trunk/src/DLS.cpp

/***************************************************************************
 *                                                                         *
 *   libgig - C++ cross-platform Gigasampler format file loader library    *
 *                                                                         *
 *   Copyright (C) 2003-2005 by Christian Schoenebeck                      *
 *                              <cuse@users.sourceforge.net>               *
 *                                                                         *
 *   This library 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 library 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 library; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include "DLS.h"

#include <time.h>

#include "helper.h"

// macros to decode connection transforms
#define CONN_TRANSFORM_SRC(x)                   ((x >> 10) & 0x000F)
#define CONN_TRANSFORM_CTL(x)                   ((x >> 4) & 0x000F)
#define CONN_TRANSFORM_DST(x)                   (x & 0x000F)
#define CONN_TRANSFORM_BIPOLAR_SRC(x)   (x & 0x4000)
#define CONN_TRANSFORM_BIPOLAR_CTL(x)   (x & 0x0100)
#define CONN_TRANSFORM_INVERT_SRC(x)    (x & 0x8000)
#define CONN_TRANSFORM_INVERT_CTL(x)    (x & 0x0200)

// macros to encode connection transforms
#define CONN_TRANSFORM_SRC_ENCODE(x)                    ((x & 0x000F) << 10)
#define CONN_TRANSFORM_CTL_ENCODE(x)                    ((x & 0x000F) << 4)
#define CONN_TRANSFORM_DST_ENCODE(x)                    (x & 0x000F)
#define CONN_TRANSFORM_BIPOLAR_SRC_ENCODE(x)    ((x) ? 0x4000 : 0)
#define CONN_TRANSFORM_BIPOLAR_CTL_ENCODE(x)    ((x) ? 0x0100 : 0)
#define CONN_TRANSFORM_INVERT_SRC_ENCODE(x)             ((x) ? 0x8000 : 0)
#define CONN_TRANSFORM_INVERT_CTL_ENCODE(x)             ((x) ? 0x0200 : 0)

#define DRUM_TYPE_MASK                  0x00000001

#define F_RGN_OPTION_SELFNONEXCLUSIVE   0x0001

#define F_WAVELINK_PHASE_MASTER         0x0001
#define F_WAVELINK_MULTICHANNEL         0x0002

#define F_WSMP_NO_TRUNCATION            0x0001
#define F_WSMP_NO_COMPRESSION           0x0002

#define MIDI_BANK_COARSE(x)             ((x & 0x00007F00) >> 8)                 // CC0
#define MIDI_BANK_FINE(x)               (x & 0x0000007F)                        // CC32
#define MIDI_BANK_MERGE(coarse, fine)   ((((uint16_t) coarse) << 7) | fine)     // CC0 + CC32
#define MIDI_BANK_ENCODE(coarse, fine)  (((coarse & 0x0000007F) << 8) | (fine & 0x0000007F))

namespace DLS {

// *************** Connection  ***************
// *

    void Connection::Init(conn_block_t* Header) {
        Source               = (conn_src_t) Header->source;
        Control              = (conn_src_t) Header->control;
        Destination          = (conn_dst_t) Header->destination;
        Scale                = Header->scale;
        SourceTransform      = (conn_trn_t) CONN_TRANSFORM_SRC(Header->transform);
        ControlTransform     = (conn_trn_t) CONN_TRANSFORM_CTL(Header->transform);
        DestinationTransform = (conn_trn_t) CONN_TRANSFORM_DST(Header->transform);
        SourceInvert         = CONN_TRANSFORM_INVERT_SRC(Header->transform);
        SourceBipolar        = CONN_TRANSFORM_BIPOLAR_SRC(Header->transform);
        ControlInvert        = CONN_TRANSFORM_INVERT_CTL(Header->transform);
        ControlBipolar       = CONN_TRANSFORM_BIPOLAR_CTL(Header->transform);
    }

    Connection::conn_block_t Connection::ToConnBlock() {
        conn_block_t c;
        c.source = Source;
        c.control = Control;
        c.destination = Destination;
        c.scale = Scale;
        c.transform = CONN_TRANSFORM_SRC_ENCODE(SourceTransform) |
                      CONN_TRANSFORM_CTL_ENCODE(ControlTransform) |
                      CONN_TRANSFORM_DST_ENCODE(DestinationTransform) |
                      CONN_TRANSFORM_INVERT_SRC_ENCODE(SourceInvert) |
                      CONN_TRANSFORM_BIPOLAR_SRC_ENCODE(SourceBipolar) |
                      CONN_TRANSFORM_INVERT_CTL_ENCODE(ControlInvert) |
                      CONN_TRANSFORM_BIPOLAR_CTL_ENCODE(ControlBipolar);
        return c;
    }


// *************** Articulation  ***************
// *

    /** @brief Constructor.
     *
     * Expects an 'artl' or 'art2' chunk to be given where the articulation
     * connections will be read from.
     *
     * @param artl - pointer to an 'artl' or 'art2' chunk
     * @throws Exception if no 'artl' or 'art2' chunk was given
     */
    Articulation::Articulation(RIFF::Chunk* artl) {
        pArticulationCk = artl;
        if (artl->GetChunkID() != CHUNK_ID_ART2 &&
            artl->GetChunkID() != CHUNK_ID_ARTL) {
              throw DLS::Exception("<artl-ck> or <art2-ck> chunk expected");
        }
        HeaderSize  = artl->ReadUint32();
        Connections = artl->ReadUint32();
        artl->SetPos(HeaderSize);

        pConnections = new Connection[Connections];
        Connection::conn_block_t connblock;
        for (uint32_t i = 0; i < Connections; i++) {
            artl->Read(&connblock.source, 1, 2);
            artl->Read(&connblock.control, 1, 2);
            artl->Read(&connblock.destination, 1, 2);
            artl->Read(&connblock.transform, 1, 2);
            artl->Read(&connblock.scale, 1, 4);
            pConnections[i].Init(&connblock);
        }
    }

    Articulation::~Articulation() {
       if (pConnections) delete[] pConnections;
    }

    /**
     * Apply articulation connections to the respective RIFF chunks. You
     * have to call File::Save() to make changes persistent.
     */
    void Articulation::UpdateChunks() {
        const int iEntrySize = 12; // 12 bytes per connection block
        pArticulationCk->Resize(HeaderSize + Connections * iEntrySize);
        uint8_t* pData = (uint8_t*) pArticulationCk->LoadChunkData();
        memccpy(&pData[0], &HeaderSize, 1, 2);
        memccpy(&pData[2], &Connections, 1, 2);
        for (uint32_t i = 0; i < Connections; i++) {
            Connection::conn_block_t c = pConnections[i].ToConnBlock();
            memccpy(&pData[HeaderSize + i * iEntrySize],     &c.source, 1, 2);
            memccpy(&pData[HeaderSize + i * iEntrySize + 2], &c.control, 1, 2);
            memccpy(&pData[HeaderSize + i * iEntrySize + 4], &c.destination, 1, 2);
            memccpy(&pData[HeaderSize + i * iEntrySize + 6], &c.transform, 1, 2);
            memccpy(&pData[HeaderSize + i * iEntrySize + 8], &c.scale, 1, 4);
        }
    }


// *************** Articulator  ***************
// *

    Articulator::Articulator(RIFF::List* ParentList) {
        pParentList    = ParentList;
        pArticulations = NULL;
    }

    Articulation* Articulator::GetFirstArticulation() {
        if (!pArticulations) LoadArticulations();
        if (!pArticulations) return NULL;
        ArticulationsIterator = pArticulations->begin();
        return (ArticulationsIterator != pArticulations->end()) ? *ArticulationsIterator : NULL;
    }

    Articulation* Articulator::GetNextArticulation() {
        if (!pArticulations) return NULL;
        ArticulationsIterator++;
        return (ArticulationsIterator != pArticulations->end()) ? *ArticulationsIterator : NULL;
    }

    void Articulator::LoadArticulations() {
        // prefer articulation level 2
        RIFF::List* lart = pParentList->GetSubList(LIST_TYPE_LAR2);
        if (!lart)  lart = pParentList->GetSubList(LIST_TYPE_LART);
        if (lart) {
            uint32_t artCkType = (lart->GetListType() == LIST_TYPE_LAR2) ? CHUNK_ID_ART2
                                                                         : CHUNK_ID_ARTL;
            RIFF::Chunk* art = lart->GetFirstSubChunk();
            while (art) {
                if (art->GetChunkID() == artCkType) {
                    if (!pArticulations) pArticulations = new ArticulationList;
                    pArticulations->push_back(new Articulation(art));
                }
                art = lart->GetNextSubChunk();
            }
        }
    }

    Articulator::~Articulator() {
        if (pArticulations) {
            ArticulationList::iterator iter = pArticulations->begin();
            ArticulationList::iterator end  = pArticulations->end();
            while (iter != end) {
                delete *iter;
                iter++;
            }
            delete pArticulations;
        }
    }

    /**
     * Apply all articulations to the respective RIFF chunks. You have to
     * call File::Save() to make changes persistent.
     */
    void Articulator::UpdateChunks() {
        ArticulationList::iterator iter = pArticulations->begin();
        ArticulationList::iterator end  = pArticulations->end();
        for (; iter != end; ++iter) {
            (*iter)->UpdateChunks();
        }
    }


// *************** Info  ***************
// *

    /** @brief Constructor.
     *
     * Initializes the info strings with values provided by a INFO list chunk.
     *
     * @param list - pointer to a list chunk which contains a INFO list chunk
     */
    Info::Info(RIFF::List* list) {
        pResourceListChunk = list;
        if (list) {
            RIFF::List* lstINFO = list->GetSubList(LIST_TYPE_INFO);
            if (lstINFO) {
                LoadString(CHUNK_ID_INAM, lstINFO, Name);
                LoadString(CHUNK_ID_IARL, lstINFO, ArchivalLocation);
                LoadString(CHUNK_ID_ICRD, lstINFO, CreationDate);
                LoadString(CHUNK_ID_ICMT, lstINFO, Comments);
                LoadString(CHUNK_ID_IPRD, lstINFO, Product);
                LoadString(CHUNK_ID_ICOP, lstINFO, Copyright);
                LoadString(CHUNK_ID_IART, lstINFO, Artists);
                LoadString(CHUNK_ID_IGNR, lstINFO, Genre);
                LoadString(CHUNK_ID_IKEY, lstINFO, Keywords);
                LoadString(CHUNK_ID_IENG, lstINFO, Engineer);
                LoadString(CHUNK_ID_ITCH, lstINFO, Technician);
                LoadString(CHUNK_ID_ISFT, lstINFO, Software);
                LoadString(CHUNK_ID_IMED, lstINFO, Medium);
                LoadString(CHUNK_ID_ISRC, lstINFO, Source);
                LoadString(CHUNK_ID_ISRF, lstINFO, SourceForm);
                LoadString(CHUNK_ID_ICMS, lstINFO, Commissioned);
            }
        }
    }

    /** @brief Load given INFO field.
     *
     * Load INFO field from INFO chunk with chunk ID \a ChunkID from INFO
     * list chunk \a lstINFO and save value to \a s.
     */
    void Info::LoadString(uint32_t ChunkID, RIFF::List* lstINFO, String& s) {
        RIFF::Chunk* ck = lstINFO->GetSubChunk(ChunkID);
        if (ck) {
            // TODO: no check for ZSTR terminated strings yet
            s = (char*) ck->LoadChunkData();
            ck->ReleaseChunkData();
        }
    }

    /** @brief Apply given INFO field to the respective chunk.
     *
     * Apply given info value to info chunk with ID \a ChunkID, which is a
     * subchunk of INFO list chunk \a lstINFO. If the given chunk already
     * exists, value \a s will be applied, otherwise if it doesn't exist yet
     * and \a sDefault is not an empty string, such a chunk will be created
     * and \a sDefault will be applied.
     *
     * @param ChunkID  - 32 bit RIFF chunk ID of INFO subchunk
     * @param lstINFO  - parent (INFO) RIFF list chunk
     * @param s        - current value of info field
     * @param sDefault - default value
     */
    void Info::SaveString(uint32_t ChunkID, RIFF::List* lstINFO, const String& s, const String& sDefault) {
        RIFF::Chunk* ck = lstINFO->GetSubChunk(ChunkID);
        if (ck) { // if chunk exists already, use 's' as value
            ck->Resize(s.size() + 1);
            char* pData = (char*) ck->LoadChunkData();
            memcpy(pData, s.c_str(), s.size() + 1);
        } else if (sDefault != "") { // create chunk and use default value
            ck = lstINFO->AddSubChunk(ChunkID, sDefault.size() + 1);
            char* pData = (char*) ck->LoadChunkData();
            memcpy(pData, sDefault.c_str(), sDefault.size() + 1);
        }
    }

    /** @brief Update chunks with current info values.
     *
     * Apply current INFO field values to the respective INFO chunks. You
     * have to call File::Save() to make changes persistent.
     */
    void Info::UpdateChunks() {
        if (!pResourceListChunk) return;

        // make sure INFO list chunk exists
        RIFF::List* lstINFO   = pResourceListChunk->GetSubList(LIST_TYPE_INFO);
        if (!lstINFO) lstINFO = pResourceListChunk->AddSubList(LIST_TYPE_INFO);

        // assemble default values in case the respective chunk is missing yet
        String defaultName = "NONAME";
        // get current date
        time_t now = time(NULL);
        tm* pNowBroken = localtime(&now);
        String defaultCreationDate = ToString(pNowBroken->tm_year) + "-" +
                                     ToString(pNowBroken->tm_mon)  + "-" +
                                     ToString(pNowBroken->tm_mday);
        String defaultSoftware = libraryName() + " " + libraryVersion();
        String defaultComments = "Created with " + libraryName() + " " + libraryVersion();

        // save values
        SaveString(CHUNK_ID_INAM, lstINFO, Name, defaultName);
        SaveString(CHUNK_ID_IARL, lstINFO, ArchivalLocation, String(""));
        SaveString(CHUNK_ID_ICRD, lstINFO, CreationDate, defaultCreationDate);
        SaveString(CHUNK_ID_ICMT, lstINFO, Comments, defaultComments);
        SaveString(CHUNK_ID_IPRD, lstINFO, Product, String(""));
        SaveString(CHUNK_ID_ICOP, lstINFO, Copyright, String(""));
        SaveString(CHUNK_ID_IART, lstINFO, Artists, String(""));
        SaveString(CHUNK_ID_IGNR, lstINFO, Genre, String(""));
        SaveString(CHUNK_ID_IKEY, lstINFO, Keywords, String(""));
        SaveString(CHUNK_ID_IENG, lstINFO, Engineer, String(""));
        SaveString(CHUNK_ID_ITCH, lstINFO, Technician, String(""));
        SaveString(CHUNK_ID_ISFT, lstINFO, Software, defaultSoftware);
        SaveString(CHUNK_ID_IMED, lstINFO, Medium, String(""));
        SaveString(CHUNK_ID_ISRC, lstINFO, Source, String(""));
        SaveString(CHUNK_ID_ISRF, lstINFO, SourceForm, String(""));
        SaveString(CHUNK_ID_ICMS, lstINFO, Commissioned, String(""));
    }


// *************** Resource ***************
// *

    /** @brief Constructor.
     *
     * Initializes the 'Resource' object with values provided by a given
     * INFO list chunk and a DLID chunk (the latter optional).
     *
     * @param Parent      - pointer to parent 'Resource', NULL if this is
     *                      the toplevel 'Resource' object
     * @param lstResource - pointer to an INFO list chunk
     */
    Resource::Resource(Resource* Parent, RIFF::List* lstResource) {
        pParent = Parent;
        pResourceList = lstResource;

        pInfo = new Info(lstResource);

        RIFF::Chunk* ckDLSID = lstResource->GetSubChunk(CHUNK_ID_DLID);
        if (ckDLSID) {
            pDLSID = new dlsid_t;
            ckDLSID->Read(&pDLSID->ulData1, 1, 4);
            ckDLSID->Read(&pDLSID->usData2, 1, 2);
            ckDLSID->Read(&pDLSID->usData3, 1, 2);
            ckDLSID->Read(pDLSID->abData, 8, 1);
        }
        else pDLSID = NULL;
    }

    Resource::~Resource() {
        if (pDLSID) delete pDLSID;
        if (pInfo)  delete pInfo;
    }

    /** @brief Update chunks with current Resource data.
     *
     * Apply Resource data persistently below the previously given resource
     * list chunk. This will currently only include the INFO data. The DLSID
     * will not be applied at the moment (yet).
     *
     * You have to call File::Save() to make changes persistent.
     */
    void Resource::UpdateChunks() {
        pInfo->UpdateChunks();
        //TODO: save DLSID
    }


// *************** Sampler ***************
// *

    Sampler::Sampler(RIFF::List* ParentList) {
        pParentList       = ParentList;
        RIFF::Chunk* wsmp = ParentList->GetSubChunk(CHUNK_ID_WSMP);
        if (wsmp) {
            uiHeaderSize   = wsmp->ReadUint32();
            UnityNote      = wsmp->ReadUint16();
            FineTune       = wsmp->ReadInt16();
            Gain           = wsmp->ReadInt32();
            SamplerOptions = wsmp->ReadUint32();
            SampleLoops    = wsmp->ReadUint32();
        } else { // 'wsmp' chunk missing
            uiHeaderSize   = 0;
            UnityNote      = 64;
            FineTune       = 0; // +- 0 cents
            Gain           = 0; // 0 dB
            SamplerOptions = F_WSMP_NO_COMPRESSION;
            SampleLoops    = 0;
        }
        NoSampleDepthTruncation = SamplerOptions & F_WSMP_NO_TRUNCATION;
        NoSampleCompression     = SamplerOptions & F_WSMP_NO_COMPRESSION;
        pSampleLoops            = (SampleLoops) ? new sample_loop_t[SampleLoops] : NULL;
        if (SampleLoops) {
            wsmp->SetPos(uiHeaderSize);
            for (uint32_t i = 0; i < SampleLoops; i++) {
                wsmp->Read(pSampleLoops + i, 4, 4);
                if (pSampleLoops[i].Size > sizeof(sample_loop_t)) { // if loop struct was extended
                    wsmp->SetPos(pSampleLoops[i].Size - sizeof(sample_loop_t), RIFF::stream_curpos);
                }
            }
        }
    }

    Sampler::~Sampler() {
        if (pSampleLoops) delete[] pSampleLoops;
    }

    /**
     * Apply all sample player options to the respective RIFF chunk. You
     * have to call File::Save() to make changes persistent.
     */
    void Sampler::UpdateChunks() {
        // make sure 'wsmp' chunk exists
        RIFF::Chunk* wsmp = pParentList->GetSubChunk(CHUNK_ID_WSMP);
        if (!wsmp) {
            uiHeaderSize = 20;
            wsmp = pParentList->AddSubChunk(CHUNK_ID_WSMP, uiHeaderSize + SampleLoops * 16);
        }
        uint8_t* pData = (uint8_t*) wsmp->LoadChunkData();
        // update headers size
        memccpy(&pData[0], &uiHeaderSize, 1, 4);
        // update respective sampler options bits
        SamplerOptions = (NoSampleDepthTruncation) ? SamplerOptions | F_WSMP_NO_TRUNCATION
                                                   : SamplerOptions & (~F_WSMP_NO_TRUNCATION);
        SamplerOptions = (NoSampleCompression) ? SamplerOptions | F_WSMP_NO_COMPRESSION
                                               : SamplerOptions & (~F_WSMP_NO_COMPRESSION);
        // update loop definitions
        for (uint32_t i = 0; i < SampleLoops; i++) {
            //FIXME: this does not handle extended loop structs correctly
            memccpy(&pData[uiHeaderSize + i * 16], pSampleLoops + i, 4, 4);
        }
    }


// *************** Sample ***************
// *

    /** @brief Constructor.
     *
     * Load an existing sample or create a new one. A 'wave' list chunk must
     * be given to this constructor. In case the given 'wave' list chunk
     * contains a 'fmt' and 'data' chunk, the format and sample data will be
     * loaded from there, otherwise default values will be used and those
     * chunks will be created when File::Save() will be called later on.
     *
     * @param pFile          - pointer to DLS::File where this sample is
     *                         located (or will be located)
     * @param waveList       - pointer to 'wave' list chunk which is (or
     *                         will be) associated with this sample
     * @param WavePoolOffset - offset of this sample data from wave pool
     *                         ('wvpl') list chunk
     */
    Sample::Sample(File* pFile, RIFF::List* waveList, unsigned long WavePoolOffset) : Resource(pFile, waveList) {
        pWaveList = waveList;
        ulWavePoolOffset = WavePoolOffset - LIST_HEADER_SIZE;
        pCkFormat = waveList->GetSubChunk(CHUNK_ID_FMT);
        pCkData   = waveList->GetSubChunk(CHUNK_ID_DATA);
        if (pCkFormat) {
            // common fields
            FormatTag              = pCkFormat->ReadUint16();
            Channels               = pCkFormat->ReadUint16();
            SamplesPerSecond       = pCkFormat->ReadUint32();
            AverageBytesPerSecond  = pCkFormat->ReadUint32();
            BlockAlign             = pCkFormat->ReadUint16();
            // PCM format specific
            if (FormatTag == WAVE_FORMAT_PCM) {
                BitDepth     = pCkFormat->ReadUint16();
                FrameSize    = (FormatTag == WAVE_FORMAT_PCM) ? (BitDepth / 8) * Channels
                                                            : 0;
            } else { // unsupported sample data format
                BitDepth     = 0;
                FrameSize    = 0;
            }
        } else { // 'fmt' chunk missing
            FormatTag              = WAVE_FORMAT_PCM;
            BitDepth               = 16;
            Channels               = 1;
            SamplesPerSecond       = 44100;
            AverageBytesPerSecond  = (BitDepth / 8) * SamplesPerSecond * Channels;
            FrameSize              = (BitDepth / 8) * Channels;
            BlockAlign             = FrameSize;
        }
        SamplesTotal = (pCkData) ? (FormatTag == WAVE_FORMAT_PCM) ? pCkData->GetSize() / FrameSize
                                                                  : 0
                                 : 0;
    }

    /** @brief Destructor.
     *
     * Removes RIFF chunks associated with this Sample and frees all
     * memory occupied by this sample.
     */
    Sample::~Sample() {
        RIFF::List* pParent = pWaveList->GetParent();
        pParent->DeleteSubChunk(pWaveList);
    }

    /** @brief Load sample data into RAM.
     *
     * In case the respective 'data' chunk exists, the sample data will be
     * loaded into RAM (if not done already) and a pointer to the data in
     * RAM will be returned. If this is a new sample, you have to call
     * Resize() with the desired sample size to create the mandatory RIFF
     * chunk for the sample wave data.
     *
     * You can call LoadChunkData() again if you previously scheduled to
     * enlarge the sample data RIFF chunk with a Resize() call. In that case
     * the buffer will be enlarged to the new, scheduled size and you can
     * already place the sample wave data to the buffer and finally call
     * File::Save() to enlarge the sample data's chunk physically and write
     * the new sample wave data in one rush. This approach is definitely
     * recommended if you have to enlarge and write new sample data to a lot
     * of samples.
     *
     * <b>Caution:</b> the buffer pointer will be invalidated once
     * File::Save() was called. You have to call LoadChunkData() again to
     * get a new, valid pointer whenever File::Save() was called.
     *
     * @returns pointer to sample data in RAM, NULL in case respective
     *          'data' chunk does not exist (yet)
     * @throws Exception if data buffer could not be enlarged
     * @see Resize(), File::Save()
     */
    void* Sample::LoadSampleData() {
        return (pCkData) ? pCkData->LoadChunkData() : NULL;
    }

    /** @brief Free sample data from RAM.
     *
     * In case sample data was previously successfully loaded into RAM with
     * LoadSampleData(), this method will free the sample data from RAM.
     */
    void Sample::ReleaseSampleData() {
        if (pCkData) pCkData->ReleaseChunkData();
    }

    /** @brief Returns sample size.
     *
     * Returns the sample wave form's data size (in sample points). This is
     * actually the current, physical size (converted to sample points) of
     * the RIFF chunk which encapsulates the sample's wave data. The
     * returned value is dependant to the current FrameSize value.
     *
     * @returns number of sample points or 0 if FormatTag != WAVE_FORMAT_PCM
     * @see FrameSize, FormatTag
     */
    unsigned long Sample::GetSize() {
        if (FormatTag != WAVE_FORMAT_PCM) return 0;
        return (pCkData) ? pCkData->GetSize() / FrameSize : 0;
    }

    /** @brief Resize sample.
     *
     * Resizes the sample's wave form data, that is the actual size of
     * sample wave data possible to be written for this sample. This call
     * will return immediately and just schedule the resize operation. You
     * should call File::Save() to actually perform the resize operation(s)
     * "physically" to the file. As this can take a while on large files, it
     * is recommended to call Resize() first on all samples which have to be
     * resized and finally to call File::Save() to perform all those resize
     * operations in one rush.
     *
     * The actual size (in bytes) is dependant to the current FrameSize
     * value. You may want to set FrameSize before calling Resize().
     *
     * <b>Caution:</b> You cannot directly write to enlarged samples before
     * calling File::Save() as this might exceed the current sample's
     * boundary!
     *
     * Also note: only WAVE_FORMAT_PCM is currently supported, that is
     * FormatTag must be WAVE_FORMAT_PCM. Trying to resize samples with
     * other formats will fail!
     *
     * @param iNewSize - new sample wave data size in sample points (must be
     *                   greater than zero)
     * @throws Excecption if FormatTag != WAVE_FORMAT_PCM
     * @throws Exception if \a iNewSize is less than 1
     * @see File::Save(), FrameSize, FormatTag
     */
    void Sample::Resize(int iNewSize) {
        if (FormatTag != WAVE_FORMAT_PCM) throw Exception("Sample's format is not WAVE_FORMAT_PCM");
        if (iNewSize < 1) throw Exception("Sample size must be at least one sample point");
        const int iSizeInBytes = iNewSize * FrameSize;
        pCkData = pWaveList->GetSubChunk(CHUNK_ID_DATA);
        if (pCkData) pCkData->Resize(iSizeInBytes);
        else pCkData = pWaveList->AddSubChunk(CHUNK_ID_DATA, iSizeInBytes);
    }

    /**
     * Sets the position within the sample (in sample points, not in
     * bytes). Use this method and <i>Read()</i> if you don't want to load
     * the sample into RAM, thus for disk streaming.
     *
     * Also note: only WAVE_FORMAT_PCM is currently supported, that is
     * FormatTag must be WAVE_FORMAT_PCM. Trying to reposition the sample
     * with other formats will fail!
     *
     * @param SampleCount  number of sample points
     * @param Whence       to which relation \a SampleCount refers to
     * @returns new position within the sample, 0 if
     *          FormatTag != WAVE_FORMAT_PCM
     * @throws Exception if no data RIFF chunk was created for the sample yet
     * @see FrameSize, FormatTag
     */
    unsigned long Sample::SetPos(unsigned long SampleCount, RIFF::stream_whence_t Whence) {
        if (FormatTag != WAVE_FORMAT_PCM) return 0; // failed: wave data not PCM format
        if (!pCkData) throw Exception("No data chunk created for sample yet, call Sample::Resize() to create one");
        unsigned long orderedBytes = SampleCount * FrameSize;
        unsigned long result = pCkData->SetPos(orderedBytes, Whence);
        return (result == orderedBytes) ? SampleCount
                                        : result / FrameSize;
    }

    /**
     * Reads \a SampleCount number of sample points from the current
     * position into the buffer pointed by \a pBuffer and increments the
     * position within the sample. Use this method and <i>SetPos()</i> if you
     * don't want to load the sample into RAM, thus for disk streaming.
     *
     * @param pBuffer      destination buffer
     * @param SampleCount  number of sample points to read
     */
    unsigned long Sample::Read(void* pBuffer, unsigned long SampleCount) {
        if (FormatTag != WAVE_FORMAT_PCM) return 0; // failed: wave data not PCM format
        return pCkData->Read(pBuffer, SampleCount, FrameSize); // FIXME: channel inversion due to endian correction?
    }

    /** @brief Write sample wave data.
     *
     * Writes \a SampleCount number of sample points from the buffer pointed
     * by \a pBuffer and increments the position within the sample. Use this
     * method to directly write the sample data to disk, i.e. if you don't
     * want or cannot load the whole sample data into RAM.
     *
     * You have to Resize() the sample to the desired size and call
     * File::Save() <b>before</b> using Write().
     *
     * @param pBuffer     - source buffer
     * @param SampleCount - number of sample points to write
     * @throws Exception if current sample size is too small
     * @see LoadSampleData()
     */
    unsigned long Sample::Write(void* pBuffer, unsigned long SampleCount) {
        if (FormatTag != WAVE_FORMAT_PCM) return 0; // failed: wave data not PCM format
        if (GetSize() < SampleCount) throw Exception("Could not write sample data, current sample size to small");
        return pCkData->Write(pBuffer, SampleCount, FrameSize); // FIXME: channel inversion due to endian correction?
    }

    /**
     * Apply sample and its settings to the respective RIFF chunks. You have
     * to call File::Save() to make changes persistent.
     *
     * @throws Exception if FormatTag != WAVE_FORMAT_PCM or no sample data
     *                   was provided yet
     */
    void Sample::UpdateChunks() {
        if (FormatTag != WAVE_FORMAT_PCM)
            throw Exception("Could not save sample, only PCM format is supported");
        // we refuse to do anything if not sample wave form was provided yet
        if (!pCkData)
            throw Exception("Could not save sample, there is no sample data to save");
        // update chunks of base class as well
        Resource::UpdateChunks();
        // make sure 'fmt' chunk exists
        RIFF::Chunk* pCkFormat = pWaveList->GetSubChunk(CHUNK_ID_FMT);
        if (!pCkFormat) pCkFormat = pWaveList->AddSubChunk(CHUNK_ID_FMT, 16); // assumes PCM format
        uint8_t* pData = (uint8_t*) pCkFormat->LoadChunkData();
        // update 'fmt' chunk
        memccpy(&pData[0], &FormatTag, 1, 2);
        memccpy(&pData[2], &Channels,  1, 2);
        memccpy(&pData[4], &SamplesPerSecond, 1, 4);
        memccpy(&pData[8], &AverageBytesPerSecond, 1, 4);
        memccpy(&pData[12], &BlockAlign, 1, 2);
        memccpy(&pData[14], &BitDepth, 1, 2); // assuming PCM format
    }


// *************** Region ***************
// *

    Region::Region(Instrument* pInstrument, RIFF::List* rgnList) : Resource(pInstrument, rgnList), Articulator(rgnList), Sampler(rgnList) {
        pCkRegion = rgnList;

        // articulation informations
        RIFF::Chunk* rgnh = rgnList->GetSubChunk(CHUNK_ID_RGNH);
        if (rgnh) {
            rgnh->Read(&KeyRange, 2, 2);
            rgnh->Read(&VelocityRange, 2, 2);
            FormatOptionFlags = rgnh->ReadUint16();
            KeyGroup = rgnh->ReadUint16();
            // Layer is optional
            if (rgnh->RemainingBytes() >= sizeof(uint16_t)) {
                rgnh->Read(&Layer, 1, sizeof(uint16_t));
            } else Layer = 0;
        } else { // 'rgnh' chunk is missing
            KeyRange.low  = 0;
            KeyRange.high = 127;
            VelocityRange.low  = 0;
            VelocityRange.high = 127;
            FormatOptionFlags = F_RGN_OPTION_SELFNONEXCLUSIVE;
            KeyGroup = 0;
            Layer = 0;
        }
        SelfNonExclusive = FormatOptionFlags & F_RGN_OPTION_SELFNONEXCLUSIVE;

        // sample informations
        RIFF::Chunk* wlnk = rgnList->GetSubChunk(CHUNK_ID_WLNK);
        if (wlnk) {
            WaveLinkOptionFlags = wlnk->ReadUint16();
            PhaseGroup          = wlnk->ReadUint16();
            Channel             = wlnk->ReadUint32();
            WavePoolTableIndex  = wlnk->ReadUint32();
        } else { // 'wlnk' chunk is missing
            WaveLinkOptionFlags = 0;
            PhaseGroup          = 0;
            Channel             = 0; // mono
            WavePoolTableIndex  = 0; // first entry in wave pool table
        }
        PhaseMaster  = WaveLinkOptionFlags & F_WAVELINK_PHASE_MASTER;
        MultiChannel = WaveLinkOptionFlags & F_WAVELINK_MULTICHANNEL;

        pSample = NULL;
    }

    /** @brief Destructor.
     *
     * Removes RIFF chunks associated with this Region.
     */
    Region::~Region() {
        RIFF::List* pParent = pCkRegion->GetParent();
        pParent->DeleteSubChunk(pCkRegion);
    }

    Sample* Region::GetSample() {
        if (pSample) return pSample;
        File* file = (File*) GetParent()->GetParent();
        unsigned long soughtoffset = file->pWavePoolTable[WavePoolTableIndex];
        Sample* sample = file->GetFirstSample();
        while (sample) {
            if (sample->ulWavePoolOffset == soughtoffset) return (pSample = sample);
            sample = file->GetNextSample();
        }
        return NULL;
    }

    /**
     * Assign another sample to this Region.
     *
     * @param pSample - sample to be assigned
     */
    void Region::SetSample(Sample* pSample) {
        this->pSample = pSample;
        WavePoolTableIndex = 0; // we update this offset when we Save()
    }

    /**
     * Apply Region settings to the respective RIFF chunks. You have to
     * call File::Save() to make changes persistent.
     *
     * @throws Exception - if the Region's sample could not be found
     */
    void Region::UpdateChunks() {
        // make sure 'rgnh' chunk exists
        RIFF::Chunk* rgnh = pCkRegion->GetSubChunk(CHUNK_ID_RGNH);
        if (!rgnh) rgnh = pCkRegion->AddSubChunk(CHUNK_ID_RGNH, 14);
        uint8_t* pData = (uint8_t*) rgnh->LoadChunkData();
        FormatOptionFlags = (SelfNonExclusive)
                                ? FormatOptionFlags | F_RGN_OPTION_SELFNONEXCLUSIVE
                                : FormatOptionFlags & (~F_RGN_OPTION_SELFNONEXCLUSIVE);
        // update 'rgnh' chunk
        memccpy(&pData[0], &KeyRange, 2, 2);
        memccpy(&pData[4], &VelocityRange, 2, 2);
        memccpy(&pData[8], &FormatOptionFlags, 1, 2);
        memccpy(&pData[10], &KeyGroup, 1, 2);
        memccpy(&pData[12], &Layer, 1, 2);

        // update chunks of base classes as well
        Resource::UpdateChunks();
        Articulator::UpdateChunks();
        Sampler::UpdateChunks();

        // make sure 'wlnk' chunk exists
        RIFF::Chunk* wlnk = pCkRegion->GetSubChunk(CHUNK_ID_WLNK);
        if (!wlnk) wlnk = pCkRegion->AddSubChunk(CHUNK_ID_WLNK, 12);
        pData = (uint8_t*) wlnk->LoadChunkData();
        WaveLinkOptionFlags = (PhaseMaster)
                                  ? WaveLinkOptionFlags | F_WAVELINK_PHASE_MASTER
                                  : WaveLinkOptionFlags & (~F_WAVELINK_PHASE_MASTER);
        WaveLinkOptionFlags = (MultiChannel)
                                  ? WaveLinkOptionFlags | F_WAVELINK_MULTICHANNEL
                                  : WaveLinkOptionFlags & (~F_WAVELINK_MULTICHANNEL);
        // get sample's wave pool table index
        int index = -1;
        File* pFile = (File*) GetParent()->GetParent();
        File::SampleList::iterator iter = pFile->pSamples->begin();
        File::SampleList::iterator end  = pFile->pSamples->end();
        for (int i = 0; iter != end; ++iter, i++) {
            if (*iter == pSample) {
                index = i;
                break;
            }
        }
        if (index < 0) throw Exception("Could not save Region, could not find Region's sample");
        WavePoolTableIndex = index;
        // update 'wlnk' chunk
        memccpy(&pData[0], &WaveLinkOptionFlags, 1, 2);
        memccpy(&pData[2], &PhaseGroup, 1, 2);
        memccpy(&pData[4], &Channel, 1, 4);
        memccpy(&pData[8], &WavePoolTableIndex, 1, 4);
    }


// *************** Instrument ***************
// *

    /** @brief Constructor.
     *
     * Load an existing instrument definition or create a new one. An 'ins'
     * list chunk must be given to this constructor. In case this 'ins' list
     * chunk contains a 'insh' chunk, the instrument data fields will be
     * loaded from there, otherwise default values will be used and the
     * 'insh' chunk will be created once File::Save() was called.
     *
     * @param pFile   - pointer to DLS::File where this instrument is
     *                  located (or will be located)
     * @param insList - pointer to 'ins' list chunk which is (or will be)
     *                  associated with this instrument
     */
    Instrument::Instrument(File* pFile, RIFF::List* insList) : Resource(pFile, insList), Articulator(insList) {
        pCkInstrument = insList;

        midi_locale_t locale;
        RIFF::Chunk* insh = pCkInstrument->GetSubChunk(CHUNK_ID_INSH);
        if (insh) {
            Regions = insh->ReadUint32();
            insh->Read(&locale, 2, 4);
        } else { // 'insh' chunk missing
            Regions = 0;
            locale.bank       = 0;
            locale.instrument = 0;
        }

        MIDIProgram    = locale.instrument;
        IsDrum         = locale.bank & DRUM_TYPE_MASK;
        MIDIBankCoarse = (uint8_t) MIDI_BANK_COARSE(locale.bank);
        MIDIBankFine   = (uint8_t) MIDI_BANK_FINE(locale.bank);
        MIDIBank       = MIDI_BANK_MERGE(MIDIBankCoarse, MIDIBankFine);

        pRegions = NULL;
    }

    Region* Instrument::GetFirstRegion() {
        if (!pRegions) LoadRegions();
        if (!pRegions) return NULL;
        RegionsIterator = pRegions->begin();
        return (RegionsIterator != pRegions->end()) ? *RegionsIterator : NULL;
    }

    Region* Instrument::GetNextRegion() {
        if (!pRegions) return NULL;
        RegionsIterator++;
        return (RegionsIterator != pRegions->end()) ? *RegionsIterator : NULL;
    }

    void Instrument::LoadRegions() {
        RIFF::List* lrgn = pCkInstrument->GetSubList(LIST_TYPE_LRGN);
        if (!lrgn) throw DLS::Exception("Mandatory chunks in <ins > chunk not found.");
        uint32_t regionCkType = (lrgn->GetSubList(LIST_TYPE_RGN2)) ? LIST_TYPE_RGN2 : LIST_TYPE_RGN; // prefer regions level 2
        RIFF::List* rgn = lrgn->GetFirstSubList();
        while (rgn) {
            if (rgn->GetListType() == regionCkType) {
                if (!pRegions) pRegions = new RegionList;
                pRegions->push_back(new Region(this, rgn));
            }
            rgn = lrgn->GetNextSubList();
        }
    }

    Region* Instrument::AddRegion() {
        if (!pRegions) pRegions = new RegionList;
        RIFF::List* lrgn = pCkInstrument->GetSubList(LIST_TYPE_LRGN);
        if (!lrgn)  lrgn = pCkInstrument->AddSubList(LIST_TYPE_LRGN);
        RIFF::List* rgn = lrgn->AddSubList(LIST_TYPE_RGN);
        Region* pNewRegion = new Region(this, rgn);
        pRegions->push_back(pNewRegion);
        return pNewRegion;
    }

    void Instrument::DeleteRegion(Region* pRegion) {
        if (!pRegions) return;
        RegionList::iterator iter = find(pRegions->begin(), pRegions->end(), pRegion);
        if (iter == pRegions->end()) return;
        pRegions->erase(iter);
        delete pRegion;
    }

    /**
     * Apply Instrument with all its Regions to the respective RIFF chunks.
     * You have to call File::Save() to make changes persistent.
     *
     * @throws Exception - on errors
     */
    void Instrument::UpdateChunks() {
        // first update base classes' chunks
        Resource::UpdateChunks();
        Articulator::UpdateChunks();
        // make sure 'insh' chunk exists
        RIFF::Chunk* insh = pCkInstrument->GetSubChunk(CHUNK_ID_INSH);
        if (!insh) insh = pCkInstrument->AddSubChunk(CHUNK_ID_INSH, 12);
        uint8_t* pData = (uint8_t*) insh->LoadChunkData();
        // update 'insh' chunk
        Regions = pRegions->size();
        midi_locale_t locale;
        locale.instrument = MIDIProgram;
        locale.bank       = MIDI_BANK_ENCODE(MIDIBankCoarse, MIDIBankFine);
        locale.bank       = (IsDrum) ? locale.bank | DRUM_TYPE_MASK : locale.bank & (~DRUM_TYPE_MASK);
        MIDIBank          = MIDI_BANK_MERGE(MIDIBankCoarse, MIDIBankFine); // just a sync, when we're at it
        memccpy(&pData[0], &Regions, 1, 4);
        memccpy(&pData[4], &locale, 2, 4);
        // update Region's chunks
        RegionList::iterator iter = pRegions->begin();
        RegionList::iterator end  = pRegions->end();
        for (; iter != end; ++iter) {
            (*iter)->UpdateChunks();
        }
    }

    /** @brief Destructor.
     *
     * Removes RIFF chunks associated with this Instrument and frees all
     * memory occupied by this instrument.
     */
    Instrument::~Instrument() {
        if (pRegions) {
            RegionList::iterator iter = pRegions->begin();
            RegionList::iterator end  = pRegions->end();
            while (iter != end) {
                delete *iter;
                iter++;
            }
            delete pRegions;
        }
        // remove instrument's chunks
        RIFF::List* pParent = pCkInstrument->GetParent();
        pParent->DeleteSubChunk(pCkInstrument);
    }


// *************** File ***************
// *

    /** @brief Constructor.
     *
     * Default constructor, use this to create an empty DLS file. You have
     * to add samples, instruments and finally call Save() to actually write
     * a DLS file.
     */
    File::File() : Resource(NULL, pRIFF = new RIFF::File(RIFF_TYPE_DLS)) {
        pVersion = new version_t;
        pVersion->major   = 0;
        pVersion->minor   = 0;
        pVersion->release = 0;
        pVersion->build   = 0;

        Instruments      = 0;
        WavePoolCount    = 0;
        pWavePoolTable   = NULL;
        pWavePoolTableHi = NULL;
        WavePoolHeaderSize = 8;

        pSamples     = NULL;
        pInstruments = NULL;

        b64BitWavePoolOffsets = false;
    }

    /** @brief Constructor.
     *
     * Load an existing DLS file.
     *
     * @param pRIFF - pointer to a RIFF file which is actually the DLS file
     *                to load
     * @throws Exception if given file is not a DLS file, expected chunks
     *                   are missing
     */
    File::File(RIFF::File* pRIFF) : Resource(NULL, pRIFF) {
        if (!pRIFF) throw DLS::Exception("NULL pointer reference to RIFF::File object.");
        this->pRIFF = pRIFF;

        RIFF::Chunk* ckVersion = pRIFF->GetSubChunk(CHUNK_ID_VERS);
        if (ckVersion) {
            pVersion = new version_t;
            ckVersion->Read(pVersion, 4, 2);
        }
        else pVersion = NULL;

        RIFF::Chunk* colh = pRIFF->GetSubChunk(CHUNK_ID_COLH);
        if (!colh) throw DLS::Exception("Mandatory chunks in RIFF list chunk not found.");
        Instruments = colh->ReadUint32();

        RIFF::Chunk* ptbl = pRIFF->GetSubChunk(CHUNK_ID_PTBL);
        if (!ptbl) throw DLS::Exception("Mandatory <ptbl> chunk not found.");
        WavePoolHeaderSize = ptbl->ReadUint32();
        WavePoolCount  = ptbl->ReadUint32();
        pWavePoolTable = new uint32_t[WavePoolCount];
        pWavePoolTableHi = new uint32_t[WavePoolCount];
        ptbl->SetPos(WavePoolHeaderSize);

        // Check for 64 bit offsets (used in gig v3 files)
        b64BitWavePoolOffsets = (ptbl->GetSize() - WavePoolHeaderSize == WavePoolCount * 8);
        if (b64BitWavePoolOffsets) {
            for (int i = 0 ; i < WavePoolCount ; i++) {
                pWavePoolTableHi[i] = ptbl->ReadUint32();
                pWavePoolTable[i] = ptbl->ReadUint32();
                if (pWavePoolTable[i] & 0x80000000)
                    throw DLS::Exception("Files larger than 2 GB not yet supported");
            }
        } else { // conventional 32 bit offsets
            ptbl->Read(pWavePoolTable, WavePoolCount, sizeof(uint32_t));
            for (int i = 0 ; i < WavePoolCount ; i++) pWavePoolTableHi[i] = 0;
        }

        pSamples     = NULL;
        pInstruments = NULL;
    }

    File::~File() {
        if (pInstruments) {
            InstrumentList::iterator iter = pInstruments->begin();
            InstrumentList::iterator end  = pInstruments->end();
            while (iter != end) {
                delete *iter;
                iter++;
            }
            delete pInstruments;
        }

        if (pSamples) {
            SampleList::iterator iter = pSamples->begin();
            SampleList::iterator end  = pSamples->end();
            while (iter != end) {
                delete *iter;
                iter++;
            }
            delete pSamples;
        }

        if (pWavePoolTable) delete[] pWavePoolTable;
        if (pWavePoolTableHi) delete[] pWavePoolTableHi;
        if (pVersion) delete pVersion;
    }

    Sample* File::GetFirstSample() {
        if (!pSamples) LoadSamples();
        if (!pSamples) return NULL;
        SamplesIterator = pSamples->begin();
        return (SamplesIterator != pSamples->end()) ? *SamplesIterator : NULL;
    }

    Sample* File::GetNextSample() {
        if (!pSamples) return NULL;
        SamplesIterator++;
        return (SamplesIterator != pSamples->end()) ? *SamplesIterator : NULL;
    }

    void File::LoadSamples() {
        RIFF::List* wvpl = pRIFF->GetSubList(LIST_TYPE_WVPL);
        if (wvpl) {
            unsigned long wvplFileOffset = wvpl->GetFilePos();
            RIFF::List* wave = wvpl->GetFirstSubList();
            while (wave) {
                if (wave->GetListType() == LIST_TYPE_WAVE) {
                    if (!pSamples) pSamples = new SampleList;
                    unsigned long waveFileOffset = wave->GetFilePos();
                    pSamples->push_back(new Sample(this, wave, waveFileOffset - wvplFileOffset));
                }
                wave = wvpl->GetNextSubList();
            }
        }
        else { // Seen a dwpl list chunk instead of a wvpl list chunk in some file (officially not DLS compliant)
            RIFF::List* dwpl = pRIFF->GetSubList(LIST_TYPE_DWPL);
            if (dwpl) {
                unsigned long dwplFileOffset = dwpl->GetFilePos();
                RIFF::List* wave = dwpl->GetFirstSubList();
                while (wave) {
                    if (wave->GetListType() == LIST_TYPE_WAVE) {
                        if (!pSamples) pSamples = new SampleList;
                        unsigned long waveFileOffset = wave->GetFilePos();
                        pSamples->push_back(new Sample(this, wave, waveFileOffset - dwplFileOffset));
                    }
                    wave = dwpl->GetNextSubList();
                }
            }
        }
    }

    /** @brief Add a new sample.
     *
     * This will create a new Sample object for the DLS file. You have to
     * call Save() to make this persistent to the file.
     *
     * @returns pointer to new Sample object
     */
    Sample* File::AddSample() {
       __ensureMandatoryChunksExist();
       RIFF::List* wvpl = pRIFF->GetSubList(LIST_TYPE_WVPL);
       // create new Sample object and its respective 'wave' list chunk
       if (!pSamples) pSamples = new SampleList;
       RIFF::List* wave = wvpl->AddSubList(LIST_TYPE_WAVE);
       Sample* pSample = new Sample(this, wave, 0 /*arbitrary value, we update offsets when we save*/);
       pSamples->push_back(pSample);
       return pSample;
    }

    /** @brief Delete a sample.
     *
     * This will delete the given Sample object from the DLS file. You have
     * to call Save() to make this persistent to the file.
     *
     * @param pSample - sample to delete
     */
    void File::DeleteSample(Sample* pSample) {
        if (!pSamples) return;
        SampleList::iterator iter = find(pSamples->begin(), pSamples->end(), pSample);
        if (iter == pSamples->end()) return;
        pSamples->erase(iter);
        delete pSample;
    }

    Instrument* File::GetFirstInstrument() {
        if (!pInstruments) LoadInstruments();
        if (!pInstruments) return NULL;
        InstrumentsIterator = pInstruments->begin();
        return (InstrumentsIterator != pInstruments->end()) ? *InstrumentsIterator : NULL;
    }

    Instrument* File::GetNextInstrument() {
        if (!pInstruments) return NULL;
        InstrumentsIterator++;
        return (InstrumentsIterator != pInstruments->end()) ? *InstrumentsIterator : NULL;
    }

    void File::LoadInstruments() {
        RIFF::List* lstInstruments = pRIFF->GetSubList(LIST_TYPE_LINS);
        if (lstInstruments) {
            RIFF::List* lstInstr = lstInstruments->GetFirstSubList();
            while (lstInstr) {
                if (lstInstr->GetListType() == LIST_TYPE_INS) {
                    if (!pInstruments) pInstruments = new InstrumentList;
                    pInstruments->push_back(new Instrument(this, lstInstr));
                }
                lstInstr = lstInstruments->GetNextSubList();
            }
        }
    }

    /** @brief Add a new instrument definition.
     *
     * This will create a new Instrument object for the DLS file. You have
     * to call Save() to make this persistent to the file.
     *
     * @returns pointer to new Instrument object
     */
    Instrument* File::AddInstrument() {
       __ensureMandatoryChunksExist();
       if (!pInstruments) pInstruments = new InstrumentList;
       RIFF::List* lstInstruments = pRIFF->GetSubList(LIST_TYPE_LINS);
       RIFF::List* lstInstr = lstInstruments->AddSubList(LIST_TYPE_INS);
       Instrument* pInstrument = new Instrument(this, lstInstr);
       pInstruments->push_back(pInstrument);
       return pInstrument;
    }

    /** @brief Delete a instrument.
     *
     * This will delete the given Instrument object from the DLS file. You
     * have to call Save() to make this persistent to the file.
     *
     * @param pInstrument - instrument to delete
     */
    void File::DeleteInstrument(Instrument* pInstrument) {
        if (!pInstruments) return;
        InstrumentList::iterator iter = find(pInstruments->begin(), pInstruments->end(), pInstrument);
        if (iter == pInstruments->end()) return;
        pInstruments->erase(iter);
        delete pInstrument;
    }

    /**
     * Apply all the DLS file's current instruments, samples and settings to
     * the respective RIFF chunks. You have to call Save() to make changes
     * persistent.
     *
     * @throws Exception - on errors
     */
    void File::UpdateChunks() {
        // first update base class's chunks
        Resource::UpdateChunks();

        // if version struct exists, update 'vers' chunk
        if (pVersion) {
            RIFF::Chunk* ckVersion    = pRIFF->GetSubChunk(CHUNK_ID_VERS);
            if (!ckVersion) ckVersion = pRIFF->AddSubChunk(CHUNK_ID_VERS, 8);
            uint8_t* pData = (uint8_t*) ckVersion->LoadChunkData();
            memccpy(pData, pVersion, 2, 4);
        }

        // update 'colh' chunk
        Instruments = (pInstruments) ? pInstruments->size() : 0;
        RIFF::Chunk* colh = pRIFF->GetSubChunk(CHUNK_ID_COLH);
        if (!colh)   colh = pRIFF->AddSubChunk(CHUNK_ID_COLH, 4);
        uint8_t* pData = (uint8_t*) colh->LoadChunkData();
        memccpy(pData, &Instruments, 1, 4);

        // update instrument's chunks
        if (pInstruments) {
            InstrumentList::iterator iter = pInstruments->begin();
            InstrumentList::iterator end  = pInstruments->end();
            for (; iter != end; ++iter) {
                (*iter)->UpdateChunks();
            }
        }

        // update 'ptbl' chunk
        const int iSamples = (pSamples) ? pSamples->size() : 0;
        const int iPtblOffsetSize = (b64BitWavePoolOffsets) ? 8 : 4;
        RIFF::Chunk* ptbl = pRIFF->GetSubChunk(CHUNK_ID_PTBL);
        if (!ptbl)   ptbl = pRIFF->AddSubChunk(CHUNK_ID_PTBL, 1 /*anything, we'll resize*/);
        const int iPtblSize = WavePoolHeaderSize + iPtblOffsetSize * iSamples;
        ptbl->Resize(iPtblSize);
        pData = (uint8_t*) ptbl->LoadChunkData();
        WavePoolCount = iSamples;
        memccpy(&pData[4], &WavePoolCount, 1, 4);
        // we actually update the sample offsets in the pool table when we Save()
        memset(&pData[WavePoolHeaderSize], 0, iPtblSize - WavePoolHeaderSize);

        // update sample's chunks
        if (pSamples) {
            SampleList::iterator iter = pSamples->begin();
            SampleList::iterator end  = pSamples->end();
            for (; iter != end; ++iter) {
                (*iter)->UpdateChunks();
            }
        }
    }

    /** @brief Save changes to another file.
     *
     * Make all changes persistent by writing them to another file.
     * <b>Caution:</b> this method is optimized for writing to
     * <b>another</b> file, do not use it to save the changes to the same
     * file! Use Save() (without path argument) in that case instead!
     * Ignoring this might result in a corrupted file!
     *
     * After calling this method, this File object will be associated with
     * the new file (given by \a Path) afterwards.
     *
     * @param Path - path and file name where everything should be written to
     */
    void File::Save(const String& Path) {
        UpdateChunks();
        pRIFF->Save(Path);
        __UpdateWavePoolTableChunk();
    }

    /** @brief Save changes to same file.
     *
     * Make all changes persistent by writing them to the actual (same)
     * file. The file might temporarily grow to a higher size than it will
     * have at the end of the saving process.
     *
     * @throws RIFF::Exception if any kind of IO error occured
     * @throws DLS::Exception  if any kind of DLS specific error occured
     */
    void File::Save() {
        UpdateChunks();
        pRIFF->Save();
        __UpdateWavePoolTableChunk();
    }

    /**
     * Checks if all (for DLS) mandatory chunks exist, if not they will be
     * created. Note that those chunks will not be made persistent until
     * Save() was called.
     */
    void File::__ensureMandatoryChunksExist() {
       // enusre 'lins' list chunk exists (mandatory for instrument definitions)
       RIFF::List* lstInstruments = pRIFF->GetSubList(LIST_TYPE_LINS);
       if (!lstInstruments) pRIFF->AddSubList(LIST_TYPE_LINS);
       // ensure 'ptbl' chunk exists (mandatory for samples)
       RIFF::Chunk* ptbl = pRIFF->GetSubChunk(CHUNK_ID_PTBL);
       if (!ptbl) {
           const int iOffsetSize = (b64BitWavePoolOffsets) ? 8 : 4;
           ptbl = pRIFF->AddSubChunk(CHUNK_ID_PTBL, WavePoolHeaderSize + iOffsetSize);
       }
       // enusre 'wvpl' list chunk exists (mandatory for samples)
       RIFF::List* wvpl = pRIFF->GetSubList(LIST_TYPE_WVPL);
       if (!wvpl) pRIFF->AddSubList(LIST_TYPE_WVPL);
    }

    /**
     * Updates (persistently) the wave pool table with offsets to all
     * currently available samples. <b>Caution:</b> this method assumes the
     * 'ptbl' chunk to be already of the correct size, so usually this
     * method is only called after a Save() call.
     *
     * @throws Exception - if 'ptbl' chunk is too small (should only occur
     *                     if there's a bug)
     */
    void File::__UpdateWavePoolTableChunk() {
        __UpdateWavePoolTable();
        RIFF::Chunk* ptbl = pRIFF->GetSubChunk(CHUNK_ID_PTBL);
        const int iOffsetSize = (b64BitWavePoolOffsets) ? 8 : 4;
        // check if 'ptbl' chunk is large enough
        WavePoolCount = (pSamples) ? pSamples->size() : 0;
        const unsigned long ulRequiredSize = WavePoolHeaderSize + iOffsetSize * WavePoolCount;
        if (ptbl->GetSize() < ulRequiredSize) throw Exception("Fatal error, 'ptbl' chunk too small");
        uint8_t* pData = (uint8_t*) ptbl->LoadChunkData();
        // update headers
        memccpy(&pData[0], &WavePoolHeaderSize, 1, 4);
        memccpy(&pData[4], &WavePoolCount, 1, 4);
        // update offsets
        if (b64BitWavePoolOffsets) {
            for (int i = 0 ; i < WavePoolCount ; i++) {
                memccpy(&pData[WavePoolHeaderSize + i*iOffsetSize], &pWavePoolTableHi[i], 1, 4);
                memccpy(&pData[WavePoolHeaderSize + i*iOffsetSize], &pWavePoolTable[i],   1, 4);
            }
        } else { // conventional 32 bit offsets
            for (int i = 0 ; i < WavePoolCount ; i++)
                memccpy(&pData[WavePoolHeaderSize + i*iOffsetSize], &pWavePoolTable[i], 1, 4);
        }
    }

    /**
     * Updates the wave pool table with offsets to all currently available
     * samples. <b>Caution:</b> this method assumes the 'wvpl' list chunk
     * exists already.
     */
    void File::__UpdateWavePoolTable() {
        WavePoolCount = (pSamples) ? pSamples->size() : 0;
        // resize wave pool table arrays
        if (pWavePoolTable)   delete[] pWavePoolTable;
        if (pWavePoolTableHi) delete[] pWavePoolTableHi;
        pWavePoolTable   = new uint32_t[WavePoolCount];
        pWavePoolTableHi = new uint32_t[WavePoolCount];
        if (!pSamples) return;
        // update offsets int wave pool table
        RIFF::List* wvpl = pRIFF->GetSubList(LIST_TYPE_WVPL);
        uint64_t wvplFileOffset = wvpl->GetFilePos();
        if (b64BitWavePoolOffsets) {
            SampleList::iterator iter = pSamples->begin();
            SampleList::iterator end  = pSamples->end();
            for (int i = 0 ; iter != end ; ++iter, i++) {
                uint64_t _64BitOffset = wvplFileOffset - (*iter)->pWaveList->GetFilePos() - LIST_HEADER_SIZE;
                (*iter)->ulWavePoolOffset = _64BitOffset;
                pWavePoolTableHi[i] = (uint32_t) (_64BitOffset >> 32);
                pWavePoolTable[i]   = (uint32_t) _64BitOffset;
            }
        } else { // conventional 32 bit offsets
            SampleList::iterator iter = pSamples->begin();
            SampleList::iterator end  = pSamples->end();
            for (int i = 0 ; iter != end ; ++iter, i++) {
                uint64_t _64BitOffset = wvplFileOffset - (*iter)->pWaveList->GetFilePos() - LIST_HEADER_SIZE;
                (*iter)->ulWavePoolOffset = _64BitOffset;
                pWavePoolTable[i] = (uint32_t) _64BitOffset;
            }
        }
    }


// *************** Exception ***************
// *

    Exception::Exception(String Message) : RIFF::Exception(Message) {
    }

    void Exception::PrintMessage() {
        std::cout << "DLS::Exception: " << Message << std::endl;
    }


// *************** functions ***************
// *

    /**
     * Returns the name of this C++ library. This is usually "libgig" of
     * course. This call is equivalent to RIFF::libraryName() and
     * gig::libraryName().
     */
    String libraryName() {
        return PACKAGE;
    }

    /**
     * Returns version of this C++ library. This call is equivalent to
     * RIFF::libraryVersion() and gig::libraryVersion().
     */
    String libraryVersion() {
        return VERSION;
    }

} // namespace DLS