diff options
| -rw-r--r-- | engines/sci/sound/drivers/midi.cpp | 69 |
1 files changed, 55 insertions, 14 deletions
diff --git a/engines/sci/sound/drivers/midi.cpp b/engines/sci/sound/drivers/midi.cpp index 80a72b9a6f..5065500f52 100644 --- a/engines/sci/sound/drivers/midi.cpp +++ b/engines/sci/sound/drivers/midi.cpp @@ -399,24 +399,37 @@ void MidiPlayer_Midi::playSwitch(bool play) { } bool MidiPlayer_Midi::isMt32GmPatch(const byte *data, int size) { - if (size < 1155) + // Need at least 1153 + 2 bytes for a GM patch. Check readMt32GmPatch() + // below for more info. + if (size < 1153 + 2) return false; + // The maximum number of bytes for an MT-32 patch is 16889. The maximum + // number of timbres is 64, which leads us to: + // 491 + 1 + 64 * 246 + 653 = 16889 if (size > 16889) return true; bool isMt32 = false; bool isMt32Gm = false; + // First, check for a GM patch. The presence of MIDI data after the + // initial 1153 + 2 bytes indicates a GM patch if (READ_LE_UINT16(data + 1153) + 1155 == size) isMt32Gm = true; - int pos = 492 + 246 * data[491]; + // Now check for a regular MT-32 patch. Check readMt32Patch() below for + // more info. + // 491 = 20 + 20 + 20 + 2 + 1 + 11 + 3 * 11 + 256 + 128 + byte timbresNr = data[491]; + int pos = 492 + 246 * timbresNr; + // Patches 49-96 if ((size >= (pos + 386)) && (READ_BE_UINT16(data + pos) == 0xabcd)) - pos += 386; + pos += 386; // 256 + 128 + 2 + // Rhythm key map + partial reserve if ((size >= (pos + 267)) && (READ_BE_UINT16(data + pos) == 0xdcba)) - pos += 267; + pos += 267; // 256 + 9 + 2 if (size == pos) isMt32 = true; @@ -460,10 +473,28 @@ void MidiPlayer_Midi::sendMt32SysEx(const uint32 addr, const byte *buf, int len, } void MidiPlayer_Midi::readMt32Patch(const byte *data, int size) { + // MT-32 patch contents: + // - 20 bytes unkown + // - 20 bytes before-SysEx message + // - 20 bytes goodbye SysEx message + // - 2 bytes volume + // - 1 byte reverb + // - 11 bytes reverb Sysex message + // - 3 * 11 reverb data + // - 256 + 128 bytes patches 1-48 + // --> total: 491 bytes + // - 1 byte number of timbres (64 max) + // - 246 * timbres timbre data + // - 2 bytes flag (0xabcd) + // - 256 + 128 bytes patches 49-96 + // - 2 bytes flag (0xdcba) + // - 256 bytes rhythm key map + // - 9 bytes partial reserve + Common::MemoryReadStream *str = new Common::MemoryReadStream(data, size); // Send before-SysEx text - str->seek(0x14); + str->seek(20); sendMt32SysEx(0x200000, str, 20); // Save goodbye message @@ -527,15 +558,25 @@ void MidiPlayer_Midi::readMt32Patch(const byte *data, int size) { } void MidiPlayer_Midi::readMt32GmPatch(const byte *data, int size) { - memcpy(_patchMap, data, 0x80); - memcpy(_keyShift, data + 0x80, 0x80); - memcpy(_volAdjust, data + 0x100, 0x80); - memcpy(_percussionMap, data + 0x180, 0x80); - _channels[MIDI_RHYTHM_CHANNEL].volAdjust = data[0x200]; - memcpy(_velocityMapIdx, data + 0x201, 0x80); - memcpy(_velocityMap, data + 0x281, 0x200); - - uint16 midiSize = READ_LE_UINT16(data + 0x481); + // GM patch contents: + // - 128 bytes patch map + // - 128 bytes key shift + // - 128 bytes volume adjustment + // - 128 bytes percussion map + // - 1 byte volume adjust for the rhythm channel + // - 128 bytes velocity map IDs + // - 512 bytes velocity map + // --> total: 1153 bytes + + memcpy(_patchMap, data, 128); + memcpy(_keyShift, data + 128, 128); + memcpy(_volAdjust, data + 256, 128); + memcpy(_percussionMap, data + 384, 128); + _channels[MIDI_RHYTHM_CHANNEL].volAdjust = data[512]; + memcpy(_velocityMapIdx, data + 513, 128); + memcpy(_velocityMap, data + 641, 512); + + uint16 midiSize = READ_LE_UINT16(data + 1153); if (midiSize > 0) { if (size < midiSize + 1155) |