def findSYNC(source):
found = []
max_value = 0
max_index = -1
pn = UT.getPN(sync_pn_seed, pnsize) * 100
#print("pn: ", pn[:20])
corrarray = []
aa = datetime.datetime.now()
for idx in range(frameSize + 2):
transformed = np.fft.fft(source[idx:idx + int(frameSize)])
begin, end = UT.getTargetFreqBand(transformed, pnsize, subband[0])
corr = abs(np.corrcoef(transformed.real[begin:end], pn)[0][1])
#corr = np.correlate(transformed[begin:end, 1], pn)
corrarray.append(corr)
if max_value <= corr:
max_value = corr
max_index = idx
bb = datetime.datetime.now()
print("execution time: ", bb - aa)
print("max: ", max_value, max_index)
print("pn_max/min : ", pn.max(), pn.min())
# plt.plot(corrarray)
# plt.show()
if max_value > detectionThreshold:
return max_index
else:
print("Can't find cross-correlation peak over 0.8, max:%d in idx:%d" %
(max_value, max_index))
return -1
def insertSYNC(inbuf, outbuf):
pn = UT.getPN(sync_pn_seed, pnsize)
for repeat in range(NUMOFSYNCREPEAT):
for idx in range(int(pnsize / partialPnSize)):
begin = idx * partialPnSize
end = begin + partialPnSize
insertBit(inbuf, outbuf, pn[begin:end],
NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN)
def insertBitOld(sourceSignal, bit, pnSeed, framesize, overwrite = False):
pn = UT.getPN(pnSeed, pnsize)
#print("insertBit, pn:", pn[:5])
if (True): # Basic Algorithm
#watermarkedSignal = np.add(originalSignal, np.multiply(pn, bit))
sourceSpectrum = np.fft.fft(sourceSignal)
#plt.plot(sourceSpectrum)
adjustedSpectrum = sourceSpectrum.copy()
# plt.plot(adjustedSpectrum[:,1])
for band in subband:
begin, end = UT.getTargetFreqBand(adjustedSpectrum, pnsize, band)
if overwrite == True:
adjustedSpectrum.real[begin:end] = pn * bit
else:
adjustedSpectrum.real[begin:end] += (pn * bit / 10000)
# plt.plot(adjustedSpectrum[:, 1])
#print ("%d -> %d " % (bit, UT.SGN(adjustedSpectrum[begin:end, 1], pn)))
watermarkedSignal = np.fft.ifft(adjustedSpectrum).real
# l1, = plt.plot(sourceSignal, label="L1")
# l2, = plt.plot(watermarkedSignal, label='l2')
# l3, = plt.plot(watermarkedSignal - sourceSignal, label='diff')
# plt.legend(handles = [l1,l2,l3])
# plt.show()
#watermarkedSignal = np.multiply(sourceSignal, np.multiply(pn, bit))
#watermarkedSignal = np.multiply(pn, bit)
#watermarkedSignal = pn
else: # improved algorithm (Not work well)
a1 = 0.005
a2 = 0.001
nlambda = 0.9
psi = UT.norminnerproduct(sourceSignal, pn)
if (psi >= 0 and bit == 1):
watermarkedSignal = np.add(sourceSignal, np.multiply(pn, a1))
elif (psi >= 0 and bit == -1):
watermarkedSignal = np.add(sourceSignal, np.multiply(pn, -1 * (a2 + nlambda * psi)))
elif (psi < 0 and bit == -1):
watermarkedSignal = np.add(sourceSignal, np.multiply(pn, -1 * a1))
elif (psi < 0 and bit == 1):
watermarkedSignal = np.add(sourceSignal, np.multiply(pn, -1 * (a2 - nlambda * psi)))
return watermarkedSignal
def printMSG(posRead):
print("---------------------------")
source, realPos = yield from rb.readfrom(frameSize * 88, posRead)
ix = 0
ppn = UT.getPN(msg_pn_seed, pnsize)
bitseq = []
for n in range(88):
begin = ix + n * frameSize
end = begin + frameSize
fram = source[begin:end]
tr = np.fft.fft(fram)
begin, end = UT.getTargetFreqBand(tr, pnsize, subband[0])
re, accu = UT.SGN(tr.real[begin:end], ppn)
bitseq.append(re)
UT.convertNegative2Zero(bitseq)
UT.print8bitAlignment(bitseq)
def showPN(position=415797, count=11, numOfShift=4):
global rb
pn = UT.getPN(sync_pn_seed, pnsize)
numOfPartialPNs = int((pnsize + partialPnSize - 1) / partialPnSize)
corrarray = np.ndarray(shape=(numOfShift, count))
corrarray.fill(0.0)
targetFrameSize = frameSize * numOfPartialPNs
orgPos = position
for shift in range(numOfShift):
position = orgPos + shift
for idx in range(count):
source, realPos = yield from rb.readfrom(targetFrameSize, position)
if (realPos != position):
print("warning!! wrong position realPos %d, position %d" %
(realPos, position))
try:
extractedPN = np.ndarray(shape=(pnsize))
extractedPN.fill(0.0)
for pnIdx in range(numOfPartialPNs):
begin = pnIdx * frameSize
end = begin + frameSize
transformed = np.fft.fft(source[begin:end])
b, e = UT.getTargetFreqBand(transformed, partialPnSize,
subband[0])
extractedPN[pnIdx * partialPnSize:(pnIdx + 1) *
partialPnSize] = transformed.real[b:e]
posRead = realPos + int(targetFrameSize)
r1, r2 = UT.SGN(extractedPN, pn)
#print("before: ", r1, extractedPN)
#extractedPN = extractedPN * r1 # pn 사인 원복
#print("after: ", r1, extractedPN)
#print (r1)
corr = abs(np.corrcoef(extractedPN, pn)[0][1])
corrarray[shift][idx] = corr
except Exception as err:
print(err)
return -1, posRead
position = posRead + targetFrameSize
print(corrarray)
plt.plot(corrarray[:, :])
plt.show()
return
def findSYNC(position, searchingMaxCorr=True):
if searchingMaxCorr:
posMaxCorr, posRead = yield from getMaxCorr(position)
if (posMaxCorr < 0):
return posMaxCorr, posRead
else:
posMaxCorr = position
# get correlations from leftmost to rightmost
corrArray = []
pn = UT.getPN(sync_pn_seed, pnsize)
numOfPartialPNs = int(pnsize / partialPnSize)
leftMostPos = basePos = posMaxCorr - (
(NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN - 1) * frameSize)
sizeOfFramesPerFullPN = frameSize * numOfPartialPNs * NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN
Nframes, realPos = yield from rb.readfrom(
(NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN *
(numOfPartialPNs + 2) * frameSize), basePos)
for idx in range(NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN * 2 - 1):
begin = idx * frameSize
end = begin + sizeOfFramesPerFullPN
extractedPN = extractPN(Nframes[begin:end],
NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN,
numOfPartialPNs)
corrArray.append(abs(np.corrcoef(extractedPN, pn)[0][1]))
basePos += frameSize
# search maximum summation
maxSummation = 0
maxSummationIdx = -1
for idx in range(NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN):
s = sum(corrArray[idx:idx + NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN])
print("::", idx, s,
corrArray[idx:idx + NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN])
if maxSummation < s:
maxSummation = s
maxSummationIdx = idx
# find next position after SYNC
initialPosMaxCorr = posMaxCorr
posMaxCorr = leftMostPos + maxSummationIdx * frameSize
print("begin of SYNC : %d -> %d" % (initialPosMaxCorr, posMaxCorr))
endOfSync = posMaxCorr + (numOfPartialPNs *
NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN * frameSize)
print("end of SYNC : ", endOfSync)
return posMaxCorr, endOfSync
def insertWM(inbuf, outbuf, msg=" "):
try:
out_writeptr = outbuf.writeptr()
print("Insert SYNC - begin", inbuf.readptr(), outbuf.writeptr())
insertSYNC(inbuf, outbuf)
print("Insert SYNC - end", inbuf.readptr(), outbuf.writeptr())
pn = UT.getPN(sync_pn_seed, pnsize)
print("pn: ", pn)
interval = int(frameSize / 8)
for di in range(int(frameSize / interval) * 2 + 1):
ePN = extractPN(outbuf, out_writeptr + interval * di)
print("Pos: ", out_writeptr + interval * di, "ePN%d : " % di,
abs(np.corrcoef(pn, ePN)[0][1]), ", epn:", ePN)
out_writeptr = outbuf.writeptr()
print("Insert MSG - begin", inbuf.readptr(), outbuf.writeptr())
insertMSG(inbuf, outbuf, msg)
print("Insert MSG - end", inbuf.readptr(), outbuf.writeptr())
# extractMSG(outbuf, out_writeptr)
except Exception as err:
print(err)
def extractSYNC(outbuf, position):
found = []
for bitIdx, value in enumerate(SYNC):
pn = UT.getPN(sync_pn_seed, pnsize)
numOfPartialPNs = int((pnsize + partialPnSize - 1) / partialPnSize)
embededData = []
for idx in range(numOfPartialPNs):
begin = idx * partialPnSize
end = begin + partialPnSize
if end > pnsize:
end = pnsize
embededDataLength = end - begin
srcBegin = position + idx * frameSize
srcEnd = srcBegin + frameSize
targetFrame, realPos = outbuf.readfromSync(frameSize, srcBegin, update_ptr=False)
srcSpectrum = np.fft.fft(targetFrame)
begin, end = UT.getTargetFreqBand(srcSpectrum, embededDataLength, subband[0])
embededData.extend(srcSpectrum.real[begin:end])
position = srcEnd
result, accuracy = UT.SGN(embededData, pn)
if (result == value):
found.append(result)
else:
break
UT.printwithsign("SYNC:", SYNC)
UT.printwithsign("BITS:", found)
if (found == SYNC):
print("SYNC is found")
return True
else:
print("SYNC is not found: ", found)
return False
def insertSYNC(inbuf, outbuf):
for repeat in range(NUMOFSYNCREPEAT):
for idx, value in enumerate(SYNC):
#print("before:::", target[idx * framelength:idx * framelength+10])
pn = UT.getPN(sync_pn_seed, pnsize)
insertBit(inbuf, outbuf, value, pn, overwrite=True)
def getMaxCorr(position):
global rb
found = []
max_corr = 0
posMaxCorr = -1
posRead = 0
pn = UT.getPN(sync_pn_seed, pnsize)
numOfPartialPNs = int((pnsize + partialPnSize - 1) / partialPnSize)
#print("pn: ", pn[:20])
corrarray = []
dotparray = []
aa = datetime.datetime.now()
targetFrameSize = frameSize * (numOfPartialPNs *
NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN) * 2
source, realPos = yield from rb.readfrom(targetFrameSize, position)
# plt.plot(source)
# plt.show()
if (realPos != position):
print("warning!! wrong position realPos %d, position %d" %
(realPos, position))
try:
idxList = [
int(i * (frameSize * NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN / 2))
for i in range(numOfPartialPNs * 2)
]
#print("getMaxCorr: pos", position, idxList)
for idx in idxList: # partialPnSize 의 절반씩 옮기면서 correlation 계산
extractedPN = []
for pnIdx in range(numOfPartialPNs):
begin = idx + pnIdx * NUM_OF_FRAMES_PER_PARTIAL_SYNC_PN * frameSize
end = begin + frameSize
transformed = np.fft.rfft(source[begin:end])
freq = [
BASE_FREQ_OF_DATA_EMBEDDING +
i * FREQ_INTERVAL_OF_DATA_EMBEDDING
for i in range(partialPnSize)
]
#print ("bef freq:", freq)
for fIdx, val in enumerate(freq):
freq[fIdx] = int(
val / (fs / 2 / (len(transformed)))) # search bands
extractedPN.append(abs(transformed[freq[fIdx]]))
#print("aft freq:", freq)
#b, e = UT.getTargetFreqBand(transformed, partialPnSize, subband[0])
posRead = realPos + idx + int(numOfPartialPNs * frameSize)
corr = abs(np.corrcoef(extractedPN, pn)[0][1])
corrarray.append(corr)
r1, r2 = UT.SGN(extractedPN, pn)
dotparray.append(r2)
if max_corr <= corr:
max_corr = corr
posMaxCorr = realPos + idx
except Exception as err:
print(err)
return -1, posRead
# plt.plot(dotparray)
# plt.plot(corrarray)
# plt.show()
bb = datetime.datetime.now()
print("execution time: ", (bb - aa).total_seconds())
print("--------------------max: %10.2f, %d" % (max_corr, posMaxCorr))
#print("pn_max/min : ", pn.max(), pn.min())
# plt.plot(corrarray)
# plt.show()
if max_corr >= detectionThreshold:
print("--------------------Found maximum:", posMaxCorr, max_corr,
posRead)
return posMaxCorr, posRead
else:
#print("Can't find cross-correlation peak over 0.8, max:%d in idx:%d" % (max_value, max_index))
return -1, posRead
