audio over python tcp error

Question

I am writing a simple python tcp code to send over a wav file however I seem to be getting stuck. can someone explain why my code is not working correctly?

Server Code

import socket, time
import scipy.io.wavfile
import numpy as np

def Main():
host = ''
port = 3333
MAX = 65535

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))

s.listen(1)
print "Listening on port..." + str(port)
c, addr = s.accept()
print "Connection from: " + str(addr)
wavFile = np.array([],dtype='int16')
i = 0
while True:
    data = c.recvfrom(MAX)
    if not data:
        break
    # print ++i
    # wavfile = np.append(wavfile,data)
    print data
timestr = time.strftime("%y%m%d-%h%m%s")
print timestr
# wavF = open(timestr + ".wav", "rw+")
scipy.io.wavfile.write(timestr + ".wav",44100, data)
c.close()

if __name__ == '__main__':
    Main()

Client Code

host, port = "", 3333

import sys , socket
import scipy.io.wavfile

# create a tcp/ip socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# connect the socket to the port where the server is listening
server_address = (host, port)
print >>sys.stderr, 'connecting to %s port %s' % server_address

input_data = scipy.io.wavfile.read('Voice 005.wav',)
audio = input_data[1]
sock.connect(server_address)
print 'have connected'
try:
    # send data
   sock.sendall(audio)
   print  "sent" + str(audio)
   sock.close()
except:
    print('something failed sending data')
finally:
    print >>sys.stderr, 'closing socket'
    print "done sending"
    sock.close()

Please help someone, I want to send an audio file to my embedded device with tcp since it crucial data to be processed on the embedded device.

Answer 1

Not sure why you go to the trouble of using scipy and numpy for this, since you can just use the array module to create binary arrays that will hold the wave file. Can you adapt and use the simple client/server example below?

(Note: I've copy/pasted a small Windows sound file called 'tada.wav' to the same folder to use with the test scripts.)

Code for the server script:

import socket

HOST = ''                 # Symbolic name meaning all available interfaces
PORT = 50007              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
print('Listening...')
conn, addr = s.accept()
print('Connected by', addr)
outfile = open("newfile.wav", 'ab')
while True:
    data = conn.recv(1024)
    if not data: break
    outfile.write(data)
conn.close()
outfile.close()
print ("Completed.")

Code for the client:

from array import array
from os import stat
import socket

arr = array('B') # create binary array to hold the wave file
result = stat("tada.wav")  # sample file is in the same folder
f = open("tada.wav", 'rb')
arr.fromfile(f, result.st_size) # using file size as the array length
print("Length of data: " + str(len(arr)))

HOST = 'localhost'
PORT = 50007

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send(arr)
print('Finished sending...')
s.close()
print('done.')

This works for me (though only tested by running both on localhost) and I end up with a second wave file that's an exact copy of the one sent by the client through the socket.