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/*
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 * jcomapi.c
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 *
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 * Copyright (C) 1994-1997, Thomas G. Lane.
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 * This file is part of the Independent JPEG Group's software.
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 * For conditions of distribution and use, see the accompanying README file.
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 *
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 * This file contains application interface routines that are used for both
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 * compression and decompression.
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 */
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#define JPEG_INTERNALS
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#include "jinclude.h"
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#include "jpeglib.h"
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/*
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 * Abort processing of a JPEG compression or decompression operation,
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 * but don't destroy the object itself.
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 *
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 * For this, we merely clean up all the nonpermanent memory pools.
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 * Note that temp files (virtual arrays) are not allowed to belong to
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 * the permanent pool, so we will be able to close all temp files here.
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 * Closing a data source or destination, if necessary, is the application's
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 * responsibility.
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 */
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GLOBAL(void)
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jpeg_abort (j_common_ptr cinfo)
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{
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  int pool;
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  /* Do nothing if called on a not-initialized or destroyed JPEG object. */
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  if (cinfo->mem == NULL)
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    return;
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  /* Releasing pools in reverse order might help avoid fragmentation
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   * with some (brain-damaged) malloc libraries.
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   */
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  for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
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    (*cinfo->mem->free_pool) (cinfo, pool);
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  }
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  /* Reset overall state for possible reuse of object */
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  if (cinfo->is_decompressor) {
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    cinfo->global_state = DSTATE_START;
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    /* Try to keep application from accessing now-deleted marker list.
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     * A bit kludgy to do it here, but this is the most central place.
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     */
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    ((j_decompress_ptr) cinfo)->marker_list = NULL;
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  } else {
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    cinfo->global_state = CSTATE_START;
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  }
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}
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/*
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 * Destruction of a JPEG object.
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 *
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 * Everything gets deallocated except the master jpeg_compress_struct itself
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 * and the error manager struct.  Both of these are supplied by the application
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 * and must be freed, if necessary, by the application.  (Often they are on
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 * the stack and so don't need to be freed anyway.)
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 * Closing a data source or destination, if necessary, is the application's
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 * responsibility.
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 */
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GLOBAL(void)
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jpeg_destroy (j_common_ptr cinfo)
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{
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  /* We need only tell the memory manager to release everything. */
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  /* NB: mem pointer is NULL if memory mgr failed to initialize. */
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  if (cinfo->mem != NULL)
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    (*cinfo->mem->self_destruct) (cinfo);
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  cinfo->mem = NULL;		/* be safe if jpeg_destroy is called twice */
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  cinfo->global_state = 0;	/* mark it destroyed */
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}
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/*
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 * Convenience routines for allocating quantization and Huffman tables.
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 * (Would jutils.c be a more reasonable place to put these?)
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 */
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GLOBAL(JQUANT_TBL *)
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jpeg_alloc_quant_table (j_common_ptr cinfo)
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{
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  JQUANT_TBL *tbl;
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  tbl = (JQUANT_TBL *)
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    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
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  tbl->sent_table = FALSE;	/* make sure this is false in any new table */
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  return tbl;
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}
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GLOBAL(JHUFF_TBL *)
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jpeg_alloc_huff_table (j_common_ptr cinfo)
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{
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  JHUFF_TBL *tbl;
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  tbl = (JHUFF_TBL *)
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    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
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  tbl->sent_table = FALSE;	/* make sure this is false in any new table */
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  return tbl;
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}
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