jcomapi.c

MCB2300_ucgui_LCD320240.rar LPC2368的uc/gui的移植

/*
 * jcomapi.c
 *
 * Copyright (C) 1994-1997, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains application interface routines that are used for both
 * compression and decompression.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/*
 * Abort processing of a JPEG compression or decompression operation,
 * but don't destroy the object itself.
 *
 * For this, we merely clean up all the nonpermanent memory pools.
 * Note that temp files (virtual arrays) are not allowed to belong to
 * the permanent pool, so we will be able to close all temp files here.
 * Closing a data source or destination, if necessary, is the application's
 * responsibility.
 */

GLOBAL(void)
jpeg_abort(j_common_ptr cinfo)
{
	int pool;

	/* Do nothing if called on a not-initialized or destroyed JPEG object. */
	if (cinfo->mem == NULL)
	{
		return;
	}

	/* Releasing pools in reverse order might help avoid fragmentation
	 * with some (brain-damaged) malloc libraries.
	 */
	for (pool = JPOOL_NUMPOOLS - 1; pool > JPOOL_PERMANENT; pool--)
	{
		(*cinfo->mem->free_pool) (cinfo, pool);
	}

	/* Reset overall state for possible reuse of object */
	if (cinfo->is_decompressor)
	{
		cinfo->global_state = DSTATE_START;
		/* Try to keep application from accessing now-deleted marker list.
		 * A bit kludgy to do it here, but this is the most central place.
		 */
		((j_decompress_ptr) cinfo)->marker_list = NULL;
	}
	else
	{
		cinfo->global_state = CSTATE_START;
	}
}


/*
 * Destruction of a JPEG object.
 *
 * Everything gets deallocated except the master jpeg_compress_struct itself
 * and the error manager struct.  Both of these are supplied by the application
 * and must be freed, if necessary, by the application.  (Often they are on
 * the stack and so don't need to be freed anyway.)
 * Closing a data source or destination, if necessary, is the application's
 * responsibility.
 */

GLOBAL(void) jpeg_destroy(j_common_ptr cinfo)
{
				 /* We need only tell the memory manager to release everything. */
				 /* NB: mem pointer is NULL if memory mgr failed to initialize. */
				 if (cinfo->mem != NULL)
				 {
					 (*cinfo->mem->self_destruct) (cinfo);
				 }
				 cinfo->mem = NULL;		/* be safe if jpeg_destroy is called twice */
				 cinfo->global_state = 0;	/* mark it destroyed */
}


/*
 * Convenience routines for allocating quantization and Huffman tables.
 * (Would jutils.c be a more reasonable place to put these?)
 */

GLOBAL(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo)
{
						 JQUANT_TBL *tbl;
						 tbl = (JQUANT_TBL *) (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
						 tbl->sent_table = FALSE;	/* make sure this is false in any new table */
						 return tbl;
}


GLOBAL(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo)
{
						JHUFF_TBL *tbl;
						tbl = (JHUFF_TBL *) (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
						tbl->sent_table = FALSE;	/* make sure this is false in any new table */
						return tbl;
}