, queue %d, target %d)\n", 
                 now_cycles, cycle, TICKS_TO_CYCLES(ts));

        // signal underrun
        m_xruns++;

        // disable the processing, will be re-enabled when
        // the xrun is handled
        m_disabled=true;
        m_is_disabled=true;

        // compose a no-data packet, we should always
        // send a valid packet
        
        // send dummy packet
        
        // construct the packet CIP-like header.  Even if this is a data-less 
        // packet the dbs field is still set as if there were data blocks 
        // present.  For data-less packets the dbc is the same as the previously
        // transmitted block.
        *quadlet = htonl(0x00000400 | ((getNodeId()&0x3f)<<24) | m_tx_dbc | (dbs<<16));
        quadlet++;
        *quadlet = htonl(0x8222ffff);
        quadlet++;
        *length = 8;

        return RAW1394_ISO_DEFER;
    }

    // we shouldn't get here
    return RAW1394_ISO_ERROR;

}

int MotuTransmitStreamProcessor::getMinimalSyncDelay() {
    return 0;
}

bool MotuTransmitStreamProcessor::prefill() {
        // this is needed because otherwise there is no data to be 
        // sent when the streaming starts
    
        int i = m_nb_buffers;
        while (i--) {
                if(!transferSilence(m_period)) {
                        debugFatal("Could not prefill transmit stream\n");
                        return false;
                }
        }
        return true;
}

bool MotuTransmitStreamProcessor::reset() {

        debugOutput( DEBUG_LEVEL_VERBOSE, "Resetting...\n");

    // we have to make sure that the buffer HEAD timestamp
    // lies in the future for every possible buffer fill case.
    int offset=(int)(m_data_buffer->getBufferSize()*m_ticks_per_frame);
    
    // we can substract the delay as it introduces
    // unnescessary delay
    offset -= m_SyncSource->getSyncDelay();
    
    m_data_buffer->setTickOffset(offset);
    
        // reset all non-device specific stuff
        // i.e. the iso stream and the associated ports
        if (!TransmitStreamProcessor::reset()) {
                debugFatal("Could not do base class reset\n");
                return false;
        }

        // we should prefill the event buffer
        if (!prefill()) {
                debugFatal("Could not prefill buffers\n");
                return false;    
        }

        return true;
}

bool MotuTransmitStreamProcessor::prepare() {
    
        debugOutput( DEBUG_LEVEL_VERBOSE, "Preparing...\n");
    
        // prepare all non-device specific stuff
        // i.e. the iso stream and the associated ports
        if (!TransmitStreamProcessor::prepare()) {
                debugFatal("Could not prepare base class\n");
                return false;
        }

        m_PeriodStat.setName("XMT PERIOD");
        m_PacketStat.setName("XMT PACKET");
        m_WakeupStat.setName("XMT WAKEUP");

        debugOutput( DEBUG_LEVEL_VERBOSE, "Event size: %d\n", m_event_size);
    
        // allocate the event buffer
        unsigned int ringbuffer_size_frames=m_nb_buffers * m_period;

    // allocate the internal buffer
    float ticks_per_frame = (TICKS_PER_SECOND*1.0) / ((float)m_framerate);
        unsigned int events_per_frame = m_framerate<=48000?8:(m_framerate<=96000?16:32);

    assert(m_data_buffer);    
    m_data_buffer->setBufferSize(ringbuffer_size_frames);
    m_data_buffer->setEventSize(m_event_size/events_per_frame);
    m_data_buffer->setEventsPerFrame(events_per_frame);
    
    m_data_buffer->setUpdatePeriod(m_period);
    m_data_buffer->setNominalRate(ticks_per_frame);
    
    // FIXME: check if the timestamp wraps at one second
    m_data_buffer->setWrapValue(TICKS_PER_SECOND);
    
    m_data_buffer->prepare();

        // Set the parameters of ports we can: we want the audio ports to be
        // period buffered, and the midi ports to be packet buffered.
        for ( PortVectorIterator it = m_Ports.begin();
          it != m_Ports.end();
          ++it ) {
                debugOutput(DEBUG_LEVEL_VERBOSE, "Setting up port %s\n",(*it)->getName().c_str());
                if(!(*it)->setBufferSize(m_period)) {
                        debugFatal("Could not set buffer size to %d\n",m_period);
                        return false;
                }

                switch ((*it)->getPortType()) {
                case Port::E_Audio:
                        if (!(*it)->setSignalType(Port::E_PeriodSignalled)) {
                                debugFatal("Could not set signal type to PeriodSignalling");
                                return false;
                        }
                        break;

                case Port::E_Midi:
                        if (!(*it)->setSignalType(Port::E_PacketSignalled)) {
                                debugFatal("Could not set signal type to PacketSignalling");
                                return false;
                        }
                        if (!(*it)->setBufferType(Port::E_RingBuffer)) {
                                debugFatal("Could not set buffer type");
                                return false;
                        }
                        if (!(*it)->setDataType(Port::E_MidiEvent)) {
                                debugFatal("Could not set data type");
                                return false;
                        }
                        // FIXME: probably need rate control too.  See
                        // Port::useRateControl() and AmdtpStreamProcessor.
                        break;
                
                case Port::E_Control:
                        if (!(*it)->setSignalType(Port::E_PeriodSignalled)) {
                                debugFatal("Could not set signal type to PeriodSignalling");
                                return false;
                        }
                        break;

                default:
                        debugWarning("Unsupported port type specified\n");
                        break;
                }
        }

        // The API specific settings of the ports are already set before
        // this routine is called, therefore we can init&prepare the ports
        if (!initPorts()) {
                debugFatal("Could not initialize ports!\n");
                return false;
        }

        if(!preparePorts()) {
                debugFatal("Could not initialize ports!\n");
                return false;
        }

        return true;
}

bool MotuTransmitStreamProcessor::prepareForStop() {

        // If the stream is disabled or isn't running there's no need to
        // wait since the MOTU *should* still be in a "zero data" state.
        //
        // If the m_streaming_active flag is 0 it indicates that the
        // transmit callback hasn't been called since a closedown was
        // requested when this function was last called.  This effectively
        // signifies that the streaming thread has been exitted due to an
        // xrun in either the receive or transmit handlers.  In this case
        // there's no point in waiting for the closedown count to hit zero
        // because it never will; the zero data will never get to the MOTU. 
        // It's best to allow an immediate stop and let the xrun handler
        // proceed as best it can.
        //
        // The ability to detect the lack of streaming also prevents the
        // "wait for stop" in the stream processor manager's stop() method
        // from hitting its timeout which in turn seems to increase the
        // probability of a successful recovery.
        if (m_is_disabled || !isRunning() || !m_streaming_active)
                return true;

        if (m_closedown_count < 0) {
                // No closedown has been initiated, so start one now.  Set
                // the closedown count to the number of zero packets which
                // will be sent to the MOTU before closing off the iso
                // streams.  FIXME: 128 packets (each containing 8 frames at
                // 48 kHz) is the experimentally-determined figure for 48
                // kHz with a period size of 1024.  It seems that at least
                // one period of zero samples need to be sent to allow for
                // inter-thread communication occuring on period boundaries. 
                // This needs to be confirmed for other rates and period
                // sizes.
                signed n_events = m_framerate<=48000?8:(m_framerate<=96000?16:32);
                m_closedown_count = m_period / n_events;

                // Set up a test to confirm that streaming is still active.
                // If the streaming function hasn't been called by the next
                // iteration through this function there's no point in
                // continuing since it means the zero data will never get to 
                // the MOTU.
                m_streaming_active = 0;
                return false;
        }

        // We are "go" for closedown once all requested zero packets
        // (initiated by a previous call to this function) have been sent to
        // the MOTU.
        return m_closedown_count == 0;
}

bool MotuTransmitStreamProcessor::prepareForStart() {
// Reset some critical variables required so the stream starts cleanly. This
// method is called once on every stream restart. Initialisations which should 
// be done once should be placed in the init() method instead.
        m_running = 0;
        m_closedown_count = -1;
        m_streaming_active = 0;

        // At this point we'll also disable the stream processor here.
        // At this stage stream processors are always explicitly re-enabled
        // after being started, so by starting in the disabled state we 
        // ensure that every start will be exactly the same.
        disable();

        return true;
}

bool MotuTransmitStreamProcessor::prepareForEnable(uint64_t time_to_enable_at) {

    debugOutput(DEBUG_LEVEL_VERBOSE,"Preparing to enable...\n");

    // for the transmit SP, we have to initialize the 
    // buffer timestamp to something sane, because this timestamp
    // is used when it is SyncSource
    
    // the time we initialize to will determine the time at which
    // the first sample in the buffer will be sent, so we should
    // make it at least 'time_to_enable_at'
    
    uint64_t now=m_handler->getCycleTimer();
    unsigned int now_secs=CYCLE_TIMER_GET_SECS(now);
    
    // check if a wraparound on the secs will happen between
    // now and the time we start
    if (CYCLE_TIMER_GET_CYCLES(now)>time_to_enable_at) {
        // the start will happen in the next second
        now_secs++;
        if (now_secs>=128) now_secs=0;
    }
    
//    uint64_t ts_head= now_secs*TICKS_PER_SECOND;
    uint64_t ts_head = time_to_enable_at*TICKS_PER_CYCLE;
    
    // we also add the nb of cycles we transmit in advance
    ts_head=addTicks(ts_head, TRANSMIT_ADVANCE_CYCLES*TICKS_PER_CYCLE);
    
    m_data_buffer->setBufferTailTimestamp(ts_head);


    if (!StreamProcessor::prepareForEnable(time_to_enable_at)) {
        debugError("StreamProcessor::prepareForEnable failed\n");
        return false;
    }

    return true;
}

bool MotuTransmitStreamProcessor::transferSilence(unsigned int size) {
    bool retval;
    
        // This function should tranfer 'size' frames of 'silence' to the event buffer
        char *dummybuffer=(char *)calloc(size,m_event_size);

        transmitSilenceBlock(dummybuffer, size, 0);

    // add the silence data to the ringbuffer
    if(m_data_buffer->writeFrames(size, dummybuffer, 0)) { 
        retval=true;
    } else {
        debugWarning("Could not write to event buffer\n");
        retval=false;
    }

        free(dummybuffer);

        return retval;
}

bool MotuTransmitStreamProcessor::putFrames(unsigned int nbframes, int64_t ts) {
    m_PeriodStat.mark(m_data_buffer->getBufferFill());
    
    debugOutput(DEBUG_LEVEL_VERY_VERBOSE, "MotuTransmitStreamProcessor::putFrames(%d, %llu)\n", nbframes, ts);
    
    // transfer the data
    m_data_buffer->blockProcessWriteFrames(nbframes, ts);

    debugOutput(DEBUG_LEVEL_VERY_VERBOSE, " New timestamp: %llu\n", ts);

    return true;
}

/* 
 * write received events to the stream ringbuffers.
 */

bool MotuTransmitStreamProcessor::processWriteBlock(char *data, 
                       unsigned int nevents, unsigned int offset) {
        bool no_problem=true;
        unsigned int i;

        // FIXME: ensure the MIDI and control streams are all zeroed until
        // such time as they are fully implemented.
        for (i=0; i<nevents; i++) {
                memset(data+4+i*m_event_size, 0x00, 6);
        }

        for ( PortVectorIterator it = m_PeriodPorts.begin();
          it != m_PeriodPorts.end();
          ++it ) {
                // If this port is disabled, don't process it
                if((*it)->isDisabled()) {continue;};
        
                //FIXME: make this into a static_cast when not DEBUG?
                Port *port=dynamic_cast<Port *>(*it);
                
                switch(port->getPortType()) {
                
                case Port::E_Audio:
                        if (encodePortToMotuEvents(static_cast<MotuAudioPort *>(*it), (quadlet_t *)data, offset, nevents)) {
                                debugWarning("Could not encode port %s to MBLA events",(*it)->getName().c_str());
                                no_problem=false;
                        }
                        break;
                // midi is a packet based port, don't process
                //      case MotuPortInfo::E_Midi:
                //              break;

                default: // ignore
                        break;
                }
        }
        return no_problem;
}

int MotuTransmitStreamProcessor::transmitSilenceBlock(char *data, 
                       unsigned int nevents, unsigned int offset) {
        // This is the same as the non-silence version, except that is
        // doesn't read from the port buffers.

        int problem=0;

        for ( PortVectorIterator it = m_PeriodPorts.begin();
          it != m_PeriodPorts.end();
          ++it ) {
                //FIXME: make this into a static_cast when not DEBUG?
                Port *port=dynamic_cast<Port *>(*it);
                
                switch(port->getPortType()) {
                
                case Port::E_Audio:
                        if (encodeSilencePortToMotuEvents(static_cast<MotuAudioPort *>(*it), (quadlet_t *)data, offset, nevents)) {
                                debugWarning("Could not encode port %s to MBLA events",(*it)->getName().c_str());
                                problem=1;
                        }
                        break;
                // midi is a packet based port, don't process
                //      case MotuPortInfo::E_Midi:
                //              break;

                default: // ignore
                        break;
                }
        }
        return problem;
}

/**
 * @brief decode a packet for the packet-based ports
 *
 * @param data Packet data
 * @param nevents number of events in data (including events of other ports & port types)
 * @param dbc DataBlockCount value for this packet
 * @return true if all successfull
 */
bool MotuTransmitStreamProcessor::encodePacketPorts(quadlet_t *data, unsigned int nevents, 
                unsigned int dbc) {
        bool ok=true;
        char byte;

        // Use char here since the target address won't necessarily be
        // aligned; use of an unaligned quadlet_t may cause issues on
        // certain architectures.  Besides, the target for MIDI data going
        // directly to the MOTU isn't structured in quadlets anyway; it is a
        // sequence of 3 unaligned bytes.
        unsigned char *target = NULL;

        for ( PortVectorIterator it = m_PacketPorts.begin();
                it != m_PacketPorts.end();
                ++it ) {

                Port *port=static_cast<Port *>(*it);
                assert(port); // this should not fail!!

                // Currently the only packet type of events for MOTU 
                // is MIDI in mbla.  However in future control data
                // might also be sent via "packet" events.
                // assert(pinfo->getFormat()==MotuPortInfo::E_Midi);

                // FIXME: MIDI output is completely untested at present.
                switch (port->getPortType()) {
                        case Port::E_Midi: {
                                MotuMidiPort *mp=static_cast<MotuMidiPort *>(*it);

                                // Send a byte if we can. MOTU MIDI data is
                                // sent using a 3-byte sequence starting at
                                // the port's position.  For now we'll
                                // always send in the first event of a
                                // packet, but this might need refinement
                                // later.
                                if (mp->canRead()) {
                                        mp->readEvent(&byte);
                                        target = (unsigned char *)data + mp->getPosition();
                                        *(target++) = 0x01;
                                        *(target++) = 0x00;
                                        *(target++) = byte;
                                }
                                break;
                        }
                        default:
                                debugOutput(DEBUG_LEVEL_VERBOSE, "Unknown packet-type port type %d\n",port->getPortType());
                                return ok;        
                }
        }

        return ok;
}

int MotuTransmitStreamProcessor::encodePortToMotuEvents(MotuAudioPort *p, quadlet_t *data, 
                       unsigned int offset, unsigned int nevents) {
// Encodes nevents worth of data from the given port into the given buffer.  The
// format of the buffer is precisely that which will be sent to the MOTU.
// The basic idea:
//   iterate over the ports
//     * get port buffer address
//     * loop over events
//         - pick right sample in event based upon PortInfo
//         - convert sample from Port format (E_Int24, E_Float, ..) to MOTU
//           native format
//
// We include the ability to start the transfer from the given offset within
// the port (expressed in frames) so the 'efficient' transfer method can be
// utilised.

        unsigned int j=0;

        // Use char here since the target address won't necessarily be 
        // aligned; use of an unaligned quadlet_t may cause issues on certain
        // architectures.  Besides, the target (data going directly to the MOTU)
        // isn't structured in quadlets anyway; it mainly consists of packed
        // 24-bit integers.
        unsigned char *target;
        target = (unsigned char *)data + p->getPosition();

        switch(p->getDataType()) {
                default:
                case Port::E_Int24:
                        {
                                quadlet_t *buffer=(quadlet_t *)(p->getBufferAddress());

                                assert(nevents + offset <= p->getBufferSize());

                                // Offset is in frames, but each port is only a single
                                // channel, so the number of frames is the same as the
                                // number of quadlets to offset (assuming the port buffer
                                // uses one quadlet per sample, which is the case currently).
                                buffer+=offset;

                                for(j = 0; j < nevents; j += 1) { // Decode nsamples
                                        *target = (*buffer >> 16) & 0xff;
                                        *(target+1) = (*buffer >> 8) & 0xff;
                                        *(target+2) = (*buffer) & 0xff;

                                        buffer++;
                                        target+=m_event_size;
                                }
                        }
                        break;
                case Port::E_Float:
                        {
                                const float multiplier = (float)(0x7FFFFF);
                                float *buffer=(float *)(p->getBufferAddress());

                                assert(nevents + offset <= p->getBufferSize());

                                buffer+=offset;

                                for(j = 0; j < nevents; j += 1) { // decode max nsamples                
                                        unsigned int v = (int)(*buffer * multiplier);
                                        *target = (v >> 16) & 0xff;
                                        *(target+1) = (v >> 8) & 0xff;
                                        *(target+2) = v & 0xff;

                                        buffer++;
                                        target+=m_event_size;
                                }
                        }
                        break;
        }

        return 0;
}

int MotuTransmitStreamProcessor::encodeSilencePortToMotuEvents(MotuAudioPort *p, quadlet_t *data, 
                       unsigned int offset, unsigned int nevents) {
        unsigned int j=0;
        unsigned char *target = (unsigned char *)data + p->getPosition();

        switch (p->getDataType()) {
        default:
        case Port::E_Int24:
        case Port::E_Float:
                for (j = 0; j < nevents; j++) {
                        *target = *(target+1) = *(target+2) = 0;
                        target += m_event_size;
                }
                break;
        }

        return 0;
}

/* --------------------- RECEIVE ----------------------- */

MotuReceiveStreamProcessor::MotuReceiveStreamProcessor(int port, int framerate, 
        unsigned int event_size)
    : ReceiveStreamProcessor(port, framerate), m_event_size(event_size),
        m_closedown_active(0) {

}

MotuReceiveStreamProcessor::~MotuReceiveStreamProcessor() {

}

bool MotuReceiveStreamProcessor::init() {

        // call the parent init
        // this has to be done before allocating the buffers, 
        // because this sets the buffersizes from the processormanager
        if(!ReceiveStreamProcessor::init()) {
                debugFatal("Could not do base class init (%d)\n",this);
                return false;
        }

        return true;
}

        // NOTE by PP: timestamp based sync fixes this automagically by
        //             enforcing that the roundtrip latency is constant:
        // Detect missed receive cycles
        // FIXME: it would be nice to advance the rx buffer by the amount of
        // frames missed.  However, since the MOTU transmits more frames per
        // cycle than the average and "catches up" with periodic empty
        // cycles it's not trivial to work out precisely how many frames
        // were missed.  Ultimately I think we need to do so if sync is to
        // be maintained across a transient receive failure.
        
enum raw1394_iso_disposition 
MotuReceiveStreamProcessor::putPacket(unsigned char *data, unsigned int length, 
                  unsigned char channel, unsigned char tag, unsigned char sy, 
                  unsigned int cycle, unsigned int dropped) {
    
        enum raw1394_iso_disposition retval=RAW1394_ISO_OK;
        // this is needed for the base class getLastCycle() to work.
        // this avoids a function call like StreamProcessor::updateLastCycle()
    m_last_cycle=cycle;

    // check our enable status
    if (!m_disabled && m_is_disabled) {
        // this means that we are trying to enable
        if (cycle == m_cycle_to_enable_at) {
            m_is_disabled=false;
            debugOutput(DEBUG_LEVEL_VERBOSE,"Enabling StreamProcessor %p at %d\n", 
                this, cycle);
                
            // the previous timestamp is the one we need to start with
            // because we're going to update the buffer again this loop
            // using writeframes
            m_data_buffer->setBufferTailTimestamp(m_last_timestamp2);

        } else {
            debugOutput(DEBUG_LEVEL_VERY_VERBOSE,
                "will enable StreamProcessor %p at %u, now is %d\n",
                    this, m_cycle_to_enable_at, cycle);
        }
    } else if (m_disabled && !m_is_disabled) {
        // trying to disable
        debugOutput(DEBUG_LEVEL_VERBOSE,"disabling StreamProcessor %p at %u\n", this, cycle);
        m_is_disabled=true;
    }
        
        // If the packet length is 8 bytes (ie: just a CIP-like header)
        // there is no isodata.
        if (length > 8) {
                // The iso data blocks from the MOTUs comprise a CIP-like
                // header followed by a number of events (8 for 1x rates, 16
                // for 2x rates, 32 for 4x rates).
                quadlet_t *quadlet = (quadlet_t *)data;
                unsigned int dbs = get_bits(ntohl(quadlet[0]), 23, 8);  // Size of one event in terms of fdf_size
                unsigned int fdf_size = get_bits(ntohl(quadlet[1]), 23, 8) == 0x22 ? 32:0; // Event unit size in bits

                // Don't even attempt to process a packet if it isn't what
                // we expect from a MOTU.  Yes, an FDF value of 32 bears
                // little relationship to the actual data (24 bit integer)
                // sent by the MOTU - it's one of those areas where MOTU
                // have taken a curious detour around the standards.
                if (tag!=1 || fdf_size!=32) {
                        return RAW1394_ISO_OK;
                }
                
                // put this after the check because event_length can become 0 on invalid packets
                unsigned int event_length = (fdf_size * dbs) / 8;       // Event size in bytes
                unsigned int n_events = (length-8) / event_length;
                
        //=> store the previous timestamp
        m_last_timestamp2=m_last_timestamp;

        //=> convert the SYT to a full timestamp in ticks
//        m_last_timestamp=sytRecvToFullTicks((uint32_t)ntohl(*(quadlet_t *)(data+8)), 
//                                        cycle, m_handler->getCycleTimer());
//***
// FIXME: it given that we later advance this to be the timestamp of the sample immediately following
// this packet, it perhaps makes more sense to acquire the timestamp of the last frame in the packet.
// Then it's just a matter of adding m_ticks_per_frame rather than frame_size times this.
uint32_t first_sph = ntohl(*(quadlet_t *)(data+8));
//        m_last_timestamp = ((first_sph & 0x1fff000)>>12)*3072 + (first_sph & 0xfff);
        m_last_timestamp = CYCLE_TIMER_TO_TICKS(first_sph & 0x1ffffff);

                // Signal that we're running
        if(!m_running && n_events && m_last_timestamp2 && m_last_timestamp) {
            debugOutput(DEBUG_LEVEL_VERBOSE,"Receive StreamProcessor %p started running at %d\n", this, cycle);
            m_running=true;
        }

        //=> don't process the stream samples when it is not enabled.
        if(m_is_disabled) {

            // we keep track of the timestamp here
            // this makes sure that we will have a somewhat accurate
            // estimate as to when a period might be ready. i.e. it will not
            // be ready earlier than this timestamp + period time
            
            // the next (possible) sample is not this one, but lies 
            // SYT_INTERVAL * rate later
            float frame_size=m_framerate<=48000?8:(m_framerate<=96000?16:32);
            uint64_t ts=addTicks(m_last_timestamp,
                                 (uint64_t)(frame_size * m_ticks_per_frame));

            // set the timestamp as if there will be a sample put into
            // the buffer by the next packet.
            m_data_buffer->setBufferTailTimestamp(ts);
            
            return RAW1394_ISO_DEFER;
        }

                debugOutput( DEBUG_LEVEL_VERY_VERBOSE, "put packet...\n");

        //=> process the packet
        // add the data payload to the ringbuffer
        if(m_data_buffer->writeFrames(n_events, (char *)(data+8), m_last_timestamp)) { 
            retval=RAW1394_ISO_OK;
            
            int dbc = get_bits(ntohl(quadlet[0]), 8, 8);
            
            // process all ports that should be handled on a per-packet base
            // this is MIDI for AMDTP (due to the need of DBC)
            if (!decodePacketPorts((quadlet_t *)(data+8), n_events, dbc)) {
                debugWarning("Problem decoding Packet Ports\n");
                retval=RAW1394_ISO_DEFER;
            }
            
        } else {
        
            debugWarning("Receive buffer overrun (cycle %d, FC=%d, PC=%d)\n", 
                 cycle, m_data_buffer->getFrameCounter(), m_handler->getPacketCount());
            
            m_xruns++;
            
            // disable the processing, will be re-enabled when
            // the xrun is handled
            m_disabled=true;
            m_is_disabled=true;

            retval=RAW1394_ISO_DEFER;
        }
    }

        return retval;
}

// returns the delay between the actual (real) time of a timestamp as received,
// and the timestamp that is passed on for the same event. This is to cope with
// ISO buffering
int MotuReceiveStreamProcessor::getMinimalSyncDelay() {
        unsigned int n_events = m_framerate<=48000?8:(m_framerate<=96000?16:32);
    
    return (int)(m_handler->getWakeupInterval() * n_events * m_ticks_per_frame);
}

bool MotuReceiveStreamProcessor::reset() {

        debugOutput( DEBUG_LEVEL_VERBOSE, "Resetting...\n");
        
    // this makes that the buffer lags a little compared to reality
    // the result is that we get some extra time before period boundaries
    // are signaled.
    // ISO buffering causes the packets to be received at max
    // m_handler->getWakeupInterval() later than the time they were received.
    // hence their payload is available this amount of time later. However, the
    // period boundary is predicted based upon earlier samples, and therefore can
    // pass before these packets are processed. Adding this extra term makes that
    // the period boundary is signalled later
    m_data_buffer->setTickOffset(m_SyncSource->getSyncDelay());

        // reset all non-device specific stuff
        // i.e. the iso stream and the associated ports
        if(!ReceiveStreamProcessor::reset()) {
                debugFatal("Could not do base class reset\n");
                return false;
        }

        return true;
}

bool MotuReceiveStreamProcessor::prepare() {

        // prepare all non-device specific stuff
        // i.e. the iso stream and the associated ports
        if(!ReceiveStreamProcessor::prepare()) {
                debugFatal("Could not prepare base class\n");
                return false;
        }

        debugOutput( DEBUG_LEVEL_VERBOSE, "Preparing...\n");

        m_PeriodStat.setName("RCV PERIOD");
        m_PacketStat.setName("RCV PACKET");
        m_WakeupStat.setName("RCV WAKEUP");

    // setup any specific stuff here
    // FIXME: m_frame_size would be a better name
        debugOutput( DEBUG_LEVEL_VERBOSE, "Event size: %d\n", m_event_size);
    
    // prepare the framerate estimate
    float ticks_per_frame = (TICKS_PER_SECOND*1.0) / ((float)m_framerate);
        
        // initialize internal buffer
        unsigned int ringbuffer_size_frames=m_nb_buffers * m_period;
        
        unsigned int events_per_frame = m_framerate<=48000?8:(m_framerate<=96000?16:32);

    assert(m_data_buffer);    
    m_data_buffer->setBufferSize(ringbuffer_size_frames);
    m_data_buffer->setEventSize(m_event_size/events_per_frame);
    m_data_buffer->setEventsPerFrame(events_per_frame); 
    
    m_data_buffer->setUpdatePeriod(m_period);
    m_data_buffer->setNominalRate(ticks_per_frame);
    
    m_data_buffer->setWrapValue(TICKS_PER_SECOND);
    
    m_data_buffer->prepare();

        // set the parameters of ports we can:
        // we want the audio ports to be period buffered,
        // and the midi ports to be packet buffered
        for ( PortVectorIterator it = m_Ports.begin();
                  it != m_Ports.end();
                  ++it )
        {
                debugOutput(DEBUG_LEVEL_VERBOSE, "Setting up port %s\n",(*it)->getName().c_str());
                
                if(!(*it)->setBufferSize(m_period)) {
                        debugFatal("Could not set buffer size to %d\n",m_period);
                        return false;
                }

                switch ((*it)->getPortType()) {
                        case Port::E_Audio:
                                if(!(*it)->setSignalType(Port::E_PeriodSignalled)) {
                                        debugFatal("Could not set signal type to PeriodSignalling");
                                        return false;
                                }
                                break;
                        case Port::E_Midi:
                                if(!(*it)->setSignalType(Port::E_PacketSignalled)) {
                                        debugFatal("Could not set signal type to PacketSignalling");
                                        return false;
                                }
                                if (!(*it)->setBufferType(Port::E_RingBuffer)) {
                                        debugFatal("Could not set buffer type");
                                        return false;
                                }
                                if (!(*it)->setDataType(Port::E_MidiEvent)) {
                                        debugFatal("Could not set data type");
                                        return false;
                                }
                                // FIXME: probably need rate control too.  See
                                // Port::useRateControl() and AmdtpStreamProcessor.
                                break;
                        case Port::E_Control:
                                if(!(*it)->setSignalType(Port::E_PeriodSignalled)) {
                                        debugFatal("Could not set signal type to PeriodSignalling");
                                        return false;
                                }
                                break;
                        default:
                                debugWarning("Unsupported port type specified\n");
                                break;
                }

        }

        // The API specific settings of the ports are already set before
        // this routine is called, therefore we can init&prepare the ports
        if(!initPorts()) {
                debugFatal("Could not initialize ports!\n");
                return false;
        }

        if(!preparePorts()) {
                debugFatal("Could not initialize ports!\n");
                return false;
        }
        
        return true;

}


bool MotuReceiveStreamProcessor::prepareForStop() {

        // A MOTU receive stream can stop at any time.  However, signify
        // that stopping is in progress because other streams (notably the
        // transmit stream) may keep going for some time and cause an
        // overflow in the receive buffers.  If a closedown is in progress
        // the receive handler simply throws all incoming data away so
        // no buffer overflow can occur.
        m_closedown_active = 1;
        return true;
}

bool MotuReceiveStreamProcessor::prepareForStart() {
// Reset some critical variables required so the stream starts cleanly. This
// method is called once on every stream restart, including those during
// xrun recovery.  Initialisations which should be done once should be
// placed in the init() method instead.
        m_running = 0;
        m_closedown_active = 0;

        // At this point we'll also disable the stream processor here.
        // At this stage stream processors are always explicitly re-enabled
        // after being started, so by starting in the disabled state we 
        // ensure that every start will be exactly the same.
        disable();

        return true;
}

bool MotuReceiveStreamProcessor::getFrames(unsigned int nbframes) {

    m_PeriodStat.mark(m_data_buffer->getBufferFill());

    // ask the buffer to process nbframes of frames
    // using it's registered client's processReadBlock(),
    // which should be ours
    m_data_buffer->blockProcessReadFrames(nbframes);

    return true;
}

/**
 * \brief write received events to the port ringbuffers.
 */
bool MotuReceiveStreamProcessor::processReadBlock(char *data, 
                                           unsigned int nevents, unsigned int offset)
{
        bool no_problem=true;
        for ( PortVectorIterator it = m_PeriodPorts.begin();
          it != m_PeriodPorts.end();
          ++it ) {
                if((*it)->isDisabled()) {continue;};

                //FIXME: make this into a static_cast when not DEBUG?
                Port *port=dynamic_cast<Port *>(*it);
                
                switch(port->getPortType()) {
                
                case Port::E_Audio:
                        if(decodeMotuEventsToPort(static_cast<MotuAudioPort *>(*it), (quadlet_t *)data, offset, nevents)) {
                                debugWarning("Could not decode packet MBLA to port %s",(*it)->getName().c_str());
                                no_problem=false;
                        }
                        break;
                // midi is a packet based port, don't process
                //      case MotuPortInfo::E_Midi:
                //              break;

                default: // ignore
                        break;
                }
        }
        return no_problem;
}

/**
 * @brief decode a packet for the packet-based ports
 *
 * @param data Packet data
 * @param nevents number of events in data (including events of other ports & port types)
 * @param dbc DataBlockCount value for this packet
 * @return true if all successfull
 */
bool MotuReceiveStreamProcessor::decodePacketPorts(quadlet_t *data, unsigned int nevents, 
                unsigned int dbc) {
        bool ok=true;

        // Use char here since the source address won't necessarily be
        // aligned; use of an unaligned quadlet_t may cause issues on
        // certain architectures.  Besides, the source for MIDI data going
        // directly to the MOTU isn't structured in quadlets anyway; it is a
        // sequence of 3 unaligned bytes.
        unsigned char *src = NULL;

        for ( PortVectorIterator it = m_PacketPorts.begin();
                it != m_PacketPorts.end();
                ++it ) {

                Port *port=dynamic_cast<Port *>(*it);
                assert(port); // this should not fail!!

                // Currently the only packet type of events for MOTU 
                // is MIDI in mbla.  However in future control data
                // might also be sent via "packet" events, so allow 
                // for this possible expansion.

                // FIXME: MIDI input is completely untested at present.
                switch (port->getPortType()) {
                        case Port::E_Midi: {
                                MotuMidiPort *mp=static_cast<MotuMidiPort *>(*it);
                                signed int sample;
                                unsigned int j = 0;
                                // Get MIDI bytes if present anywhere in the
                                // packet.  MOTU MIDI data is sent using a
                                // 3-byte sequence starting at the port's
                                // position.  It's thought that there can never
                                // be more than one MIDI byte per packet, but
                                // for completeness we'll check the entire packet
                                // anyway.
                                src = (unsigned char *)data + mp->getPosition();
                                while (j < nevents) {
                                        if (*src==0x01 && *(src+1)==0x00) {
                                                sample = *(src+2);
                                                if (!mp->writeEvent(&sample)) {
                                                        debugWarning("MIDI packet port events lost\n");
                                                        ok = false;
                                                }
                                        }
                                        j++;
                                        src += m_event_size;
                                }
                                break;
                        }
                        default:
                                debugOutput(DEBUG_LEVEL_VERBOSE, "Unknown packet-type port format %d\n",port->getPortType());
                                return ok;        
                }
        }

        return ok;
}

signed int MotuReceiveStreamProcessor::decodeMotuEventsToPort(MotuAudioPort *p, 
                quadlet_t *data, unsigned int offset, unsigned int nevents)
{
        unsigned int j=0;

        // Use char here since a port's source address won't necessarily be
        // aligned; use of an unaligned quadlet_t may cause issues on
        // certain architectures.  Besides, the source (data coming directly
        // from the MOTU) isn't structured in quadlets anyway; it mainly
        // consists of packed 24-bit integers.

        unsigned char *src_data;
        src_data = (unsigned char *)data + p->getPosition();

        switch(p->getDataType()) {
                default:
                case Port::E_Int24:
                        {
                                quadlet_t *buffer=(quadlet_t *)(p->getBufferAddress());

                                assert(nevents + offset <= p->getBufferSize());

                                // Offset is in frames, but each port is only a single
                                // channel, so the number of frames is the same as the
                                // number of quadlets to offset (assuming the port buffer
                                // uses one quadlet per sample, which is the case currently).
                                buffer+=offset;

                                for(j = 0; j < nevents; j += 1) { // Decode nsamples
                                        *buffer = (*src_data<<16)+(*(src_data+1)<<8)+*(src_data+2);
                                        // Sign-extend highest bit of 24-bit int.
                                        // FIXME: this isn't strictly needed since E_Int24 is a 24-bit,
                                        // but doing so shouldn't break anything and makes the data
                                        // easier to deal with during debugging.
                                        if (*src_data & 0x80)
                                                *buffer |= 0xff000000;

                                        buffer++;
                                        src_data+=m_event_size;
                                }
                        }
                        break;
                case Port::E_Float:
                        {
                                const float multiplier = 1.0f / (float)(0x7FFFFF);
                                float *buffer=(float *)(p->getBufferAddress());

                                assert(nevents + offset <= p->getBufferSize());

                                buffer+=offset;

                                for(j = 0; j < nevents; j += 1) { // decode max nsamples                
        
                                        unsigned int v = (*src_data<<16)+(*(src_data+1)<<8)+*(src_data+2);

                                        // sign-extend highest bit of 24-bit int
                                        int tmp = (int)(v << 8) / 256;
                
                                        *buffer = tmp * multiplier;
                                
                                        buffer++;
                                        src_data+=m_event_size;
                                }
                        }
                        break;
        }

        return 0;
}

signed int MotuReceiveStreamProcessor::setEventSize(unsigned int size) {
        m_event_size = size;
        return 0;
}

unsigned int MotuReceiveStreamProcessor::getEventSize(void) {
//
// Return the size of a single event sent by the MOTU as part of an iso
// data packet in bytes.
//
        return m_event_size;
}

void MotuReceiveStreamProcessor::setVerboseLevel(int l) {
        setDebugLevel(l);
        ReceiveStreamProcessor::setVerboseLevel(l);
}

} // end of namespace FreebobStreaming