stuff-from-scratch/src/audio/midi/MidiReader.cpp
2020-07-04 19:43:08 +01:00

379 lines
10 KiB
C++

#include "MidiReader.h"
#include "MidiDocument.h"
#include "ByteUtils.h"
#include "MidiTrack.h"
#include "BinaryFile.h"
#include <fstream>
#include <iostream>
#include <cstring>
#include <bitset>
MidiReader::MidiReader()
:mDocument(),
mTrackByteCount(0),
mLastChannelEventType(MidiChannelEvent::Type::NONE)
{
}
bool MidiReader::ProcessHeader(std::ifstream& file)
{
if(!BinaryFile::CheckNextDWord(file, HeaderLabel))
{
return false;
}
int length = 0;
if(!BinaryFile::GetNextDWord(file, length))
{
return false;
}
if(!BinaryFile::GetNextWord(file, mDocument.mFormatType))
{
return false;
}
if(!BinaryFile::GetNextWord(file, mDocument.mExpectedTracks))
{
return false;
}
ProcessTimeDivision(file);
return true;
}
bool MidiReader::ProcessTimeDivision(std::ifstream& file)
{
int time_division;
if(!BinaryFile::GetNextWord(file, time_division, false))
{
return false;
}
const int TOP_7_BITS = 0x7F00; // 0111 1111 - 0000 0000
mDocument.mUseFps = ByteUtils::GetWordFirstBit(time_division);
mDocument.mFps = ((~time_division & TOP_7_BITS) >> 8) - 1; // Reverse 2complement of next 7 bits
mDocument.ticksPerFrame = ByteUtils::GetWordLastByte(time_division);
return true;
}
int MidiReader::ProcessTimeDelta(std::ifstream& file)
{
char c;
file.get(c);
mTrackByteCount ++;
if(unsigned(c >> 7) == 0)
{
int delta = int(c);
std::cout << "Time delta final: " << delta << "|" << std::bitset<16>(c)<< std::endl;
return delta;
}
int working_c = c;
int final_c = 0;
unsigned count = 0;
std::cout << "Working " << std::bitset<8>(working_c) << std::endl;
while(unsigned(working_c >> 7) != 0)
{
char corrected = (working_c &= ~(1UL << 7));
final_c <<= 7;
final_c |= (corrected << 7*count);
char file_c;
file.get(file_c);
mTrackByteCount ++;
working_c = int(file_c);
std::cout << "Working " << std::bitset<8>(working_c) << std::endl;
count ++;
}
std::cout << "Time delta start: " << std::bitset<16>(final_c) << std::endl;
final_c <<= 7;
std::cout << "Time delta pre: " << std::bitset<16>(final_c) << std::endl;
final_c |= (working_c << 7*(count-1));
int delta = int(final_c);
std::cout << "Time delta final: " << delta << "|" << std::bitset<16>(final_c)<< std::endl;
return delta;
}
bool MidiReader::ProcessTrackNameMetaEvent(std::ifstream& file, MetaMidiEvent& event)
{
event.SetIsTrackName();
int length = 0;
BinaryFile::GetNextByteAsInt(file, length);
mTrackByteCount ++;
std::string name;
BinaryFile::GetNextString(file, name, length);
mTrackByteCount += length;
std::cout << "Track name: " << name << "|" << length <<std::endl;
event.SetLabel(name);
return true;
}
bool MidiReader::ProcessSetTempoMetaEvent(std::ifstream& file, MetaMidiEvent& event)
{
event.SetIsSetTempo();
int length = 0;
BinaryFile::GetNextByteAsInt(file, length);
mTrackByteCount ++;
std::string buffer;
BinaryFile::GetNextNBytes(file, buffer.data(), length);
mTrackByteCount += length;
int tempo = ByteUtils::ToInt(buffer.data(), length);
const int MICROSECONDS_PER_MINUTE = 60000000;
std::cout << "Got tempo "<< tempo << "|" << MICROSECONDS_PER_MINUTE/tempo<< std::endl;
event.SetValue(tempo);
return true;
}
bool MidiReader::ProcessTimeSignatureMetaEvent(std::ifstream& file, MetaMidiEvent& event)
{
event.SetIsTimeSignature();
int length = 0;
BinaryFile::GetNextByteAsInt(file, length);
mTrackByteCount ++;
int numer = 0;
BinaryFile::GetNextByteAsInt(file, numer);
mTrackByteCount ++;
int denom = 0;
BinaryFile::GetNextByteAsInt(file, denom);
mTrackByteCount ++;
int metro = 0;
BinaryFile::GetNextByteAsInt(file, metro);
mTrackByteCount ++;
int f32s = 0;
BinaryFile::GetNextByteAsInt(file, f32s);
mTrackByteCount ++;
std::cout << "Time sig " << length << "|" << numer << "|" << denom << "|" << metro << "|" << f32s << std::endl;
return true;
}
bool MidiReader::ProcessMetaEvent(std::ifstream& file, MetaMidiEvent& event)
{
char c;
file.get(c);
mTrackByteCount ++;
if(MetaMidiEvent::IsTrackName(c))
{
ProcessTrackNameMetaEvent(file, event);
}
else if(MetaMidiEvent::IsSetTempo(c))
{
ProcessSetTempoMetaEvent(file, event);
}
else if(MetaMidiEvent::IsTimeSignature(c))
{
ProcessTimeSignatureMetaEvent(file, event);
}
else
{
std::cout << "something else" << std::endl;
std::cout << "Next " << std::bitset<8>(c) << "|" <<std::endl;
}
return true;
}
bool MidiReader::ProcessMidiEventData(std::ifstream& file, MidiChannelEvent& event, char c)
{
int value0 = int(c);
int value1 = 0;
BinaryFile::GetNextByteAsInt(file, value1);
mTrackByteCount ++;
event.SetValues(value0, value1);
std::cout << "sdata: " << value0 << "|" << value1 << "|" << std::endl;
return true;
}
bool MidiReader::ProcessMidiEventData(std::ifstream& file, MidiChannelEvent& event)
{
int value0 = 0;
BinaryFile::GetNextByteAsInt(file, value0);
mTrackByteCount ++;
int value1 = 0;
BinaryFile::GetNextByteAsInt(file, value1);
mTrackByteCount ++;
event.SetValues(value0, value1);
std::cout << "data: " << value0 << "|" << value1 << "|" << std::endl;
return true;
}
bool MidiReader::ProcessMidiChannelEvent(std::ifstream& file, char firstByte, MidiChannelEvent& event)
{
int first_four_bits = 0xF0;
int second_four_bits = 0xF;
int event_type = (firstByte & first_four_bits) >> 4;
int midi_channel = (firstByte & second_four_bits) >> 4;
std::cout << "Channel: " << midi_channel << std::endl;
if(MidiChannelEvent::IsStatusByte(event_type))
{
if(MidiChannelEvent::IsControllerEvent(event_type))
{
event.SetType(MidiChannelEvent::Type::CONTROLLER);
mLastChannelEventType = MidiChannelEvent::Type::CONTROLLER;
std::cout << "Controller Event"<< std::endl;
ProcessMidiEventData(file, event);
}
else if(MidiChannelEvent::IsProgramEvent(event_type))
{
event.SetType(MidiChannelEvent::Type::PROGRAM);
mLastChannelEventType = MidiChannelEvent::Type::PROGRAM;
std::cout << "Program Event"<< std::endl;
int value0 = 0;
BinaryFile::GetNextByteAsInt(file, value0);
mTrackByteCount ++;
std::cout << "value " << value0 << std::endl;
}
else if(MidiChannelEvent::IsNoteOnEvent(event_type))
{
event.SetType(MidiChannelEvent::Type::NOTE_ON);
mLastChannelEventType = MidiChannelEvent::Type::NOTE_ON;
std::cout << "Note on Event"<< std::endl;
ProcessMidiEventData(file, event);
}
else if(MidiChannelEvent::IsNoteOffEvent(event_type))
{
event.SetType(MidiChannelEvent::Type::NOTE_OFF);
mLastChannelEventType = MidiChannelEvent::Type::NOTE_OFF;
std::cout << "Note off Event"<< std::endl;
ProcessMidiEventData(file, event);
}
else
{
std::cout << "Unknown status event: " << std::bitset<8>(firstByte) << "|" << event_type <<std::endl;
}
}
else
{
if(mLastChannelEventType == MidiChannelEvent::Type::CONTROLLER)
{
std::cout << "Controller running event: " <<std::endl;
ProcessMidiEventData(file, event, firstByte);
}
else if(mLastChannelEventType == MidiChannelEvent::Type::NOTE_ON)
{
std::cout << "Note on running event: " <<std::endl;
ProcessMidiEventData(file, event, firstByte);
}
else if(mLastChannelEventType == MidiChannelEvent::Type::NOTE_OFF)
{
std::cout << "Note off running event: " <<std::endl;
ProcessMidiEventData(file, event, firstByte);
}
else
{
std::cout << "Unknown running event: " <<std::endl;
}
}
return true;
}
bool MidiReader::ProcessEvent(std::ifstream& file, MidiTrack& track)
{
char c;
int timeDelta = ProcessTimeDelta(file);
file.get(c);
std::cout << std::bitset<8>(c) << std::endl;
mTrackByteCount ++;
if(MidiEvent::IsMetaEvent(c))
{
MetaMidiEvent event;
event.SetTimeDelta(timeDelta);
std::cout << "Meta event " <<std::endl;
ProcessMetaEvent(file, event);
track.AddEvent(event);
}
else if(MidiEvent::IsSysExEvent(c))
{
std::cout << "Sysex event" << std::endl;
}
else
{ // Midi event
MidiChannelEvent event;
event.SetTimeDelta(timeDelta);
std::cout << "Midi event" << std::endl;
ProcessMidiChannelEvent(file, c, event);
}
return true;
}
bool MidiReader::ProcessTrackChunk(std::ifstream& file, bool debug)
{
if(!BinaryFile::CheckNextDWord(file, TrackChunkLabel))
{
return false;
}
int chunkSize = 0;
if(!BinaryFile::GetNextDWord(file, chunkSize))
{
return false;
}
std::cout << "Chunk size: "<< chunkSize << std::endl;
mTrackByteCount = 0;
MidiTrack track;
unsigned iter_count = 0;
while(mTrackByteCount < unsigned(chunkSize))
{
std::cout << "-------------" << std::endl;
ProcessEvent(file, track);
std::cout << "Track byte count: "<< mTrackByteCount << std::endl;
if(debug && iter_count == 25)
{
return true;
}
iter_count ++;
}
mDocument.mTracks.push_back(track);
return true;
}
void MidiReader::Read(const std::string& path)
{
std::ifstream file(path);
if(!ProcessHeader(file))
{
std::cout << "Problem processing header" << std::endl;
return;
}
int trackCount = 0;
if(!ProcessTrackChunk(file))
{
std::cout << "Problem processing track chunk" << std::endl;
return;
}
trackCount ++;
std::cout << "****************************************" << std::endl;
std::cout << "Track 2" << std::endl;
if(!ProcessTrackChunk(file, true))
{
std::cout << "Problem processing track chunk" << std::endl;
return;
}
trackCount ++;
file.close();
}