diff options
author | scuri <scuri> | 2008-10-17 06:10:15 +0000 |
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committer | scuri <scuri> | 2008-10-17 06:10:15 +0000 |
commit | 5a422aba704c375a307a902bafe658342e209906 (patch) | |
tree | 5005011e086bb863d8fb587ad3319bbec59b2447 /src/libtiff/tif_fax3.h |
First commit - moving from LuaForge to SourceForge
Diffstat (limited to 'src/libtiff/tif_fax3.h')
-rw-r--r-- | src/libtiff/tif_fax3.h | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/src/libtiff/tif_fax3.h b/src/libtiff/tif_fax3.h new file mode 100644 index 0000000..99ced5f --- /dev/null +++ b/src/libtiff/tif_fax3.h @@ -0,0 +1,525 @@ +/* $Id: tif_fax3.h,v 1.1 2008/10/17 06:16:07 scuri Exp $ */ + +/* + * Copyright (c) 1990-1997 Sam Leffler + * Copyright (c) 1991-1997 Silicon Graphics, Inc. + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that (i) the above copyright notices and this permission notice appear in + * all copies of the software and related documentation, and (ii) the names of + * Sam Leffler and Silicon Graphics may not be used in any advertising or + * publicity relating to the software without the specific, prior written + * permission of Sam Leffler and Silicon Graphics. + * + * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, + * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY + * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + * + * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR + * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, + * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, + * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF + * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#ifndef _FAX3_ +#define _FAX3_ +/* + * TIFF Library. + * + * CCITT Group 3 (T.4) and Group 4 (T.6) Decompression Support. + * + * Decoder support is derived, with permission, from the code + * in Frank Cringle's viewfax program; + * Copyright (C) 1990, 1995 Frank D. Cringle. + */ +#include "tiff.h" + +/* + * To override the default routine used to image decoded + * spans one can use the pseduo tag TIFFTAG_FAXFILLFUNC. + * The routine must have the type signature given below; + * for example: + * + * fillruns(unsigned char* buf, uint32* runs, uint32* erun, uint32 lastx) + * + * where buf is place to set the bits, runs is the array of b&w run + * lengths (white then black), erun is the last run in the array, and + * lastx is the width of the row in pixels. Fill routines can assume + * the run array has room for at least lastx runs and can overwrite + * data in the run array as needed (e.g. to append zero runs to bring + * the count up to a nice multiple). + */ +typedef void (*TIFFFaxFillFunc)(unsigned char*, uint32*, uint32*, uint32); + +/* + * The default run filler; made external for other decoders. + */ +#if defined(__cplusplus) +extern "C" { +#endif +extern void _TIFFFax3fillruns(unsigned char*, uint32*, uint32*, uint32); +#if defined(__cplusplus) +} +#endif + + +/* finite state machine codes */ +#define S_Null 0 +#define S_Pass 1 +#define S_Horiz 2 +#define S_V0 3 +#define S_VR 4 +#define S_VL 5 +#define S_Ext 6 +#define S_TermW 7 +#define S_TermB 8 +#define S_MakeUpW 9 +#define S_MakeUpB 10 +#define S_MakeUp 11 +#define S_EOL 12 + +typedef struct { /* state table entry */ + unsigned char State; /* see above */ + unsigned char Width; /* width of code in bits */ + uint32 Param; /* unsigned 32-bit run length in bits */ +} TIFFFaxTabEnt; + +extern const TIFFFaxTabEnt TIFFFaxMainTable[]; +extern const TIFFFaxTabEnt TIFFFaxWhiteTable[]; +extern const TIFFFaxTabEnt TIFFFaxBlackTable[]; + +/* + * The following macros define the majority of the G3/G4 decoder + * algorithm using the state tables defined elsewhere. To build + * a decoder you need some setup code and some glue code. Note + * that you may also need/want to change the way the NeedBits* + * macros get input data if, for example, you know the data to be + * decoded is properly aligned and oriented (doing so before running + * the decoder can be a big performance win). + * + * Consult the decoder in the TIFF library for an idea of what you + * need to define and setup to make use of these definitions. + * + * NB: to enable a debugging version of these macros define FAX3_DEBUG + * before including this file. Trace output goes to stdout. + */ + +#ifndef EndOfData +#define EndOfData() (cp >= ep) +#endif +/* + * Need <=8 or <=16 bits of input data. Unlike viewfax we + * cannot use/assume a word-aligned, properly bit swizzled + * input data set because data may come from an arbitrarily + * aligned, read-only source such as a memory-mapped file. + * Note also that the viewfax decoder does not check for + * running off the end of the input data buffer. This is + * possible for G3-encoded data because it prescans the input + * data to count EOL markers, but can cause problems for G4 + * data. In any event, we don't prescan and must watch for + * running out of data since we can't permit the library to + * scan past the end of the input data buffer. + * + * Finally, note that we must handle remaindered data at the end + * of a strip specially. The coder asks for a fixed number of + * bits when scanning for the next code. This may be more bits + * than are actually present in the data stream. If we appear + * to run out of data but still have some number of valid bits + * remaining then we makeup the requested amount with zeros and + * return successfully. If the returned data is incorrect then + * we should be called again and get a premature EOF error; + * otherwise we should get the right answer. + */ +#ifndef NeedBits8 +#define NeedBits8(n,eoflab) do { \ + if (BitsAvail < (n)) { \ + if (EndOfData()) { \ + if (BitsAvail == 0) /* no valid bits */ \ + goto eoflab; \ + BitsAvail = (n); /* pad with zeros */ \ + } else { \ + BitAcc |= ((uint32) bitmap[*cp++])<<BitsAvail; \ + BitsAvail += 8; \ + } \ + } \ +} while (0) +#endif +#ifndef NeedBits16 +#define NeedBits16(n,eoflab) do { \ + if (BitsAvail < (n)) { \ + if (EndOfData()) { \ + if (BitsAvail == 0) /* no valid bits */ \ + goto eoflab; \ + BitsAvail = (n); /* pad with zeros */ \ + } else { \ + BitAcc |= ((uint32) bitmap[*cp++])<<BitsAvail; \ + if ((BitsAvail += 8) < (n)) { \ + if (EndOfData()) { \ + /* NB: we know BitsAvail is non-zero here */ \ + BitsAvail = (n); /* pad with zeros */ \ + } else { \ + BitAcc |= ((uint32) bitmap[*cp++])<<BitsAvail; \ + BitsAvail += 8; \ + } \ + } \ + } \ + } \ +} while (0) +#endif +#define GetBits(n) (BitAcc & ((1<<(n))-1)) +#define ClrBits(n) do { \ + BitsAvail -= (n); \ + BitAcc >>= (n); \ +} while (0) + +#ifdef FAX3_DEBUG +static const char* StateNames[] = { + "Null ", + "Pass ", + "Horiz ", + "V0 ", + "VR ", + "VL ", + "Ext ", + "TermW ", + "TermB ", + "MakeUpW", + "MakeUpB", + "MakeUp ", + "EOL ", +}; +#define DEBUG_SHOW putchar(BitAcc & (1 << t) ? '1' : '0') +#define LOOKUP8(wid,tab,eoflab) do { \ + int t; \ + NeedBits8(wid,eoflab); \ + TabEnt = tab + GetBits(wid); \ + printf("%08lX/%d: %s%5d\t", (long) BitAcc, BitsAvail, \ + StateNames[TabEnt->State], TabEnt->Param); \ + for (t = 0; t < TabEnt->Width; t++) \ + DEBUG_SHOW; \ + putchar('\n'); \ + fflush(stdout); \ + ClrBits(TabEnt->Width); \ +} while (0) +#define LOOKUP16(wid,tab,eoflab) do { \ + int t; \ + NeedBits16(wid,eoflab); \ + TabEnt = tab + GetBits(wid); \ + printf("%08lX/%d: %s%5d\t", (long) BitAcc, BitsAvail, \ + StateNames[TabEnt->State], TabEnt->Param); \ + for (t = 0; t < TabEnt->Width; t++) \ + DEBUG_SHOW; \ + putchar('\n'); \ + fflush(stdout); \ + ClrBits(TabEnt->Width); \ +} while (0) + +#define SETVALUE(x) do { \ + *pa++ = RunLength + (x); \ + printf("SETVALUE: %d\t%d\n", RunLength + (x), a0); \ + a0 += x; \ + RunLength = 0; \ +} while (0) +#else +#define LOOKUP8(wid,tab,eoflab) do { \ + NeedBits8(wid,eoflab); \ + TabEnt = tab + GetBits(wid); \ + ClrBits(TabEnt->Width); \ +} while (0) +#define LOOKUP16(wid,tab,eoflab) do { \ + NeedBits16(wid,eoflab); \ + TabEnt = tab + GetBits(wid); \ + ClrBits(TabEnt->Width); \ +} while (0) + +/* + * Append a run to the run length array for the + * current row and reset decoding state. + */ +#define SETVALUE(x) do { \ + *pa++ = RunLength + (x); \ + a0 += (x); \ + RunLength = 0; \ +} while (0) +#endif + +/* + * Synchronize input decoding at the start of each + * row by scanning for an EOL (if appropriate) and + * skipping any trash data that might be present + * after a decoding error. Note that the decoding + * done elsewhere that recognizes an EOL only consumes + * 11 consecutive zero bits. This means that if EOLcnt + * is non-zero then we still need to scan for the final flag + * bit that is part of the EOL code. + */ +#define SYNC_EOL(eoflab) do { \ + if (EOLcnt == 0) { \ + for (;;) { \ + NeedBits16(11,eoflab); \ + if (GetBits(11) == 0) \ + break; \ + ClrBits(1); \ + } \ + } \ + for (;;) { \ + NeedBits8(8,eoflab); \ + if (GetBits(8)) \ + break; \ + ClrBits(8); \ + } \ + while (GetBits(1) == 0) \ + ClrBits(1); \ + ClrBits(1); /* EOL bit */ \ + EOLcnt = 0; /* reset EOL counter/flag */ \ +} while (0) + +/* + * Cleanup the array of runs after decoding a row. + * We adjust final runs to insure the user buffer is not + * overwritten and/or undecoded area is white filled. + */ +#define CLEANUP_RUNS() do { \ + if (RunLength) \ + SETVALUE(0); \ + if (a0 != lastx) { \ + badlength(a0, lastx); \ + while (a0 > lastx && pa > thisrun) \ + a0 -= *--pa; \ + if (a0 < lastx) { \ + if (a0 < 0) \ + a0 = 0; \ + if ((pa-thisrun)&1) \ + SETVALUE(0); \ + SETVALUE(lastx - a0); \ + } else if (a0 > lastx) { \ + SETVALUE(lastx); \ + SETVALUE(0); \ + } \ + } \ +} while (0) + +/* + * Decode a line of 1D-encoded data. + * + * The line expanders are written as macros so that they can be reused + * but still have direct access to the local variables of the "calling" + * function. + * + * Note that unlike the original version we have to explicitly test for + * a0 >= lastx after each black/white run is decoded. This is because + * the original code depended on the input data being zero-padded to + * insure the decoder recognized an EOL before running out of data. + */ +#define EXPAND1D(eoflab) do { \ + for (;;) { \ + for (;;) { \ + LOOKUP16(12, TIFFFaxWhiteTable, eof1d); \ + switch (TabEnt->State) { \ + case S_EOL: \ + EOLcnt = 1; \ + goto done1d; \ + case S_TermW: \ + SETVALUE(TabEnt->Param); \ + goto doneWhite1d; \ + case S_MakeUpW: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + unexpected("WhiteTable", a0); \ + goto done1d; \ + } \ + } \ + doneWhite1d: \ + if (a0 >= lastx) \ + goto done1d; \ + for (;;) { \ + LOOKUP16(13, TIFFFaxBlackTable, eof1d); \ + switch (TabEnt->State) { \ + case S_EOL: \ + EOLcnt = 1; \ + goto done1d; \ + case S_TermB: \ + SETVALUE(TabEnt->Param); \ + goto doneBlack1d; \ + case S_MakeUpB: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + unexpected("BlackTable", a0); \ + goto done1d; \ + } \ + } \ + doneBlack1d: \ + if (a0 >= lastx) \ + goto done1d; \ + if( *(pa-1) == 0 && *(pa-2) == 0 ) \ + pa -= 2; \ + } \ +eof1d: \ + prematureEOF(a0); \ + CLEANUP_RUNS(); \ + goto eoflab; \ +done1d: \ + CLEANUP_RUNS(); \ +} while (0) + +/* + * Update the value of b1 using the array + * of runs for the reference line. + */ +#define CHECK_b1 do { \ + if (pa != thisrun) while (b1 <= a0 && b1 < lastx) { \ + b1 += pb[0] + pb[1]; \ + pb += 2; \ + } \ +} while (0) + +/* + * Expand a row of 2D-encoded data. + */ +#define EXPAND2D(eoflab) do { \ + while (a0 < lastx) { \ + LOOKUP8(7, TIFFFaxMainTable, eof2d); \ + switch (TabEnt->State) { \ + case S_Pass: \ + CHECK_b1; \ + b1 += *pb++; \ + RunLength += b1 - a0; \ + a0 = b1; \ + b1 += *pb++; \ + break; \ + case S_Horiz: \ + if ((pa-thisrun)&1) { \ + for (;;) { /* black first */ \ + LOOKUP16(13, TIFFFaxBlackTable, eof2d); \ + switch (TabEnt->State) { \ + case S_TermB: \ + SETVALUE(TabEnt->Param); \ + goto doneWhite2da; \ + case S_MakeUpB: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + goto badBlack2d; \ + } \ + } \ + doneWhite2da:; \ + for (;;) { /* then white */ \ + LOOKUP16(12, TIFFFaxWhiteTable, eof2d); \ + switch (TabEnt->State) { \ + case S_TermW: \ + SETVALUE(TabEnt->Param); \ + goto doneBlack2da; \ + case S_MakeUpW: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + goto badWhite2d; \ + } \ + } \ + doneBlack2da:; \ + } else { \ + for (;;) { /* white first */ \ + LOOKUP16(12, TIFFFaxWhiteTable, eof2d); \ + switch (TabEnt->State) { \ + case S_TermW: \ + SETVALUE(TabEnt->Param); \ + goto doneWhite2db; \ + case S_MakeUpW: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + goto badWhite2d; \ + } \ + } \ + doneWhite2db:; \ + for (;;) { /* then black */ \ + LOOKUP16(13, TIFFFaxBlackTable, eof2d); \ + switch (TabEnt->State) { \ + case S_TermB: \ + SETVALUE(TabEnt->Param); \ + goto doneBlack2db; \ + case S_MakeUpB: \ + case S_MakeUp: \ + a0 += TabEnt->Param; \ + RunLength += TabEnt->Param; \ + break; \ + default: \ + goto badBlack2d; \ + } \ + } \ + doneBlack2db:; \ + } \ + CHECK_b1; \ + break; \ + case S_V0: \ + CHECK_b1; \ + SETVALUE(b1 - a0); \ + b1 += *pb++; \ + break; \ + case S_VR: \ + CHECK_b1; \ + SETVALUE(b1 - a0 + TabEnt->Param); \ + b1 += *pb++; \ + break; \ + case S_VL: \ + CHECK_b1; \ + SETVALUE(b1 - a0 - TabEnt->Param); \ + b1 -= *--pb; \ + break; \ + case S_Ext: \ + *pa++ = lastx - a0; \ + extension(a0); \ + goto eol2d; \ + case S_EOL: \ + *pa++ = lastx - a0; \ + NeedBits8(4,eof2d); \ + if (GetBits(4)) \ + unexpected("EOL", a0); \ + ClrBits(4); \ + EOLcnt = 1; \ + goto eol2d; \ + default: \ + badMain2d: \ + unexpected("MainTable", a0); \ + goto eol2d; \ + badBlack2d: \ + unexpected("BlackTable", a0); \ + goto eol2d; \ + badWhite2d: \ + unexpected("WhiteTable", a0); \ + goto eol2d; \ + eof2d: \ + prematureEOF(a0); \ + CLEANUP_RUNS(); \ + goto eoflab; \ + } \ + } \ + if (RunLength) { \ + if (RunLength + a0 < lastx) { \ + /* expect a final V0 */ \ + NeedBits8(1,eof2d); \ + if (!GetBits(1)) \ + goto badMain2d; \ + ClrBits(1); \ + } \ + SETVALUE(0); \ + } \ +eol2d: \ + CLEANUP_RUNS(); \ +} while (0) +#endif /* _FAX3_ */ |