app.py

import os, random, re
from fractions import Fraction
from midiutil.MidiFile import MIDIFile
import streamlit as st
import mido, openai

if 'path' not in st.session_state:
    st.session_state['path'] = os.path.realpath(os.path.dirname(__file__))
if 'sessionID' not in st.session_state:
    st.session_state['sessionID'] = random.randint(0,99999999)
if 'history' not in st.session_state:
    st.session_state['history'] = []
if 'downloadable' not in st.session_state:
    st.session_state['downloadable'] = False
notes = [['C'], ['Db', 'C#'], ['D'], ['Eb', 'D#'], ['E'], ['F'], ['Gb', 'F#'], ['G'], ['Ab', 'G#'], ['A'], ['Bb', 'A#'], ['B']]
monsters = [r'(?<![A-Za-z\d])([A-G](?:#|b)?\d-(?:\d+\/\d+|\d+))(?![A-Za-z\d])', r'(?<![A-Za-z\d])([A-G](?:#|b)?\d(?:-\d+(?:\/\d+)?(?:-\d+(?:\.\d+)?)?)+)(?![A-Za-z\d])']
examples = ['\n\nNotation looks like this:\n(Note-duration)\nC4-1/4, Eb4-1/4, D4-1/8, Eb4-1/8, C4-1/4', '\n\nNotation looks like this:\n(Note-duration-time in beats)\nC4-1/4-0, Eb4-1/8-2.5, D4-1/4-3, F4-1/4-3 etc.']

def noteToInt(n):
    oct = int(n[-1])
    letter = n[:-1]
    id = 0
    for ix, x in enumerate(notes):
        for y in x:
            if letter == y:
                id = ix
    return id+oct*12+12

def midiToStr(mPath, nIndex):
    midIn = mido.MidiFile(os.path.expanduser(mPath))
    ticks = midIn.ticks_per_beat
    midOut = []
    globalT = 0
    opens = {}
    for track in midIn.tracks:
        for msg in track:
            if msg.type == 'note_on' or msg.type == 'note_off':
                globalT += msg.time/ticks
                if msg.note in opens:
                    noteTime = opens[msg.note]
                    noteTime = int(noteTime) if noteTime.is_integer() else noteTime
                    noteDur = str(Fraction((globalT-noteTime)/4))
                    noteDur = str(round((globalT-noteTime),3)) if len(noteDur)>=6 else noteDur
                    if nIndex:
                        midOut.append('-'.join([notes[msg.note%12][0]+str(msg.note//12-1), noteDur, str(round(noteTime,3))]))
                    else:
                        midOut.append('-'.join([notes[msg.note%12][0]+str(msg.note//12-1), noteDur]))
                    del opens[msg.note]
                if msg.type == 'note_on':
                    opens[msg.note] = globalT
    return ', '.join(midOut)

st.markdown('# GPT-4 2 Midi\n#### AI Generated Polyphonic Music\n##### plus conversion tools for use with Chat-GPT\napp by [d3nt](https://github.com/d3n7/)')
notation = st.selectbox('Notation', ('Polyphonic', 'Monophonic'))
main, m2t, t2m = st.tabs(['GPT4-To-Midi', 'Midi-2-Text', 'Text-2-Midi'])

with main:
    userPrompt = st.text_input('Prompt', 'Full piece of sad music with multiple parts. Plan out the structure beforehand, including chords, parts (soprano, alto, tenor, bass), meter, etc.')
    with st.expander('System Prompt'):
        sysPrompt = st.text_input('', 'You are MusicGPT, a music creation and completion chat bot that. When a user gives you a prompt, you return them a song showing the notes, durations, and times that they occur. Respond with just the music.')
    openaikey = st.text_input('OpenAI API Key', type='password')
    modelV = st.selectbox('Model', ('GPT-4', 'GPT-3.5-Turbo'))
    col1, col2 = st.columns(2)
    with col1:
        newSession = st.checkbox('New Session', True)
    with col2:
        showOutput = st.checkbox('Show Output', True)
    uploadMidi = st.file_uploader('Upload a midi file (OPTIONAL)')
    col3, col4 = st.columns(2)
    with col3:
        if st.button('Ask GPT'):
            if userPrompt != '' and sysPrompt != '' and  openaikey != '':
                notationIndex = int(notation=='Polyphonic')

                if newSession:
                    st.session_state['history'] = [{'role': 'system', 'content': sysPrompt+examples[notationIndex]}]

                prompt = userPrompt
                if uploadMidi:
                    filename = ''.join(uploadMidi.name.split('.')[:-1])+str(st.session_state['sessionID'])+'.'+''.join(uploadMidi.name.split('.')[-1])
                    midiPath = os.path.join(st.session_state['path'], filename)
                    with open(midiPath, 'wb') as f:
                        f.write(uploadMidi.getbuffer())
                    prompt += '\n'+midiToStr(midiPath, notationIndex)
                    os.remove(midiPath)
                st.session_state['history'].append({'role': 'user', 'content': prompt})

                openai.api_key = openaikey
                with st.spinner('Talking to OpenAI...'):
                    r = openai.ChatCompletion.create(
                        model=modelV.lower(),
                        messages=st.session_state['history']
                    )
                response = r['choices'][0]['message']['content']
                st.session_state['history'].append({'role': 'assistant', 'content': response})

                noteInfo = []
                for i in re.findall(monsters[notationIndex], response):
                    n = i.split('-')
                    if notationIndex:
                        noteInfo.append([noteToInt(n[0]), float(Fraction(n[1]))*4, float(n[2])])  #note, duration, time
                    else:
                        noteInfo.append([noteToInt(n[0]), float(Fraction(n[1]))*4])  # note, duration

                song = MIDIFile(1, deinterleave=False)
                time = 0
                for i in noteInfo:
                    if notationIndex:
                        pitch, dur, time = i
                    else:
                        pitch, dur = i
                    song.addNote(0, 0, pitch, time, dur, 100)
                    if not notationIndex:
                        time += dur
                with open(os.path.join(st.session_state['path'], 'out.mid'), 'wb') as f:
                    song.writeFile(f)
                if not st.session_state['downloadable']:
                    st.session_state['downloadable'] = True
            else:
                st.warning('Make sure OpenAI key, prompt, and system prompt are entered', icon='⚠️')
    with col4:
        if st.session_state['downloadable']:
            with open(os.path.join(st.session_state['path'], 'out.mid'), 'rb') as f:
                st.download_button('Download Midi', f, file_name='song.mid', key='main')
    if showOutput:
        with st.container():
            for i in st.session_state['history']:
                st.text(i['role']+': '+i['content']+'\n')

with m2t:
    inMidi = st.file_uploader('Input')
    if st.button('Convert', key='1'):
        if inMidi:
            filename = ''.join(inMidi.name.split('.')[:-1]) + str(st.session_state['sessionID']) + '.' + ''.join(inMidi.name.split('.')[-1])
            midiPath = os.path.join(st.session_state['path'], filename)
            with open(midiPath, 'wb') as f:
                f.write(inMidi.getbuffer())
            st.text_area('Output', midiToStr(midiPath, notation=='Polyphonic'))
            os.remove(midiPath)

with t2m:
    inText = st.text_input('Input')
    if st.button('Convert', key='2'):
        notationIndex = int(notation=='Polyphonic')
        noteInfo = []
        for i in re.findall(monsters[notationIndex], inText):
            n = i.split('-')
            if notationIndex:
                noteInfo.append([noteToInt(n[0]), float(Fraction(n[1])) * 4, float(n[2])])  # note, duration, time
            else:
                noteInfo.append([noteToInt(n[0]), float(Fraction(n[1])) * 4])  # note, duration
        song = MIDIFile(1, deinterleave=False)
        time = 0
        for i in noteInfo:
            if notationIndex:
                pitch, dur, time = i
            else:
                pitch, dur = i
            song.addNote(0, 0, pitch, time, dur, 100)
            if not notationIndex:
                time += dur
        with open(os.path.join(st.session_state['path'], 't2m.mid'), 'wb') as f:
            song.writeFile(f)
        with open(os.path.join(st.session_state['path'], 't2m.mid'), 'rb') as f:
            st.download_button('Download Midi', f, file_name='song.mid', key='t2m')