MidiFileParserState.h

#pragma once
#include "RingBuffer.h"
 
namespace midi {
 
enum midi_parser_status {
  MIDI_PARSER_DELAY = -3,
  MIDI_PARSER_EOB = -2,
  MIDI_PARSER_ERROR = -1,
  MIDI_PARSER_INIT = 0,
  MIDI_PARSER_HEADER = 1,
  MIDI_PARSER_TRACK = 2,
  MIDI_PARSER_TRACK_MIDI = 3,
  MIDI_PARSER_TRACK_META = 4,
  MIDI_PARSER_TRACK_SYSEX = 5,
};
 
enum midi_file_format {
  MIDI_FILE_FORMAT_SINGLE_TRACK = 0,
  MIDI_FILE_FORMAT_MULTIPLE_TRACKS = 1,
  MIDI_FILE_FORMAT_MULTIPLE_SONGS = 2,
};
 
struct midi_header {
  int32_t size;
  uint16_t format;
  int16_t tracks_count;
  int16_t time_division;
};
 
struct midi_track {
  int32_t size;
  int32_t number; // track number
};
 
enum midi_status {
  MIDI_STATUS_NA = 0x0,
  MIDI_STATUS_NOTE_OFF = 0x8,
  MIDI_STATUS_NOTE_ON = 0x9,
  MIDI_STATUS_NOTE_AT = 0xA, // after touch
  MIDI_STATUS_CC = 0xB,      // control change
  MIDI_STATUS_PGM_CHANGE = 0xC,
  MIDI_STATUS_CHANNEL_AT = 0xD, // after touch
  MIDI_STATUS_PITCH_BEND = 0xE,
};
 
enum midi_meta {
  MIDI_META_SEQ_NUM = 0x00,
  MIDI_META_TEXT = 0x01,
  MIDI_META_COPYRIGHT = 0x02,
  MIDI_META_TRACK_NAME = 0x03,
  MIDI_META_INSTRUMENT_NAME = 0x04,
  MIDI_META_LYRICS = 0x05,
  MIDI_META_MAKER = 0x06,
  MIDI_META_CUE_POINT = 0x07,
  MIDI_META_CHANNEL_PREFIX = 0x20,
  MIDI_META_END_OF_TRACK = 0x2F,
  MIDI_META_SET_TEMPO = 0x51,
  MIDI_META_SMPTE_OFFSET = 0x54,
  MIDI_META_TIME_SIGNATURE = 0x58,
  MIDI_META_KEY_SIGNATURE = 0x59,
  MIDI_META_SEQ_SPECIFIC = 0x7F,
};
 
struct midi_midi_event {
  unsigned status : 4;
  unsigned channel : 4;
  uint8_t param1;
  uint8_t param2;
};
 
struct midi_time_event : public midi_midi_event {
  uint64_t time_ms;
  operator bool() { return status != 0; }
};
 
 
struct midi_meta_event {
  uint8_t type;
  int32_t length;
  const uint8_t *bytes; // reference to the input buffer
};
 
struct midi_sysex_event {
  uint8_t sysex;
  uint8_t type;
  int32_t length;
  const uint8_t *bytes; // reference to the input buffer
};
 
struct midi_parser_state {
  midi_parser_state() = default;
  midi_parser_state(midi_parser_status status){
    this->status = status;
  }
  enum midi_parser_status status;
  enum midi_parser_status status_internal;
  enum midi_status buffered_status;
  unsigned buffered_channel;
 
  /* input buffer */
  midi::RingBuffer in;
 
  /* result */
  int64_t vtime;
  int64_t vtime_ms=0;
  // microseconds per quarter note - or from latest Set Tempo event
  uint64_t tempo = 1000;
  struct midi_header header;
  struct midi_track track;
  struct midi_midi_event midi;
  struct midi_meta_event meta;
  struct midi_sysex_event sysex;
 
  int64_t timeInTicks() {
    return vtime;
  }
 
  uint64_t timeInMs() {
    if (vtime_ms!=0) return vtime_ms;
    float ticks_per_quarter = header.time_division!=0 ? header.time_division: 48;
    float us_per_quarter = tempo;
    float us_per_tick = us_per_quarter / ticks_per_quarter;
    float milliseconds = timeInTicks() * us_per_tick / 1000;
    return milliseconds;
  }
 
};
 
} // ns