#!/usr/bin/python
# Copyright (C) 2012 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from consts import *
import numpy as np
import scipy as sp
import scipy.fftpack as fft
import matplotlib.pyplot as plt
import sys
sys.path.append(sys.path[0])
import calc_delay
# check if amplitude of DUT's playback
# lies in the given error boundary
# input: host record
# sampling rate
# low frequency in Hz,
# high frequency in Hz,
# allowed error in negative side for pass in %,
# allowed error ih positive side for pass
# output: min value in negative side, normalized to 1.0
# max value in positive side
# calculated freq spectrum in amplittude
def do_check_spectrum_playback(hostData, samplingRate, fLow, fHigh, margainLow, margainHigh):
# reduce FFT resolution to have averaging effects
N = 512 if (len(hostData) > 512) else len(hostData)
iLow = N * fLow / samplingRate + 1 # 1 for DC
if iLow > (N / 2 - 1):
iLow = (N / 2 - 1)
iHigh = N * fHigh / samplingRate + 1 # 1 for DC
if iHigh > (N / 2 + 1):
iHigh = N / 2 + 1
print fLow, iLow, fHigh, iHigh, samplingRate
Phh, freqs = plt.psd(hostData, NFFT=N, Fs=samplingRate, Fc=0, detrend=plt.mlab.detrend_none,\
window=plt.mlab.window_hanning, noverlap=0, pad_to=None, sides='onesided',\
scale_by_freq=False)
print len(Phh)
print "Phh", abs(Phh[iLow:iHigh])
spectrum = np.sqrt(abs(Phh[iLow:iHigh]))
spectrumMean = np.mean(spectrum)
spectrum = spectrum / spectrumMean
print "Mean ", spectrumMean
print "Normalized spectrum", spectrum
positiveMax = abs(max(spectrum))
negativeMin = abs(min(spectrum))
passFail = True if (positiveMax < (margainHigh / 100.0 + 1.0)) and\
((1.0 - negativeMin) < margainLow / 100.0) else False
spectrumResult = np.zeros(len(spectrum), dtype=np.int16)
for i in range(len(spectrum)):
spectrumResult[i] = spectrum[i] * 1024 # make fixed point
print "positiveMax", positiveMax, "negativeMin", negativeMin
return (passFail, negativeMin, positiveMax, spectrumResult)
def check_spectrum_playback(inputData, inputTypes):
output = []
outputData = []
outputTypes = []
# basic sanity check
inputError = False
if (inputTypes[0] != TYPE_MONO):
inputError = True
if (inputTypes[1] != TYPE_I64):
inputError = True
if (inputTypes[2] != TYPE_I64):
inputError = True
if (inputTypes[3] != TYPE_I64):
inputError = True
if (inputTypes[4] != TYPE_DOUBLE):
inputError = True
if (inputTypes[5] != TYPE_DOUBLE):
inputError = True
if inputError:
output.append(RESULT_ERROR)
output.append(outputData)
output.append(outputTypes)
return output
hostData = inputData[0]
samplingRate = inputData[1]
fLow = inputData[2]
fHigh = inputData[3]
margainLow = inputData[4]
margainHigh = inputData[5]
(passFail, minError, maxError, Spectrum) = do_check_spectrum_playback(hostData, \
samplingRate, fLow, fHigh, margainLow, margainHigh)
if passFail:
output.append(RESULT_PASS)
else:
output.append(RESULT_OK)
outputData.append(minError)
outputTypes.append(TYPE_DOUBLE)
outputData.append(maxError)
outputTypes.append(TYPE_DOUBLE)
outputData.append(Spectrum)
outputTypes.append(TYPE_MONO)
output.append(outputData)
output.append(outputTypes)
return output
# test code
if __name__=="__main__":
sys.path.append(sys.path[0])
mod = __import__("gen_random")
peakAmpl = 10000
durationInMSec = 1000
samplingRate = 44100
fLow = 500
fHigh = 15000
data = getattr(mod, "do_gen_random")(peakAmpl, durationInMSec, samplingRate, fHigh,\
stereo=False)
print len(data)
(passFail, minVal, maxVal, amp) = do_check_spectrum_playback(data, samplingRate, fLow,\
fHigh, 1.0, 1.0)
plt.plot(amp)
plt.show()