DLS.cpp

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/***************************************************************************
 *                                                                         *
 *   libgig - C++ cross-platform Gigasampler format file access library    *
 *                                                                         *
 *   Copyright (C) 2003-2007 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 <algorithm>
#include <time.h>

#ifdef __APPLE__
#include <CoreFoundation/CFUUID.h>
#elif defined(HAVE_UUID_UUID_H)
#include <uuid/uuid.h>
#endif

#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                  0x80000000

#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  ***************
// *

    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;
    }

    void Articulation::UpdateChunks() {
        const int iEntrySize = 12; // 12 bytes per connection block
        pArticulationCk->Resize(HeaderSize + Connections * iEntrySize);
        uint8_t* pData = (uint8_t*) pArticulationCk->LoadChunkData();
        store16(&pData[0], HeaderSize);
        store16(&pData[2], Connections);
        for (uint32_t i = 0; i < Connections; i++) {
            Connection::conn_block_t c = pConnections[i].ToConnBlock();
            store16(&pData[HeaderSize + i * iEntrySize],     c.source);
            store16(&pData[HeaderSize + i * iEntrySize + 2], c.control);
            store16(&pData[HeaderSize + i * iEntrySize + 4], c.destination);
            store16(&pData[HeaderSize + i * iEntrySize + 6], c.transform);
            store32(&pData[HeaderSize + i * iEntrySize + 8], c.scale);
        }
    }



// *************** 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;
        }
    }

    void Articulator::UpdateChunks() {
        if (pArticulations) {
            ArticulationList::iterator iter = pArticulations->begin();
            ArticulationList::iterator end  = pArticulations->end();
            for (; iter != end; ++iter) {
                (*iter)->UpdateChunks();
            }
        }
    }



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

    Info::Info(RIFF::List* list) {
        pFixedStringLengths = NULL;
        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);
                LoadString(CHUNK_ID_ISBJ, lstINFO, Subject);
            }
        }
    }

    Info::~Info() {
    }

    void Info::SetFixedStringLengths(const string_length_t* lengths) {
        pFixedStringLengths = lengths;
    }

    void Info::LoadString(uint32_t ChunkID, RIFF::List* lstINFO, String& s) {
        RIFF::Chunk* ck = lstINFO->GetSubChunk(ChunkID);
        ::LoadString(ck, s); // function from helper.h
    }

    void Info::SaveString(uint32_t ChunkID, RIFF::List* lstINFO, const String& s, const String& sDefault) {
        int size = 0;
        if (pFixedStringLengths) {
            for (int i = 0 ; pFixedStringLengths[i].length ; i++) {
                if (pFixedStringLengths[i].chunkId == ChunkID) {
                    size = pFixedStringLengths[i].length;
                    break;
                }
            }
        }
        RIFF::Chunk* ck = lstINFO->GetSubChunk(ChunkID);
        ::SaveString(ChunkID, ck, lstINFO, s, sDefault, size != 0, size); // function from helper.h
    }

    void Info::UpdateChunks() {
        if (!pResourceListChunk) return;

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

        String defaultName = "";
        String defaultCreationDate = "";
        String defaultSoftware = "";
        String defaultComments = "";

        uint32_t resourceType = pResourceListChunk->GetListType();

        if (!lstINFO) {
            lstINFO = pResourceListChunk->AddSubList(LIST_TYPE_INFO);

            // assemble default values
            defaultName = "NONAME";

            if (resourceType == RIFF_TYPE_DLS) {
                // get current date
                time_t now = time(NULL);
                tm* pNowBroken = localtime(&now);
                char buf[11];
                strftime(buf, 11, "%F", pNowBroken);
                defaultCreationDate = buf;

                defaultComments = "Created with " + libraryName() + " " + libraryVersion();
            }
            if (resourceType == RIFF_TYPE_DLS || resourceType == LIST_TYPE_INS)
            {
                defaultSoftware = libraryName() + " " + libraryVersion();
            }
        }

        // save values

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



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

    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;
    }

    void Resource::UpdateChunks() {
        pInfo->UpdateChunks();

        if (pDLSID) {
            // make sure 'dlid' chunk exists
            RIFF::Chunk* ckDLSID = pResourceList->GetSubChunk(CHUNK_ID_DLID);
            if (!ckDLSID) ckDLSID = pResourceList->AddSubChunk(CHUNK_ID_DLID, 16);
            uint8_t* pData = (uint8_t*)ckDLSID->LoadChunkData();
            // update 'dlid' chunk
            store32(&pData[0], pDLSID->ulData1);
            store16(&pData[4], pDLSID->usData2);
            store16(&pData[6], pDLSID->usData3);
            memcpy(&pData[8], pDLSID->abData, 8);
        }
    }

    void Resource::GenerateDLSID() {
#if defined(WIN32) || defined(__APPLE__) || defined(HAVE_UUID_GENERATE)

        if (!pDLSID) pDLSID = new dlsid_t;

#ifdef WIN32

        UUID uuid;
        UuidCreate(&uuid);
        pDLSID->ulData1 = uuid.Data1;
        pDLSID->usData2 = uuid.Data2;
        pDLSID->usData3 = uuid.Data3;
        memcpy(pDLSID->abData, uuid.Data4, 8);

#elif defined(__APPLE__)

        CFUUIDRef uuidRef = CFUUIDCreate(NULL);
        CFUUIDBytes uuid = CFUUIDGetUUIDBytes(uuidRef);
        CFRelease(uuidRef);
        pDLSID->ulData1 = uuid.byte0 | uuid.byte1 << 8 | uuid.byte2 << 16 | uuid.byte3 << 24;
        pDLSID->usData2 = uuid.byte4 | uuid.byte5 << 8;
        pDLSID->usData3 = uuid.byte6 | uuid.byte7 << 8;
        pDLSID->abData[0] = uuid.byte8;
        pDLSID->abData[1] = uuid.byte9;
        pDLSID->abData[2] = uuid.byte10;
        pDLSID->abData[3] = uuid.byte11;
        pDLSID->abData[4] = uuid.byte12;
        pDLSID->abData[5] = uuid.byte13;
        pDLSID->abData[6] = uuid.byte14;
        pDLSID->abData[7] = uuid.byte15;
#else
        uuid_t uuid;
        uuid_generate(uuid);
        pDLSID->ulData1 = uuid[0] | uuid[1] << 8 | uuid[2] << 16 | uuid[3] << 24;
        pDLSID->usData2 = uuid[4] | uuid[5] << 8;
        pDLSID->usData3 = uuid[6] | uuid[7] << 8;
        memcpy(pDLSID->abData, &uuid[8], 8);
#endif
#endif
    }


// *************** 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   = 20;
            UnityNote      = 60;
            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;
    }

    void Sampler::SetGain(int32_t gain) {
        Gain = gain;
    }

    void Sampler::UpdateChunks() {
        // make sure 'wsmp' chunk exists
        RIFF::Chunk* wsmp = pParentList->GetSubChunk(CHUNK_ID_WSMP);
        int wsmpSize = uiHeaderSize + SampleLoops * 16;
        if (!wsmp) {
            wsmp = pParentList->AddSubChunk(CHUNK_ID_WSMP, wsmpSize);
        } else if (wsmp->GetSize() != wsmpSize) {
            wsmp->Resize(wsmpSize);
        }
        uint8_t* pData = (uint8_t*) wsmp->LoadChunkData();
        // update headers size
        store32(&pData[0], uiHeaderSize);
        // 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);
        store16(&pData[4], UnityNote);
        store16(&pData[6], FineTune);
        store32(&pData[8], Gain);
        store32(&pData[12], SamplerOptions);
        store32(&pData[16], SampleLoops);
        // update loop definitions
        for (uint32_t i = 0; i < SampleLoops; i++) {
            //FIXME: this does not handle extended loop structs correctly
            store32(&pData[uiHeaderSize + i * 16], pSampleLoops[i].Size);
            store32(&pData[uiHeaderSize + i * 16 + 4], pSampleLoops[i].LoopType);
            store32(&pData[uiHeaderSize + i * 16 + 8], pSampleLoops[i].LoopStart);
            store32(&pData[uiHeaderSize + i * 16 + 12], pSampleLoops[i].LoopLength);
        }
    }

    void Sampler::AddSampleLoop(sample_loop_t* pLoopDef) {
        sample_loop_t* pNewLoops = new sample_loop_t[SampleLoops + 1];
        // copy old loops array
        for (int i = 0; i < SampleLoops; i++) {
            pNewLoops[i] = pSampleLoops[i];
        }
        // add the new loop
        pNewLoops[SampleLoops] = *pLoopDef;
        // auto correct size field
        pNewLoops[SampleLoops].Size = sizeof(DLS::sample_loop_t);
        // free the old array and update the member variables
        if (SampleLoops) delete[] pSampleLoops;
        pSampleLoops = pNewLoops;
        SampleLoops++;
    }

    void Sampler::DeleteSampleLoop(sample_loop_t* pLoopDef) {
        sample_loop_t* pNewLoops = new sample_loop_t[SampleLoops - 1];
        // copy old loops array (skipping given loop)
        for (int i = 0, o = 0; i < SampleLoops; i++) {
            if (&pSampleLoops[i] == pLoopDef) continue;
            if (o == SampleLoops - 1)
                throw Exception("Could not delete Sample Loop, because it does not exist");
            pNewLoops[o] = pSampleLoops[i];
            o++;
        }
        // free the old array and update the member variables
        if (SampleLoops) delete[] pSampleLoops;
        pSampleLoops = pNewLoops;
        SampleLoops--;
    }



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

    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 == DLS_WAVE_FORMAT_PCM) {
                BitDepth     = pCkFormat->ReadUint16();
                FrameSize    = (BitDepth / 8) * Channels;
            } else { // unsupported sample data format
                BitDepth     = 0;
                FrameSize    = 0;
            }
        } else { // 'fmt' chunk missing
            FormatTag              = DLS_WAVE_FORMAT_PCM;
            BitDepth               = 16;
            Channels               = 1;
            SamplesPerSecond       = 44100;
            AverageBytesPerSecond  = (BitDepth / 8) * SamplesPerSecond * Channels;
            FrameSize              = (BitDepth / 8) * Channels;
            BlockAlign             = FrameSize;
        }
        SamplesTotal = (pCkData) ? (FormatTag == DLS_WAVE_FORMAT_PCM) ? pCkData->GetSize() / FrameSize
                                                                      : 0
                                 : 0;
    }

    Sample::~Sample() {
        RIFF::List* pParent = pWaveList->GetParent();
        pParent->DeleteSubChunk(pWaveList);
    }

    void* Sample::LoadSampleData() {
        return (pCkData) ? pCkData->LoadChunkData() : NULL;
    }

    void Sample::ReleaseSampleData() {
        if (pCkData) pCkData->ReleaseChunkData();
    }

    unsigned long Sample::GetSize() {
        if (FormatTag != DLS_WAVE_FORMAT_PCM) return 0;
        return (pCkData) ? pCkData->GetSize() / FrameSize : 0;
    }

    void Sample::Resize(int iNewSize) {
        if (FormatTag != DLS_WAVE_FORMAT_PCM) throw Exception("Sample's format is not DLS_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);
    }

    unsigned long Sample::SetPos(unsigned long SampleCount, RIFF::stream_whence_t Whence) {
        if (FormatTag != DLS_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;
    }

    unsigned long Sample::Read(void* pBuffer, unsigned long SampleCount) {
        if (FormatTag != DLS_WAVE_FORMAT_PCM) return 0; // failed: wave data not PCM format
        return pCkData->Read(pBuffer, SampleCount, FrameSize); // FIXME: channel inversion due to endian correction?
    }

    unsigned long Sample::Write(void* pBuffer, unsigned long SampleCount) {
        if (FormatTag != DLS_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?
    }

    void Sample::UpdateChunks() {
        if (FormatTag != DLS_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