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* This file is part of OpenTTD.
* OpenTTD 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, version 2.
* OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/* @file midifile.cpp Parser for standard MIDI files */
#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>
#include "../console_func.h"
#include "../console_internal.h"
/* SMF reader based on description at: http://www.somascape.org/midi/tech/mfile.html */
static MidiFile *_midifile_instance = nullptr;
/**
* Retrieve a well-known MIDI system exclusive message.
* @param msg Which sysex message to retrieve
* @param[out] length Receives the length of the returned buffer
* @return Pointer to byte buffer with sysex message
*/
const byte *MidiGetStandardSysexMessage(MidiSysexMessage msg, size_t &length)
{
static byte reset_gm_sysex[] = { 0xF0, 0x7E, 0x7F, 0x09, 0x01, 0xF7 };
static byte reset_gs_sysex[] = { 0xF0, 0x41, 0x10, 0x42, 0x12, 0x40, 0x00, 0x7F, 0x00, 0x41, 0xF7 };
static byte reset_xg_sysex[] = { 0xF0, 0x43, 0x10, 0x4C, 0x00, 0x00, 0x7E, 0x00, 0xF7 };
static byte roland_reverb_sysex[] = { 0xF0, 0x41, 0x10, 0x42, 0x12, 0x40, 0x01, 0x30, 0x02, 0x04, 0x00, 0x40, 0x40, 0x00, 0x00, 0x09, 0xF7 };
switch (msg) {
case MidiSysexMessage::ResetGM:
length = lengthof(reset_gm_sysex);
return reset_gm_sysex;
case MidiSysexMessage::ResetGS:
length = lengthof(reset_gs_sysex);
return reset_gs_sysex;
case MidiSysexMessage::ResetXG:
length = lengthof(reset_xg_sysex);
return reset_xg_sysex;
case MidiSysexMessage::RolandSetReverb:
length = lengthof(roland_reverb_sysex);
return roland_reverb_sysex;
default:
NOT_REACHED();
}
}
/**
* Owning byte buffer readable as a stream.
* RAII-compliant to make teardown in error situations easier.
*/
class ByteBuffer {
byte *buf;
size_t buflen;
size_t pos;
public:
/**
* Construct buffer from data in a file.
* If file does not have sufficient bytes available, the object is constructed
* in an error state, that causes all further function calls to fail.
* @param file file to read from at current position
* @param len number of bytes to read
*/
ByteBuffer(FILE *file, size_t len)
{
this->buf = MallocT<byte>(len);
if (fread(this->buf, 1, len, file) == len) {
this->buflen = len;
this->pos = 0;
} else {
/* invalid state */
this->buflen = 0;
}
}
/**
* Destructor, frees the buffer.
*/
~ByteBuffer()
{
free(this->buf);
}
/**
* Return whether the buffer was constructed successfully.
* @return true is the buffer contains data
*/
bool IsValid() const
{
return this->buflen > 0;
}
/**
* Return whether reading has reached the end of the buffer.
* @return true if there are no more bytes available to read
*/
bool IsEnd() const
{
return this->pos >= this->buflen;
}
/**
* Read a single byte from the buffer.
* @param[out] b returns the read value
* @return true if a byte was available for reading
*/
bool ReadByte(byte &b)
{
if (this->IsEnd()) return false;
b = this->buf[this->pos++];
return true;
}
/**
* Read a MIDI file variable length value.
* Each byte encodes 7 bits of the value, most-significant bits are encoded first.
* If the most significant bit in a byte is set, there are further bytes encoding the value.
* @param[out] res returns the read value
* @return true if there was data available
*/
bool ReadVariableLength(uint32 &res)
{
res = 0;
byte b = 0;
do {
if (this->IsEnd()) return false;
b = this->buf[this->pos++];
res = (res << 7) | (b & 0x7F);
} while (b & 0x80);
return true;
}
/**
* Read bytes into a buffer.
* @param[out] dest buffer to copy into
* @param length number of bytes to read
* @return true if the requested number of bytes were available
*/
bool ReadBuffer(byte *dest, size_t length)
{
if (this->IsEnd()) return false;
if (this->buflen - this->pos < length) return false;
memcpy(dest, this->buf + this->pos, length);
this->pos += length;
return true;
}
/**
* Read bytes into a MidiFile::DataBlock.
* @param[out] dest DataBlock to copy into
* @param length number of bytes to read
* @return true if the requested number of bytes were available
*/
bool ReadDataBlock(MidiFile::DataBlock *dest, size_t length)
{
if (this->IsEnd()) return false;
if (this->buflen - this->pos < length) return false;
dest->data.insert(dest->data.end(), this->buf + this->pos, this->buf + this->pos + length);
this->pos += length;
return true;
}
/**
* Skip over a number of bytes in the buffer.
* @param count number of bytes to skip over
* @return true if there were enough bytes available
*/
bool Skip(size_t count)
{
if (this->IsEnd()) return false;
if (this->buflen - this->pos < count) return false;
this->pos += count;
return true;
}
/**
* Go a number of bytes back to re-read.
* @param count number of bytes to go back
* @return true if at least count bytes had been read previously
*/
bool Rewind(size_t count)
{
if (count > this->pos) return false;
this->pos -= count;
return true;
}
};
static bool ReadTrackChunk(FILE *file, MidiFile &target)
{
byte buf[4];
const byte magic[] = { 'M', 'T', 'r', 'k' };
if (fread(buf, sizeof(magic), 1, file) != 1) {
return false;
}
if (memcmp(magic, buf, sizeof(magic)) != 0) {
return false;
}
/* Read chunk length and then the whole chunk */
uint32 chunk_length;
if (fread(&chunk_length, 1, 4, file) != 4) {
return false;
}
chunk_length = FROM_BE32(chunk_length);
ByteBuffer chunk(file, chunk_length);
if (!chunk.IsValid()) {
return false;
}
target.blocks.push_back(MidiFile::DataBlock());
MidiFile::DataBlock *block = &target.blocks.back();
byte last_status = 0;
bool running_sysex = false;
while (!chunk.IsEnd()) {
/* Read deltatime for event, start new block */
uint32 deltatime = 0;
if (!chunk.ReadVariableLength(deltatime)) {
return false;
}
if (deltatime > 0) {
target.blocks.push_back(MidiFile::DataBlock(block->ticktime + deltatime));
block = &target.blocks.back();
}
/* 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
* convert to explicit status */
chunk.Rewind(1);
status = last_status;
goto running_status;
} else if ((status & 0xF0) != 0xF0) {
/* Regular channel message */
last_status = status;
running_status:
switch (status & 0xF0) {
case MIDIST_NOTEOFF:
case MIDIST_NOTEON:
case MIDIST_POLYPRESS:
case MIDIST_CONTROLLER:
case MIDIST_PITCHBEND:
/* 3 byte messages */
block->data.push_back(status);
if (!chunk.ReadDataBlock(block, 2)) {
return false;
}
break;
case MIDIST_PROGCHG:
case MIDIST_CHANPRESS:
/* 2 byte messages */
block->data.push_back(status);
if (!chunk.ReadByte(buf[0])) {
return false;
}
block->data.push_back(buf[0]);
break;
default:
NOT_REACHED();
}
} else if (status == MIDIST_SMF_META) {
/* Meta event, read event type byte and data length */
if (!chunk.ReadByte(buf[0])) {
return false;
}
uint32 length = 0;
if (!chunk.ReadVariableLength(length)) {
return false;
}
switch (buf[0]) {
case 0x2F:
/* end of track, no more data (length != 0 is illegal) */
return (length == 0);
case 0x51:
/* tempo change */
if (length != 3) return false;
if (!chunk.ReadBuffer(buf, 3)) return false;
target.tempos.push_back(MidiFile::TempoChange(block->ticktime, buf[0] << 16 | buf[1] << 8 | buf[2]));
break;
default:
/* unimportant meta event, skip over it */
if (!chunk.Skip(length)) {
return false;
}
break;
}
} else if (status == MIDIST_SYSEX || (status == MIDIST_SMF_ESCAPE && running_sysex)) {
/* System exclusive message */
uint32 length = 0;
if (!chunk.ReadVariableLength(length)) {
return false;
}
block->data.push_back(0xF0);
if (!chunk.ReadDataBlock(block, length)) {
return false;
}
if (block->data.back() != 0xF7) {
/* Engage Casio weirdo mode - convert to normal sysex */
running_sysex = true;
block->data.push_back(0xF7);
} else {
running_sysex = false;
}
} else if (status == MIDIST_SMF_ESCAPE) {
/* Escape sequence */
uint32 length = 0;
if (!chunk.ReadVariableLength(length)) {
return false;
}
if (!chunk.ReadDataBlock(block, length)) {
return false;
}
} else {
/* Messages undefined in standard midi files:
* 0xF1 - MIDI time code quarter frame
* 0xF2 - Song position pointer
* 0xF3 - Song select
* 0xF4 - undefined/reserved
* 0xF5 - undefined/reserved
* 0xF6 - Tune request for analog synths
* 0xF8..0xFE - System real-time messages
*/
return false;
}
}
NOT_REACHED();
}
template<typename T>
bool TicktimeAscending(const T &a, const T &b)
{
return a.ticktime < b.ticktime;
}
static bool FixupMidiData(MidiFile &target)
{
/* Sort all tempo changes and events */
std::sort(target.tempos.begin(), target.tempos.end(), TicktimeAscending<MidiFile::TempoChange>);
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 */
target.tempos.push_back(MidiFile::TempoChange(0, 500000));
}
/* Add sentinel tempo at end */
target.tempos.push_back(MidiFile::TempoChange(UINT32_MAX, 0));
/* 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.data.size() == 0) {
continue;
} else if (block.ticktime > last_ticktime || merged_blocks.size() == 0) {
merged_blocks.push_back(block);
last_ticktime = block.ticktime;
} else {
merged_blocks.back().data.insert(merged_blocks.back().data.end(), block.data.begin(), block.data.end());
}
}
std::swap(merged_blocks, target.blocks);
/* Annotate blocks with real time */
last_ticktime = 0;
uint32 last_realtime = 0;
size_t cur_tempo = 0, cur_block = 0;
while (cur_block < target.blocks.size()) {
MidiFile::DataBlock &block = target.blocks[cur_block];
MidiFile::TempoChange &tempo = target.tempos[cur_tempo];
MidiFile::TempoChange &next_tempo = target.tempos[cur_tempo+1];
if (block.ticktime <= next_tempo.ticktime) {
/* block is within the current tempo */
int64 tickdiff = block.ticktime - last_ticktime;
last_ticktime = block.ticktime;
last_realtime += uint32(tickdiff * tempo.tempo / target.tickdiv);
block.realtime = last_realtime;
cur_block++;
} else {
/* tempo change occurs before this block */
int64 tickdiff = next_tempo.ticktime - last_ticktime;
last_ticktime = next_tempo.ticktime;
last_realtime += uint32(tickdiff * tempo.tempo / target.tickdiv); // current tempo until the tempo change
cur_tempo++;
}
}
return true;
}
/**
* Read the header of a standard MIDI file.
* @param[in] filename name of file to read from
* @param[out] header filled with data read
* @return true if the file could be opened and contained a header with correct format
*/
bool MidiFile::ReadSMFHeader(const char *filename, SMFHeader &header)
{
FILE *file = FioFOpenFile(filename, "rb", Subdirectory::BASESET_DIR);
if (!file) return false;
bool result = ReadSMFHeader(file, header);
FioFCloseFile(file);
return result;
}
/**
* Read the header of a standard MIDI file.
* The function will consume 14 bytes from the current file pointer position.
* @param[in] file open file to read from (should be in binary mode)
* @param[out] header filled with data read
* @return true if a header in correct format could be read from the file
*/
bool MidiFile::ReadSMFHeader(FILE *file, SMFHeader &header)
{
/* Try to read header, fixed size */
byte buffer[14];
if (fread(buffer, sizeof(buffer), 1, file) != 1) {
return false;
}
/* 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 */
header.format = (buffer[8] << 8) | buffer[9];
header.tracks = (buffer[10] << 8) | buffer[11];
header.tickdiv = (buffer[12] << 8) | buffer[13];
return true;
}
/**
* Load a standard MIDI file.
* @param filename name of the file to load
* @returns true if loaded was successful
*/
bool MidiFile::LoadFile(const char *filename)
{
_midifile_instance = this;
this->blocks.clear();
this->tempos.clear();
this->tickdiv = 0;
bool success = false;
FILE *file = FioFOpenFile(filename, "rb", Subdirectory::BASESET_DIR);
if (file == nullptr) return false;
SMFHeader header;
if (!ReadSMFHeader(file, header)) goto cleanup;
/* Only format 0 (single-track) and format 1 (multi-track single-song) are accepted for now */
if (header.format != 0 && header.format != 1) goto cleanup;
/* Doesn't support SMPTE timecode files */
if ((header.tickdiv & 0x8000) != 0) goto cleanup;
this->tickdiv = header.tickdiv;
for (; header.tracks > 0; header.tracks--) {
if (!ReadTrackChunk(file, *this)) {
goto cleanup;
}
}
success = FixupMidiData(*this);
cleanup:
FioFCloseFile(file);
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 ⌖ ///< 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.push_back(b1);
block.data.push_back(b2);
}
static void AddMidiData(MidiFile::DataBlock &block, byte b1, byte b2, byte b3)
{
block.data.push_back(b1);
block.data.push_back(b2);
block.data.push_back(b3);
}
/**
* Construct a TTD DOS music format decoder.
* @param data Buffer of song data from CAT file, ownership remains with caller
* @param length 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)
{
_midifile_instance = this;
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 != nullptr) {
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
*/
void MidiFile::MoveFrom(MidiFile &other)
{
std::swap(this->blocks, other.blocks);
std::swap(this->tempos, other.tempos);
this->tickdiv = other.tickdiv;
_midifile_instance = this;
other.blocks.clear();
other.tempos.clear();
other.tickdiv = 0;
}
static void WriteVariableLen(FILE *f, uint32 value)
{
if (value <= 0x7F) {
byte tb = value;
fwrite(&tb, 1, 1, f);
} else if (value <= 0x3FFF) {
byte tb[2];
tb[1] = value & 0x7F; value >>= 7;
tb[0] = (value & 0x7F) | 0x80; value >>= 7;
fwrite(tb, 1, sizeof(tb), f);
} else if (value <= 0x1FFFFF) {
byte tb[3];
tb[2] = value & 0x7F; value >>= 7;
tb[1] = (value & 0x7F) | 0x80; value >>= 7;
tb[0] = (value & 0x7F) | 0x80; value >>= 7;
fwrite(tb, 1, sizeof(tb), f);
} else if (value <= 0x0FFFFFFF) {
byte tb[4];
tb[3] = value & 0x7F; value >>= 7;
tb[2] = (value & 0x7F) | 0x80; value >>= 7;
tb[1] = (value & 0x7F) | 0x80; value >>= 7;
tb[0] = (value & 0x7F) | 0x80; value >>= 7;
fwrite(tb, 1, sizeof(tb), f);
}
}
/**
* Write a Standard MIDI File containing the decoded music.
* @param filename Name of file to write to
* @return True if the file was written to completion
*/
bool MidiFile::WriteSMF(const char *filename)
{
FILE *f = FioFOpenFile(filename, "wb", Subdirectory::NO_DIRECTORY);
if (!f) {
return false;
}
/* SMF header */
const byte fileheader[] = {
'M', 'T', 'h', 'd', // block name
0x00, 0x00, 0x00, 0x06, // BE32 block length, always 6 bytes
0x00, 0x00, // writing format 0 (all in one track)
0x00, 0x01, // containing 1 track (BE16)
(byte)(this->tickdiv >> 8), (byte)this->tickdiv, // tickdiv in BE16
};
fwrite(fileheader, sizeof(fileheader), 1, f);
/* Track header */
const byte trackheader[] = {
'M', 'T', 'r', 'k', // block name
0, 0, 0, 0, // BE32 block length, unknown at this time
};
fwrite(trackheader, sizeof(trackheader), 1, f);
/* Determine position to write the actual track block length at */
size_t tracksizepos = ftell(f) - 4;
/* Write blocks in sequence */
uint32 lasttime = 0;
size_t nexttempoindex = 0;
for (size_t bi = 0; bi < this->blocks.size(); bi++) {
DataBlock &block = this->blocks[bi];
TempoChange &nexttempo = this->tempos[nexttempoindex];
uint32 timediff = block.ticktime - lasttime;
/* Check if there is a tempo change before this block */
if (nexttempo.ticktime < block.ticktime) {
timediff = nexttempo.ticktime - lasttime;
}
/* Write delta time for block */
lasttime += timediff;
bool needtime = false;
WriteVariableLen(f, timediff);
/* Write tempo change if there is one */
if (nexttempo.ticktime <= block.ticktime) {
byte tempobuf[6] = { MIDIST_SMF_META, 0x51, 0x03, 0, 0, 0 };
tempobuf[3] = (nexttempo.tempo & 0x00FF0000) >> 16;
tempobuf[4] = (nexttempo.tempo & 0x0000FF00) >> 8;
tempobuf[5] = (nexttempo.tempo & 0x000000FF);
fwrite(tempobuf, sizeof(tempobuf), 1, f);
nexttempoindex++;
needtime = true;
}
/* If a tempo change occurred between two blocks, rather than
* at start of this one, start over with delta time for the block. */
if (nexttempo.ticktime < block.ticktime) {
/* Start loop over at same index */
bi--;
continue;
}
/* Write each block data command */
byte *dp = block.data.data();
while (dp < block.data.data() + block.data.size()) {
/* Always zero delta time inside blocks */
if (needtime) {
fputc(0, f);
}
needtime = true;
/* Check message type and write appropriate number of bytes */
switch (*dp & 0xF0) {
case MIDIST_NOTEOFF:
case MIDIST_NOTEON:
case MIDIST_POLYPRESS:
case MIDIST_CONTROLLER:
case MIDIST_PITCHBEND:
fwrite(dp, 1, 3, f);
dp += 3;
continue;
case MIDIST_PROGCHG:
case MIDIST_CHANPRESS:
fwrite(dp, 1, 2, f);
dp += 2;
continue;
}
/* Sysex needs to measure length and write that as well */
if (*dp == MIDIST_SYSEX) {
fwrite(dp, 1, 1, f);
dp++;
byte *sysexend = dp;
while (*sysexend != MIDIST_ENDSYSEX) sysexend++;
ptrdiff_t sysexlen = sysexend - dp;
WriteVariableLen(f, sysexlen);
fwrite(dp, 1, sysexend - dp, f);
dp = sysexend + 1;
continue;
}
/* Fail for any other commands */
fclose(f);
return false;
}
}
/* End of track marker */
static const byte track_end_marker[] = { 0x00, MIDIST_SMF_META, 0x2F, 0x00 };
fwrite(&track_end_marker, sizeof(track_end_marker), 1, f);
/* Fill out the RIFF block length */
size_t trackendpos = ftell(f);
fseek(f, tracksizepos, SEEK_SET);
uint32 tracksize = (uint32)(trackendpos - tracksizepos - 4); // blindly assume we never produce files larger than 2 GB
tracksize = TO_BE32(tracksize);
fwrite(&tracksize, 4, 1, f);
fclose(f);
return true;
}
/**
* Get the name of a Standard MIDI File for a given song.
* For songs already in SMF format, just returns the original.
* Otherwise the song is converted, written to a temporary-ish file, and the written filename is returned.
* @param song Song definition to query
* @return Full filename string, empty string if failed
*/
std::string MidiFile::GetSMFFile(const MusicSongInfo &song)
{
if (song.filetype == MTT_STANDARDMIDI) {
char filename[MAX_PATH];
if (FioFindFullPath(filename, lastof(filename), Subdirectory::BASESET_DIR, song.filename)) {
return std::string(filename);
} else if (FioFindFullPath(filename, lastof(filename), Subdirectory::OLD_GM_DIR, song.filename)) {
return std::string(filename);
} else {
return std::string();
}
}
if (song.filetype != MTT_MPSMIDI) return std::string();
char basename[MAX_PATH];
{
const char *fnstart = strrchr(song.filename, PATHSEPCHAR);
if (fnstart == nullptr) {
fnstart = song.filename;
} else {
fnstart++;
}
/* Remove all '.' characters from filename */
char *wp = basename;
for (const char *rp = fnstart; *rp != '\0'; rp++) {
if (*rp != '.') *wp++ = *rp;
}
*wp++ = '\0';
}
char tempdirname[MAX_PATH];
FioGetFullPath(tempdirname, lastof(tempdirname), Searchpath::SP_AUTODOWNLOAD_DIR, Subdirectory::BASESET_DIR, basename);
if (!AppendPathSeparator(tempdirname, lastof(tempdirname))) return std::string();
FioCreateDirectory(tempdirname);
char output_filename[MAX_PATH];
seprintf(output_filename, lastof(output_filename), "%s%d.mid", tempdirname, song.cat_index);
if (FileExists(output_filename)) {
/* If the file already exists, assume it's the correct decoded data */
return std::string(output_filename);
}
byte *data;
size_t datalen;
data = GetMusicCatEntryData(song.filename, song.cat_index, datalen);
if (data == nullptr) return std::string();
MidiFile midifile;
if (!midifile.LoadMpsData(data, datalen)) {
free(data);
return std::string();
}
free(data);
if (midifile.WriteSMF(output_filename)) {
return std::string(output_filename);
} else {
return std::string();
}
}
static bool CmdDumpSMF(byte argc, char *argv[])
{
if (argc == 0) {
IConsolePrint(CC_WARNING, "Write the current song to a Standard MIDI File. Usage: 'dumpsmf <filename>'");
return true;
}
if (argc != 2) {
IConsolePrint(CC_WARNING, "You must specify a filename to write MIDI data to.");
return false;
}
if (_midifile_instance == nullptr) {
IConsolePrint(CC_ERROR, "There is no MIDI file loaded currently, make sure music is playing, and you're using a driver that works with raw MIDI.");
return false;
}
char fnbuf[MAX_PATH] = { 0 };
if (seprintf(fnbuf, lastof(fnbuf), "%s%s", FiosGetScreenshotDir(), argv[1]) >= (int)lengthof(fnbuf)) {
IConsolePrint(CC_ERROR, "Filename too long.");
return false;
}
IConsolePrintF(CC_INFO, "Dumping MIDI to: %s", fnbuf);
if (_midifile_instance->WriteSMF(fnbuf)) {
IConsolePrint(CC_INFO, "File written successfully.");
return true;
} else {
IConsolePrint(CC_ERROR, "An error occurred writing MIDI file.");
return false;
}
}
static void RegisterConsoleMidiCommands()
{
static bool registered = false;
if (!registered) {
IConsoleCmdRegister("dumpsmf", CmdDumpSMF);
registered = true;
}
}
MidiFile::MidiFile()
{
RegisterConsoleMidiCommands();
}
MidiFile::~MidiFile()
{
if (_midifile_instance == this) {
_midifile_instance = nullptr;
}
}
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