amplify.py

#!/usr/bin/python

# amplify.py: Amplifies a WAV file by the given scaling factor
#             and output to specified file
 
import sys
from audiofile import *

if len(sys.argv) < 4:
    print "Usage: amplify.py in_file out_file scale_factor"
    sys.exit(1)

in_filename  = sys.argv[1]
out_filename = sys.argv[2]
scale_factor = float(sys.argv[3])

fin = AudioFile(in_filename,'r')
fout = AudioFile(out_filename,'w')
fout.setparams(fin.getnchannels(), 
               fin.getsampwidth(), 
               fin.getframerate(), 
               0,
               'NONE',
               'not compressed')

num_frames = fin.getnframes()
num_channels = fin.getnchannels()

def transform(data,scale_factor):
    sample = int(data * scale_factor)
    return sample

while (fin.tell() < num_frames):
    frame_data = fin.read(1)
    for data in frame_data:
        out_frame = transform(data,scale_factor)
        fout.write(out_frame)

fout.close()  
fin.close()