jbig2dec

Update of /cvsroot/jbig2dec/jbig2dec
In directory sc8-pr-cvs1:/tmp/cvs-serv637

Modified Files:
	Makefile.am jbig2_segment.c 
Added Files:
	jbig2_metadata.c jbig2_metadata.h 
Log Message:
Add support for ASCII-format comment extension segments. So far it's just
useful for printing out the contents through the error callback; eventually
there should be a public interface of the metadata tables and references from
the associated ctx/page/segments.


--- NEW FILE: jbig2_metadata.c ---
/*
    jbig2dec
    
    Copyright (c) 2001-2002 artofcode LLC.
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    $Id: jbig2_metadata.c,v 1.1 2003/03/05 02:44:43 giles Exp $
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif 
#include "os_types.h"

#include <stdlib.h>
#include <string.h>

#include "jbig2.h"
#include "jbig2_priv.h"
#include "jbig2_metadata.h"

/* metadata key,value list object */
Jbig2Metadata *jbig2_metadata_new(Jbig2Ctx *ctx, Jbig2Encoding encoding)
{
    Jbig2Metadata *md = jbig2_alloc(ctx->allocator, sizeof(Jbig2Metadata));
    
    if (md != NULL) {
        md->encoding = encoding;
        md->entries = 0;
        md->max_entries = 4;
        md->keys = jbig2_alloc(ctx->allocator, md->max_entries*sizeof(char*));
        md->values = jbig2_alloc(ctx->allocator, md->max_entries*sizeof(char*));
        if (md->keys == NULL || md->values == NULL) {
            jbig2_metadata_free(ctx, md);
            md = NULL;
        }
    }
    return md;
}

void jbig2_metadata_free(Jbig2Ctx *ctx, Jbig2Metadata *md)
{
    if (md->keys) jbig2_free(ctx->allocator, md->keys);
    if (md->values) jbig2_free(ctx->allocator, md->values);
    jbig2_free(ctx->allocator, md);
}

static char *jbig2_strndup(Jbig2Ctx *ctx, const char *c, const int len)
{
    char *s = jbig2_alloc(ctx->allocator, len*sizeof(char));
    if (s == NULL) {
        jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1,
            "unable to duplicate comment string");
    } else {
        memcpy(s, c, len);
    }
    return s;
}

int jbig2_metadata_add(Jbig2Ctx *ctx, Jbig2Metadata *md,
                        const char *key, const int key_length,
                        const char *value, const int value_length)
{
    char **keys, **values;
    
    /* grow the array if necessary */
    if (md->entries == md->max_entries) {
        md->max_entries >>= 2;
        keys = jbig2_realloc(ctx->allocator, md->keys, md->max_entries);
        values = jbig2_realloc(ctx->allocator, md->values, md->max_entries);
        if (keys == NULL || values == NULL) {
            jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1,
                "unable to resize metadata structure");
            return -1;
        }
        md->keys = keys;
        md->values = values;
    }
    
    /* copy the passed key,value pair */
    md->keys[md->entries] = jbig2_strndup(ctx, key, key_length);
    md->values[md->entries] = jbig2_strndup(ctx, value, value_length);
    md->entries++;
    
    return 0;
}


/* decode an ascii comment segment 7.4.15.1 */
int jbig2_parse_comment_ascii(Jbig2Ctx *ctx, Jbig2Segment *segment,
                               const uint8_t *segment_data)
{
    char *s = (char *)segment_data + 4;
    char *end = (char *)segment_data + segment->data_length;
    Jbig2Metadata *comment;
    char *key, *value;
    int key_length, value_length;
    
    jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
        "ASCII comment data");
        
    comment = jbig2_metadata_new(ctx, JBIG2_ENCODING_ASCII);
    if (comment == NULL) {
        jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
            "unable to allocate comment structure");
        return -1;
    }
    /* loop over the segment data pulling out the key,value pairs */
    while(*s && s < end) {
        key_length = strlen(s) + 1;
        key = s; s += key_length;
        if (s >= end) goto too_short;
        value_length = strlen(s) + 1;
        value = s; s += value_length;
        if (s >= end) goto too_short;
        jbig2_metadata_add(ctx, comment, key, key_length, value, value_length);
        jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
            "'%s'\t'%s'", key, value);
    }
    
    /* TODO: associate with ctx, page, or referred-to segment(s) */
    segment->result = comment;
    
    return 0;
    
too_short:
    jbig2_metadata_free(ctx, comment);
    return jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
        "unexpected end of comment segment");
}

/* decode a UCS-16 comment segement 7.4.15.2 */
int jbig2_parse_comment_unicode(Jbig2Ctx *ctx, Jbig2Segment *segment,
                               const uint8_t *segment_data)
{
    return jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
        "unhandled unicode comment segment");
}

--- NEW FILE: jbig2_metadata.h ---
/*
    jbig2dec
    
    Copyright (c) 2001-2002 artofcode LLC.
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    $Id: jbig2_metadata.h,v 1.1 2003/03/05 02:44:43 giles Exp $
*/


#ifndef _JBIG2_METADATA_H
#define _JBIG2_METADATA_H

/* metadata from extension segments */

/* these bits should be moved to jbig2.h for public access */
typedef enum {
    JBIG2_ENCODING_ASCII,
    JBIG2_ENCODING_UCS16
} Jbig2Encoding;

typedef struct _Jbig2Metadata Jbig2Metadata;

Jbig2Metadata *jbig2_metadata_new(Jbig2Ctx *ctx, Jbig2Encoding encoding);
void jbig2_metadata_free(Jbig2Ctx *ctx, Jbig2Metadata *md);
int jbig2_metadata_add(Jbig2Ctx *ctx, Jbig2Metadata *md,
                        const char *key, const int key_length,
                        const char *value, const int value_length);

struct _Jbig2Metadata {
    Jbig2Encoding encoding;
    char **keys, **values;
    int entries, max_entries;
};

/* these bits can go to jbig2_priv.h */
int jbig2_parse_comment_ascii(Jbig2Ctx *ctx, Jbig2Segment *segment,
                                const uint8_t *segment_data);
int jbig2_parse_comment_unicode(Jbig2Ctx *ctx, Jbig2Segment *segment,
                               const uint8_t *segment_data);

#endif /* _JBIG2_METADATA_H */

Index: Makefile.am
===================================================================
RCS file: /cvsroot/jbig2dec/jbig2dec/Makefile.am,v
retrieving revision 1.14
retrieving revision 1.15
diff -u -r1.14 -r1.15
--- Makefile.am	4 Mar 2003 16:52:47 -0000	1.14
+++ Makefile.am	5 Mar 2003 02:44:43 -0000	1.15
@@ -16,7 +16,8 @@
 	jbig2.h jbig2_priv.h jbig2_image.h \
 	jbig2_arith.h jbig2_arith_iaid.h jbig2_arith_int.h \
 	jbig2_huffman.h jbig2_hufftab.h jbig2_mmr.h \
-	jbig2_generic.h jbig2_symbol_dict.h
+	jbig2_generic.h jbig2_symbol_dict.h \
+	jbig2_metadata.c jbig2_metadata.h
 
 bin_PROGRAMS = jbig2dec
 #noinst_PROGRAMS = test_huffman test_arith

Index: jbig2_segment.c
===================================================================
RCS file: /cvsroot/jbig2dec/jbig2dec/jbig2_segment.c,v
retrieving revision 1.20
retrieving revision 1.21
diff -u -r1.20 -r1.21
--- jbig2_segment.c	4 Mar 2003 17:29:24 -0000	1.20
+++ jbig2_segment.c	5 Mar 2003 02:44:43 -0000	1.21
@@ -136,6 +136,39 @@
   info->flags = segment_data[16];
 }
 
+int jbig2_parse_extension_segment(Jbig2Ctx *ctx, Jbig2Segment *segment,
+                            const uint8_t *segment_data)
+{
+    uint32_t type;
+    bool reserved, dependent, necessary;
+
+    type = jbig2_get_int32(segment_data);
+    
+    reserved = type & 0x20000000;
+    dependent = type & 0x40000000;
+    necessary = type & 0x80000000;
+
+    if (necessary && !reserved) {
+        jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
+            "extension segment is marked 'necessary' but not 'reservered' contrary to spec");
+    }
+    
+    switch (type) {
+        case 0x20000000: return jbig2_parse_comment_ascii(ctx, segment, segment_data);
+        case 0x20000002: return jbig2_parse_comment_unicode(ctx, segment, segment_data);
+        default:
+            if (necessary) {
+                return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number,
+                    "unhandled necessary extension segment type 0x%08x", type);
+            } else {
+                return jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
+                    "unhandled extension segment");
+            }
+    }
+    
+    return 0;
+}
+
 int jbig2_parse_segment (Jbig2Ctx *ctx, Jbig2Segment *segment,
 			 const uint8_t *segment_data)
 {
@@ -198,8 +231,7 @@
       return jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
         "unhandled table segment");
     case 62:
-      return jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
-        "unhandled extension segment");
+      return jbig2_parse_extension_segment(ctx, segment, segment_data);
     default:
         jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
           "unknown segment type %d", segment->flags & 63);