rewrote prototype inhertence
This commit is contained in:
sbarman
parent
99ffc9991e
commit
438c565f45
650
pdf.js
650
pdf.js
@ -345,213 +345,206 @@ var FlateStream = (function() {
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DecodeStream.call(this);
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}
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constructor.prototype = {
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getBits: function(bits) {
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var codeSize = this.codeSize;
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var codeBuf = this.codeBuf;
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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constructor.prototype = Object.create(DecodeStream.prototype);
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var b;
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while (codeSize < bits) {
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad encoding in flate stream");
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codeBuf |= b << codeSize;
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codeSize += 8;
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}
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b = codeBuf & ((1 << bits) - 1);
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this.codeBuf = codeBuf >> bits;
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this.codeSize = codeSize -= bits;
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this.bytesPos = bytesPos;
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return b;
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},
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getCode: function(table) {
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var codes = table[0];
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var maxLen = table[1];
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var codeSize = this.codeSize;
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var codeBuf = this.codeBuf;
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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constructor.prototype.getBits = function(bits) {
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var codeSize = this.codeSize;
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var codeBuf = this.codeBuf;
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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while (codeSize < maxLen) {
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var b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad encoding in flate stream");
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codeBuf |= (b << codeSize);
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codeSize += 8;
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}
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var code = codes[codeBuf & ((1 << maxLen) - 1)];
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var codeLen = code >> 16;
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var codeVal = code & 0xffff;
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if (codeSize == 0|| codeSize < codeLen || codeLen == 0)
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var b;
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while (codeSize < bits) {
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad encoding in flate stream");
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this.codeBuf = (codeBuf >> codeLen);
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codeBuf |= b << codeSize;
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codeSize += 8;
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}
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b = codeBuf & ((1 << bits) - 1);
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this.codeBuf = codeBuf >> bits;
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this.codeSize = codeSize -= bits;
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this.bytesPos = bytesPos;
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return b;
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};
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constructor.prototype.getCode = function(table) {
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var codes = table[0];
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var maxLen = table[1];
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var codeSize = this.codeSize;
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var codeBuf = this.codeBuf;
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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while (codeSize < maxLen) {
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var b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad encoding in flate stream");
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codeBuf |= (b << codeSize);
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codeSize += 8;
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}
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var code = codes[codeBuf & ((1 << maxLen) - 1)];
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var codeLen = code >> 16;
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var codeVal = code & 0xffff;
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if (codeSize == 0|| codeSize < codeLen || codeLen == 0)
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error("Bad encoding in flate stream");
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this.codeBuf = (codeBuf >> codeLen);
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this.codeSize = (codeSize - codeLen);
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this.bytesPos = bytesPos;
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return codeVal;
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},
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generateHuffmanTable: function(lengths) {
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var n = lengths.length;
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};
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constructor.prototype.generateHuffmanTable = function(lengths) {
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var n = lengths.length;
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// find max code length
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var maxLen = 0;
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for (var i = 0; i < n; ++i) {
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if (lengths[i] > maxLen)
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maxLen = lengths[i];
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}
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// find max code length
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var maxLen = 0;
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for (var i = 0; i < n; ++i) {
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if (lengths[i] > maxLen)
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maxLen = lengths[i];
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}
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// build the table
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var size = 1 << maxLen;
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var codes = Uint32Array(size);
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for (var len = 1, code = 0, skip = 2;
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len <= maxLen;
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++len, code <<= 1, skip <<= 1) {
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for (var val = 0; val < n; ++val) {
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if (lengths[val] == len) {
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// bit-reverse the code
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var code2 = 0;
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var t = code;
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for (var i = 0; i < len; ++i) {
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code2 = (code2 << 1) | (t & 1);
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t >>= 1;
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}
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// fill the table entries
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for (var i = code2; i < size; i += skip)
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codes[i] = (len << 16) | val;
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++code;
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// build the table
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var size = 1 << maxLen;
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var codes = Uint32Array(size);
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for (var len = 1, code = 0, skip = 2;
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len <= maxLen;
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++len, code <<= 1, skip <<= 1) {
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for (var val = 0; val < n; ++val) {
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if (lengths[val] == len) {
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// bit-reverse the code
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var code2 = 0;
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var t = code;
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for (var i = 0; i < len; ++i) {
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code2 = (code2 << 1) | (t & 1);
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t >>= 1;
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}
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}
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}
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return [codes, maxLen];
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},
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readBlock: function() {
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function repeat(stream, array, len, offset, what) {
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var repeat = stream.getBits(len) + offset;
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while (repeat-- > 0)
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array[i++] = what;
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}
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// fill the table entries
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for (var i = code2; i < size; i += skip)
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codes[i] = (len << 16) | val;
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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// read block header
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var hdr = this.getBits(3);
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if (hdr & 1)
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this.eof = true;
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hdr >>= 1;
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var b;
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if (hdr == 0) { // uncompressed block
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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var blockLen = b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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blockLen |= (b << 8);
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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var check = b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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check |= (b << 8);
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if (check != (~this.blockLen & 0xffff))
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error("Bad uncompressed block length in flate stream");
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var bufferLength = this.bufferLength;
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var buffer = this.ensureBuffer(bufferLength + blockLen);
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this.bufferLength = bufferLength + blockLen;
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for (var n = bufferLength; n < blockLen; ++n) {
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if (typeof (b = bytes[bytesPos++]) == "undefined") {
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this.eof = true;
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break;
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}
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buffer[n] = b;
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}
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return;
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}
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var litCodeTable;
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var distCodeTable;
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if (hdr == 1) { // compressed block, fixed codes
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litCodeTable = fixedLitCodeTab;
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distCodeTable = fixedDistCodeTab;
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} else if (hdr == 2) { // compressed block, dynamic codes
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var numLitCodes = this.getBits(5) + 257;
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var numDistCodes = this.getBits(5) + 1;
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var numCodeLenCodes = this.getBits(4) + 4;
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// build the code lengths code table
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var codeLenCodeLengths = Array(codeLenCodeMap.length);
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var i = 0;
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while (i < numCodeLenCodes)
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codeLenCodeLengths[codeLenCodeMap[i++]] = this.getBits(3);
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var codeLenCodeTab = this.generateHuffmanTable(codeLenCodeLengths);
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// build the literal and distance code tables
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var len = 0;
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var i = 0;
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var codes = numLitCodes + numDistCodes;
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var codeLengths = new Array(codes);
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while (i < codes) {
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var code = this.getCode(codeLenCodeTab);
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if (code == 16) {
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repeat(this, codeLengths, 2, 3, len);
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} else if (code == 17) {
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repeat(this, codeLengths, 3, 3, len = 0);
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} else if (code == 18) {
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repeat(this, codeLengths, 7, 11, len = 0);
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} else {
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codeLengths[i++] = len = code;
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}
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}
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litCodeTable = this.generateHuffmanTable(
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codeLengths.slice(0, numLitCodes));
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distCodeTable = this.generateHuffmanTable(
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codeLengths.slice(numLitCodes, codes));
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} else {
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error("Unknown block type in flate stream");
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}
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var pos = this.bufferLength;
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while (true) {
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var code1 = this.getCode(litCodeTable);
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if (code1 == 256) {
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this.bufferLength = pos;
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return;
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}
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if (code1 < 256) {
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var buffer = this.ensureBuffer(pos + 1);
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buffer[pos++] = code1;
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} else {
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code1 -= 257;
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code1 = lengthDecode[code1];
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var code2 = code1 >> 16;
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if (code2 > 0)
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code2 = this.getBits(code2);
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var len = (code1 & 0xffff) + code2;
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code1 = this.getCode(distCodeTable);
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code1 = distDecode[code1];
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code2 = code1 >> 16;
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if (code2 > 0)
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code2 = this.getBits(code2);
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var dist = (code1 & 0xffff) + code2;
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var buffer = this.ensureBuffer(pos + len);
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for (var k = 0; k < len; ++k, ++pos)
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buffer[pos] = buffer[pos - dist];
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++code;
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}
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}
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}
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};
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var thisPrototype = constructor.prototype;
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var superPrototype = DecodeStream.prototype;
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for (var i in superPrototype) {
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if (!thisPrototype[i])
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thisPrototype[i] = superPrototype[i];
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}
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return [codes, maxLen];
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};
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constructor.prototype.readBlock = function() {
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function repeat(stream, array, len, offset, what) {
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var repeat = stream.getBits(len) + offset;
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while (repeat-- > 0)
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array[i++] = what;
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}
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var bytes = this.bytes;
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var bytesPos = this.bytesPos;
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// read block header
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var hdr = this.getBits(3);
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if (hdr & 1)
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this.eof = true;
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hdr >>= 1;
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var b;
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if (hdr == 0) { // uncompressed block
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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var blockLen = b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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blockLen |= (b << 8);
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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var check = b;
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if (typeof (b = bytes[bytesPos++]) == "undefined")
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error("Bad block header in flate stream");
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check |= (b << 8);
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if (check != (~this.blockLen & 0xffff))
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error("Bad uncompressed block length in flate stream");
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var bufferLength = this.bufferLength;
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var buffer = this.ensureBuffer(bufferLength + blockLen);
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this.bufferLength = bufferLength + blockLen;
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for (var n = bufferLength; n < blockLen; ++n) {
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if (typeof (b = bytes[bytesPos++]) == "undefined") {
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this.eof = true;
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break;
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}
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buffer[n] = b;
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}
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return;
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}
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var litCodeTable;
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var distCodeTable;
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if (hdr == 1) { // compressed block, fixed codes
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litCodeTable = fixedLitCodeTab;
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distCodeTable = fixedDistCodeTab;
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} else if (hdr == 2) { // compressed block, dynamic codes
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var numLitCodes = this.getBits(5) + 257;
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var numDistCodes = this.getBits(5) + 1;
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var numCodeLenCodes = this.getBits(4) + 4;
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// build the code lengths code table
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var codeLenCodeLengths = Array(codeLenCodeMap.length);
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var i = 0;
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while (i < numCodeLenCodes)
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codeLenCodeLengths[codeLenCodeMap[i++]] = this.getBits(3);
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var codeLenCodeTab = this.generateHuffmanTable(codeLenCodeLengths);
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// build the literal and distance code tables
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var len = 0;
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var i = 0;
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var codes = numLitCodes + numDistCodes;
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var codeLengths = new Array(codes);
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while (i < codes) {
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var code = this.getCode(codeLenCodeTab);
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if (code == 16) {
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repeat(this, codeLengths, 2, 3, len);
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} else if (code == 17) {
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repeat(this, codeLengths, 3, 3, len = 0);
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} else if (code == 18) {
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repeat(this, codeLengths, 7, 11, len = 0);
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} else {
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codeLengths[i++] = len = code;
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}
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}
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litCodeTable =
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this.generateHuffmanTable(codeLengths.slice(0, numLitCodes));
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distCodeTable =
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this.generateHuffmanTable(codeLengths.slice(numLitCodes, codes));
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} else {
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error("Unknown block type in flate stream");
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}
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var pos = this.bufferLength;
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while (true) {
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var code1 = this.getCode(litCodeTable);
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if (code1 == 256) {
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this.bufferLength = pos;
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return;
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}
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if (code1 < 256) {
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var buffer = this.ensureBuffer(pos + 1);
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buffer[pos++] = code1;
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} else {
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code1 -= 257;
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code1 = lengthDecode[code1];
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var code2 = code1 >> 16;
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if (code2 > 0)
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code2 = this.getBits(code2);
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var len = (code1 & 0xffff) + code2;
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code1 = this.getCode(distCodeTable);
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code1 = distDecode[code1];
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code2 = code1 >> 16;
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if (code2 > 0)
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code2 = this.getBits(code2);
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var dist = (code1 & 0xffff) + code2;
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var buffer = this.ensureBuffer(pos + len);
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for (var k = 0; k < len; ++k, ++pos)
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buffer[pos] = buffer[pos - dist];
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}
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}
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};
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return constructor;
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})();
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@ -586,155 +579,148 @@ var PredictorStream = (function() {
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DecodeStream.call(this);
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}
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constructor.prototype = {
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readBlockTiff : function() {
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var buffer = this.buffer;
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var pos = this.pos;
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constructor.prototype = Object.create(DecodeStream.prototype);
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var rowBytes = this.rowBytes;
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var pixBytes = this.pixBytes;
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constructor.prototype.readBlockTiff = function() {
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var buffer = this.buffer;
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var pos = this.pos;
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var rowBytes = this.rowBytes;
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var pixBytes = this.pixBytes;
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var buffer = this.buffer;
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var bufferLength = this.bufferLength;
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this.ensureBuffer(bufferLength + rowBytes);
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var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes);
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var bits = this.bits;
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var colors = this.colors;
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var buffer = this.buffer;
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var bufferLength = this.bufferLength;
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this.ensureBuffer(bufferLength + rowBytes);
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var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes);
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var rawBytes = this.stream.getBytes(rowBytes);
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if (bits === 1) {
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var inbuf = 0;
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for (var i = 0; i < rowBytes; ++i) {
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var c = rawBytes[i];
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inBuf = (inBuf << 8) | c;
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// bitwise addition is exclusive or
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// first shift inBuf and then add
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currentRow[i] = (c ^ (inBuf >> colors)) & 0xFF;
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// truncate inBuf (assumes colors < 16)
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inBuf &= 0xFFFF;
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}
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} else if (bits === 8) {
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for (var i = 0; i < colors; ++i)
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currentRow[i] = rawBytes[i];
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for (; i < rowBytes; ++i)
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currentRow[i] = currentRow[i - colors] + rawBytes[i];
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} else {
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var compArray = new Uint8Array(colors + 1);
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var bitMask = (1 << bits) - 1;
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var inbuf = 0, outbut = 0;
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var inbits = 0, outbits = 0;
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var j = 0, k = 0;
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var columns = this.columns;
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for (var i = 0; i < columns; ++i) {
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for (var kk = 0; kk < colors; ++kk) {
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if (inbits < bits) {
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inbuf = (inbuf << 8) | (rawBytes[j++] & 0xFF);
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inbits += 8;
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}
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compArray[kk] = (compArray[kk] +
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(inbuf >> (inbits - bits))) & bitMask;
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inbits -= bits;
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outbuf = (outbuf << bits) | compArray[kk];
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outbits += bits;
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if (outbits >= 8) {
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currentRow[k++] = (outbuf >> (outbits - 8)) & 0xFF;
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outbits -= 8;
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}
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var bits = this.bits;
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var colors = this.colors;
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var rawBytes = this.stream.getBytes(rowBytes);
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if (bits === 1) {
|
||||
var inbuf = 0;
|
||||
for (var i = 0; i < rowBytes; ++i) {
|
||||
var c = rawBytes[i];
|
||||
inBuf = (inBuf << 8) | c;
|
||||
// bitwise addition is exclusive or
|
||||
// first shift inBuf and then add
|
||||
currentRow[i] = (c ^ (inBuf >> colors)) & 0xFF;
|
||||
// truncate inBuf (assumes colors < 16)
|
||||
inBuf &= 0xFFFF;
|
||||
}
|
||||
} else if (bits === 8) {
|
||||
for (var i = 0; i < colors; ++i)
|
||||
currentRow[i] = rawBytes[i];
|
||||
for (; i < rowBytes; ++i)
|
||||
currentRow[i] = currentRow[i - colors] + rawBytes[i];
|
||||
} else {
|
||||
var compArray = new Uint8Array(colors + 1);
|
||||
var bitMask = (1 << bits) - 1;
|
||||
var inbuf = 0, outbut = 0;
|
||||
var inbits = 0, outbits = 0;
|
||||
var j = 0, k = 0;
|
||||
var columns = this.columns;
|
||||
for (var i = 0; i < columns; ++i) {
|
||||
for (var kk = 0; kk < colors; ++kk) {
|
||||
if (inbits < bits) {
|
||||
inbuf = (inbuf << 8) | (rawBytes[j++] & 0xFF);
|
||||
inbits += 8;
|
||||
}
|
||||
compArray[kk] = (compArray[kk] +
|
||||
(inbuf >> (inbits - bits))) & bitMask;
|
||||
inbits -= bits;
|
||||
outbuf = (outbuf << bits) | compArray[kk];
|
||||
outbits += bits;
|
||||
if (outbits >= 8) {
|
||||
currentRow[k++] = (outbuf >> (outbits - 8)) & 0xFF;
|
||||
outbits -= 8;
|
||||
}
|
||||
}
|
||||
if (outbits > 0) {
|
||||
currentRow[k++] = (outbuf << (8 - outbits)) +
|
||||
(inbuf & ((1 << (8 - outbits)) - 1))
|
||||
}
|
||||
}
|
||||
this.bufferLength += rowBytes;
|
||||
},
|
||||
readBlockPng : function() {
|
||||
var buffer = this.buffer;
|
||||
var pos = this.pos;
|
||||
|
||||
var rowBytes = this.rowBytes;
|
||||
var pixBytes = this.pixBytes;
|
||||
|
||||
var predictor = this.stream.getByte();
|
||||
var rawBytes = this.stream.getBytes(rowBytes);
|
||||
|
||||
var buffer = this.buffer;
|
||||
var bufferLength = this.bufferLength;
|
||||
this.ensureBuffer(bufferLength + pixBytes);
|
||||
|
||||
var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes);
|
||||
var prevRow = buffer.subarray(bufferLength - rowBytes, bufferLength);
|
||||
if (prevRow.length == 0)
|
||||
prevRow = currentRow;
|
||||
|
||||
switch (predictor) {
|
||||
case 0:
|
||||
break;
|
||||
case 1:
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = rawBytes[i];
|
||||
for (; i < rowBytes; ++i)
|
||||
currentRow[i] = (currentRow[i - pixBytes] + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 2:
|
||||
for (var i = 0; i < rowBytes; ++i)
|
||||
currentRow[i] = (prevRow[i] + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 3:
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = (prevRow[i] >> 1) + rawBytes[i];
|
||||
for (; i < rowBytes; ++i)
|
||||
currentRow[i] = (((prevRow[i] + currentRow[i - pixBytes])
|
||||
>> 1) + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 4:
|
||||
// we need to save the up left pixels values. the simplest way
|
||||
// is to create a new buffer
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = rawBytes[i];
|
||||
for (; i < rowBytes; ++i) {
|
||||
var up = prevRow[i];
|
||||
var upLeft = lastRow[i - pixBytes];
|
||||
var left = currentRow[i - pixBytes];
|
||||
var p = left + up - upLeft;
|
||||
|
||||
var pa = p - left;
|
||||
if (pa < 0)
|
||||
pa = -pa;
|
||||
var pb = p - up;
|
||||
if (pb < 0)
|
||||
pb = -pb;
|
||||
var pc = p - upLeft;
|
||||
if (pc < 0)
|
||||
pc = -pc;
|
||||
|
||||
var c = rawBytes[i];
|
||||
if (pa <= pb && pa <= pc)
|
||||
currentRow[i] = left + c;
|
||||
else if (pb <= pc)
|
||||
currentRow[i] = up + c;
|
||||
else
|
||||
currentRow[i] = upLeft + c;
|
||||
break;
|
||||
}
|
||||
default:
|
||||
error("Unsupported predictor");
|
||||
break;
|
||||
if (outbits > 0) {
|
||||
currentRow[k++] = (outbuf << (8 - outbits)) +
|
||||
(inbuf & ((1 << (8 - outbits)) - 1))
|
||||
}
|
||||
this.bufferLength += rowBytes;
|
||||
},
|
||||
}
|
||||
this.bufferLength += rowBytes;
|
||||
};
|
||||
constructor.prototype.readBlockPng = function() {
|
||||
var buffer = this.buffer;
|
||||
var pos = this.pos;
|
||||
|
||||
var rowBytes = this.rowBytes;
|
||||
var pixBytes = this.pixBytes;
|
||||
|
||||
var predictor = this.stream.getByte();
|
||||
var rawBytes = this.stream.getBytes(rowBytes);
|
||||
|
||||
var buffer = this.buffer;
|
||||
var bufferLength = this.bufferLength;
|
||||
this.ensureBuffer(bufferLength + pixBytes);
|
||||
|
||||
var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes);
|
||||
var prevRow = buffer.subarray(bufferLength - rowBytes, bufferLength);
|
||||
if (prevRow.length == 0)
|
||||
prevRow = currentRow;
|
||||
|
||||
switch (predictor) {
|
||||
case 0:
|
||||
break;
|
||||
case 1:
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = rawBytes[i];
|
||||
for (; i < rowBytes; ++i)
|
||||
currentRow[i] = (currentRow[i - pixBytes] + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 2:
|
||||
for (var i = 0; i < rowBytes; ++i)
|
||||
currentRow[i] = (prevRow[i] + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 3:
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = (prevRow[i] >> 1) + rawBytes[i];
|
||||
for (; i < rowBytes; ++i)
|
||||
currentRow[i] = (((prevRow[i] + currentRow[i - pixBytes])
|
||||
>> 1) + rawBytes[i]) & 0xFF;
|
||||
break;
|
||||
case 4:
|
||||
// we need to save the up left pixels values. the simplest way
|
||||
// is to create a new buffer
|
||||
for (var i = 0; i < pixBytes; ++i)
|
||||
currentRow[i] = rawBytes[i];
|
||||
for (; i < rowBytes; ++i) {
|
||||
var up = prevRow[i];
|
||||
var upLeft = lastRow[i - pixBytes];
|
||||
var left = currentRow[i - pixBytes];
|
||||
var p = left + up - upLeft;
|
||||
|
||||
var pa = p - left;
|
||||
if (pa < 0)
|
||||
pa = -pa;
|
||||
var pb = p - up;
|
||||
if (pb < 0)
|
||||
pb = -pb;
|
||||
var pc = p - upLeft;
|
||||
if (pc < 0)
|
||||
pc = -pc;
|
||||
|
||||
var c = rawBytes[i];
|
||||
if (pa <= pb && pa <= pc)
|
||||
currentRow[i] = left + c;
|
||||
else if (pb <= pc)
|
||||
currentRow[i] = up + c;
|
||||
else
|
||||
currentRow[i] = upLeft + c;
|
||||
break;
|
||||
}
|
||||
default:
|
||||
error("Unsupported predictor");
|
||||
break;
|
||||
}
|
||||
this.bufferLength += rowBytes;
|
||||
};
|
||||
|
||||
var thisPrototype = constructor.prototype;
|
||||
var superPrototype = DecodeStream.prototype;
|
||||
for (var i in superPrototype) {
|
||||
if (!thisPrototype[i])
|
||||
thisPrototype[i] = superPrototype[i];
|
||||
}
|
||||
|
||||
return constructor;
|
||||
})();
|
||||
|
||||
Loading…
Reference in New Issue
Block a user