Midi Analyser

# Open MIDI file
print("NOTE: The midi file must be in the same directory as this .exe file!", "\n")

fil = input("Enter the name of the midi file you want analysed: ")

if fil[-4] + fil[-3] + fil[-2] + fil[-1] != ".mid":
    fil += ".mid"

mFile = open(fil, 'rb')

print("\n" + "Analysing", fil, "\n")

# Checks if file is MIDI
hChunk = mFile.read(4)
if hChunk != b'MThd':
    raise ValueError('Not a MIDI file')

contents = mFile.read()

# Close MIDI file again
mFile.close()

# Number of bytes in the MIDI file
midi_len = len(contents)

# Puts all bytes into this list
midi_bytes = []

for i in range(0, midi_len):
    byte = "x{:02X}".format(contents[i])
    midi_bytes.append(byte)
# To compare integers with given values you can just do : contents[i]==0x4d

# ---------------HEADER CHUNK--------------- #
# Find Format, number of tracks, 'delta time' of MIDI
for i in range(0, 10): # Header chunck is 14 bytes long (first 4 was removed)
    if i == 5: # Checks format
        if midi_bytes[i] == "x00":
            print("Format: Single track", "\n")
        elif midi_bytes[i] == "x01":
            print("Format: Multiple track", "\n")
        elif midi_bytes[i] == "x02":
            print("Format: Multiple song (i.e. a series of single track songs)", "\n")

    if i == 7: # Finds number of tracks in MIDI
        num_track = int(midi_bytes[i][1:3], 16)
        print("Number of tracks:", num_track, "\n")

    if i == 8: #Finds delta timing
        n = midi_bytes[i][1:3] + midi_bytes[i + 1][1:3]
        num_delta = int(n, 16)
        print("Number of ticks per quater note:", num_delta, "\n")
# ------------------END--------------------- #

# Remove head chunk - no longer needed
for i in range(0, 10):
    del midi_bytes[0]

# --------------TRACK CHUNK----------------- #
# INFO
# All the differant keys
keys = {
    '0 C': 0,
    '1 C#': 0,
    '2 D': 0,
    '3 D#': 0,
    '4 E': 0,
    '5 F': 0,
    '6 F#': 0,
    '7 G': 0,
    '8 G#': 0,
    '9 A': 0,
    'A A#': 0,
    'B B': 0
}

for i in range(0, len(midi_bytes) - 3): # iterates through the midi (without head chunk)
    # Looks for start of track chunk (MTrk)
    if midi_bytes[i][1:3] + \
       midi_bytes[i + 1][1:3] + \
       midi_bytes[i + 2][1:3] + \
       midi_bytes[i + 3][1:3] == "4D54726B":
        # Found a track chunk

        # How long is the chunk?
        len_of_chunk = int(midi_bytes[i + 4][1:3] +
                           midi_bytes[i + 5][1:3] +
                           midi_bytes[i + 6][1:3] +
                           midi_bytes[i + 7][1:3], 16)

        # print("debug - chunk found") #DEBUG

        # iterates through that chunk (from 8 bytes after chunk start to length of chunk + 8 (from the 8 after))
        for j in range(9, len_of_chunk + 8):
            # Looks for keys

            bit = int(midi_bytes[j][1:3], 16)

            if midi_bytes[j - 1][1] == "8" and bit <= 127:

                # print(bit) # For debugging

                if bit % 12 == 0:
                    # C found
                    keys["0 C"] += 1
                elif bit % 12 == 1:
                    # C# found
                    keys["1 C#"] += 1
                elif bit % 12 == 2:
                    # D found
                    keys["2 D"] += 1
                elif bit % 12 == 3:
                    # D# found
                    keys["3 D#"] += 1
                elif bit % 12 == 4:
                    # E found
                    keys["4 E"] += 1
                elif bit % 12 == 5:
                    # F found
                    keys["5 F"] += 1
                elif bit % 12 == 6:
                    # F# found
                    keys["6 F#"] += 1
                elif bit % 12 == 7:
                    # G found
                    keys["7 G"] += 1
                elif bit % 12 == 8:
                    # G# found
                    keys["8 G#"] += 1
                elif bit % 12 == 9:
                    # A found
                    keys["9 A"] += 1
                elif bit % 12 == 10:
                    # A# found
                    keys["A A#"] += 1
                elif bit % 12 == 11:
                    # B found
                    keys["B B"] += 1

keys_in_total = 0

# Find the total amount of keys by adding them together
for k, v in keys.items():
    keys_in_total += v

# Print it in a pretty fashion
for k, v in sorted(keys.items()):
    percent = round((v / keys_in_total) * 50)  # To make it print in percent
    leftover = 50 - percent
    if len(k) == 4:  # This if statement just makes the output prettier
        print(k[2::], "|", "#" * percent + "." * leftover, "|", v)
    else: # Maybe change # to █ ?
        print(k[2::], "", "|", "#" * percent + "." * leftover, "|", v)
print("\n" + "Notes in total:", keys_in_total)
# DOESNT WORK ON CRY ME A RIVER !?

# print(midi_bytes)

# Stops it from closing instantly
input("\n" + "Press 'Enter' to exit")