shithub: jbig2

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Adds some support for "embedded" format, with separate global and page
streams. Also fixes some minor bugs.


git-svn-id: http://svn.ghostscript.com/jbig2dec/trunk@37 ded80894-8fb9-0310-811b-c03f3676ab4d

--- a/jbig2dec.c

+++ b/jbig2dec.c

@@ -8,7 +8,7 @@

     the Free Software Foundation; either version 2 of the License, or

     (at your option) any later version.

-    $Id: jbig2dec.c,v 1.9 2001/06/26 00:30:00 giles Exp $

+    $Id: jbig2dec.c,v 1.10 2002/02/09 22:31:53 raph Exp $

 */

 #include <stdio.h>

@@ -25,6 +25,7 @@

 struct _Jbig2Ctx {

   FILE *f;

   int offset;

+  int eof;

   int32 n_pages;

   byte flags;

@@ -63,8 +64,13 @@

 int32

 get_bytes (Jbig2Ctx *ctx, byte *buf, int size, int off)

 {

+  int n_bytes;

+

   fseek (ctx->f, off, SEEK_SET);

-  return fread (buf, 1, size, ctx->f);

+  n_bytes = fread (buf, 1, size, ctx->f);

+  if (n_bytes < size)

+    ctx->eof = TRUE;

+  return n_bytes;

 }

 int16

@@ -104,6 +110,7 @@

   /* Annex D.4 */

   ctx = (Jbig2Ctx *)malloc (sizeof(Jbig2Ctx));

   ctx->f = f;

+  ctx->eof = FALSE;

   get_bytes (ctx, buf, 9, 0);

   if (memcmp (buf, header, 8))

     {

@@ -120,9 +127,9 @@

     {

       ctx->offset = 13;

       ctx->n_pages = get_int32 (ctx, 9);

-	}

-  

-  if(!ctx->flags & JBIG2_FILE_FLAGS_SEQUENTIAL_ACCESS) {

+    }

+

+  if(!(ctx->flags & JBIG2_FILE_FLAGS_SEQUENTIAL_ACCESS)) {

 	printf("warning: random access header organization.\n");

 	printf("we don't handle that yet.\n");

 	free(ctx);

@@ -132,6 +139,18 @@

   return ctx;

 }

+static Jbig2Ctx *

+jbig2_open_embedded (FILE *f_globals, FILE *f_page)

+{

+  Jbig2Ctx *ctx;

+

+  ctx = (Jbig2Ctx *)malloc (sizeof(Jbig2Ctx));

+  ctx->f = f_globals;

+  ctx->eof = 0;

+  ctx->offset = 0;

+  return ctx;

+}

+

 static Jbig2SegmentHeader *

 jbig2_read_segment_header (Jbig2Ctx *ctx)

 {

@@ -144,6 +163,12 @@

   /* 7.2.2 */

   result->segment_number = get_int32 (ctx, offset);

+  if (ctx->eof)

+    {

+      free (result);

+      return NULL;

+    }

+

   /* 7.2.3 */

   get_bytes (ctx, &result->flags, 1, offset + 4);

@@ -208,10 +233,10 @@

   /* FIXME: there are quite a few of these conditions to check */

   /* maybe #ifdef CONFORMANCE and a separate routine */

-  if(!SDHUFF && !(result->flags & 0x0006)) {

+  if(!SDHUFF && (result->flags & 0x0006)) {

 	printf("warning: SDHUFF is zero, but contrary to spec SDHUFFDH is not.\n");

   }

-  if(!SDHUFF && !(result->flags & 0x0018)) {

+  if(!SDHUFF && (result->flags & 0x0018)) {

 	printf("warning: SDHUFF is zero, but contrary to spec SDHUFFDW is not.\n");

   }

@@ -324,6 +349,8 @@

   Jbig2PageInfo	*page_info;

   sh = jbig2_read_segment_header (ctx);

+  if (sh == NULL)

+    return TRUE;

   printf("segment %d (%d bytes)\t", sh->segment_number, sh->data_length);

   switch (sh->flags & 63)

@@ -407,12 +434,10 @@

 }

 static void

-dump_jbig2 (FILE *f)

+dump_jbig2 (Jbig2Ctx *ctx)

 {

-  Jbig2Ctx *ctx;

   bool last;

-  ctx = jbig2_open (f);

   if (!ctx) return;

   printf ("Number of pages = %d\n", ctx->n_pages);

@@ -424,18 +449,64 @@

     }

 }

+static int

+usage (void)

+{

+  fprintf (stderr, "Usage: jbig2dec file.jbig2\n");

+  return 1;

+}

+

 int

 main (int argc, char **argv)

 {

-  FILE *f;

+  FILE *f = NULL, *f_page = NULL;

+  Jbig2Ctx *ctx;

   if (argc < 2)

-    return -1;

-  f = fopen (argv[1], "rb");

-  if (f == NULL)

-    return -1;

+    return usage ();

-  dump_jbig2 (f);

-  fclose (f);

+  if (argc == 2)

+    {

+      char *fn = argv[1];

+

+      f = fopen (fn, "rb");

+      if (f == NULL)

+	{

+	  fprintf (stderr, "error opening %s\n", fn);

+	  return 1;

+	}

+      ctx = jbig2_open (f);

+      if (ctx != NULL)

+	dump_jbig2 (ctx);

+      fclose (f);

+    }

+  else if (argc == 3)

+    {

+      char *fn = argv[1], *fn_page = argv[2];

+

+      f = fopen (fn, "rb");

+      if (f == NULL)

+	{

+	  fprintf (stderr, "error opening %s\n", fn);

+	  return 1;

+	}

+

+      f_page = fopen (fn_page, "rb");

+      if (f_page == NULL)

+	{

+	  fprintf (stderr, "error opening %s\n", fn_page);

+	  return 1;

+	}

+      ctx = jbig2_open_embedded (f, f_page);

+      if (ctx != NULL)

+	dump_jbig2 (ctx);

+      ctx->f = f_page;

+      ctx->offset = 0;

+      ctx->eof = FALSE;

+      dump_jbig2 (ctx);

+      fclose (f);

+      fclose (f_page);

+    }

+

   return 0;

 }