root/branches/api-cleanup/src/libstreaming/amdtp/AmdtpTransmitStreamProcessor.cpp

/*
 * Copyright (C) 2005-2007 by Pieter Palmers
 *
 * This file is part of FFADO
 * FFADO = Free Firewire (pro-)audio drivers for linux
 *
 * FFADO is based upon FreeBoB.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "config.h"
#include "AmdtpTransmitStreamProcessor.h"
#include "AmdtpPort.h"
#include "../StreamProcessorManager.h"
#include "devicemanager.h"

#include "libutil/Time.h"

#include "libieee1394/ieee1394service.h"
#include "libieee1394/IsoHandlerManager.h"
#include "libieee1394/cycletimer.h"

#include <netinet/in.h>
#include <assert.h>

#define AMDTP_FLOAT_MULTIPLIER 2147483392.0

namespace Streaming
{

/* transmit */
AmdtpTransmitStreamProcessor::AmdtpTransmitStreamProcessor(FFADODevice &parent, int dimension)
        : StreamProcessor(parent, ePT_Transmit)
        , m_dimension( dimension )
        , m_dbc( 0 )
        , m_nb_audio_ports( 0 )
        , m_nb_midi_ports( 0 )
{}

enum StreamProcessor::eChildReturnValue
AmdtpTransmitStreamProcessor::generatePacketHeader (
    unsigned char *data, unsigned int *length,
    unsigned char *tag, unsigned char *sy,
    int cycle, unsigned int dropped, unsigned int max_length )
{
    struct iec61883_packet *packet = ( struct iec61883_packet * ) data;
    /* Our node ID can change after a bus reset, so it is best to fetch
    * our node ID for each packet. */
    packet->sid = m_1394service.getLocalNodeId() & 0x3f;

    packet->dbs = m_dimension;
    packet->fn = 0;
    packet->qpc = 0;
    packet->sph = 0;
    packet->reserved = 0;
    packet->dbc = m_dbc;
    packet->eoh1 = 2;
    packet->fmt = IEC61883_FMT_AMDTP;

    *tag = IEC61883_TAG_WITH_CIP;
    *sy = 0;

    signed int fc;
    uint64_t presentation_time;
    unsigned int presentation_cycle;
    int cycles_until_presentation;

    uint64_t transmit_at_time;
    unsigned int transmit_at_cycle;
    int cycles_until_transmit;

    debugOutput ( DEBUG_LEVEL_ULTRA_VERBOSE, "Try for cycle %d\n", cycle );
    // check whether the packet buffer has packets for us to send.
    // the base timestamp is the one of the next sample in the buffer
    ffado_timestamp_t ts_head_tmp;
    m_data_buffer->getBufferHeadTimestamp ( &ts_head_tmp, &fc ); // thread safe

    // the timestamp gives us the time at which we want the sample block
    // to be output by the device
    presentation_time = ( uint64_t ) ts_head_tmp;
    m_last_timestamp = presentation_time;

    // now we calculate the time when we have to transmit the sample block
    transmit_at_time = substractTicks ( presentation_time, AMDTP_TRANSMIT_TRANSFER_DELAY );

    // calculate the cycle this block should be presented in
    // (this is just a virtual calculation since at that time it should
    //  already be in the device's buffer)
    presentation_cycle = ( unsigned int ) ( TICKS_TO_CYCLES ( presentation_time ) );

    // calculate the cycle this block should be transmitted in
    transmit_at_cycle = ( unsigned int ) ( TICKS_TO_CYCLES ( transmit_at_time ) );

    // we can check whether this cycle is within the 'window' we have
    // to send this packet.
    // first calculate the number of cycles left before presentation time
    cycles_until_presentation = diffCycles ( presentation_cycle, cycle );

    // we can check whether this cycle is within the 'window' we have
    // to send this packet.
    // first calculate the number of cycles left before presentation time
    cycles_until_transmit = diffCycles ( transmit_at_cycle, cycle );

    if (dropped) {
        debugOutput ( DEBUG_LEVEL_VERBOSE,
                    "Gen HDR: CY=%04u, TC=%04u, CUT=%04d, TST=%011llu (%04u), TSP=%011llu (%04u)\n",
                    cycle,
                    transmit_at_cycle, cycles_until_transmit,
                    transmit_at_time, ( unsigned int ) TICKS_TO_CYCLES ( transmit_at_time ),
                    presentation_time, ( unsigned int ) TICKS_TO_CYCLES ( presentation_time ) );
    }
    // two different options:
    // 1) there are not enough frames for one packet
    //      => determine wether this is a problem, since we might still
    //         have some time to send it
    // 2) there are enough packets
    //      => determine whether we have to send them in this packet
    if ( fc < ( signed int ) m_syt_interval )
    {
        // not enough frames in the buffer,

        // we can still postpone the queueing of the packets
        // if we are far enough ahead of the presentation time
        if ( cycles_until_presentation <= AMDTP_MIN_CYCLES_BEFORE_PRESENTATION )
        {
            debugOutput ( DEBUG_LEVEL_VERBOSE,
                        "Insufficient frames (P): N=%02d, CY=%04u, TC=%04u, CUT=%04d\n",
                        fc, cycle, transmit_at_cycle, cycles_until_transmit );
            // we are too late
            return eCRV_XRun;
        }
        else
        {
            unsigned int now_cycle = ( unsigned int ) ( TICKS_TO_CYCLES ( m_1394service.getCycleTimerTicks() ) );

            debugOutput ( DEBUG_LEVEL_VERBOSE,
                        "Insufficient frames (NP): N=%02d, CY=%04u, TC=%04u, CUT=%04d, NOW=%04d\n",
                        fc, cycle, transmit_at_cycle, cycles_until_transmit, now_cycle );
            debugWarning("Insufficient frames (NP): N=%02d, CY=%04u, TC=%04u, CUT=%04d, NOW=%04d\n",
                         fc, cycle, transmit_at_cycle, cycles_until_transmit, now_cycle );

            // there is still time left to send the packet
            // we want the system to give this packet another go at a later time instant
            return eCRV_Again; // note that the raw1394 again system doesn't work as expected

            // we could wait here for a certain time before trying again. However, this
            // is not going to work since we then block the iterator thread, hence also 
            // the receiving code, meaning that we are not processing received packets,
            // and hence there is no progression in the number of frames available.

            // for example:
            // SleepRelativeUsec(125); // one cycle
            // goto try_block_of_frames;

            // or more advanced, calculate how many cycles we are ahead of 'now' and
            // base the sleep on that.

            // note that this requires that there is one thread for each IsoHandler,
            // otherwise we're in the deadlock described above.
        }
    }
    else
    {
        // there are enough frames, so check the time they are intended for
        // all frames have a certain 'time window' in which they can be sent
        // this corresponds to the range of the timestamp mechanism:
        // we can send a packet 15 cycles in advance of the 'presentation time'
        // in theory we can send the packet up till one cycle before the presentation time,
        // however this is not very smart.

        // There are 3 options:
        // 1) the frame block is too early
        //      => send an empty packet
        // 2) the frame block is within the window
        //      => send it
        // 3) the frame block is too late
        //      => discard (and raise xrun?)
        //         get next block of frames and repeat

        if(cycles_until_transmit < 0)
        {
            // we are too late
            debugOutput(DEBUG_LEVEL_VERBOSE,
                        "Too late: CY=%04u, TC=%04u, CUT=%04d, TSP=%011llu (%04u)\n",
                        cycle,
                        transmit_at_cycle, cycles_until_transmit,
                        presentation_time, (unsigned int)TICKS_TO_CYCLES(presentation_time) );
            //debugShowBackLogLines(200);
//             // however, if we can send this sufficiently before the presentation
//             // time, it could be harmless.
//             // NOTE: dangerous since the device has no way of reporting that it didn't get
//             //       this packet on time.
//             if(cycles_until_presentation >= AMDTP_MIN_CYCLES_BEFORE_PRESENTATION)
//             {
//                 // we are not that late and can still try to transmit the packet
//                 m_dbc += fillDataPacketHeader(packet, length, m_last_timestamp);
//                 return (fc < (signed)(2*m_syt_interval) ? eCRV_Defer : eCRV_Packet);
//             }
//             else   // definitely too late
//             {
                return eCRV_XRun;
//             }
        }
        else if(cycles_until_transmit <= AMDTP_MAX_CYCLES_TO_TRANSMIT_EARLY)
        {
            // it's time send the packet
            m_dbc += fillDataPacketHeader(packet, length, m_last_timestamp);
            return (fc < (signed)(2*m_syt_interval) ? eCRV_Defer : eCRV_Packet);
        }
        else
        {
            debugOutput ( DEBUG_LEVEL_VERY_VERBOSE,
                        "Too early: CY=%04u, TC=%04u, CUT=%04d, TST=%011llu (%04u), TSP=%011llu (%04u)\n",
                        cycle,
                        transmit_at_cycle, cycles_until_transmit,
                        transmit_at_time, ( unsigned int ) TICKS_TO_CYCLES ( transmit_at_time ),
                        presentation_time, ( unsigned int ) TICKS_TO_CYCLES ( presentation_time ) );
#ifdef DEBUG
            if ( cycles_until_transmit > AMDTP_MAX_CYCLES_TO_TRANSMIT_EARLY + 1 )
            {
                debugOutput ( DEBUG_LEVEL_VERY_VERBOSE,
                            "Way too early: CY=%04u, TC=%04u, CUT=%04d, TST=%011llu (%04u), TSP=%011llu (%04u)\n",
                            cycle,
                            transmit_at_cycle, cycles_until_transmit,
                            transmit_at_time, ( unsigned int ) TICKS_TO_CYCLES ( transmit_at_time ),
                            presentation_time, ( unsigned int ) TICKS_TO_CYCLES ( presentation_time ) );
            }
#endif
            // we are too early, send only an empty packet
            return eCRV_EmptyPacket;
        }
    }
    return eCRV_Invalid;
}

enum StreamProcessor::eChildReturnValue
AmdtpTransmitStreamProcessor::generatePacketData (
    unsigned char *data, unsigned int *length,
    unsigned char *tag, unsigned char *sy,
    int cycle, unsigned int dropped, unsigned int max_length )
{
    if ( m_data_buffer->readFrames ( m_syt_interval, ( char * ) ( data + 8 ) ) )
    {
        debugOutput ( DEBUG_LEVEL_ULTRA_VERBOSE, "XMIT DATA (cy %04d): TSP=%011llu (%04u)\n",
                    cycle, m_last_timestamp, ( unsigned int ) TICKS_TO_CYCLES ( m_last_timestamp ) );
        return eCRV_OK;
    }
    else return eCRV_XRun;

}

enum StreamProcessor::eChildReturnValue
AmdtpTransmitStreamProcessor::generateSilentPacketHeader (
    unsigned char *data, unsigned int *length,
    unsigned char *tag, unsigned char *sy,
    int cycle, unsigned int dropped, unsigned int max_length )
{
    struct iec61883_packet *packet = ( struct iec61883_packet * ) data;
    debugOutput ( DEBUG_LEVEL_ULTRA_VERBOSE, "XMIT NONE (cy %04d): CY=%04u, TSP=%011llu (%04u)\n",
                cycle, m_last_timestamp, ( unsigned int ) TICKS_TO_CYCLES ( m_last_timestamp ) );

    /* Our node ID can change after a bus reset, so it is best to fetch
    * our node ID for each packet. */
    packet->sid = m_1394service.getLocalNodeId() & 0x3f;

    packet->dbs = m_dimension;
    packet->fn = 0;
    packet->qpc = 0;
    packet->sph = 0;
    packet->reserved = 0;
    packet->dbc = m_dbc;
    packet->eoh1 = 2;
    packet->fmt = IEC61883_FMT_AMDTP;

    *tag = IEC61883_TAG_WITH_CIP;
    *sy = 0;

    m_dbc += fillNoDataPacketHeader ( packet, length );
    return eCRV_OK;
}

enum StreamProcessor::eChildReturnValue
AmdtpTransmitStreamProcessor::generateSilentPacketData (
    unsigned char *data, unsigned int *length,
    unsigned char *tag, unsigned char *sy,
    int cycle, unsigned int dropped, unsigned int max_length )
{
    return eCRV_OK; // no need to do anything
}

unsigned int AmdtpTransmitStreamProcessor::fillDataPacketHeader (
    struct iec61883_packet *packet, unsigned int* length,
    uint32_t ts )
{

    packet->fdf = m_fdf;

    // convert the timestamp to SYT format
    uint16_t timestamp_SYT = TICKS_TO_SYT ( ts );
    packet->syt = ntohs ( timestamp_SYT );

    *length = m_syt_interval*sizeof ( quadlet_t ) *m_dimension + 8;

    return m_syt_interval;
}

unsigned int AmdtpTransmitStreamProcessor::fillNoDataPacketHeader (
    struct iec61883_packet *packet, unsigned int* length )
{

    // no-data packets have syt=0xFFFF
    // and have the usual amount of events as dummy data (?)
    packet->fdf = IEC61883_FDF_NODATA;
    packet->syt = 0xffff;

    // FIXME: either make this a setting or choose
    bool send_payload=true;
    if ( send_payload )
    {
        // this means no-data packets with payload (DICE doesn't like that)
        *length = 2*sizeof ( quadlet_t ) + m_syt_interval * m_dimension * sizeof ( quadlet_t );
        return m_syt_interval;
    }
    else
    {
        // dbc is not incremented
        // this means no-data packets without payload
        *length = 2*sizeof ( quadlet_t );
        return 0;
    }
}

unsigned int
AmdtpTransmitStreamProcessor::getSytInterval() {
    switch (m_StreamProcessorManager.getNominalRate()) {
        case 32000:
        case 44100:
        case 48000:
            return 8;
        case 88200:
        case 96000:
            return 16;
        case 176400:
        case 192000:
            return 32;
        default:
            debugError("Unsupported rate: %d\n", m_StreamProcessorManager.getNominalRate());
            return 0;
    }
}
unsigned int
AmdtpTransmitStreamProcessor::getFDF() {
    switch (m_StreamProcessorManager.getNominalRate()) {
        case 32000: return IEC61883_FDF_SFC_32KHZ;
        case 44100: return IEC61883_FDF_SFC_44K1HZ;
        case 48000: return IEC61883_FDF_SFC_48KHZ;
        case 88200: return IEC61883_FDF_SFC_88K2HZ;
        case 96000: return IEC61883_FDF_SFC_96KHZ;
        case 176400: return IEC61883_FDF_SFC_176K4HZ;
        case 192000: return IEC61883_FDF_SFC_192KHZ;
        default:
            debugError("Unsupported rate: %d\n", m_StreamProcessorManager.getNominalRate());
            return 0;
    }
}

bool AmdtpTransmitStreamProcessor::prepareChild()
{
    debugOutput ( DEBUG_LEVEL_VERBOSE, "Preparing (%p)...\n", this );
    m_syt_interval = getSytInterval();
    m_fdf = getFDF();

    iec61883_cip_init (
        &m_cip_status,
        IEC61883_FMT_AMDTP,
        m_fdf,
        m_StreamProcessorManager.getNominalRate(),
        m_dimension,
        m_syt_interval );

    if (!initPortCache()) {
        debugError("Could not init port cache\n");
        return false;
    }

    return true;
}

/*
* compose the event streams for the packets from the port buffers
*/
bool AmdtpTransmitStreamProcessor::processWriteBlock ( char *data,
        unsigned int nevents, unsigned int offset )
{
    bool no_problem = true;
    updatePortCache();

    if(!encodeAudioPorts((quadlet_t *)data, offset, nevents)) {
        debugError("Could not encode audio ports\n");
        return false;
    }

//     for ( PortVectorIterator it = m_Ports.begin();
//           it != m_Ports.end();
//           ++it )
//     {
//         if ( (*it)->isDisabled() ) { continue; };
// 
//         //FIXME: make this into a static_cast when not DEBUG?
//         AmdtpPortInfo *pinfo = dynamic_cast<AmdtpPortInfo *> ( *it );
//         assert ( pinfo ); // this should not fail!!
// 
//         switch( pinfo->getFormat() )
//         {
//             case AmdtpPortInfo::E_MBLA:
//                 if( encodePortToMBLAEvents(static_cast<AmdtpAudioPort *>(*it), (quadlet_t *)data, offset, nevents) )
//                 {
//                     debugWarning ( "Could not encode port %s to MBLA events", (*it)->getName().c_str() );
//                     no_problem = false;
//                 }
//                 break;
//             case AmdtpPortInfo::E_SPDIF: // still unimplemented
//                 break;
//             case AmdtpPortInfo::E_Midi:
//                 if( encodePortToMidiEvents(static_cast<AmdtpMidiPort *>(*it), (quadlet_t *)data, offset, nevents) )
//                 {
//                     debugWarning ( "Could not encode port %s to Midi events", (*it)->getName().c_str() );
//                     no_problem = false;
//                 }
//                 break;
//             default: // ignore
//                 break;
//         }
//     }
    return no_problem;
}

bool
AmdtpTransmitStreamProcessor::transmitSilenceBlock(
    char *data, unsigned int nevents, unsigned int offset)
{
    bool no_problem = true;
    for(PortVectorIterator it = m_Ports.begin();
        it != m_Ports.end();
        ++it )
    {
        //FIXME: make this into a static_cast when not DEBUG?
        AmdtpPortInfo *pinfo=dynamic_cast<AmdtpPortInfo *>(*it);
        assert(pinfo); // this should not fail!!

        switch( pinfo->getFormat() )
        {
            case AmdtpPortInfo::E_MBLA:
                if ( encodeSilencePortToMBLAEvents(static_cast<AmdtpAudioPort *>(*it), (quadlet_t *)data, offset, nevents) )
                {
                    debugWarning("Could not encode silence for port %s to MBLA events", (*it)->getName().c_str());
                    no_problem = false;
                }
                break;
            case AmdtpPortInfo::E_SPDIF: // still unimplemented
                break;
            case AmdtpPortInfo::E_Midi:
                if( encodeSilencePortToMidiEvents(static_cast<AmdtpMidiPort *>(*it), (quadlet_t *)data, offset, nevents) )
                {
                    debugWarning ( "Could not encode silence for port %s to Midi events", (*it)->getName().c_str() );
                    no_problem = false;
                }
                break;
            default: // ignore
                break;
        }
    }
    return no_problem;
}

int AmdtpTransmitStreamProcessor::encodePortToMBLAEvents ( AmdtpAudioPort *p, quadlet_t *data,
        unsigned int offset, unsigned int nevents )
{
    unsigned int j=0;

    quadlet_t *target_event;

    target_event= ( quadlet_t * ) ( data + p->getPosition() );

    switch ( m_StreamProcessorManager.getAudioDataType() )
    {
        default:
            debugError("bad type: %d\n", m_StreamProcessorManager.getAudioDataType());
            return -1;
        case StreamProcessorManager::eADT_Int24:
        {
            quadlet_t *buffer= ( quadlet_t * ) ( p->getBufferAddress() );

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

            buffer+=offset;

            for ( j = 0; j < nevents; j += 1 )   // decode max nsamples
            {
                *target_event = htonl ( ( * ( buffer ) & 0x00FFFFFF ) | 0x40000000 );
                buffer++;
                target_event += m_dimension;
            }
        }
        break;
        case StreamProcessorManager::eADT_Float:
        {
            float *buffer= ( float * ) ( p->getBufferAddress() );

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

            buffer+=offset;

            for ( j = 0; j < nevents; j += 1 )   // decode max nsamples
            {

                // don't care for overflow
                float v = *buffer * AMDTP_FLOAT_MULTIPLIER;  // v: -231 .. 231
                unsigned int tmp = ( ( int ) v );
                *target_event = htonl ( ( tmp >> 8 ) | 0x40000000 );

                buffer++;
                target_event += m_dimension;
            }
        }
        break;
    }

    return 0;
}

// note: make sure that the midi events in the port buffer are only placed on (buffer+offset+x)%8 == 0
// i.e. 8 frame aligned
int AmdtpTransmitStreamProcessor::encodePortToMidiEvents ( AmdtpMidiPort *p, quadlet_t *data,
        unsigned int offset, unsigned int nevents )
{
    unsigned int j=0;
    unsigned int position = p->getPosition();
    unsigned int location = p->getLocation();

    quadlet_t *target_event;
    quadlet_t tmpval;

    quadlet_t *buffer = (quadlet_t *)(p->getBufferAddress());

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

    buffer+=offset;

    for ( j = location; j < nevents; j += 8 )
    {
        target_event = (quadlet_t *) (data + ((j * m_dimension) + position));

        if ( *buffer & 0xFF000000 )   // we can send a byte
        {
            tmpval = ((*buffer)<<16) & 0x00FF0000;
            tmpval=IEC61883_AM824_SET_LABEL(tmpval, IEC61883_AM824_LABEL_MIDI_1X);
            *target_event = htonl(tmpval);

            // debugOutput ( DEBUG_LEVEL_VERBOSE, "MIDI port %s, pos=%u, loc=%u, nevents=%u, dim=%d\n",
            //            p->getName().c_str(), position, location, nevents, m_dimension );
            // debugOutput ( DEBUG_LEVEL_VERBOSE, "base=%p, target=%p, value=%08X\n",
            //            data, target_event, tmpval );
        } else {
            // can't send a byte, either because there is no byte,
            // or because this would exceed the maximum rate
            // FIXME: this can be ifdef optimized since it's a constant
            *target_event = htonl(IEC61883_AM824_SET_LABEL(0, IEC61883_AM824_LABEL_MIDI_NO_DATA));
        }
        buffer+=8;
    }

    return 0;
}

int AmdtpTransmitStreamProcessor::encodeSilencePortToMBLAEvents ( AmdtpAudioPort *p, quadlet_t *data,
        unsigned int offset, unsigned int nevents )
{
    unsigned int j=0;

    quadlet_t *target_event;

    target_event= ( quadlet_t * ) ( data + p->getPosition() );

    switch ( m_StreamProcessorManager.getAudioDataType() )
    {
        default:
        case StreamProcessorManager::eADT_Int24:
        case StreamProcessorManager::eADT_Float:
        {
            for ( j = 0; j < nevents; j += 1 )   // decode max nsamples
            {
                *target_event = htonl ( 0x40000000 );
                target_event += m_dimension;
            }
        }
        break;
    }

    return 0;
}

int AmdtpTransmitStreamProcessor::encodeSilencePortToMidiEvents ( AmdtpMidiPort *p, quadlet_t *data,
        unsigned int offset, unsigned int nevents )
{
    unsigned int j=0;
    unsigned int position = p->getPosition();
    unsigned int location = p->getLocation();

    quadlet_t *target_event;

    for ( j = location; j < nevents; j += 8 )
    {
        target_event = (quadlet_t *) (data + ((j * m_dimension) + position));
        *target_event=htonl(IEC61883_AM824_SET_LABEL(0, IEC61883_AM824_LABEL_MIDI_NO_DATA));
    }

    return 0;
}

/**
 * @brief encodes all audio ports in the cache to events
 * @param data 
 * @param offset 
 * @param nevents 
 * @return 
 */
bool
AmdtpTransmitStreamProcessor::encodeAudioPorts(quadlet_t *data,
                                               unsigned int offset,
                                               unsigned int nevents)
{
    unsigned int j=0;

    quadlet_t *target_event;
    unsigned int i;
    for (i = 0; i < m_nb_audio_ports; i++) {
        struct _MBLA_port_cache p = m_audio_ports.at(i);
        target_event = (quadlet_t *)(data + i);
        assert(nevents + offset <= p.buffer_size );

        switch ( m_StreamProcessorManager.getAudioDataType() )
        {
            case StreamProcessorManager::eADT_Float:
            {
                float *buffer = (float *)(p.buffer);
                buffer += offset;

                for (j = 0;j < nevents; j += 1)   // decode max nsamples
                {
                    // don't care for overflow
                    float v = (*buffer) * AMDTP_FLOAT_MULTIPLIER;
                    unsigned int tmp = ((int) v);
                    *target_event = htonl ( ( tmp >> 8 ) | 0x40000000 );
                    buffer++;
                    target_event += m_dimension;
                }
            }
            break;
            case StreamProcessorManager::eADT_Int24:
            {
                uint32_t *buffer = (uint32_t *)(p.buffer);
                buffer += offset;

                for (j = 0; j < nevents; j += 1)   // decode max nsamples
                {
                    *target_event = htonl(((*buffer) & 0x00FFFFFF) | 0x40000000);
                    buffer++;
                    target_event += m_dimension;
                }
            }
            break;
            default:
                debugError("bad type: %d\n", m_StreamProcessorManager.getAudioDataType());
                return false;
        }
    }
    return true;
}


bool
AmdtpTransmitStreamProcessor::initPortCache() {
    // make use of the fact that audio ports are the first ports in
    // the cluster as per AMDTP. so we can sort the ports by position
    // and have very efficient lookups:
    // m_float_ports.at(i).buffer -> audio stream i buffer
    m_nb_audio_ports = 0;
    m_audio_ports.clear();
    
    m_nb_midi_ports = 0;
    
    for(PortVectorIterator it = m_Ports.begin();
        it != m_Ports.end();
        ++it )
    {
        AmdtpPortInfo *pinfo=dynamic_cast<AmdtpPortInfo *>(*it);
        assert(pinfo); // this should not fail!!

        switch( pinfo->getFormat() )
        {
            case AmdtpPortInfo::E_MBLA:
                m_nb_audio_ports++;
                break;
            case AmdtpPortInfo::E_SPDIF: // still unimplemented
                break;
            case AmdtpPortInfo::E_Midi:
                m_nb_midi_ports++;
                break;
            default: // ignore
                break;
        }
    }

    unsigned int idx;
    for (idx = 0; idx < m_nb_audio_ports; idx++) {
        for(PortVectorIterator it = m_Ports.begin();
            it != m_Ports.end();
            ++it )
        {
            AmdtpPortInfo *pinfo=dynamic_cast<AmdtpPortInfo *>(*it);
            debugOutput(DEBUG_LEVEL_VERBOSE, "idx %u: looking at port %s at position %u\n",
                                              idx, (*it)->getName().c_str(), pinfo->getPosition());
            if(pinfo->getPosition() == idx) {
                struct _MBLA_port_cache p;
                p.port = dynamic_cast<AmdtpAudioPort *>(*it);
                if(p.port == NULL) {
                    debugError("Port is not an AmdtpAudioPort!\n");
                    return false;
                }
//                p.position = pinfo->getPosition();
                p.buffer = NULL; // to be filled by updatePortCache
#ifdef DEBUG
                p.buffer_size = (*it)->getBufferSize();
#endif

                m_audio_ports.push_back(p);
                debugOutput(DEBUG_LEVEL_VERBOSE, "Cached port %s at position %u\n",
                                                 p.port->getName().c_str(), idx);
                goto next_index;
            }
        }
        debugError("No MBLA port found for position %d\n", idx);
        return false;
next_index:
        continue;
    }

    return true;
}

void
AmdtpTransmitStreamProcessor::updatePortCache() {
    unsigned int idx;
    for (idx = 0; idx < m_nb_audio_ports; idx++) {
        AmdtpAudioPort *port = m_audio_ports.at(idx).port;
        m_audio_ports.at(idx).buffer = port->getBufferAddress();
    }
}

} // end of namespace Streaming