def test_bad_wavread(self):
""" Check wavread on bad file"""
# Create a tmp audio file with non wav format, write some random data into it,
# and check it can not be opened by wavread
rfd, fd, cfilename = open_tmp_file('pysndfiletest.wav')
try:
nbuff = 22050
noise = 0.1 * N.random.randn(nbuff)
# Open the copy file for writing
format = audio_format('aiff', 'pcm16')
b = Sndfile(cfilename, 'w', format, 1, nbuff)
b.write_frames(noise)
b.close()
b = Sndfile(cfilename, 'r')
rcnoise = b.read_frames(nbuff)
b.close()
try:
rnoise = wavread(cfilename)[0]
raise Exception("wavread on non wav file succeded, expected to fail")
except ValueError, e:
pass
#print str(e) + ", as expected"
finally:
close_tmp_file(rfd, cfilename)
def _test_write(self, func, format, filext):
""" Check *write functions from matpi """
rfd1, fd1, cfilename1 = open_tmp_file('matapi_test.' + filext)
rfd2, fd2, cfilename2 = open_tmp_file('matapi_test.' + filext)
try:
nbuff = 22050
fs = nbuff
noise = 0.1 * N.random.randn(nbuff)
# Open the first file for writing with Sndfile
b = Sndfile(cfilename1, 'w', format, 1, fs)
b.write_frames(noise)
b.close()
# Write same data with wavwrite
func(noise, cfilename2, fs)
# Compare if both files have both same audio data and same
# meta-data
f1 = Sndfile(cfilename1)
f2 = Sndfile(cfilename2)
assert_array_equal(f1.read_frames(f1.nframes), f2.read_frames(f2.nframes))
assert_equal(f1.format, f2.format)
assert_equal(f1.samplerate, f2.samplerate)
assert_equal(f1.channels, f2.channels)
f1.close()
f2.close()
finally:
close_tmp_file(rfd1, cfilename1)
close_tmp_file(rfd2, cfilename2)
def _test_read(self, func, format, filext):
# Create a tmp audio file, write some random data into it, and check it
# is the expected data when read from a function from the matapi.
rfd, fd, cfilename = open_tmp_file('pySndfiletest.' + filext)
try:
nbuff = 22050
noise = 0.1 * N.random.randn(nbuff)
# Open the copy file for writing
b = Sndfile(cfilename, 'w', format, 1, nbuff)
b.write_frames(noise)
b.close()
# Reread the data
b = Sndfile(cfilename, 'r')
rcnoise = b.read_frames(nbuff)
b.close()
rnoise = func(cfilename)[0]
assert_array_equal(rnoise, rcnoise)
finally:
close_tmp_file(rfd, cfilename)
from audiolab import Format, Sndfile
# Use 24 bits encoding, big endian
format = Format('wav', 'pcm24', 'big')
f = Sndfile('foo.wav', 'w', format, 2, 48000)
import numpy as np
from audiolab import Sndfile
f = Sndfile('test.wav', 'r')
# Sndfile instances can be queried for the audio file meta-data
fs = f.samplerate
nc = f.channels
enc = f.encoding
# Reading is straightfoward
data = f.read_frames(1000)
# This reads the next 1000 frames, e.g. from 1000 to 2000, but as single precision
data_float = f.read_frames(1000, dtype=np.float32)
import numpy as np
from audiolab import Format, Sndfile
filename = 'foo.wav'
# Create some data to save as audio data: one second of stereo white noise
data = np.random.randn(48000, 2)
# Create a Sndfile instance for writing wav files @ 48000 Hz
format = Format('wav')
f = Sndfile(filename, 'w', format, 2, 48000)
# Write the first 500 frames of the signal. Note that the write_frames method
# uses tmp's numpy dtype to determine how to write to the file; sndfile also
# converts the data on the fly if necessary
f.write_frames(data[:500])
f.close()
