ref: 4369688dfbf2235ed466f38af4ddd11ab781ceaf
parent: 9cd558cd34c857cb3fc15167a754d1619ecc57d3
author: giles <giles@ded80894-8fb9-0310-811b-c03f3676ab4d>
date: Sun Jun 10 02:50:58 EDT 2001
renamed jbig2.* to the more eponymous jbig2dec.* git-svn-id: http://svn.ghostscript.com/jbig2dec/trunk@19 ded80894-8fb9-0310-811b-c03f3676ab4d
--- a/jbig2.c
+++ /dev/null
@@ -1,242 +1,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "jbig2.h"
-
-typedef struct _Jbig2SegmentHeader Jbig2SegmentHeader;
-typedef struct _Jbig2SymbolDictionary Jbig2SymbolDictionary;
-
-struct _Jbig2Ctx {- FILE *f;
- int offset;
-
- byte flags;
- int32 n_pages;
-};
-
-struct _Jbig2SegmentHeader {- int32 segment_number;
- byte flags;
- int referred_to_segment_count;
- int32 page_association;
- int data_length;
-};
-
-struct _Jbig2SymbolDictionary {- int16 flags;
- int8 SDAT_flags[8];
- byte SDRAT_flags[4];
- int32 SDNUMEXSYMS;
- int32 SDNUMNEWSYMS;
-};
-
-int32
-get_bytes (Jbig2Ctx *ctx, byte *buf, int size, int off)
-{- fseek (ctx->f, off, SEEK_SET);
- return fread (buf, 1, size, ctx->f);
-}
-
-int16
-get_int16 (Jbig2Ctx *ctx, int off)
-{- byte buf[2];
-
- get_bytes (ctx, buf, 2, off);
- return (buf[0] << 8) | buf[1];
-}
-
-int32
-get_int32 (Jbig2Ctx *ctx, int off)
-{- byte buf[4];
-
- get_bytes (ctx, buf, 4, off);
- return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
-}
-
-static Jbig2Ctx *
-jbig2_open (FILE *f)
-{- byte buf[9];
- const byte header[8] = { 0x97, 0x4a, 0x42, 0x32, 0x0d, 0x0a, 0x1a, 0x0a };- Jbig2Ctx *ctx;
-
- /* Annex D.4 */
- ctx = (Jbig2Ctx *)malloc (sizeof(Jbig2Ctx));
- ctx->f = f;
- get_bytes (ctx, buf, 9, 0);
- if (memcmp (buf, header, 8))
- {- printf ("not a JBIG2 file\n");- return NULL;
- }
- ctx->flags = buf[8];
- if (ctx->flags & 2)
- {- ctx->offset = 9;
- }
- else
- {- ctx->offset = 13;
- ctx->n_pages = get_int32 (ctx, 9);
- }
- return ctx;
-}
-
-static Jbig2SegmentHeader *
-jbig2_read_segment_header (Jbig2Ctx *ctx)
-{- Jbig2SegmentHeader *result = (Jbig2SegmentHeader *)malloc(sizeof(Jbig2SegmentHeader));
- int32 offset = ctx->offset;
- byte rtscarf;
- int referred_to_segment_count;
- byte spa;
-
- /* 7.2.2 */
- result->segment_number = get_int32 (ctx, offset);
-
- /* 7.2.3 */
- get_bytes (ctx, &result->flags, 1, offset + 4);
-
- /* 7.2.4 */
- get_bytes (ctx, &rtscarf, 1, offset + 5);
- if ((rtscarf & 0xe0) == 0xe0)
- {- printf ("long form of rtscarf, can't handle!\n");- }
- else
- {- referred_to_segment_count = (rtscarf >> 5);
- offset += 6 + referred_to_segment_count;
- }
- result->referred_to_segment_count = referred_to_segment_count;
- /* todo: read referred to segment numbers */
-
- /* 7.2.6 */
- get_bytes (ctx, &spa, 1, offset);
- if (result->flags & 64)
- {- printf ("long form of spa, can't handle!\n");- }
- result->page_association = spa;
-
- /* 7.2.7 */
- result->data_length = get_int32 (ctx, offset + 1);
- ctx->offset = offset + 5;
-
- return result;
-}
-
-static Jbig2SymbolDictionary *
-jbig2_read_symbol_dictionary (Jbig2Ctx *ctx)
-{- Jbig2SymbolDictionary *result = (Jbig2SymbolDictionary *)malloc(sizeof(Jbig2SymbolDictionary));
- int32 offset = ctx->offset;
- bool SDHUFF, SDREFAGG, SDRTEMPLATE;
- int sdat_bytes;
-
- /* 7.4.2.1.1 */
- result->flags = get_int16 (ctx, offset);
- offset += 2;
-
- SDHUFF = result->flags & 1;
- SDREFAGG = (result->flags >> 1) & 1;
- SDRTEMPLATE = (result->flags >> 12) & 1;
-
- /* 7.4.2.1.2 */
- if (!SDHUFF)
- {- int SDTEMPLATE = (result->flags >> 10) & 3;
- if (SDTEMPLATE == 0)
- sdat_bytes = 8;
- else
- sdat_bytes = 2;
- }
- else
- sdat_bytes = 0;
- get_bytes (ctx, result->SDAT_flags, sdat_bytes, offset);
- memset (&result->SDAT_flags + sdat_bytes, 0, 8 - sdat_bytes);
- offset += sdat_bytes;
-
- /* 7.4.2.1.3 */
- if (SDREFAGG && !SDRTEMPLATE)
- {- get_bytes (ctx, result->SDRAT_flags, 4, offset);
- offset += 4;
- }
-
- /* 7.4.2.1.4 */
- result->SDNUMEXSYMS = get_int32 (ctx, offset);
-
- /* 7.4.2.1.5 */
- result->SDNUMNEWSYMS = get_int32 (ctx, offset + 4);
- offset += 8;
-
- return result;
-}
-
-static void
-dump_symbol_dictionary (Jbig2SymbolDictionary *sd)
-{- printf ("segment type = symbol dictionary, flags = %04x, numexsyms = %d, numnewsyms = %d\n",- sd->flags, sd->SDNUMEXSYMS, sd->SDNUMNEWSYMS);
-}
-
-static bool
-dump_segment (Jbig2Ctx *ctx)
-{- Jbig2SegmentHeader *sh;
- int32 offset;
- Jbig2SymbolDictionary *sd;
-
- sh = jbig2_read_segment_header (ctx);
- offset = ctx->offset;
- printf ("segment number = %d, flags = %02x, page %d, %d bytes\n",- sh->segment_number, sh->flags, sh->page_association, sh->data_length);
- switch (sh->flags & 63)
- {- case 0:
- sd = jbig2_read_symbol_dictionary (ctx);
- dump_symbol_dictionary (sd);
- break;
- case 51:
- printf ("segment type = end of file\n");- return TRUE;
- }
- ctx->offset = offset + sh->data_length;
- return FALSE;
-}
-
-static void
-dump_jbig2 (FILE *f)
-{- Jbig2Ctx *ctx;
- bool last;
-
- ctx = jbig2_open (f);
- printf ("Number of pages = %d\n", ctx->n_pages);- for (;;)
- {- last = dump_segment (ctx);
- if (last)
- break;
- }
-}
-
-int
-main (int argc, char **argv)
-{- FILE *f;
-
- if (argc < 2)
- return -1;
- f = fopen (argv[1], "rb");
- if (f == NULL)
- return -1;
-
- dump_jbig2 (f);
- fclose (f);
- return 0;
-}
--- a/jbig2.h
+++ /dev/null
@@ -1,31 +1,0 @@
-typedef unsigned char byte;
-typedef int bool;
-typedef unsigned int uint32;
-typedef int int32;
-typedef short int16;
-typedef signed char int8;
-
-#define TRUE 1
-#define FALSE 0
-
-typedef struct _Jbig2Ctx Jbig2Ctx;
-
-int32
-get_bytes (Jbig2Ctx *ctx, byte *buf, int size, int off);
-
-int16
-get_int16 (Jbig2Ctx *ctx, int off);
-
-int32
-get_int32 (Jbig2Ctx *ctx, int off);
-
-/* The word stream design is a compromise between simplicity and
- trying to amortize the number of method calls. Each ::get_next_word
- invocation pulls 4 bytes from the stream, packed big-endian into a
- 32 bit word. The offset argument is provided as a convenience. It
- begins at 0 and increments by 4 for each successive invocation. */
-typedef struct _Jbig2WordStream Jbig2WordStream;
-
-struct _Jbig2WordStream {- int32 (*get_next_word) (Jbig2WordStream *self, int offset);
-};
--- /dev/null
+++ b/jbig2dec.c
@@ -1,0 +1,242 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "jbig2.h"
+
+typedef struct _Jbig2SegmentHeader Jbig2SegmentHeader;
+typedef struct _Jbig2SymbolDictionary Jbig2SymbolDictionary;
+
+struct _Jbig2Ctx {+ FILE *f;
+ int offset;
+
+ byte flags;
+ int32 n_pages;
+};
+
+struct _Jbig2SegmentHeader {+ int32 segment_number;
+ byte flags;
+ int referred_to_segment_count;
+ int32 page_association;
+ int data_length;
+};
+
+struct _Jbig2SymbolDictionary {+ int16 flags;
+ int8 SDAT_flags[8];
+ byte SDRAT_flags[4];
+ int32 SDNUMEXSYMS;
+ int32 SDNUMNEWSYMS;
+};
+
+int32
+get_bytes (Jbig2Ctx *ctx, byte *buf, int size, int off)
+{+ fseek (ctx->f, off, SEEK_SET);
+ return fread (buf, 1, size, ctx->f);
+}
+
+int16
+get_int16 (Jbig2Ctx *ctx, int off)
+{+ byte buf[2];
+
+ get_bytes (ctx, buf, 2, off);
+ return (buf[0] << 8) | buf[1];
+}
+
+int32
+get_int32 (Jbig2Ctx *ctx, int off)
+{+ byte buf[4];
+
+ get_bytes (ctx, buf, 4, off);
+ return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+}
+
+static Jbig2Ctx *
+jbig2_open (FILE *f)
+{+ byte buf[9];
+ const byte header[8] = { 0x97, 0x4a, 0x42, 0x32, 0x0d, 0x0a, 0x1a, 0x0a };+ Jbig2Ctx *ctx;
+
+ /* Annex D.4 */
+ ctx = (Jbig2Ctx *)malloc (sizeof(Jbig2Ctx));
+ ctx->f = f;
+ get_bytes (ctx, buf, 9, 0);
+ if (memcmp (buf, header, 8))
+ {+ printf ("not a JBIG2 file\n");+ return NULL;
+ }
+ ctx->flags = buf[8];
+ if (ctx->flags & 2)
+ {+ ctx->offset = 9;
+ }
+ else
+ {+ ctx->offset = 13;
+ ctx->n_pages = get_int32 (ctx, 9);
+ }
+ return ctx;
+}
+
+static Jbig2SegmentHeader *
+jbig2_read_segment_header (Jbig2Ctx *ctx)
+{+ Jbig2SegmentHeader *result = (Jbig2SegmentHeader *)malloc(sizeof(Jbig2SegmentHeader));
+ int32 offset = ctx->offset;
+ byte rtscarf;
+ int referred_to_segment_count;
+ byte spa;
+
+ /* 7.2.2 */
+ result->segment_number = get_int32 (ctx, offset);
+
+ /* 7.2.3 */
+ get_bytes (ctx, &result->flags, 1, offset + 4);
+
+ /* 7.2.4 */
+ get_bytes (ctx, &rtscarf, 1, offset + 5);
+ if ((rtscarf & 0xe0) == 0xe0)
+ {+ printf ("long form of rtscarf, can't handle!\n");+ }
+ else
+ {+ referred_to_segment_count = (rtscarf >> 5);
+ offset += 6 + referred_to_segment_count;
+ }
+ result->referred_to_segment_count = referred_to_segment_count;
+ /* todo: read referred to segment numbers */
+
+ /* 7.2.6 */
+ get_bytes (ctx, &spa, 1, offset);
+ if (result->flags & 64)
+ {+ printf ("long form of spa, can't handle!\n");+ }
+ result->page_association = spa;
+
+ /* 7.2.7 */
+ result->data_length = get_int32 (ctx, offset + 1);
+ ctx->offset = offset + 5;
+
+ return result;
+}
+
+static Jbig2SymbolDictionary *
+jbig2_read_symbol_dictionary (Jbig2Ctx *ctx)
+{+ Jbig2SymbolDictionary *result = (Jbig2SymbolDictionary *)malloc(sizeof(Jbig2SymbolDictionary));
+ int32 offset = ctx->offset;
+ bool SDHUFF, SDREFAGG, SDRTEMPLATE;
+ int sdat_bytes;
+
+ /* 7.4.2.1.1 */
+ result->flags = get_int16 (ctx, offset);
+ offset += 2;
+
+ SDHUFF = result->flags & 1;
+ SDREFAGG = (result->flags >> 1) & 1;
+ SDRTEMPLATE = (result->flags >> 12) & 1;
+
+ /* 7.4.2.1.2 */
+ if (!SDHUFF)
+ {+ int SDTEMPLATE = (result->flags >> 10) & 3;
+ if (SDTEMPLATE == 0)
+ sdat_bytes = 8;
+ else
+ sdat_bytes = 2;
+ }
+ else
+ sdat_bytes = 0;
+ get_bytes (ctx, result->SDAT_flags, sdat_bytes, offset);
+ memset (&result->SDAT_flags + sdat_bytes, 0, 8 - sdat_bytes);
+ offset += sdat_bytes;
+
+ /* 7.4.2.1.3 */
+ if (SDREFAGG && !SDRTEMPLATE)
+ {+ get_bytes (ctx, result->SDRAT_flags, 4, offset);
+ offset += 4;
+ }
+
+ /* 7.4.2.1.4 */
+ result->SDNUMEXSYMS = get_int32 (ctx, offset);
+
+ /* 7.4.2.1.5 */
+ result->SDNUMNEWSYMS = get_int32 (ctx, offset + 4);
+ offset += 8;
+
+ return result;
+}
+
+static void
+dump_symbol_dictionary (Jbig2SymbolDictionary *sd)
+{+ printf ("segment type = symbol dictionary, flags = %04x, numexsyms = %d, numnewsyms = %d\n",+ sd->flags, sd->SDNUMEXSYMS, sd->SDNUMNEWSYMS);
+}
+
+static bool
+dump_segment (Jbig2Ctx *ctx)
+{+ Jbig2SegmentHeader *sh;
+ int32 offset;
+ Jbig2SymbolDictionary *sd;
+
+ sh = jbig2_read_segment_header (ctx);
+ offset = ctx->offset;
+ printf ("segment number = %d, flags = %02x, page %d, %d bytes\n",+ sh->segment_number, sh->flags, sh->page_association, sh->data_length);
+ switch (sh->flags & 63)
+ {+ case 0:
+ sd = jbig2_read_symbol_dictionary (ctx);
+ dump_symbol_dictionary (sd);
+ break;
+ case 51:
+ printf ("segment type = end of file\n");+ return TRUE;
+ }
+ ctx->offset = offset + sh->data_length;
+ return FALSE;
+}
+
+static void
+dump_jbig2 (FILE *f)
+{+ Jbig2Ctx *ctx;
+ bool last;
+
+ ctx = jbig2_open (f);
+ printf ("Number of pages = %d\n", ctx->n_pages);+ for (;;)
+ {+ last = dump_segment (ctx);
+ if (last)
+ break;
+ }
+}
+
+int
+main (int argc, char **argv)
+{+ FILE *f;
+
+ if (argc < 2)
+ return -1;
+ f = fopen (argv[1], "rb");
+ if (f == NULL)
+ return -1;
+
+ dump_jbig2 (f);
+ fclose (f);
+ return 0;
+}
--- /dev/null
+++ b/jbig2dec.h
@@ -1,0 +1,31 @@
+typedef unsigned char byte;
+typedef int bool;
+typedef unsigned int uint32;
+typedef int int32;
+typedef short int16;
+typedef signed char int8;
+
+#define TRUE 1
+#define FALSE 0
+
+typedef struct _Jbig2Ctx Jbig2Ctx;
+
+int32
+get_bytes (Jbig2Ctx *ctx, byte *buf, int size, int off);
+
+int16
+get_int16 (Jbig2Ctx *ctx, int off);
+
+int32
+get_int32 (Jbig2Ctx *ctx, int off);
+
+/* The word stream design is a compromise between simplicity and
+ trying to amortize the number of method calls. Each ::get_next_word
+ invocation pulls 4 bytes from the stream, packed big-endian into a
+ 32 bit word. The offset argument is provided as a convenience. It
+ begins at 0 and increments by 4 for each successive invocation. */
+typedef struct _Jbig2WordStream Jbig2WordStream;
+
+struct _Jbig2WordStream {+ int32 (*get_next_word) (Jbig2WordStream *self, int offset);
+};