c2e79d4555
* Better preamble detection to skip most of the messages we'll likely not be able to decode. * A Phase correction algorithm that improves the recognition compared to the previous algorithm used. * Javascript output in debug mode, and a debug.html file that can be used in order to see graphically undecoded samples. * Ability to detect cross-read messages, that are, messages that happen to start and end across two different reads from the device or file. * A few bugx fixed. * README improved.
199 lines
5.6 KiB
HTML
199 lines
5.6 KiB
HTML
<!DOCTYPE html>
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<html>
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<body>
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<head>
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<script>
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var frames = [];
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var currentFrame = 144;
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var modes_checksum_table = [
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0x3935ea, 0x1c9af5, 0xf1b77e, 0x78dbbf, 0xc397db, 0x9e31e9, 0xb0e2f0, 0x587178,
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0x2c38bc, 0x161c5e, 0x0b0e2f, 0xfa7d13, 0x82c48d, 0xbe9842, 0x5f4c21, 0xd05c14,
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0x682e0a, 0x341705, 0xe5f186, 0x72f8c3, 0xc68665, 0x9cb936, 0x4e5c9b, 0xd8d449,
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0x939020, 0x49c810, 0x24e408, 0x127204, 0x093902, 0x049c81, 0xfdb444, 0x7eda22,
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0x3f6d11, 0xe04c8c, 0x702646, 0x381323, 0xe3f395, 0x8e03ce, 0x4701e7, 0xdc7af7,
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0x91c77f, 0xb719bb, 0xa476d9, 0xadc168, 0x56e0b4, 0x2b705a, 0x15b82d, 0xf52612,
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0x7a9309, 0xc2b380, 0x6159c0, 0x30ace0, 0x185670, 0x0c2b38, 0x06159c, 0x030ace,
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0x018567, 0xff38b7, 0x80665f, 0xbfc92b, 0xa01e91, 0xaff54c, 0x57faa6, 0x2bfd53,
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0xea04ad, 0x8af852, 0x457c29, 0xdd4410, 0x6ea208, 0x375104, 0x1ba882, 0x0dd441,
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0xf91024, 0x7c8812, 0x3e4409, 0xe0d800, 0x706c00, 0x383600, 0x1c1b00, 0x0e0d80,
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0x0706c0, 0x038360, 0x01c1b0, 0x00e0d8, 0x00706c, 0x003836, 0x001c1b, 0xfff409,
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0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000,
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0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000,
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0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000
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];
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function modesChecksum(frame) {
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var crc = 0;
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var bits = frame.bits;
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var offset = (bits == 112) ? 0 : (112-56);
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for(var j = 0; j < bits; j++) {
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var byte = j/8;
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var bit = j%8;
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var bitmask = 1 << (7-bit);
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/* If bit is set, xor with corresponding table entry. */
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if (frame.hex.charCodeAt(byte) & bitmask)
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crc ^= modes_checksum_table[j+offset];
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}
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return crc; /* 24 bit checksum. */
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}
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function getFrameChecksum(frame) {
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var res = "";
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for (j = 0; j < frame.hex.length; j++) {
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var val = frame.hex.charCodeAt(j);
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var h = val.toString(16);
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if (h.length == 1) h = "0"+h;
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res += h;
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}
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return res;
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}
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function displayFrame(i) {
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var div = document.getElementById("frame");
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var msgbits = 8+112;
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var frame = frames[i];
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var padding = frame.mag.length - msgbits*2;
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/* Remove the old representation. */
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var nodes = div.childNodes.length;
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for(var j = 0; j < nodes; j++) {
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div.removeChild(div.firstChild);
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}
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/* Display the new one. */
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for (var j = -padding; j < msgbits*2+padding; j++) {
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var m = frame.mag[j+padding];
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var type;
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if (j < 0) type = "noise";
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if (j >= 0 && j < 16) type = "pre";
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if (j >= 16) {
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if (!(j % 2)) {
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var next = frame.mag[j+padding+1];
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if (m > next)
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type = "one";
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else
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type = "zero";
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}
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var bit = (j-16)/2;
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if (bit == frame.fix1 ||
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bit == frame.fix2)
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type = "err";
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}
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var sample = document.createElement("div");
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sample.setAttribute("class","sample "+type);
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sample.setAttribute("title","sample "+j+" ("+m+")");
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sample.style.left = ""+((j+padding)*4)+"px";
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sample.style.height = ""+(m/256)+"px";
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div.appendChild(sample);
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}
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document.getElementById("info").innerHTML =
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"#"+currentFrame+" "+frame.descr+"<br>"+
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"Bits:"+frame.bits+"<br>"+
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"DF : "+(frame.hex.charCodeAt(0) >> 3)+"<br>"+
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"fix1: "+frame.fix1+"<br>"+
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"fix2: "+frame.fix2+"<br>"+
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"hex : "+getFrameChecksum(frame)+"<br>"+
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"crc (computed): "+modesChecksum(frame).toString(16)+"<br>";
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}
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function recomputeHex(frame) {
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var padding = frame.mag.length - (112+8)*2;
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var b = [];
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var hex = "";
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/* Get bits */
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for (var j = 0; j < frame.bits*2; j += 2) {
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var bit;
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var l = frame.mag[padding+j+16];
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var r = frame.mag[padding+j+1+16];
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if (l > r)
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bit = 1;
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else
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bit = 0;
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b.push(bit);
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}
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/* Pack into bytes */
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for (j = 0; j < frame.bits; j+= 8) {
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hex += String.fromCharCode(
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b[j]<<7 |
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b[j+1]<<6 |
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b[j+2]<<5 |
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b[j+3]<<4 |
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b[j+4]<<3 |
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b[j+5]<<2 |
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b[j+6]<<1 |
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b[j+7]);
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}
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frame.hex = hex;
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}
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window.onload = function() {
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document.getElementById("next").onclick = function() {
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if (currentFrame != frames.length-1) currentFrame++;
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displayFrame(currentFrame);
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}
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document.getElementById("prev").onclick = function() {
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if (currentFrame != 0) currentFrame--;
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displayFrame(currentFrame);
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}
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document.getElementById("ca").onclick = function() {
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correctAmplitude(frames[currentFrame]);
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recomputeHex(frames[currentFrame]);
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displayFrame(currentFrame);
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}
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document.getElementById("re").onclick = function() {
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recomputeHex(frames[currentFrame]);
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displayFrame(currentFrame);
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}
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displayFrame(currentFrame);
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}
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</script>
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<script src="frames.js"></script>
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<style>
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#frame {
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width: 1024px;
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height: 255px;
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border: 1px #aaa solid;
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position: relative;
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}
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.sample {
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position: absolute;
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bottom: 0px;
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}
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.pre {
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width:4px;
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background-color: orange;
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}
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.one {
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width:4px;
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background-color: #0000cc;
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}
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.zero {
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width:4px;
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background-color: #aaaaaa;
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}
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.err {
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width:4px;
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background-color: #cc6666;
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}
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.noise {
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width:2px;
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background-color: #ffffff;
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border: 1px #aaa dotted;
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}
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</style>
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</head>
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<div id="frame">
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</div>
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<pre id="info">
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</pre>
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<input type="button" id="prev" value="Prev frame">
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<input type="button" id="next" value="Next frame">
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<input type="button" id="re" value="Recompute Hex">
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</body>
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</html>
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