ref: 0a9304dad738268b27556717bf83936c15618506
dir: /jbig2.c/
#include <stdint.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include "jbig2.h"
#include "jbig2_priv.h"
static void *
jbig2_default_alloc (Jbig2Allocator *allocator, size_t size)
{
return malloc (size);
}
static void
jbig2_default_free (Jbig2Allocator *allocator, void *p)
{
free (p);
}
static void *
jbig2_default_realloc (Jbig2Allocator *allocator, void *p, size_t size)
{
return realloc (p, size);
}
static Jbig2Allocator jbig2_default_allocator =
{
jbig2_default_alloc,
jbig2_default_free,
jbig2_default_realloc
};
void *
jbig2_alloc (Jbig2Allocator *allocator, size_t size)
{
return allocator->alloc (allocator, size);
}
void
jbig2_free (Jbig2Allocator *allocator, void *p)
{
allocator->free (allocator, p);
}
void *
jbig2_realloc (Jbig2Allocator *allocator, void *p, size_t size)
{
return allocator->realloc (allocator, p, size);
}
int
jbig2_error (Jbig2Ctx *ctx, Jbig2Severity severity, int seg_idx,
const char *fmt, ...)
{
char buf[1024];
va_list ap;
int n;
va_start (ap, fmt);
n = vsnprintf (buf, sizeof(buf), fmt, ap);
va_end (ap);
if (n < 0 || n == sizeof(buf))
strcpy (buf, "jbig2_error: error in generating error string");
return ctx->error_callback (ctx->error_callback_data, buf, severity, seg_idx);
}
Jbig2Ctx *
jbig2_ctx_new (Jbig2Allocator *allocator,
Jbig2Options options,
Jbig2GlobalCtx *global_ctx,
Jbig2ErrorCallback error_callback,
void *error_callback_data)
{
Jbig2Ctx *result;
if (allocator == NULL)
allocator = &jbig2_default_allocator;
result = (Jbig2Ctx *)jbig2_alloc (allocator, sizeof(Jbig2Ctx));
result->allocator = allocator;
result->options = options;
result->global_ctx = (const Jbig2Ctx *)global_ctx;
result->error_callback = error_callback;
result->error_callback_data = error_callback_data;
result->state = (options & JBIG2_OPTIONS_EMBEDDED) ?
JBIG2_FILE_SEQUENTIAL_HEADER :
JBIG2_FILE_HEADER;
result->buf = NULL;
result->sh_list = NULL;
result->n_sh = 0;
result->n_sh_max = 1;
result->sh_ix = 0;
return result;
}
static int32_t
jbig2_get_int32 (uint8_t *buf)
{
return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
}
static Jbig2SegmentHeader *
jbig2_parse_segment_header (Jbig2Ctx *ctx, uint8_t *buf, size_t buf_size,
size_t *p_header_size)
{
Jbig2SegmentHeader *result;
byte rtscarf;
int32_t rtscarf_long;
int referred_to_segment_count;
int referred_to_segment_size;
int pa_size;
int offset;
/* minimum possible size of a jbig2 segment header */
if (buf_size < 11)
return NULL;
result = (Jbig2SegmentHeader *)jbig2_alloc(ctx->allocator,
sizeof(Jbig2SegmentHeader));
/* 7.2.2 */
result->segment_number = jbig2_get_int32 (buf);
/* 7.2.3 */
result->flags = buf[4];
/* 7.2.4 */
rtscarf = buf[5];
if ((rtscarf & 0xe0) == 0xe0)
{
rtscarf_long = jbig2_get_int32(buf + 5);
referred_to_segment_count = rtscarf_long & 0x1fffffff;
offset = 5 + 4 + (referred_to_segment_count + 1) / 8;
}
else
{
referred_to_segment_count = (rtscarf >> 5);
offset = 5 + 1;
}
result->referred_to_segment_count = referred_to_segment_count;
/* 7.2.5 */
/* todo: read referred to segment numbers */
/* For now, we skip them. */
referred_to_segment_size = result->segment_number <= 256 ? 1:
result->segment_number <= 65536 ? 2:
4;
offset += referred_to_segment_count * referred_to_segment_size;
/* 7.2.6 */
pa_size = result->flags & 0x40 ? 4 : 1;
if (offset + pa_size + 4 > buf_size)
{
jbig2_free (ctx->allocator, result);
return NULL;
}
if (result->flags & 0x40) {
result->page_association = jbig2_get_int32(buf + offset);
offset += 4;
} else {
result->page_association = buf[offset++];
}
/* 7.2.7 */
result->data_length = jbig2_get_int32 (buf + offset);
*p_header_size = offset + 4;
return result;
}
void
jbig2_free_segment_header (Jbig2Ctx *ctx, Jbig2SegmentHeader *sh)
{
jbig2_free (ctx->allocator, sh);
}
int
jbig2_write (Jbig2Ctx *ctx, const unsigned char *data, size_t size)
{
const int initial_buf_size = 1024;
if (ctx->buf == NULL)
{
int buf_size = initial_buf_size;
do
buf_size <<= 1;
while (buf_size < size);
ctx->buf = (byte *)jbig2_alloc (ctx->allocator, size);
ctx->buf_size = buf_size;
ctx->buf_rd_ix = 0;
ctx->buf_wr_ix = 0;
}
else if (ctx->buf_wr_ix + size > ctx->buf_size)
{
if (ctx->buf_rd_ix <= (ctx->buf_size >> 1) &&
ctx->buf_wr_ix - ctx->buf_rd_ix + size <= ctx->buf_size)
{
memcpy (ctx->buf, ctx->buf + ctx->buf_rd_ix,
ctx->buf_wr_ix - ctx->buf_rd_ix);
}
else
{
byte *buf;
int buf_size = initial_buf_size;
do
buf_size <<= 1;
while (buf_size < ctx->buf_wr_ix - ctx->buf_rd_ix + size);
buf = (byte *)jbig2_alloc (ctx->allocator, buf_size);
memcpy (buf, ctx->buf + ctx->buf_rd_ix,
ctx->buf_wr_ix - ctx->buf_rd_ix);
jbig2_free (ctx->allocator, ctx->buf);
ctx->buf = buf;
ctx->buf_size = buf_size;
}
ctx->buf_wr_ix -= ctx->buf_rd_ix;
ctx->buf_rd_ix = 0;
}
memcpy (ctx->buf + ctx->buf_wr_ix, data, size);
ctx->buf_wr_ix += size;
/* data has now been added to buffer */
for (;;)
{
const byte jbig2_id_string[8] = { 0x97, 0x4a, 0x42, 0x32, 0x0d, 0x0a, 0x1a, 0x0a };
Jbig2SegmentHeader *sh;
size_t header_size;
int code;
switch (ctx->state)
{
case JBIG2_FILE_HEADER:
if (ctx->buf_wr_ix - ctx->buf_rd_ix < 9)
return 0;
if (memcmp(ctx->buf + ctx->buf_rd_ix, jbig2_id_string, 8))
{
jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1,
"Not a JBIG2 file header");
return -1;
}
ctx->file_header_flags = ctx->buf[ctx->buf_rd_ix + 8];
if (!(ctx->file_header_flags & 2))
{
if (ctx->buf_wr_ix - ctx->buf_rd_ix < 13)
return 0;
ctx->n_pages = jbig2_get_int32(ctx->buf + ctx->buf_rd_ix + 9);
ctx->buf_rd_ix += 13;
}
else
ctx->buf_rd_ix += 9;
if (ctx->file_header_flags & 1)
{
ctx->state = JBIG2_FILE_SEQUENTIAL_HEADER;
}
else
{
ctx->state = JBIG2_FILE_RANDOM_HEADERS;
ctx->n_sh_max = 16;
}
break;
case JBIG2_FILE_SEQUENTIAL_HEADER:
case JBIG2_FILE_RANDOM_HEADERS:
sh = jbig2_parse_segment_header(ctx, ctx->buf + ctx->buf_rd_ix,
ctx->buf_wr_ix - ctx->buf_rd_ix,
&header_size);
if (sh == NULL)
return 0;
ctx->buf_rd_ix += header_size;
if (ctx->sh_list == NULL)
ctx->sh_list = jbig2_alloc(ctx->allocator, ctx->n_sh_max *
sizeof(Jbig2SegmentHeader *));
else if (ctx->n_sh == ctx->n_sh_max)
/* Note to rillian: I usually define a macro to make this
less ungainly. */
ctx->sh_list = (Jbig2SegmentHeader **)jbig2_realloc(ctx->allocator,
ctx->sh_list,
(ctx->n_sh_max <<= 2) * sizeof(Jbig2SegmentHeader *));
ctx->sh_list[ctx->n_sh++] = sh;
if (ctx->state == JBIG2_FILE_RANDOM_HEADERS)
{
if ((sh->flags & 63) == 51) /* end of file */
ctx->state = JBIG2_FILE_RANDOM_BODIES;
}
else
ctx->state = JBIG2_FILE_SEQUENTIAL_BODY;
break;
case JBIG2_FILE_SEQUENTIAL_BODY:
case JBIG2_FILE_RANDOM_BODIES:
sh = ctx->sh_list[ctx->sh_ix];
if (sh->data_length > ctx->buf_wr_ix - ctx->buf_rd_ix)
return 0;
code = jbig2_write_segment(ctx, sh, ctx->buf + ctx->buf_rd_ix);
ctx->buf_rd_ix += sh->data_length;
jbig2_free_segment_header(ctx, sh);
ctx->sh_list[ctx->sh_ix] = NULL;
if (ctx->state == JBIG2_FILE_RANDOM_BODIES)
{
ctx->sh_ix++;
if (ctx->sh_ix == ctx->n_sh)
ctx->state = JBIG2_FILE_EOF;
}
else
{
ctx->n_sh = 0;
ctx->state = JBIG2_FILE_SEQUENTIAL_HEADER;
}
if (code < 0)
{
ctx->state = JBIG2_FILE_EOF;
return code;
}
break;
case JBIG2_FILE_EOF:
if (ctx->buf_rd_ix == ctx->buf_wr_ix)
return 0;
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, -1,
"Garbage beyond end of file");
return -1;
}
}
return 0;
}
/* get_bits */
void
jbig2_ctx_free (Jbig2Ctx *ctx)
{
Jbig2Allocator *ca = ctx->allocator;
int i;
jbig2_free(ca, ctx->buf);
if (ctx->sh_list != NULL)
{
for (i = ctx->sh_ix; i < ctx->n_sh; i++)
jbig2_free_segment_header(ctx, ctx->sh_list[i]);
jbig2_free(ca, ctx->sh_list);
}
jbig2_free(ca, ctx);
}
Jbig2GlobalCtx *jbig2_make_global_ctx (Jbig2Ctx *ctx)
{
return (Jbig2GlobalCtx *)ctx;
}
void jbig2_global_ctx_free(Jbig2GlobalCtx *global_ctx)
{
jbig2_ctx_free((Jbig2Ctx *)global_ctx);
}
int jbig2_write_segment (Jbig2Ctx *ctx, Jbig2SegmentHeader *sh,
const uint8_t *segment_data)
{
jbig2_error(ctx, JBIG2_SEVERITY_INFO, sh->segment_number,
"Segment %d, flags=%x, type=%d, data_length=%d",
sh->segment_number, sh->flags, sh->flags & 63,
sh->data_length);
return 0;
}