--- kpdf/xpdf/xpdf/Stream.cc +++ kpdf/xpdf/xpdf/Stream.cc @@ -1277,23 +1277,28 @@ CCITTFaxStream::CCITTFaxStream(Stream *s endOfLine = endOfLineA; byteAlign = byteAlignA; columns = columnsA; - if (columns < 1 || columns >= INT_MAX / sizeof(short)) { - error(getPos(), "Bad number of columns in CCITTFaxStream"); - exit(1); + if (columns < 1) { + columns = 1; + } else if (columns > INT_MAX - 2) { + columns = INT_MAX - 2; } rows = rowsA; endOfBlock = endOfBlockA; black = blackA; - refLine = (short *)gmallocn(columns + 4, sizeof(short)); - codingLine = (short *)gmallocn(columns + 3, sizeof(short)); + // 0 <= codingLine[0] < codingLine[1] < ... < codingLine[n] = columns + // ---> max codingLine size = columns + 1 + // refLine has one extra guard entry at the end + // ---> max refLine size = columns + 2 + codingLine = (int *)gmallocn(columns + 1, sizeof(int)); + refLine = (int *)gmallocn(columns + 2, sizeof(int)); eof = gFalse; row = 0; nextLine2D = encoding < 0; inputBits = 0; - codingLine[0] = 0; - codingLine[1] = refLine[2] = columns; - a0 = 1; + codingLine[0] = columns; + a0i = 0; + outputBits = 0; buf = EOF; } @@ -1312,9 +1317,9 @@ void CCITTFaxStream::reset() { row = 0; nextLine2D = encoding < 0; inputBits = 0; - codingLine[0] = 0; - codingLine[1] = refLine[2] = columns; - a0 = 1; + codingLine[0] = columns; + a0i = 0; + outputBits = 0; buf = EOF; // skip any initial zero bits and end-of-line marker, and get the 2D @@ -1331,163 +1336,228 @@ void CCITTFaxStream::reset() { } } +inline void CCITTFaxStream::addPixels(int a1, int blackPixels) { + if (a1 > codingLine[a0i]) { + if (a1 > columns) { + error(getPos(), "CCITTFax row is wrong length (%d)", a1); + err = gTrue; + a1 = columns; + } + if ((a0i & 1) ^ blackPixels) { + ++a0i; + } + codingLine[a0i] = a1; + } +} + +inline void CCITTFaxStream::addPixelsNeg(int a1, int blackPixels) { + if (a1 > codingLine[a0i]) { + if (a1 > columns) { + error(getPos(), "CCITTFax row is wrong length (%d)", a1); + err = gTrue; + a1 = columns; + } + if ((a0i & 1) ^ blackPixels) { + ++a0i; + } + codingLine[a0i] = a1; + } else if (a1 < codingLine[a0i]) { + if (a1 < 0) { + error(getPos(), "Invalid CCITTFax code"); + err = gTrue; + a1 = 0; + } + while (a0i > 0 && a1 <= codingLine[a0i - 1]) { + --a0i; + } + codingLine[a0i] = a1; + } +} + int CCITTFaxStream::lookChar() { short code1, code2, code3; - int a0New; - GBool err, gotEOL; - int ret; - int bits, i; + int b1i, blackPixels, i, bits; + GBool gotEOL; - // if at eof just return EOF - if (eof && codingLine[a0] >= columns) { - return EOF; + if (buf != EOF) { + return buf; } // read the next row - err = gFalse; - if (codingLine[a0] >= columns) { + if (outputBits == 0) { + + // if at eof just return EOF + if (eof) { + return EOF; + } + + err = gFalse; // 2-D encoding if (nextLine2D) { - for (i = 0; codingLine[i] < columns; ++i) + for (i = 0; codingLine[i] < columns; ++i) { refLine[i] = codingLine[i]; - refLine[i] = refLine[i + 1] = columns; - b1 = 1; - a0New = codingLine[a0 = 0] = 0; - do { + } + refLine[i++] = columns; + refLine[i] = columns; + codingLine[0] = 0; + a0i = 0; + b1i = 0; + blackPixels = 0; + // invariant: + // refLine[b1i-1] <= codingLine[a0i] < refLine[b1i] < refLine[b1i+1] + // <= columns + // exception at left edge: + // codingLine[a0i = 0] = refLine[b1i = 0] = 0 is possible + // exception at right edge: + // refLine[b1i] = refLine[b1i+1] = columns is possible + while (codingLine[a0i] < columns) { code1 = getTwoDimCode(); switch (code1) { case twoDimPass: - if (refLine[b1] < columns) { - a0New = refLine[b1 + 1]; - b1 += 2; + addPixels(refLine[b1i + 1], blackPixels); + if (refLine[b1i + 1] < columns) { + b1i += 2; } break; case twoDimHoriz: - if ((a0 & 1) == 0) { - code1 = code2 = 0; + code1 = code2 = 0; + if (blackPixels) { do { - code1 += code3 = getWhiteCode(); + code1 += code3 = getBlackCode(); } while (code3 >= 64); do { - code2 += code3 = getBlackCode(); + code2 += code3 = getWhiteCode(); } while (code3 >= 64); } else { - code1 = code2 = 0; do { - code1 += code3 = getBlackCode(); + code1 += code3 = getWhiteCode(); } while (code3 >= 64); do { - code2 += code3 = getWhiteCode(); + code2 += code3 = getBlackCode(); } while (code3 >= 64); } - if (code1 > 0 || code2 > 0) { - codingLine[a0 + 1] = a0New + code1; - ++a0; - a0New = codingLine[a0 + 1] = codingLine[a0] + code2; - ++a0; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + addPixels(codingLine[a0i] + code1, blackPixels); + if (codingLine[a0i] < columns) { + addPixels(codingLine[a0i] + code2, blackPixels ^ 1); + } + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; } break; - case twoDimVert0: - a0New = codingLine[++a0] = refLine[b1]; - if (refLine[b1] < columns) { - ++b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertR3: + addPixels(refLine[b1i] + 3, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + ++b1i; + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertR1: - a0New = codingLine[++a0] = refLine[b1] + 1; - if (refLine[b1] < columns) { - ++b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertR2: + addPixels(refLine[b1i] + 2, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + ++b1i; + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertL1: - if (a0 == 0 || refLine[b1] - 1 > a0New) { - a0New = codingLine[++a0] = refLine[b1] - 1; - --b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertR1: + addPixels(refLine[b1i] + 1, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + ++b1i; + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertR2: - a0New = codingLine[++a0] = refLine[b1] + 2; - if (refLine[b1] < columns) { - ++b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVert0: + addPixels(refLine[b1i], blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + ++b1i; + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertL2: - if (a0 == 0 || refLine[b1] - 2 > a0New) { - a0New = codingLine[++a0] = refLine[b1] - 2; - --b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertL3: + addPixelsNeg(refLine[b1i] - 3, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + if (b1i > 0) { + --b1i; + } else { + ++b1i; + } + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertR3: - a0New = codingLine[++a0] = refLine[b1] + 3; - if (refLine[b1] < columns) { - ++b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertL2: + addPixelsNeg(refLine[b1i] - 2, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + if (b1i > 0) { + --b1i; + } else { + ++b1i; + } + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; - case twoDimVertL3: - if (a0 == 0 || refLine[b1] - 3 > a0New) { - a0New = codingLine[++a0] = refLine[b1] - 3; - --b1; - while (refLine[b1] <= codingLine[a0] && refLine[b1] < columns) - b1 += 2; + case twoDimVertL1: + addPixelsNeg(refLine[b1i] - 1, blackPixels); + blackPixels ^= 1; + if (codingLine[a0i] < columns) { + if (b1i > 0) { + --b1i; + } else { + ++b1i; + } + while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) { + b1i += 2; + } } break; case EOF: + addPixels(columns, 0); eof = gTrue; - codingLine[a0 = 0] = columns; - return EOF; + break; default: error(getPos(), "Bad 2D code %04x in CCITTFax stream", code1); + addPixels(columns, 0); err = gTrue; break; } - } while (codingLine[a0] < columns); + } // 1-D encoding } else { - codingLine[a0 = 0] = 0; - while (1) { + codingLine[0] = 0; + a0i = 0; + blackPixels = 0; + while (codingLine[a0i] < columns) { code1 = 0; - do { - code1 += code3 = getWhiteCode(); - } while (code3 >= 64); - codingLine[a0+1] = codingLine[a0] + code1; - ++a0; - if (codingLine[a0] >= columns) - break; - code2 = 0; - do { - code2 += code3 = getBlackCode(); - } while (code3 >= 64); - codingLine[a0+1] = codingLine[a0] + code2; - ++a0; - if (codingLine[a0] >= columns) - break; - } - } - - if (codingLine[a0] != columns) { - error(getPos(), "CCITTFax row is wrong length (%d)", codingLine[a0]); - // force the row to be the correct length - while (codingLine[a0] > columns) { - --a0; + if (blackPixels) { + do { + code1 += code3 = getBlackCode(); + } while (code3 >= 64); + } else { + do { + code1 += code3 = getWhiteCode(); + } while (code3 >= 64); + } + addPixels(codingLine[a0i] + code1, blackPixels); + blackPixels ^= 1; } - codingLine[++a0] = columns; - err = gTrue; } // byte-align the row @@ -1548,14 +1618,17 @@ int CCITTFaxStream::lookChar() { // this if we know the stream contains end-of-line markers because // the "just plow on" technique tends to work better otherwise } else if (err && endOfLine) { - do { + while (1) { + code1 = lookBits(13); if (code1 == EOF) { eof = gTrue; return EOF; } + if ((code1 >> 1) == 0x001) { + break; + } eatBits(1); - code1 = lookBits(13); - } while ((code1 >> 1) != 0x001); + } eatBits(12); if (encoding > 0) { eatBits(1); @@ -1563,11 +1636,11 @@ int CCITTFaxStream::lookChar() { } } - a0 = 0; - outputBits = codingLine[1] - codingLine[0]; - if (outputBits == 0) { - a0 = 1; - outputBits = codingLine[2] - codingLine[1]; + // set up for output + if (codingLine[0] > 0) { + outputBits = codingLine[a0i = 0]; + } else { + outputBits = codingLine[a0i = 1]; } ++row; @@ -1575,39 +1648,43 @@ int CCITTFaxStream::lookChar() { // get a byte if (outputBits >= 8) { - ret = ((a0 & 1) == 0) ? 0xff : 0x00; - if ((outputBits -= 8) == 0) { - ++a0; - if (codingLine[a0] < columns) { - outputBits = codingLine[a0 + 1] - codingLine[a0]; - } + buf = (a0i & 1) ? 0x00 : 0xff; + outputBits -= 8; + if (outputBits == 0 && codingLine[a0i] < columns) { + ++a0i; + outputBits = codingLine[a0i] - codingLine[a0i - 1]; } } else { bits = 8; - ret = 0; + buf = 0; do { if (outputBits > bits) { - i = bits; - bits = 0; - if ((a0 & 1) == 0) { - ret |= 0xff >> (8 - i); + buf <<= bits; + if (!(a0i & 1)) { + buf |= 0xff >> (8 - bits); } - outputBits -= i; + outputBits -= bits; + bits = 0; } else { - i = outputBits; - bits -= outputBits; - if ((a0 & 1) == 0) { - ret |= (0xff >> (8 - i)) << bits; + buf <<= outputBits; + if (!(a0i & 1)) { + buf |= 0xff >> (8 - outputBits); } + bits -= outputBits; outputBits = 0; - ++a0; - if (codingLine[a0] < columns) { - outputBits = codingLine[a0 + 1] - codingLine[a0]; + if (codingLine[a0i] < columns) { + ++a0i; + outputBits = codingLine[a0i] - codingLine[a0i - 1]; + } else if (bits > 0) { + buf <<= bits; + bits = 0; } } - } while (bits > 0 && codingLine[a0] < columns); + } while (bits); + } + if (black) { + buf ^= 0xff; } - buf = black ? (ret ^ 0xff) : ret; return buf; } @@ -1649,6 +1726,9 @@ short CCITTFaxStream::getWhiteCode() { code = 0; // make gcc happy if (endOfBlock) { code = lookBits(12); + if (code == EOF) { + return 1; + } if ((code >> 5) == 0) { p = &whiteTab1[code]; } else { @@ -1661,6 +1741,9 @@ short CCITTFaxStream::getWhiteCode() { } else { for (n = 1; n <= 9; ++n) { code = lookBits(n); + if (code == EOF) { + return 1; + } if (n < 9) { code <<= 9 - n; } @@ -1672,6 +1755,9 @@ short CCITTFaxStream::getWhiteCode() { } for (n = 11; n <= 12; ++n) { code = lookBits(n); + if (code == EOF) { + return 1; + } if (n < 12) { code <<= 12 - n; } @@ -1697,9 +1783,12 @@ short CCITTFaxStream::getBlackCode() { code = 0; // make gcc happy if (endOfBlock) { code = lookBits(13); + if (code == EOF) { + return 1; + } if ((code >> 7) == 0) { p = &blackTab1[code]; - } else if ((code >> 9) == 0) { + } else if ((code >> 9) == 0 && (code >> 7) != 0) { p = &blackTab2[(code >> 1) - 64]; } else { p = &blackTab3[code >> 7]; @@ -1711,6 +1800,9 @@ short CCITTFaxStream::getBlackCode() { } else { for (n = 2; n <= 6; ++n) { code = lookBits(n); + if (code == EOF) { + return 1; + } if (n < 6) { code <<= 6 - n; } @@ -1722,6 +1814,9 @@ short CCITTFaxStream::getBlackCode() { } for (n = 7; n <= 12; ++n) { code = lookBits(n); + if (code == EOF) { + return 1; + } if (n < 12) { code <<= 12 - n; } @@ -1735,6 +1830,9 @@ short CCITTFaxStream::getBlackCode() { } for (n = 10; n <= 13; ++n) { code = lookBits(n); + if (code == EOF) { + return 1; + } if (n < 13) { code <<= 13 - n; } --- kpdf/xpdf/xpdf/Stream.h +++ kpdf/xpdf/xpdf/Stream.h @@ -519,13 +519,15 @@ private: int row; // current row int inputBuf; // input buffer int inputBits; // number of bits in input buffer - short *refLine; // reference line changing elements - int b1; // index into refLine - short *codingLine; // coding line changing elements - int a0; // index into codingLine + int *codingLine; // coding line changing elements + int *refLine; // reference line changing elements + int a0i; // index into codingLine + GBool err; // error on current line int outputBits; // remaining ouput bits int buf; // character buffer + void addPixels(int a1, int black); + void addPixelsNeg(int a1, int black); short getTwoDimCode(); short getWhiteCode(); short getBlackCode();