/*
* Load_gdm.cpp
* ------------
* Purpose: GDM (BWSB Soundsystem) module loader
* Notes : This code is partly based on zilym's original code / specs (which are utterly wrong :P).
* Thanks to the MenTaLguY for gdm.txt and ajs for gdm2s3m and some hints.
*
* Hint 1: Most (all?) of the unsupported features were not supported in 2GDM / BWSB either.
* Hint 2: Files will be played like their original formats would be played in MPT, so no
* BWSB quirks including crashes and freezes are supported. :-P
* Authors: Johannes Schultz
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#include "stdafx.h"
#include "Loaders.h"
#include "mod_specifications.h"
OPENMPT_NAMESPACE_BEGIN
// GDM File Header
struct GDMFileHeader
{
char magic[4]; // ID: 'GDM\xFE'
char songTitle[32]; // Music's title
char songMusician[32]; // Name of music's composer
char dosEOF[3]; // 13, 10, 26
char magic2[4]; // ID: 'GMFS'
uint8le formatMajorVer; // Format major version
uint8le formatMinorVer; // Format minor version
uint16le trackerID; // Composing Tracker ID code (00 = 2GDM)
uint8le trackerMajorVer; // Tracker's major version
uint8le trackerMinorVer; // Tracker's minor version
uint8le panMap[32]; // 0-Left to 15-Right, 255-N/U
uint8le masterVol; // Range: 0...64
uint8le tempo; // Initial music tempo (6)
uint8le bpm; // Initial music BPM (125)
uint16le originalFormat; // Original format ID:
// 1-MOD, 2-MTM, 3-S3M, 4-669, 5-FAR, 6-ULT, 7-STM, 8-MED, 9-PSM
// (versions of 2GDM prior to v1.15 won't set this correctly)
// 2GDM v1.17 will only spit out 0-byte files when trying to convert a PSM16 file,
// and fail outright when trying to convert a new PSM file.
uint32le orderOffset;
uint8le lastOrder; // Number of orders in module - 1
uint32le patternOffset;
uint8le lastPattern; // Number of patterns in module - 1
uint32le sampleHeaderOffset;
uint32le sampleDataOffset;
uint8le lastSample; // Number of samples in module - 1
uint32le messageTextOffset; // Offset of song message
uint32le messageTextLength;
uint32le scrollyScriptOffset; // Offset of scrolly script (huh?)
uint16le scrollyScriptLength;
uint32le textGraphicOffset; // Offset of text graphic (huh?)
uint16le textGraphicLength;
};
MPT_BINARY_STRUCT(GDMFileHeader, 157)
// GDM Sample Header
struct GDMSampleHeader
{
enum SampleFlags
{
smpLoop = 0x01,
smp16Bit = 0x02, // 16-Bit samples are not handled correctly by 2GDM (not implemented)
smpVolume = 0x04, // Use default volume
smpPanning = 0x08,
smpLZW = 0x10, // LZW-compressed samples are not implemented in 2GDM
smpStereo = 0x20, // Stereo samples are not handled correctly by 2GDM (not implemented)
};
char name[32]; // sample's name
char fileName[12]; // sample's filename
uint8le emsHandle; // useless
uint32le length; // length in bytes
uint32le loopBegin; // loop start in samples
uint32le loopEnd; // loop end in samples
uint8le flags; // see SampleFlags
uint16le c4Hertz; // frequency
uint8le volume; // default volume
uint8le panning; // default pan
};
MPT_BINARY_STRUCT(GDMSampleHeader, 62)
static constexpr MODTYPE gdmFormatOrigin[] =
{
MOD_TYPE_NONE, MOD_TYPE_MOD, MOD_TYPE_MTM, MOD_TYPE_S3M, MOD_TYPE_669, MOD_TYPE_FAR, MOD_TYPE_ULT, MOD_TYPE_STM, MOD_TYPE_MED, MOD_TYPE_PSM
};
static constexpr mpt::uchar gdmFormatOriginType[][4] =
{
UL_(""), UL_("mod"), UL_("mtm"), UL_("s3m"), UL_("669"), UL_("far"), UL_("ult"), UL_("stm"), UL_("med"), UL_("psm")
};
static constexpr const mpt::uchar * gdmFormatOriginFormat[] =
{
UL_(""),
UL_("Generic MOD"),
UL_("MultiTracker"),
UL_("Scream Tracker 3"),
UL_("Composer 669 / UNIS 669"),
UL_("Farandole Composer"),
UL_("UltraTracker"),
UL_("Scream Tracker 2"),
UL_("OctaMED"),
UL_("Epic Megagames MASI")
};
static bool ValidateHeader(const GDMFileHeader &fileHeader)
{
if(std::memcmp(fileHeader.magic, "GDM\xFE", 4)
|| fileHeader.dosEOF[0] != 13 || fileHeader.dosEOF[1] != 10 || fileHeader.dosEOF[2] != 26
|| std::memcmp(fileHeader.magic2, "GMFS", 4)
|| fileHeader.formatMajorVer != 1 || fileHeader.formatMinorVer != 0
|| fileHeader.originalFormat >= std::size(gdmFormatOrigin)
|| fileHeader.originalFormat == 0)
{
return false;
}
return true;
}
CSoundFile::ProbeResult CSoundFile::ProbeFileHeaderGDM(MemoryFileReader file, const uint64 *pfilesize)
{
GDMFileHeader fileHeader;
if(!file.ReadStruct(fileHeader))
{
return ProbeWantMoreData;
}
if(!ValidateHeader(fileHeader))
{
return ProbeFailure;
}
MPT_UNREFERENCED_PARAMETER(pfilesize);
return ProbeSuccess;
}
bool CSoundFile::ReadGDM(FileReader &file, ModLoadingFlags loadFlags)
{
file.Rewind();
GDMFileHeader fileHeader;
if(!file.ReadStruct(fileHeader))
{
return false;
}
if(!ValidateHeader(fileHeader))
{
return false;
}
if(loadFlags == onlyVerifyHeader)
{
return true;
}
InitializeGlobals(gdmFormatOrigin[fileHeader.originalFormat]);
m_SongFlags.set(SONG_IMPORTED);
m_modFormat.formatName = U_("General Digital Music");
m_modFormat.type = U_("gdm");
m_modFormat.madeWithTracker = MPT_UFORMAT("BWSB 2GDM {}.{}")(fileHeader.trackerMajorVer, fileHeader.formatMinorVer);
m_modFormat.originalType = gdmFormatOriginType[fileHeader.originalFormat];
m_modFormat.originalFormatName = gdmFormatOriginFormat[fileHeader.originalFormat];
m_modFormat.charset = mpt::Charset::CP437;
// Song name
m_songName = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.songTitle);
// Artist name
{
std::string artist = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.songMusician);
if(artist != "Unknown")
{
m_songArtist = mpt::ToUnicode(mpt::Charset::CP437, artist);
}
}
// Read channel pan map... 0...15 = channel panning, 16 = surround channel, 255 = channel does not exist
m_nChannels = 32;
for(CHANNELINDEX i = 0; i < 32; i++)
{
ChnSettings[i].Reset();
if(fileHeader.panMap[i] < 16)
{
ChnSettings[i].nPan = static_cast<uint16>(std::min((fileHeader.panMap[i] * 16) + 8, 256));
} else if(fileHeader.panMap[i] == 16)
{
ChnSettings[i].nPan = 128;
ChnSettings[i].dwFlags = CHN_SURROUND;
} else if(fileHeader.panMap[i] == 0xFF)
{
m_nChannels = i;
break;
}
}
if(m_nChannels < 1)
{
return false;
}
m_nDefaultGlobalVolume = std::min(fileHeader.masterVol * 4u, 256u);
m_nDefaultSpeed = fileHeader.tempo;
m_nDefaultTempo.Set(fileHeader.bpm);
// Read orders
if(file.Seek(fileHeader.orderOffset))
{
ReadOrderFromFile<uint8>(Order(), file, fileHeader.lastOrder + 1, 0xFF, 0xFE);
}
// Read samples
if(!file.Seek(fileHeader.sampleHeaderOffset))
{
return false;
}
m_nSamples = fileHeader.lastSample + 1;
// Sample headers
for(SAMPLEINDEX smp = 1; smp <= m_nSamples; smp++)
{
GDMSampleHeader gdmSample;
if(!file.ReadStruct(gdmSample))
{
break;
}
ModSample &sample = Samples[smp];
sample.Initialize();
m_szNames[smp] = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, gdmSample.name);
sample.filename = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, gdmSample.fileName);
sample.nC5Speed = gdmSample.c4Hertz;
if(UseFinetuneAndTranspose())
{
// Use the same inaccurate table as 2GDM for translating back to finetune, as our own routines
// give slightly different results for the provided sample rates that may result in transpose != 0.
static constexpr uint16 rate2finetune[] = { 8363, 8424, 8485, 8547, 8608, 8671, 8734, 8797, 7894, 7951, 8009, 8067, 8125, 8184, 8244, 8303 };
for(uint8 i = 0; i < 16; i++)
{
if(sample.nC5Speed == rate2finetune[i])
{
sample.nFineTune = MOD2XMFineTune(i);
break;
}
}
}
sample.nGlobalVol = 64; // Not supported in this format
sample.nLength = gdmSample.length; // in bytes
// Sample format
if(gdmSample.flags & GDMSampleHeader::smp16Bit)
{
sample.uFlags.set(CHN_16BIT);
sample.nLength /= 2;
}
sample.nLoopStart = gdmSample.loopBegin;
sample.nLoopEnd = gdmSample.loopEnd - 1;
if(gdmSample.flags & GDMSampleHeader::smpLoop)
sample.uFlags.set(CHN_LOOP);
if((gdmSample.flags & GDMSampleHeader::smpVolume) && gdmSample.volume != 0xFF)
sample.nVolume = std::min(static_cast<uint8>(gdmSample.volume), uint8(64)) * 4;
else
sample.uFlags.set(SMP_NODEFAULTVOLUME);
if(gdmSample.flags & GDMSampleHeader::smpPanning)
{
// Default panning is used
sample.uFlags.set(CHN_PANNING);
// 0...15, 16 = surround (not supported), 255 = no default panning
sample.nPan = static_cast<uint16>((gdmSample.panning > 15) ? 128 : std::min((gdmSample.panning * 16) + 8, 256));
sample.uFlags.set(CHN_SURROUND, gdmSample.panning == 16);
} else
{
sample.nPan = 128;
}
}
// Read sample data
if((loadFlags & loadSampleData) && file.Seek(fileHeader.sampleDataOffset))
{
for(SAMPLEINDEX smp = 1; smp <= GetNumSamples(); smp++)
{
SampleIO(
Samples[smp].uFlags[CHN_16BIT] ? SampleIO::_16bit : SampleIO::_8bit,
SampleIO::mono,
SampleIO::littleEndian,
SampleIO::unsignedPCM)
.ReadSample(Samples[smp], file);
}
}
// Read patterns
Patterns.ResizeArray(fileHeader.lastPattern + 1);
const CModSpecifications &modSpecs = GetModSpecifications(GetBestSaveFormat());
bool onlyAmigaNotes = true;
// We'll start at position patternsOffset and decode all patterns
file.Seek(fileHeader.patternOffset);
for(PATTERNINDEX pat = 0; pat <= fileHeader.lastPattern; pat++)
{
// Read pattern length *including* the two "length" bytes
uint16 patternLength = file.ReadUint16LE();
if(patternLength <= 2)
{
// Huh, no pattern data present?
continue;
}
FileReader chunk = file.ReadChunk(patternLength - 2);
if(!(loadFlags & loadPatternData) || !chunk.IsValid() || !Patterns.Insert(pat, 64))
{
continue;
}
enum
{
rowDone = 0x00, // Advance to next row
channelMask = 0x1F, // Mask for retrieving channel information
noteFlag = 0x20, // Note / instrument information present
effectFlag = 0x40, // Effect information present
effectMask = 0x1F, // Mask for retrieving effect command
effectMore = 0x20, // Another effect follows
};
for(ROWINDEX row = 0; row < 64; row++)
{
PatternRow rowBase = Patterns[pat].GetRow(row);
uint8 channelByte;
// If channel byte is zero, advance to next row.
while((channelByte = chunk.ReadUint8()) != rowDone)
{
CHANNELINDEX channel = channelByte & channelMask;
if(channel >= m_nChannels) break; // Better safe than sorry!
ModCommand &m = rowBase[channel];
if(channelByte & noteFlag)
{
// Note and sample follows
auto [note, instr] = chunk.ReadArray<uint8, 2>();
if(note)
{
note = (note & 0x7F) - 1; // High bit = no-retrig flag (notes with portamento have this set)
m.note = (note & 0x0F) + 12 * (note >> 4) + 12 + NOTE_MIN;
if(!m.IsAmigaNote())
{
onlyAmigaNotes = false;
}
}
m.instr = instr;
}
if(channelByte & effectFlag)
{
// Effect(s) follow(s)
m.command = CMD_NONE;
m.volcmd = VOLCMD_NONE;
while(chunk.CanRead(2))
{
// We may want to restore the old command in some cases.
const ModCommand oldCmd = m;
const auto [effByte, param] = chunk.ReadArray<uint8, 2>();
m.param = param;
// Effect translation LUT
static constexpr EffectCommand gdmEffTrans[] =
{
CMD_NONE, CMD_PORTAMENTOUP, CMD_PORTAMENTODOWN, CMD_TONEPORTAMENTO,
CMD_VIBRATO, CMD_TONEPORTAVOL, CMD_VIBRATOVOL, CMD_TREMOLO,
CMD_TREMOR, CMD_OFFSET, CMD_VOLUMESLIDE, CMD_POSITIONJUMP,
CMD_VOLUME, CMD_PATTERNBREAK, CMD_MODCMDEX, CMD_SPEED,
CMD_ARPEGGIO, CMD_NONE /* set internal flag */, CMD_RETRIG, CMD_GLOBALVOLUME,
CMD_FINEVIBRATO, CMD_NONE, CMD_NONE, CMD_NONE,
CMD_NONE, CMD_NONE, CMD_NONE, CMD_NONE,
CMD_NONE, CMD_NONE, CMD_S3MCMDEX, CMD_TEMPO,
};
// Translate effect
uint8 command = effByte & effectMask;
if(command < std::size(gdmEffTrans))
m.command = gdmEffTrans[command];
else
m.command = CMD_NONE;
// Fix some effects
switch(m.command)
{
case CMD_PORTAMENTOUP:
case CMD_PORTAMENTODOWN:
if(m.param >= 0xE0 && m_nType != MOD_TYPE_MOD)
m.param = 0xDF; // Don't spill into fine slide territory
break;
case CMD_TONEPORTAVOL:
case CMD_VIBRATOVOL:
if(m.param & 0xF0)
m.param &= 0xF0;
break;
case CMD_VOLUME:
m.param = std::min(m.param, uint8(64));
if(modSpecs.HasVolCommand(VOLCMD_VOLUME))
{
m.volcmd = VOLCMD_VOLUME;
m.vol = m.param;
// Don't destroy old command, if there was one.
m.command = oldCmd.command;
m.param = oldCmd.param;
}
break;
case CMD_MODCMDEX:
switch(m.param >> 4)
{
case 0x8:
m.command = CMD_PORTAMENTOUP;
m.param = 0xE0 | (m.param & 0x0F);
break;
case 0x9:
m.command = CMD_PORTAMENTODOWN;
m.param = 0xE0 | (m.param & 0x0F);
break;
default:
if(!modSpecs.HasCommand(CMD_MODCMDEX))
m.ExtendedMODtoS3MEffect();
break;
}
break;
case CMD_RETRIG:
if(!modSpecs.HasCommand(CMD_RETRIG) && modSpecs.HasCommand(CMD_MODCMDEX))
{
// Retrig in "MOD style"
m.command = CMD_MODCMDEX;
m.param = 0x90 | (m.param & 0x0F);
}
break;
case CMD_S3MCMDEX:
// Some really special commands
if(m.param == 0x01)
{
// Surround (implemented in 2GDM but not in BWSB itself)
m.param = 0x91;
} else if((m.param & 0xF0) == 0x80)
{
// 4-Bit Panning
if (!modSpecs.HasCommand(CMD_S3MCMDEX))
m.command = CMD_MODCMDEX;
} else
{
// All other effects are implemented neither in 2GDM nor in BWSB.
m.command = CMD_NONE;
}
break;
}
// Move pannings to volume column - should never happen
if(m.command == CMD_S3MCMDEX && ((m.param >> 4) == 0x8) && m.volcmd == VOLCMD_NONE)
{
m.volcmd = VOLCMD_PANNING;
m.vol = ((m.param & 0x0F) * 64 + 8) / 15;
m.command = oldCmd.command;
m.param = oldCmd.param;
}
if(!(effByte & effectMore))
break;
}
}
}
}
}
m_SongFlags.set(SONG_AMIGALIMITS | SONG_ISAMIGA, GetType() == MOD_TYPE_MOD && GetNumChannels() == 4 && onlyAmigaNotes);
// Read song comments
if(fileHeader.messageTextLength > 0 && file.Seek(fileHeader.messageTextOffset))
{
m_songMessage.Read(file, fileHeader.messageTextLength, SongMessage::leAutodetect);
}
return true;
}
OPENMPT_NAMESPACE_END