ref: b96cdbe82fa6cb51ac91072ad86e084d739fd9be
parent: 543b9bdc85dfeb84ed855084595407d6bf49d8f6
author: Simon Howard <fraggle@gmail.com>
date: Fri Mar 27 20:24:50 EDT 2009
Initial MIDI file parsing code. Subversion-branch: /branches/opl-branch Subversion-revision: 1489
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -156,6 +156,7 @@
i_sdlsound.c \
i_sdlmusic.c \
i_oplmusic.c \
+midifile.c midifile.h \
mus2mid.c mus2mid.h
SOURCE_FILES = $(MAIN_SOURCE_FILES) \
--- /dev/null
+++ b/src/midifile.c
@@ -1,0 +1,287 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 Simon Howard
+//
+// This program 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; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program 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 this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+// Reading of MIDI files.
+//
+//-----------------------------------------------------------------------------
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "doomtype.h"
+#include "i_swap.h"
+#include "midifile.h"
+
+#define HEADER_CHUNK_ID "MThd"
+#define TRACK_CHUNK_ID "MTrk"
+
+typedef struct
+{+ byte chunk_id[4];
+ unsigned int chunk_size;
+} chunk_header_t;
+
+typedef struct
+{+ chunk_header_t chunk_header;
+ unsigned short format_type;
+ unsigned short num_tracks;
+ unsigned int time_division;
+} midi_header_t;
+
+struct midi_file_s
+{+ FILE *stream;
+ midi_header_t header;
+ unsigned int data_len;
+};
+
+static boolean CheckChunkHeader(chunk_header_t *chunk,
+ char *expected_id)
+{+ boolean result;
+
+ result = (strcmp((char *) chunk->chunk_id, expected_id) == 0);
+
+ if (!result)
+ {+ fprintf(stderr, "CheckChunkHeader: Expected '%s' chunk header!\n",
+ expected_id);
+ }
+
+ return result;
+}
+
+// Read and check the header chunk.
+
+static boolean ReadHeaderChunk(midi_file_t *file)
+{+ size_t bytes_read;
+
+ bytes_read = fread(&file->header, sizeof(midi_header_t), 1, file->stream);
+
+ if (bytes_read < sizeof(midi_header_t))
+ {+ return false;
+ }
+
+ if (!CheckChunkHeader(&file->header.chunk_header, HEADER_CHUNK_ID)
+ || LONG(file->header.chunk_header.chunk_size) != 6)
+ {+ fprintf(stderr, "ReadHeaderChunk: Invalid MIDI chunk header!\n");
+ return false;
+ }
+
+ if (SHORT(file->header.format_type) != 0
+ || SHORT(file->header.num_tracks) != 1)
+ {+ fprintf(stderr, "ReadHeaderChunk: Only single track, "
+ "type 0 MIDI files supported!\n");
+ return false;
+ }
+
+ return true;
+}
+
+// Read and check the track chunk header
+
+static boolean ReadTrackChunk(midi_file_t *file)
+{+ size_t bytes_read;
+ chunk_header_t chunk_header;
+
+ bytes_read = fread(&chunk_header, sizeof(chunk_header_t), 1, file->stream);
+
+ if (bytes_read < sizeof(chunk_header))
+ {+ return false;
+ }
+
+ if (!CheckChunkHeader(&chunk_header, TRACK_CHUNK_ID))
+ {+ return false;
+ }
+
+ file->data_len = LONG(chunk_header.chunk_size);
+
+ return true;
+}
+
+midi_file_t *MIDI_OpenFile(char *filename)
+{+ midi_file_t *file;
+
+ file = malloc(sizeof(midi_file_t));
+
+ if (file == NULL)
+ {+ return NULL;
+ }
+
+ // Open file
+
+ file->stream = fopen(filename, "rb");
+
+ if (file->stream == NULL)
+ {+ fprintf(stderr, "Failed to open '%s'\n", filename);
+ free(file);
+ return NULL;
+ }
+
+ // Read MIDI file header
+
+ if (!ReadHeaderChunk(file))
+ {+ fclose(file->stream);
+ free(file);
+ return NULL;
+ }
+
+ // Read track header
+
+ if (!ReadTrackChunk(file))
+ {+ fclose(file->stream);
+ free(file);
+ return NULL;
+ }
+
+ return file;
+}
+
+void MIDI_CloseFile(midi_file_t *file)
+{+ fclose(file->stream);
+ free(file);
+}
+
+// Read a MIDI channel event.
+// two_param indicates that the event type takes two parameters
+// (three byte) otherwise it is single parameter (two byte)
+
+static boolean ReadChannelEvent(midi_file_t *file, midi_event_t *event,
+ int event_type, boolean two_param)
+{+ int c;
+
+ // Set basics:
+
+ event->event_type = event_type >> 4;
+ event->data.channel.channel = event_type & 0xf;
+
+ // Read parameters:
+
+ c = fgetc(file->stream);
+
+ if (c == EOF)
+ {+ return false;
+ }
+
+ event->data.channel.param1 = c;
+
+ // Second parameter:
+
+ if (two_param)
+ {+ c = fgetc(file->stream);
+
+ if (c == EOF)
+ {+ return false;
+ }
+
+ event->data.channel.param2 = c;
+ }
+
+ return true;
+}
+
+// Read sysex event:
+
+static boolean ReadSysExEvent(midi_file_t *file, midi_event_t *event,
+ int event_type)
+{+ // TODO
+ return false;
+}
+
+// Read meta event:
+
+static boolean ReadMetaEvent(midi_file_t *file, midi_event_t *event)
+{+ // TODO
+ return false;
+}
+
+boolean MIDI_ReadEvent(midi_file_t *file, midi_event_t *event)
+{+ int event_type;
+
+ event_type = fgetc(file->stream);
+
+ if (event_type == EOF)
+ {+ return false;
+ }
+
+ // Check event type:
+
+ switch (event_type >> 4)
+ {+ // Two parameter channel events:
+
+ case MIDI_EVENT_NOTE_OFF:
+ case MIDI_EVENT_NOTE_ON:
+ case MIDI_EVENT_AFTERTOUCH:
+ case MIDI_EVENT_CONTROLLER:
+ case MIDI_EVENT_PITCH_BEND:
+ return ReadChannelEvent(file, event, event_type, true);
+
+ // Single parameter channel events:
+
+ case MIDI_EVENT_PROGRAM_CHANGE:
+ case MIDI_EVENT_CHAN_AFTERTOUCH:
+ return ReadChannelEvent(file, event, event_type, false);
+
+ // Other event types:
+
+ case 0xf:
+ if (event_type == MIDI_EVENT_SYSEX
+ || event_type == MIDI_EVENT_SYSEX_SPLIT)
+ {+ return ReadSysExEvent(file, event, event_type);
+ }
+ else if (event_type == MIDI_EVENT_META)
+ {+ return ReadMetaEvent(file, event);
+ }
+
+ // Fall-through deliberate -
+
+ default:
+ fprintf(stderr, "Unknown MIDI event type: 0x%x\n", event_type);
+ return false;
+ }
+}
+
--- /dev/null
+++ b/src/midifile.h
@@ -1,0 +1,135 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 Simon Howard
+//
+// This program 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; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program 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 this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+// MIDI file parsing.
+//
+//-----------------------------------------------------------------------------
+
+#ifndef MIDIFILE_H
+#define MIDIFILE_H
+
+typedef struct midi_file_s midi_file_t;
+
+typedef enum
+{+ MIDI_EVENT_NOTE_OFF = 0x8,
+ MIDI_EVENT_NOTE_ON = 0x9,
+ MIDI_EVENT_AFTERTOUCH = 0xa,
+ MIDI_EVENT_CONTROLLER = 0xb,
+ MIDI_EVENT_PROGRAM_CHANGE = 0xc,
+ MIDI_EVENT_CHAN_AFTERTOUCH = 0xd,
+ MIDI_EVENT_PITCH_BEND = 0xe,
+
+ MIDI_EVENT_SYSEX = 0xf0,
+ MIDI_EVENT_SYSEX_SPLIT = 0xf7,
+ MIDI_EVENT_META = 0xff,
+} midi_event_type_t;
+
+typedef enum
+{+ MIDI_CONTROLLER_BANK_SELECT = 0x0,
+ MIDI_CONTROLLER_MODULATION = 0x1,
+ MIDI_CONTROLLER_BREATH_CONTROL = 0x2,
+ MIDI_CONTROLLER_FOOT_CONTROL = 0x3,
+ MIDI_CONTROLLER_PORTAMENTO = 0x4,
+ MIDI_CONTROLLER_DATA_ENTRY = 0x5,
+} midi_controller_t;
+
+typedef enum
+{+ MIDI_META_SEQUENCE_NUMBER = 0x0,
+
+ MIDI_META_TEXT = 0x1,
+ MIDI_META_COPYRIGHT = 0x2,
+ MIDI_META_TRACK_NAME = 0x3,
+ MIDI_META_INSTR_NAME = 0x4,
+ MIDI_META_LYRICS = 0x5,
+ MIDI_META_MARKER = 0x6,
+ MIDI_META_CUE_POINT = 0x7,
+
+ MIDI_META_CHANNEL_PREFIX = 0x8,
+ MIDI_META_END_OF_TRACK = 0x9,
+ MIDI_META_SET_TEMPO = 0xa,
+ MIDI_META_SMPTE_OFFSET = 0xb,
+ MIDI_META_TIME_SIGNATURE = 0xc,
+ MIDI_META_KEY_SIGNATURE = 0xd,
+ MIDI_META_SEQUENCER_SPECIFIC = 0xe,
+} midi_meta_event_type_t;
+
+typedef struct
+{+ // Meta event type:
+
+ unsigned int type;
+
+ // Length:
+
+ unsigned int length;
+
+ // Meta event data:
+
+ byte *data;
+} midi_meta_event_data_t;
+
+typedef struct
+{+ // Length:
+
+ unsigned int length;
+
+ // Event data:
+
+ byte *data;
+} midi_sysex_event_data_t;
+
+typedef struct
+{+ // The channel number to which this applies:
+
+ unsigned int channel;
+
+ // Extra parameters:
+
+ unsigned int param1;
+ unsigned int param2;
+} midi_channel_event_data_t;
+
+typedef struct
+{+ // Time between the previous event and this event.
+ unsigned int delta_time;
+
+ // Type of event:
+ midi_event_type_t event_type;
+
+ union
+ {+ midi_channel_event_data_t channel;
+ midi_meta_event_data_t meta;
+ midi_sysex_event_data_t sysex;
+ } data;
+} midi_event_t;
+
+midi_file_t *MIDI_OpenFile(char *filename);
+void MIDI_CloseFile(midi_file_t *file);
+
+#endif /* #ifndef MIDIFILE_H */
+