summaryrefslogtreecommitdiff
path: root/src/music
diff options
context:
space:
mode:
Diffstat (limited to 'src/music')
-rw-r--r--src/music/midifile.cpp407
-rw-r--r--src/music/midifile.hpp4
-rw-r--r--src/music/win32_m.cpp8
3 files changed, 402 insertions, 17 deletions
diff --git a/src/music/midifile.cpp b/src/music/midifile.cpp
index eb7e02303..b10bd180e 100644
--- a/src/music/midifile.cpp
+++ b/src/music/midifile.cpp
@@ -12,12 +12,14 @@
#include "midifile.hpp"
#include "../fileio_func.h"
#include "../fileio_type.h"
+#include "../string_func.h"
#include "../core/endian_func.hpp"
+#include "../base_media_base.h"
#include "midi.h"
#include <algorithm>
-/* implementation based on description at: http://www.somascape.org/midi/tech/mfile.html */
+/* SMF reader based on description at: http://www.somascape.org/midi/tech/mfile.html */
/**
@@ -158,7 +160,7 @@ static bool ReadTrackChunk(FILE *file, MidiFile &target)
return false;
}
- /* read chunk length and then the whole chunk */
+ /* Read chunk length and then the whole chunk */
uint32 chunk_length;
if (fread(&chunk_length, 1, 4, file) != 4) {
return false;
@@ -176,7 +178,7 @@ static bool ReadTrackChunk(FILE *file, MidiFile &target)
byte last_status = 0;
bool running_sysex = false;
while (!chunk.IsEnd()) {
- /* read deltatime for event, start new block */
+ /* Read deltatime for event, start new block */
uint32 deltatime = 0;
if (!chunk.ReadVariableLength(deltatime)) {
return false;
@@ -186,14 +188,14 @@ static bool ReadTrackChunk(FILE *file, MidiFile &target)
block = &target.blocks.back();
}
- /* read status byte */
+ /* Read status byte */
byte status;
if (!chunk.ReadByte(status)) {
return false;
}
if ((status & 0x80) == 0) {
- /* high bit not set means running status message, status is same as last
+ /* High bit not set means running status message, status is same as last
* convert to explicit status */
chunk.Rewind(1);
status = last_status;
@@ -266,7 +268,7 @@ static bool ReadTrackChunk(FILE *file, MidiFile &target)
return false;
}
if (data[length] != 0xF7) {
- /* engage Casio weirdo mode - convert to normal sysex */
+ /* Engage Casio weirdo mode - convert to normal sysex */
running_sysex = true;
*block->data.Append() = 0xF7;
} else {
@@ -312,18 +314,20 @@ static bool FixupMidiData(MidiFile &target)
std::sort(target.blocks.begin(), target.blocks.end(), TicktimeAscending<MidiFile::DataBlock>);
if (target.tempos.size() == 0) {
- /* no tempo information, assume 120 bpm (500,000 microseconds per beat */
+ /* No tempo information, assume 120 bpm (500,000 microseconds per beat */
target.tempos.push_back(MidiFile::TempoChange(0, 500000));
}
- /* add sentinel tempo at end */
+ /* Add sentinel tempo at end */
target.tempos.push_back(MidiFile::TempoChange(UINT32_MAX, 0));
- /* merge blocks with identical tick times */
+ /* Merge blocks with identical tick times */
std::vector<MidiFile::DataBlock> merged_blocks;
uint32 last_ticktime = 0;
for (size_t i = 0; i < target.blocks.size(); i++) {
MidiFile::DataBlock &block = target.blocks[i];
- if (block.ticktime > last_ticktime || merged_blocks.size() == 0) {
+ if (block.data.Length() == 0) {
+ continue;
+ } else if (block.ticktime > last_ticktime || merged_blocks.size() == 0) {
merged_blocks.push_back(block);
last_ticktime = block.ticktime;
} else {
@@ -333,7 +337,7 @@ static bool FixupMidiData(MidiFile &target)
}
std::swap(merged_blocks, target.blocks);
- /* annotate blocks with real time */
+ /* Annotate blocks with real time */
last_ticktime = 0;
uint32 last_realtime = 0;
size_t cur_tempo = 0, cur_block = 0;
@@ -390,13 +394,13 @@ bool MidiFile::ReadSMFHeader(FILE *file, SMFHeader &header)
return false;
}
- /* check magic, 'MThd' followed by 4 byte length indicator (always = 6 in SMF) */
+ /* Check magic, 'MThd' followed by 4 byte length indicator (always = 6 in SMF) */
const byte magic[] = { 'M', 'T', 'h', 'd', 0x00, 0x00, 0x00, 0x06 };
if (MemCmpT(buffer, magic, sizeof(magic)) != 0) {
return false;
}
- /* read the parameters of the file */
+ /* Read the parameters of the file */
header.format = (buffer[8] << 8) | buffer[9];
header.tracks = (buffer[10] << 8) | buffer[11];
header.tickdiv = (buffer[12] << 8) | buffer[13];
@@ -416,6 +420,7 @@ bool MidiFile::LoadFile(const char *filename)
bool success = false;
FILE *file = FioFOpenFile(filename, "rb", Subdirectory::BASESET_DIR);
+ if (file == NULL) return false;
SMFHeader header;
if (!ReadSMFHeader(file, header)) goto cleanup;
@@ -440,6 +445,381 @@ cleanup:
return success;
}
+
+/**
+ * Decoder for "MPS MIDI" format data.
+ * This format for MIDI music is also used in a few other Microprose games contemporary with Transport Tycoon.
+ *
+ * The song data are usually packed inside a CAT file, with one CAT chunk per song. The song titles are used as names for the CAT chunks.
+ *
+ * Unlike the Standard MIDI File format, which is based on the IFF structure, the MPS MIDI format is best described as two linked lists of sub-tracks,
+ * the first list contains a number of reusable "segments", and the second list contains the "master tracks". Each list is prefixed with a byte
+ * giving the number of elements in the list, and the actual list is just a byte count (BE16 format) for the segment/track followed by the actual data,
+ * there is no index as such, so the entire data must be seeked through to build an index.
+ *
+ * The actual MIDI data inside each track is almost standard MIDI, prefixing every event with a delay, encoded using the same variable-length format
+ * used in SMF. A few status codes have changed meaning in MPS MIDI: 0xFE changes control from master track to a segment, 0xFD returns from a segment
+ * to the master track, and 0xFF is used to end the song. (In Standard MIDI all those values must only occur in real-time data.)
+ *
+ * As implemented in the original decoder, there is no support for recursively calling segments from segments, i.e. code 0xFE must only occur in
+ * a master track, and code 0xFD must only occur in a segment. There are no checks made for this, it's assumed that the only input data will ever
+ * be the original game music, not music from other games, or new productions.
+ *
+ * Additionally, some program change and controller events are given special meaning, see comments in the code.
+ */
+struct MpsMachine {
+ /** Starting parameter and playback status for one channel/track */
+ struct Channel {
+ byte cur_program; ///< program selected, used for velocity scaling (lookup into programvelocities array)
+ byte running_status; ///< last midi status code seen
+ uint16 delay; ///< frames until next command
+ uint32 playpos; ///< next byte to play this channel from
+ uint32 startpos; ///< start position of master track
+ uint32 returnpos; ///< next return position after playing a segment
+ Channel() : cur_program(0xFF), running_status(0), delay(0), playpos(0), startpos(0), returnpos(0) { }
+ };
+ Channel channels[16]; ///< playback status for each MIDI channel
+ std::vector<uint32> segments; ///< pointers into songdata to repeatable data segments
+ int16 tempo_ticks; ///< ticker that increments when playing a frame, decrements before playing a frame
+ int16 current_tempo; ///< threshold for actually playing a frame
+ int16 initial_tempo; ///< starting tempo of song
+ bool shouldplayflag; ///< not-end-of-song flag
+
+ static const int TEMPO_RATE;
+ static const byte programvelocities[128];
+
+ const byte *songdata; ///< raw data array
+ size_t songdatalen; ///< length of song data
+ MidiFile &target; ///< recipient of data
+
+ /** Overridden MIDI status codes used in the data format */
+ enum MpsMidiStatus {
+ MPSMIDIST_SEGMENT_RETURN = 0xFD, ///< resume playing master track from stored position
+ MPSMIDIST_SEGMENT_CALL = 0xFE, ///< store current position of master track playback, and begin playback of a segment
+ MPSMIDIST_ENDSONG = 0xFF, ///< immediately end the song
+ };
+
+ static void AddMidiData(MidiFile::DataBlock &block, byte b1, byte b2)
+ {
+ *block.data.Append() = b1;
+ *block.data.Append() = b2;
+ }
+ static void AddMidiData(MidiFile::DataBlock &block, byte b1, byte b2, byte b3)
+ {
+ *block.data.Append() = b1;
+ *block.data.Append() = b2;
+ *block.data.Append() = b3;
+ }
+
+ /**
+ * Construct a TTD DOS music format decoder.
+ * @param songdata Buffer of song data from CAT file, ownership remains with caller
+ * @param songdatalen Length of the data buffer in bytes
+ * @param target MidiFile object to add decoded data to
+ */
+ MpsMachine(const byte *data, size_t length, MidiFile &target)
+ : songdata(data), songdatalen(length), target(target)
+ {
+ uint32 pos = 0;
+ int loopmax;
+ int loopidx;
+
+ /* First byte is the initial "tempo" */
+ this->initial_tempo = this->songdata[pos++];
+
+ /* Next byte is a count of callable segments */
+ loopmax = this->songdata[pos++];
+ for (loopidx = 0; loopidx < loopmax; loopidx++) {
+ /* Segments form a linked list in the stream,
+ * first two bytes in each is an offset to the next.
+ * Two bytes between offset to next and start of data
+ * are unaccounted for. */
+ this->segments.push_back(pos + 4);
+ pos += FROM_LE16(*(const int16 *)(this->songdata + pos));
+ }
+
+ /* After segments follows list of master tracks for each channel,
+ * also prefixed with a byte counting actual tracks. */
+ loopmax = this->songdata[pos++];
+ for (loopidx = 0; loopidx < loopmax; loopidx++) {
+ /* Similar structure to segments list, but also has
+ * the MIDI channel number as a byte before the offset
+ * to next track. */
+ byte ch = this->songdata[pos++];
+ this->channels[ch].startpos = pos + 4;
+ pos += FROM_LE16(*(const int16 *)(this->songdata + pos));
+ }
+ }
+
+ /**
+ * Read an SMF-style variable length value (note duration) from songdata.
+ * @param pos Position to read from, updated to point to next byte after the value read
+ * @return Value read from data stream
+ */
+ uint16 ReadVariableLength(uint32 &pos)
+ {
+ byte b = 0;
+ uint16 res = 0;
+ do {
+ b = this->songdata[pos++];
+ res = (res << 7) + (b & 0x7F);
+ } while (b & 0x80);
+ return res;
+ }
+
+ /**
+ * Prepare for playback from the beginning. Resets the song pointer for every track to the beginning.
+ */
+ void RestartSong()
+ {
+ for (int ch = 0; ch < 16; ch++) {
+ Channel &chandata = this->channels[ch];
+ if (chandata.startpos != 0) {
+ /* Active track, set position to beginning */
+ chandata.playpos = chandata.startpos;
+ chandata.delay = this->ReadVariableLength(chandata.playpos);
+ } else {
+ /* Inactive track, mark as such */
+ chandata.playpos = 0;
+ chandata.delay = 0;
+ }
+ }
+ }
+
+ /**
+ * Play one frame of data from one channel
+ */
+ uint16 PlayChannelFrame(MidiFile::DataBlock &outblock, int channel)
+ {
+ uint16 newdelay = 0;
+ byte b1, b2;
+ Channel &chandata = this->channels[channel];
+
+ do {
+ /* Read command/status byte */
+ b1 = this->songdata[chandata.playpos++];
+
+ /* Command 0xFE, call segment from master track */
+ if (b1 == MPSMIDIST_SEGMENT_CALL) {
+ b1 = this->songdata[chandata.playpos++];
+ chandata.returnpos = chandata.playpos;
+ chandata.playpos = this->segments[b1];
+ newdelay = this->ReadVariableLength(chandata.playpos);
+ if (newdelay == 0) {
+ continue;
+ }
+ return newdelay;
+ }
+
+ /* Command 0xFD, return from segment to master track */
+ if (b1 == MPSMIDIST_SEGMENT_RETURN) {
+ chandata.playpos = chandata.returnpos;
+ chandata.returnpos = 0;
+ newdelay = this->ReadVariableLength(chandata.playpos);
+ if (newdelay == 0) {
+ continue;
+ }
+ return newdelay;
+ }
+
+ /* Command 0xFF, end of song */
+ if (b1 == MPSMIDIST_ENDSONG) {
+ this->shouldplayflag = false;
+ return 0;
+ }
+
+ /* Regular MIDI channel message status byte */
+ if (b1 >= 0x80) {
+ /* Save the status byte as running status for the channel
+ * and read another byte for first parameter to command */
+ chandata.running_status = b1;
+ b1 = this->songdata[chandata.playpos++];
+ }
+
+ switch (chandata.running_status & 0xF0) {
+ case MIDIST_NOTEOFF:
+ case MIDIST_NOTEON:
+ b2 = this->songdata[chandata.playpos++];
+ if (b2 != 0) {
+ /* Note on, read velocity and scale according to rules */
+ int16 velocity;
+ if (channel == 9) {
+ /* Percussion channel, fixed velocity scaling not in the table */
+ velocity = (int16)b2 * 0x50;
+ } else {
+ /* Regular channel, use scaling from table */
+ velocity = b2 * programvelocities[chandata.cur_program];
+ }
+ b2 = (velocity / 128) & 0x00FF;
+ AddMidiData(outblock, MIDIST_NOTEON + channel, b1, b2);
+ } else {
+ /* Note off */
+ AddMidiData(outblock, MIDIST_NOTEON + channel, b1, 0);
+ }
+ break;
+ case MIDIST_CONTROLLER:
+ b2 = this->songdata[chandata.playpos++];
+ if (b1 == MIDICT_MODE_MONO) {
+ /* Unknown what the purpose of this is.
+ * Occurs in "Can't get There from Here" and in "Aliens Ate my Railway" a few times each.
+ * Possibly intended to give hints to other (non-GM) music drivers decoding the song.
+ */
+ break;
+ } else if (b1 == 0) {
+ /* Standard MIDI controller 0 is "bank select", override meaning to change tempo.
+ * This is not actually used in any of the original songs. */
+ if (b2 != 0) {
+ this->current_tempo = ((int)b2) * 48 / 60;
+ }
+ break;
+ } else if (b1 == MIDICT_EFFECTS1) {
+ /* Override value of this controller, default mapping is Reverb Send Level according to MMA RP-023.
+ * Unknown what the purpose of this particular value is. */
+ b2 = 30;
+ }
+ AddMidiData(outblock, MIDIST_CONTROLLER + channel, b1, b2);
+ break;
+ case MIDIST_PROGCHG:
+ if (b1 == 0x7E) {
+ /* Program change to "Applause" is originally used
+ * to cause the song to loop, but that gets handled
+ * separately in the output driver here.
+ * Just end the song. */
+ this->shouldplayflag = false;
+ break;
+ }
+ /* Used for note velocity scaling lookup */
+ chandata.cur_program = b1;
+ /* Two programs translated to a third, this is likely to
+ * provide three different velocity scalings of "brass". */
+ if (b1 == 0x57 || b1 == 0x3F) {
+ b1 = 0x3E;
+ }
+ AddMidiData(outblock, MIDIST_PROGCHG + channel, b1);
+ break;
+ case MIDIST_PITCHBEND:
+ b2 = this->songdata[chandata.playpos++];
+ AddMidiData(outblock, MIDIST_PITCHBEND + channel, b1, b2);
+ break;
+ default:
+ break;
+ }
+
+ newdelay = this->ReadVariableLength(chandata.playpos);
+ } while (newdelay == 0);
+
+ return newdelay;
+ }
+
+ /**
+ * Play one frame of data into a block.
+ */
+ bool PlayFrame(MidiFile::DataBlock &block)
+ {
+ /* Update tempo/ticks counter */
+ this->tempo_ticks -= this->current_tempo;
+ if (this->tempo_ticks > 0) {
+ return true;
+ }
+ this->tempo_ticks += TEMPO_RATE;
+
+ /* Look over all channels, play those active */
+ for (int ch = 0; ch < 16; ch++) {
+ Channel &chandata = this->channels[ch];
+ if (chandata.playpos != 0) {
+ if (chandata.delay == 0) {
+ chandata.delay = this->PlayChannelFrame(block, ch);
+ }
+ chandata.delay--;
+ }
+ }
+
+ return this->shouldplayflag;
+ }
+
+ /**
+ * Perform playback of whole song.
+ */
+ bool PlayInto()
+ {
+ /* Tempo seems to be handled as TEMPO_RATE = 148 ticks per second.
+ * Use this as the tickdiv, and define the tempo to be one second (1M microseconds) per tickdiv.
+ * MIDI software loading exported files will show a bogus tempo, but playback will be correct. */
+ this->target.tickdiv = TEMPO_RATE;
+ this->target.tempos.push_back(MidiFile::TempoChange(0, 1000000));
+
+ /* Initialize playback simulation */
+ this->RestartSong();
+ this->shouldplayflag = true;
+ this->current_tempo = (int32)this->initial_tempo * 24 / 60;
+ this->tempo_ticks = this->current_tempo;
+
+ /* Always reset percussion channel to program 0 */
+ this->target.blocks.push_back(MidiFile::DataBlock());
+ AddMidiData(this->target.blocks.back(), MIDIST_PROGCHG+9, 0x00);
+
+ /* Technically should be an endless loop, but having
+ * a maximum (about 10 minutes) avoids getting stuck,
+ * in case of corrupted data. */
+ for (uint32 tick = 0; tick < 100000; tick+=1) {
+ this->target.blocks.push_back(MidiFile::DataBlock());
+ auto &block = this->target.blocks.back();
+ block.ticktime = tick;
+ if (!this->PlayFrame(block)) {
+ break;
+ }
+ }
+ return true;
+ }
+};
+/** Frames/ticks per second for music playback */
+const int MpsMachine::TEMPO_RATE = 148;
+/** Base note velocities for various GM programs */
+const byte MpsMachine::programvelocities[128] = {
+ 100, 100, 100, 100, 100, 90, 100, 100, 100, 100, 100, 90, 100, 100, 100, 100,
+ 100, 100, 85, 100, 100, 100, 100, 100, 100, 100, 100, 100, 90, 90, 110, 80,
+ 100, 100, 100, 90, 70, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
+ 100, 100, 90, 100, 100, 100, 100, 100, 100, 120, 100, 100, 100, 120, 100, 127,
+ 100, 100, 90, 100, 100, 100, 100, 100, 100, 95, 100, 100, 100, 100, 100, 100,
+ 100, 100, 100, 100, 100, 100, 100, 115, 100, 100, 100, 100, 100, 100, 100, 100,
+ 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
+ 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
+};
+
+/**
+ * Create MIDI data from song data for the original Microprose music drivers.
+ * @param data pointer to block of data
+ * @param length size of data in bytes
+ * @return true if the data could be loaded
+ */
+bool MidiFile::LoadMpsData(const byte *data, size_t length)
+{
+ MpsMachine machine(data, length, *this);
+ return machine.PlayInto() && FixupMidiData(*this);
+}
+
+bool MidiFile::LoadSong(const MusicSongInfo &song)
+{
+ switch (song.filetype) {
+ case MTT_STANDARDMIDI:
+ return this->LoadFile(song.filename);
+ case MTT_MPSMIDI:
+ {
+ size_t songdatalen = 0;
+ byte *songdata = GetMusicCatEntryData(song.filename, song.cat_index, songdatalen);
+ if (songdata != NULL) {
+ bool result = this->LoadMpsData(songdata, songdatalen);
+ free(songdata);
+ return result;
+ } else {
+ return false;
+ }
+ }
+ default:
+ NOT_REACHED();
+ }
+}
+
/**
* Move data from other to this, and clears other.
* @param other object containing loaded data to take over
@@ -454,4 +834,3 @@ void MidiFile::MoveFrom(MidiFile &other)
other.tempos.clear();
other.tickdiv = 0;
}
-
diff --git a/src/music/midifile.hpp b/src/music/midifile.hpp
index d077f63cd..e41435364 100644
--- a/src/music/midifile.hpp
+++ b/src/music/midifile.hpp
@@ -17,6 +17,8 @@
#include "midi.h"
#include <vector>
+struct MusicSongInfo;
+
struct MidiFile {
struct DataBlock {
uint32 ticktime; ///< tick number since start of file this block should be triggered at
@@ -35,6 +37,8 @@ struct MidiFile {
uint16 tickdiv; ///< ticks per quarter note
bool LoadFile(const char *filename);
+ bool LoadMpsData(const byte *data, size_t length);
+ bool LoadSong(const MusicSongInfo &song);
void MoveFrom(MidiFile &other);
static bool ReadSMFHeader(const char *filename, SMFHeader &header);
diff --git a/src/music/win32_m.cpp b/src/music/win32_m.cpp
index 8e5adeab2..51528133b 100644
--- a/src/music/win32_m.cpp
+++ b/src/music/win32_m.cpp
@@ -307,12 +307,14 @@ void CALLBACK TimerCallback(UINT uTimerID, UINT, DWORD_PTR dwUser, DWORD_PTR, DW
void MusicDriver_Win32::PlaySong(const MusicSongInfo &song)
{
- if (song.filetype != MTT_STANDARDMIDI) return;
-
DEBUG(driver, 2, "Win32-MIDI: PlaySong: entry");
EnterCriticalSection(&_midi.lock);
- _midi.next_file.LoadFile(song.filename);
+ if (!_midi.next_file.LoadSong(song)) {
+ LeaveCriticalSection(&_midi.lock);
+ return;
+ }
+
_midi.next_segment.start = 0;
_midi.next_segment.end = 0;
_midi.next_segment.loop = false;
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-12-03 01:03:46 +0000