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- #include "tiffiop.h"
- #ifdef PACKBITS_SUPPORT
- #include <stdio.h>
- static int
- PackBitsPreEncode(TIFF* tif, uint16 s)
- {
- (void) s;
- if (!(tif->tif_data = (uint8*)_TIFFmalloc(sizeof(tmsize_t))))
- return (0);
-
- if (isTiled(tif))
- *(tmsize_t*)tif->tif_data = TIFFTileRowSize(tif);
- else
- *(tmsize_t*)tif->tif_data = TIFFScanlineSize(tif);
- return (1);
- }
- static int
- PackBitsPostEncode(TIFF* tif)
- {
- if (tif->tif_data)
- _TIFFfree(tif->tif_data);
- return (1);
- }
- static int
- PackBitsEncode(TIFF* tif, uint8* buf, tmsize_t cc, uint16 s)
- {
- unsigned char* bp = (unsigned char*) buf;
- uint8* op;
- uint8* ep;
- uint8* lastliteral;
- long n, slop;
- int b;
- enum { BASE, LITERAL, RUN, LITERAL_RUN } state;
- (void) s;
- op = tif->tif_rawcp;
- ep = tif->tif_rawdata + tif->tif_rawdatasize;
- state = BASE;
- lastliteral = 0;
- while (cc > 0) {
-
- b = *bp++, cc--, n = 1;
- for (; cc > 0 && b == *bp; cc--, bp++)
- n++;
- again:
- if (op + 2 >= ep) {
-
- if (state == LITERAL || state == LITERAL_RUN) {
- slop = (long)(op - lastliteral);
- tif->tif_rawcc += (tmsize_t)(lastliteral - tif->tif_rawcp);
- if (!TIFFFlushData1(tif))
- return (-1);
- op = tif->tif_rawcp;
- while (slop-- > 0)
- *op++ = *lastliteral++;
- lastliteral = tif->tif_rawcp;
- } else {
- tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
- if (!TIFFFlushData1(tif))
- return (-1);
- op = tif->tif_rawcp;
- }
- }
- switch (state) {
- case BASE:
- if (n > 1) {
- state = RUN;
- if (n > 128) {
- *op++ = (uint8) -127;
- *op++ = (uint8) b;
- n -= 128;
- goto again;
- }
- *op++ = (uint8)(-(n-1));
- *op++ = (uint8) b;
- } else {
- lastliteral = op;
- *op++ = 0;
- *op++ = (uint8) b;
- state = LITERAL;
- }
- break;
- case LITERAL:
- if (n > 1) {
- state = LITERAL_RUN;
- if (n > 128) {
- *op++ = (uint8) -127;
- *op++ = (uint8) b;
- n -= 128;
- goto again;
- }
- *op++ = (uint8)(-(n-1));
- *op++ = (uint8) b;
- } else {
- if (++(*lastliteral) == 127)
- state = BASE;
- *op++ = (uint8) b;
- }
- break;
- case RUN:
- if (n > 1) {
- if (n > 128) {
- *op++ = (uint8) -127;
- *op++ = (uint8) b;
- n -= 128;
- goto again;
- }
- *op++ = (uint8)(-(n-1));
- *op++ = (uint8) b;
- } else {
- lastliteral = op;
- *op++ = 0;
- *op++ = (uint8) b;
- state = LITERAL;
- }
- break;
- case LITERAL_RUN:
-
- if (n == 1 && op[-2] == (uint8) -1 &&
- *lastliteral < 126) {
- state = (((*lastliteral) += 2) == 127 ?
- BASE : LITERAL);
- op[-2] = op[-1];
- } else
- state = RUN;
- goto again;
- }
- }
- tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
- tif->tif_rawcp = op;
- return (1);
- }
- static int
- PackBitsEncodeChunk(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
- {
- tmsize_t rowsize = *(tmsize_t*)tif->tif_data;
- while (cc > 0) {
- tmsize_t chunk = rowsize;
-
- if( cc < chunk )
- chunk = cc;
- if (PackBitsEncode(tif, bp, chunk, s) < 0)
- return (-1);
- bp += chunk;
- cc -= chunk;
- }
- return (1);
- }
- static int
- PackBitsDecode(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
- {
- static const char module[] = "PackBitsDecode";
- char *bp;
- tmsize_t cc;
- long n;
- int b;
- (void) s;
- bp = (char*) tif->tif_rawcp;
- cc = tif->tif_rawcc;
- while (cc > 0 && occ > 0) {
- n = (long) *bp++, cc--;
-
- if (n >= 128)
- n -= 256;
- if (n < 0) {
- if (n == -128)
- continue;
- n = -n + 1;
- if( occ < (tmsize_t)n )
- {
- TIFFWarningExt(tif->tif_clientdata, module,
- "Discarding %lu bytes to avoid buffer overrun",
- (unsigned long) ((tmsize_t)n - occ));
- n = (long)occ;
- }
- occ -= n;
- b = *bp++, cc--;
- while (n-- > 0)
- *op++ = (uint8) b;
- } else {
- if (occ < (tmsize_t)(n + 1))
- {
- TIFFWarningExt(tif->tif_clientdata, module,
- "Discarding %lu bytes to avoid buffer overrun",
- (unsigned long) ((tmsize_t)n - occ + 1));
- n = (long)occ - 1;
- }
- if (cc < (tmsize_t) (n+1))
- {
- TIFFWarningExt(tif->tif_clientdata, module,
- "Terminating PackBitsDecode due to lack of data.");
- break;
- }
- _TIFFmemcpy(op, bp, ++n);
- op += n; occ -= n;
- bp += n; cc -= n;
- }
- }
- tif->tif_rawcp = (uint8*) bp;
- tif->tif_rawcc = cc;
- if (occ > 0) {
- TIFFErrorExt(tif->tif_clientdata, module,
- "Not enough data for scanline %lu",
- (unsigned long) tif->tif_row);
- return (0);
- }
- return (1);
- }
- int
- TIFFInitPackBits(TIFF* tif, int scheme)
- {
- (void) scheme;
- tif->tif_decoderow = PackBitsDecode;
- tif->tif_decodestrip = PackBitsDecode;
- tif->tif_decodetile = PackBitsDecode;
- tif->tif_preencode = PackBitsPreEncode;
- tif->tif_postencode = PackBitsPostEncode;
- tif->tif_encoderow = PackBitsEncode;
- tif->tif_encodestrip = PackBitsEncodeChunk;
- tif->tif_encodetile = PackBitsEncodeChunk;
- return (1);
- }
- #endif
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