I have been working on an assignment on musical note analysis and I have the Python code for it. However, I am required to convert it to Matlab, and I have come across some issues here. I have not attempted something of the sort before.
The Python Code:
import numpy as np
import wave
import struct
def find_nearest(array,value):
idx = (np.abs(array-value)).argmin()
return array[idx]
window_size = 2205
beta = 1
max_notes = 100
sampling_freq = 44100
threshold = 600
array = [1046.50, 1174.66, 1318.51, 1396.91, 1567.98, 1760.00, 1975.53,
2093.00, 2349.32, 2637.02, 2793.83, 3135.96, 3520.00, 3951.07,
4186.01, 4698.63, 5274.04, 5587.65, 6271.93, 7040.00, 7902.13]
notes = ['C6', 'D6', 'E6', 'F6', 'G6', 'A6', 'B6',
'C7', 'D7', 'E7', 'F7', 'G7', 'A7', 'B7',
'C8', 'D8', 'E8', 'F8', 'G8', 'A8', 'B8']
Identified_Notes = []
print ('\n\nReading Audio File...')
sound_file = wave.open(r'C://Audio_Analysis.wav', 'r')
file_length = sound_file.getnframes()
sound = np.zeros(file_length)
mean_square = []
sound_square = np.zeros(file_length)
for i in range(file_length):
data = sound_file.readframes(1)
data = struct.unpack("<h", data)
sound[i] = int(data[0])
sound = np.divide(sound, float(2**15)) # Normalize data in range -1 to 1
print(sound)
sound_square = np.square(sound)
frequency = []
dft = []
i = 0
j = 0
k = 0
print(len(sound_square)-window_size)
while(i<=len(sound_square)-window_size):
s = 0.0
j = 0
while(j<=window_size):
s = s + sound_square[i+j]
j = j + 1
if s < threshold:
if(i-k>window_size*4):
dft = np.array(dft)
dft = np.fft.fft(sound[k:i])
dft=np.argsort(dft)
if(dft[0]>dft[-1] and dft[1]>dft[-1]):
i_max = dft[-1]
elif(dft[1]>dft[0] and dft[-1]>dft[0]):
i_max = dft[0]
else :
i_max = dft[1]
frequency.append((i_max*sampling_freq)/(i-k))
dft = []
k = i+1
i = i + window_size
print('length:',len(frequency))
print("frequencies:")
for i in frequency :
print(i)
idx = (np.abs(array-i)).argmin()
Identified_Notes.append(notes[idx])
print(Identified_Notes)
The Python Code does work by the way.
My attempt at converting it to Matlab Code:
window_size = 2205;
beta = 1;
max_notes = 100;
sampling_freq = 44100;
threshold = 600;
array = py.list({py.list([1046.50,1174.66,1318.51,1396.91,1567.98,1760.00,1975.53]),py.list([2093.00,2349.32,2637.02,2793.83,3135.96,3520.00,2951.07]),py.list([4186.01,4698.63,5274.04,5587.65,6271.93,7040.00,7902.13])});
notes = py.list({py.list(['C6','D6','E6','F6','G6','A6','B6']),py.list(['C7','D7','E7','F7','G7','A7','B7']),py.list(['C8','D8','E8','F8','G8','A8','B8'])});
Identified_Notes = py.list();
fprintf('\n\nReading Audio File...')
sound_file = py.wave.open("C://Audio_Analysis.wav",'r');
file_length = sound_file.getnframes();
sound = py.numpy.zeros(file_length);
mean_square = py.list();
sound_square = py.numpy.zeros(file_length);
for i = file_length
data = py.wave.sound_file.readframes(1);
data = py.struct.unpack("<h",data);
sound(i) = int32(data(0));
end
sound = py.numpy.divide(sound,double(2^15));
py.print(sound)
sound_square = py.numpy.square(sound);
frequency = py.list();
dft = py.list();
i = 0;
j = 0;
k = 0;
fprintf(py.len(sound_square)-window_size)
while i <= (py.len(sound_square)-window_size)
s = 0.0;
j = 0;
while j <= window_size
s = s + sound_square(i+j);
j = j + 1;
end
if s < threshold
if (i-k) > window_size*4
dft = py.numpy.array(dft);
dft = py.numpy.fft.fft(sound(k:i));
dft = py.numpy.argsort(dft);
df = cellfun(@char,cell(dft),'UniformOutput',false)
if (df(0) > df(-1) && df(1) > df(-1))
i_max = df(-1);
elseif (df(1) > df(0) && df(-1) > df(0))
i_max = df(0);
else
i_max = dft(1);
end
frequency.append((i_max*sampling_freq)/(i-k));
dft.clear();
k = i + 1;
end
end
i = i + window_size;
end
py.print("length:",py.len(frequency))
fprintf('frequencies:')
for i = frequency
py.print(i)
idx = min(py.numpy.abs(array-i));
Identified_Notes.append(notes(idx));
end
py.print(Identified_Notes)
function y = find_nearest(array,value)
idx = min(py.numpy.abs(array-value));
end
I've read some Matlab documentation to try this out, but I am quite clueless here. I get the following errors, though there may be more:
How do I go from here?