public static SidTuneBase load(ref byte[] dataBuf)
{
// File format check
if (dataBuf.Length < 4)
{
return(null);
}
UInt32 magic = sidendian.endian_big32(dataBuf);
if ((magic != PSID_ID) &&
(magic != RSID_ID))
{
return(null);
}
psidHeader pHeader = new psidHeader();
readHeader(dataBuf, ref pHeader);
PSID tune = new PSID();
tune.tryLoad(ref pHeader);
return(tune);
}
private static void readHeader(byte[] dataBuf, ref psidHeader hdr)
{
// Due to security concerns, input must be at least as long as version 1
// header plus 16-bit C64 load address. That is the area which will be
// accessed.
if (dataBuf.Length < (psid_headerSize + 2))
{
throw new loadError(ERR_TRUNCATED);
}
// Read v1 fields
hdr.id = sidendian.endian_big32(new Ptr <byte>(dataBuf, 0));
hdr.version = sidendian.endian_big16(new Ptr <byte>(dataBuf, 4));
hdr.data = sidendian.endian_big16(new Ptr <byte>(dataBuf, 6));
hdr.load = sidendian.endian_big16(new Ptr <byte>(dataBuf, 8));
hdr.init = sidendian.endian_big16(new Ptr <byte>(dataBuf, 10));
hdr.play = sidendian.endian_big16(new Ptr <byte>(dataBuf, 12));
hdr.songs = sidendian.endian_big16(new Ptr <byte>(dataBuf, 14));
hdr.start = sidendian.endian_big16(new Ptr <byte>(dataBuf, 16));
hdr.speed = sidendian.endian_big32(new Ptr <byte>(dataBuf, 18));
mem.memcpy(ref hdr.name, new Ptr <byte>(dataBuf, 22), PSID_MAXSTRLEN);
mem.memcpy(ref hdr.author, new Ptr <byte>(dataBuf, 54), PSID_MAXSTRLEN);
mem.memcpy(ref hdr.released, new Ptr <byte>(dataBuf, 86), PSID_MAXSTRLEN);
if (hdr.version >= 2)
{
if (dataBuf.Length < (psidv2_headerSize + 2))
{
throw new loadError(ERR_TRUNCATED);
}
// Read v2/3/4 fields
hdr.flags = sidendian.endian_big16(new Ptr <byte>(dataBuf, 118));
hdr.relocStartPage = dataBuf[120];
hdr.relocPages = dataBuf[121];
hdr.sidChipBase2 = dataBuf[122];
hdr.sidChipBase3 = dataBuf[123];
}
}
private void tryLoad(ref psidHeader pHeader)
{
SidTuneInfo.compatibility_t compatibility = SidTuneInfo.compatibility_t.COMPATIBILITY_C64;
// Require a valid ID and version number.
if (pHeader.id == PSID_ID)
{
switch (pHeader.version)
{
case 1:
compatibility = SidTuneInfo.compatibility_t.COMPATIBILITY_PSID;
break;
case 2:
case 3:
case 4:
break;
default:
throw new loadError(TXT_UNKNOWN_PSID);
}
info.m_formatString = TXT_FORMAT_PSID;
}
else if (pHeader.id == RSID_ID)
{
switch (pHeader.version)
{
case 2:
case 3:
case 4:
break;
default:
throw new loadError(TXT_UNKNOWN_RSID);
}
info.m_formatString = TXT_FORMAT_RSID;
compatibility = SidTuneInfo.compatibility_t.COMPATIBILITY_R64;
}
fileOffset = pHeader.data;
info.m_loadAddr = pHeader.load;
info.m_initAddr = pHeader.init;
info.m_playAddr = pHeader.play;
info.m_songs = pHeader.songs;
info.m_startSong = pHeader.start;
info.m_compatibility = compatibility;
info.m_relocPages = 0;
info.m_relocStartPage = 0;
UInt32 speed = pHeader.speed;
SidTuneInfo.clock_t clock = SidTuneInfo.clock_t.CLOCK_UNKNOWN;
bool musPlayer = false;
if (pHeader.version >= 2)
{
UInt16 flags = pHeader.flags;
// Check clock
if ((flags & (UInt16)Psid.PSID_MUS) != 0)
{ // MUS tunes run at any speed
clock = SidTuneInfo.clock_t.CLOCK_ANY;
musPlayer = true;
}
else
{
switch ((flags & (UInt16)Psid.PSID_CLOCK))
{
case (UInt16)Psid_Clock.PSID_CLOCK_ANY:
clock = SidTuneInfo.clock_t.CLOCK_ANY;
break;
case (UInt16)Psid_Clock.PSID_CLOCK_PAL:
clock = SidTuneInfo.clock_t.CLOCK_PAL;
break;
case (UInt16)Psid_Clock.PSID_CLOCK_NTSC:
clock = SidTuneInfo.clock_t.CLOCK_NTSC;
break;
default:
break;
}
}
// These flags are only available for the appropriate
// file formats
switch (compatibility)
{
case SidTuneInfo.compatibility_t.COMPATIBILITY_C64:
if ((flags & (UInt16)Psid.PSID_SPECIFIC) != 0)
{
info.m_compatibility = SidTuneInfo.compatibility_t.COMPATIBILITY_PSID;
}
break;
case SidTuneInfo.compatibility_t.COMPATIBILITY_R64:
if ((flags & (UInt16)Psid.PSID_BASIC) != 0)
{
info.m_compatibility = SidTuneInfo.compatibility_t.COMPATIBILITY_BASIC;
}
break;
default:
break;
}
info.m_clockSpeed = clock;
info.m_sidModels[0] = getSidModel((UInt16)(flags >> 4));
info.m_relocStartPage = pHeader.relocStartPage;
info.m_relocPages = pHeader.relocPages;
if (pHeader.version >= 3)
{
if (validateAddress(pHeader.sidChipBase2))
{
info.m_sidChipAddresses.Add((UInt16)(0xd000 | (pHeader.sidChipBase2 << 4)));
info.m_sidModels.Add(getSidModel((UInt16)(flags >> 6)));
}
if (pHeader.version >= 4)
{
if (pHeader.sidChipBase3 != pHeader.sidChipBase2 &&
validateAddress(pHeader.sidChipBase3))
{
info.m_sidChipAddresses.Add((UInt16)(0xd000 | (pHeader.sidChipBase3 << 4)));
info.m_sidModels.Add((SidTuneInfo.model_t)(getSidModel((UInt16)(flags >> 8))));
}
}
}
}
// Check reserved fields to force real c64 compliance
// as required by the RSID specification
if (compatibility == SidTuneInfo.compatibility_t.COMPATIBILITY_R64)
{
if ((info.m_loadAddr != 0) ||
(info.m_playAddr != 0) ||
(speed != 0))
{
throw new loadError(ERR_INVALID);
}
// Real C64 tunes appear as CIA
speed = 0xffffffff;// ~0;
}
// Create the speed/clock setting table.
convertOldStyleSpeedToTables(speed, (Int64)clock);
// Copy info strings.
info.m_infoString.Add(Encoding.ASCII.GetString(pHeader.name, 0, PSID_MAXSTRLEN));
info.m_infoString.Add(Encoding.ASCII.GetString(pHeader.author, 0, PSID_MAXSTRLEN));
info.m_infoString.Add(Encoding.ASCII.GetString(pHeader.released, 0, PSID_MAXSTRLEN));
if (musPlayer)
{
throw new loadError("Compute!'s Sidplayer MUS data is not supported yet"); // TODO
}
}
