Csv To Wav Python

Hi i have this code that suppose to convert csv file to wav file. it creates a wav file but we don't hear anything. If i put 10 rows in the csv file, it make an about 1 min wav fil

Solution 1:

RESOLVED ! Here the code for converting a CSV file in a WAV file. The CSV file must have 2 columns: The first is the time of the sample - in this file it doesn't matter so you can put 0 to all this column. The second column is the sample itself - for example if your sample is 16 bit length - the sample should be between -32678 and 32767 ( int range ). This number will be normalize between -1 and 1 in line 56. After the have this file you just have to run the .py with the filename of the csv file as an argument. ( like python generate.py sinewave.csv ).

#!/usr/bin/python

import wave
import struct
import sys
import csv
import numpy 
from scipy.io import wavfile
from scipy.signal import resample

def write_wav(data, filename, framerate, amplitude):
    wavfile = wave.open(filename,'w')
    nchannels = 1
    sampwidth = 2
    framerate = framerate
    nframes = len(data)
    comptype = "NONE"
    compname = "not compressed"
    wavfile.setparams((nchannels,
                        sampwidth,
                        framerate,
                        nframes,
                        comptype,
                        compname))
    frames = []
    for s in data:
        mul = int(s * amplitude)
        frames.append(struct.pack('h', mul))

    frames = ''.join(frames)
    wavfile.writeframes(frames)
    wavfile.close()
    print("%s written" %(filename)) 


if __name__ == "__main__":
    if len(sys.argv) <= 1:
        print ("You must supply a filename to generate")
        exit(-1)
    for fname in sys.argv[1:]:

        data = []
        for time, value in csv.reader(open(fname, 'U'), delimiter=','):
            try:
                data.append(float(value))#Here you can see that the time column is skipped
            except ValueError:
                pass # Just skip it


        arr = numpy.array(data)#Just organize all your samples into an array
        # Normalize data
        arr /= numpy.max(numpy.abs(data)) #Divide all your samples by the max sample value
        filename_head, extension = fname.rsplit(".", 1)        
        data_resampled = resample( arr, len(data) )
        wavfile.write('rec.wav', 16000, data_resampled) #resampling at 16khz
        print ("File written succesfully !")

Enjoy !

CSV example:
0 , 20
0 , 15
0 , -40
0 , -1000
...

Solution 2:

Use pysoundfile

import pandas as pd
import soundfile as sf

# assume we have columns 'time' and 'value'
df = pd.read_csv('recording.csv')

# compute sample rate, assuming times are in seconds
times = df['time'].values
n_measurements = len(times)
timespan_seconds = times[-1] - times[0]
sample_rate_hz = int(n_measurements / timespan_seconds)

# write data
data = df['value'].values
sf.write('recording.wav', data, sample_rate_hz)