ref: 4c517739877594997a67dfd383c80c8d3dacc96b
dir: /jbig2_page.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_page.c,v 1.7 2002/07/04 13:34:29 giles Exp $
*/
#include <stdlib.h>
#include "jbig2.h"
#include "jbig2_priv.h"
#ifdef OUTPUT_PBM
#include "jbig2_image.h"
#endif
/* dump the page struct info */
static void
dump_page_info(Jbig2Ctx *ctx, Jbig2Segment *segment, Jbig2Page *page)
{
if (page->x_resolution == 0) {
jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
"page %d image is %dx%d (unknown res)", page->number,
page->width, page->height);
} else if (page->x_resolution == page->y_resolution) {
jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
"page %d image is %dx%d (%d ppm)", page->number,
page->width, page->height,
page->x_resolution);
} else {
jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
"page %d image is %dx%d (%dx%d ppm)", page->number,
page->width, page->height,
page->x_resolution, page->y_resolution);
}
if (page->striped) {
jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
"\tmaximum stripe size: %d", page->stripe_size);
}
}
/**
* jbig2_read_page_info: parse page info segment
*
* parse the page info segment data and fill out a corresponding
* Jbig2Page struct is returned, including allocating an image
* buffer for the page (or the first stripe)
**/
int
jbig2_read_page_info (Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data)
{
Jbig2Page *page;
/* a new page info segment implies the previous page is finished */
page = &(ctx->pages[ctx->current_page]);
if ((page->number != 0) &&
((page->state == JBIG2_PAGE_NEW) || (page->state == JBIG2_PAGE_FREE))) {
page->state = JBIG2_PAGE_COMPLETE;
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
"unexpected page info segment, marking previous page finished");
}
/* find a free page */
{
int index, j;
index = ctx->current_page;
while (ctx->pages[index].state != JBIG2_PAGE_FREE) {
index++;
if (index >= ctx->max_page_index) { // FIXME: should also look for freed pages?
/* grow the list */
jbig2_realloc(ctx->allocator, ctx->pages, (ctx->max_page_index <<= 2) * sizeof(Jbig2Page));
for (j=index; j < ctx->max_page_index; j++) {
/* note to raph: and look, it gets worse! */
ctx->pages[j].state = JBIG2_PAGE_FREE;
ctx->pages[j].number = 0;
ctx->pages[j].image = NULL;
}
}
}
page = &(ctx->pages[index]);
ctx->current_page = index;
page->state = JBIG2_PAGE_NEW;
page->number = segment->page_association;
}
// FIXME: would be nice if we tried to work around this
if (segment->data_length < 19) {
return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number,
"segment too short");
}
/* 7.4.8.x */
page->width = jbig2_get_int32(segment_data);
page->height = jbig2_get_int32(segment_data + 4);
page->x_resolution = jbig2_get_int32(segment_data + 8);
page->y_resolution = jbig2_get_int32(segment_data + 12);
page->flags = segment_data[16];
/* 7.4.8.6 */
{
int16_t striping = jbig2_get_int16(segment_data +17);
if (striping & 0x8000) {
page->striped = TRUE;
page->stripe_size = striping & 0x7FFF;
} else {
page->striped = FALSE;
page->stripe_size = 0; /* would page->height be better? */
}
}
if (page->height == 0xFFFFFFFF && page->striped == FALSE) {
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
"height is unspecified but page is not markes as striped");
page->striped = TRUE;
}
if (segment->data_length > 19) {
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
"extra data in segment");
}
dump_page_info(ctx, segment, page);
/* allocate an approprate page image buffer */
/* 7.4.8.2 */
if (page->height == 0xFFFFFFFF) {
page->image = jbig2_image_new(ctx, page->width, page->stripe_size);
} else {
page->image = jbig2_image_new(ctx, page->width, page->height);
}
if (page->image == NULL) {
jbig2_free(ctx->allocator, page);
return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number,
"failed to allocate buffer for page image");
} else {
jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, segment->number,
"allocated %dx%d page image (%d bytes)",
page->image->width, page->image->height,
page->image->stride*page->image->height);
}
return 0;
}
/**
* jbig2_complete_page: complete a page image
*
* called upon seeing an 'end of page' segment, this routine
* marks a page as completed. final compositing and output
* of the page image will also happen from here (NYI)
**/
int
jbig2_complete_page (Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data)
{
uint32_t page_number = ctx->pages[ctx->current_page].number;
if (segment->page_association != page_number) {
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
"end of page marker for page %d doesn't match current page number %d",
segment->page_association, page_number);
}
ctx->pages[ctx->current_page].state = JBIG2_PAGE_COMPLETE;
jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number,
"end of page %d", page_number);
#ifdef OUTPUT_PBM
jbig2_image_write_pbm(ctx->pages[ctx->current_page].image, stdout);
#endif
return 0;
}
/**
* jbig2_get_page: return the next available page image buffer
*
* the client can call this at any time to check if any pages
* have been decoded. If so, it returns the first available
* one. The client should then call jbig2_release_page() when
* it no longer needs to refer to the image buffer.
*
* since this is a public routine for the library clients, we
* return an image structure pointer, even though the function
* name refers to a page; the page structure is private.
**/
Jbig2Image *jbig2_get_page(Jbig2Ctx *ctx)
{
int index;
/* search for a completed page */
for (index=0; index < ctx->max_page_index; index++) {
if (ctx->pages[index].state == JBIG2_PAGE_COMPLETE) {
ctx->pages[index].state = JBIG2_PAGE_RETURNED;
jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, -1,
"page %d returned to the client", ctx->pages[index].number);
return ctx->pages[index].image;
}
}
/* no pages available */
return NULL;
}
/**
* jbig2_release_page: tell the library a page can be freed
**/
int jbig2_release_page(Jbig2Ctx *ctx, Jbig2Image *image)
{
int index;
/* find the matching page struct and mark it released */
for (index = 0; index < ctx->max_page_index; index++) {
if (ctx->pages[index].image == image) {
ctx->pages[index].state = JBIG2_PAGE_RELEASED;
jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, -1,
"page %d released by the client", ctx->pages[index].number);
return 0;
}
}
/* no matching pages */
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, -1,
"jbig2_release_page called on unknown page");
return 1;
}