xref: /plan9/sys/src/cmd/gs/jpeg/jcomapi.c (revision 7dd7cddf99dd7472612f1413b4da293630e6b1bc)
1*7dd7cddfSDavid du Colombier /*
2*7dd7cddfSDavid du Colombier  * jcomapi.c
3*7dd7cddfSDavid du Colombier  *
4*7dd7cddfSDavid du Colombier  * Copyright (C) 1994-1996, Thomas G. Lane.
5*7dd7cddfSDavid du Colombier  * This file is part of the Independent JPEG Group's software.
6*7dd7cddfSDavid du Colombier  * For conditions of distribution and use, see the accompanying README file.
7*7dd7cddfSDavid du Colombier  *
8*7dd7cddfSDavid du Colombier  * This file contains application interface routines that are used for both
9*7dd7cddfSDavid du Colombier  * compression and decompression.
10*7dd7cddfSDavid du Colombier  */
11*7dd7cddfSDavid du Colombier 
12*7dd7cddfSDavid du Colombier #define JPEG_INTERNALS
13*7dd7cddfSDavid du Colombier #include "jinclude.h"
14*7dd7cddfSDavid du Colombier #include "jpeglib.h"
15*7dd7cddfSDavid du Colombier 
16*7dd7cddfSDavid du Colombier 
17*7dd7cddfSDavid du Colombier /*
18*7dd7cddfSDavid du Colombier  * Abort processing of a JPEG compression or decompression operation,
19*7dd7cddfSDavid du Colombier  * but don't destroy the object itself.
20*7dd7cddfSDavid du Colombier  *
21*7dd7cddfSDavid du Colombier  * For this, we merely clean up all the nonpermanent memory pools.
22*7dd7cddfSDavid du Colombier  * Note that temp files (virtual arrays) are not allowed to belong to
23*7dd7cddfSDavid du Colombier  * the permanent pool, so we will be able to close all temp files here.
24*7dd7cddfSDavid du Colombier  * Closing a data source or destination, if necessary, is the application's
25*7dd7cddfSDavid du Colombier  * responsibility.
26*7dd7cddfSDavid du Colombier  */
27*7dd7cddfSDavid du Colombier 
28*7dd7cddfSDavid du Colombier GLOBAL(void)
29*7dd7cddfSDavid du Colombier jpeg_abort (j_common_ptr cinfo)
30*7dd7cddfSDavid du Colombier {
31*7dd7cddfSDavid du Colombier   int pool;
32*7dd7cddfSDavid du Colombier 
33*7dd7cddfSDavid du Colombier   /* Releasing pools in reverse order might help avoid fragmentation
34*7dd7cddfSDavid du Colombier    * with some (brain-damaged) malloc libraries.
35*7dd7cddfSDavid du Colombier    */
36*7dd7cddfSDavid du Colombier   for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
37*7dd7cddfSDavid du Colombier     (*cinfo->mem->free_pool) (cinfo, pool);
38*7dd7cddfSDavid du Colombier   }
39*7dd7cddfSDavid du Colombier 
40*7dd7cddfSDavid du Colombier   /* Reset overall state for possible reuse of object */
41*7dd7cddfSDavid du Colombier   cinfo->global_state = (cinfo->is_decompressor ? DSTATE_START : CSTATE_START);
42*7dd7cddfSDavid du Colombier }
43*7dd7cddfSDavid du Colombier 
44*7dd7cddfSDavid du Colombier 
45*7dd7cddfSDavid du Colombier /*
46*7dd7cddfSDavid du Colombier  * Destruction of a JPEG object.
47*7dd7cddfSDavid du Colombier  *
48*7dd7cddfSDavid du Colombier  * Everything gets deallocated except the master jpeg_compress_struct itself
49*7dd7cddfSDavid du Colombier  * and the error manager struct.  Both of these are supplied by the application
50*7dd7cddfSDavid du Colombier  * and must be freed, if necessary, by the application.  (Often they are on
51*7dd7cddfSDavid du Colombier  * the stack and so don't need to be freed anyway.)
52*7dd7cddfSDavid du Colombier  * Closing a data source or destination, if necessary, is the application's
53*7dd7cddfSDavid du Colombier  * responsibility.
54*7dd7cddfSDavid du Colombier  */
55*7dd7cddfSDavid du Colombier 
56*7dd7cddfSDavid du Colombier GLOBAL(void)
57*7dd7cddfSDavid du Colombier jpeg_destroy (j_common_ptr cinfo)
58*7dd7cddfSDavid du Colombier {
59*7dd7cddfSDavid du Colombier   /* We need only tell the memory manager to release everything. */
60*7dd7cddfSDavid du Colombier   /* NB: mem pointer is NULL if memory mgr failed to initialize. */
61*7dd7cddfSDavid du Colombier   if (cinfo->mem != NULL)
62*7dd7cddfSDavid du Colombier     (*cinfo->mem->self_destruct) (cinfo);
63*7dd7cddfSDavid du Colombier   cinfo->mem = NULL;		/* be safe if jpeg_destroy is called twice */
64*7dd7cddfSDavid du Colombier   cinfo->global_state = 0;	/* mark it destroyed */
65*7dd7cddfSDavid du Colombier }
66*7dd7cddfSDavid du Colombier 
67*7dd7cddfSDavid du Colombier 
68*7dd7cddfSDavid du Colombier /*
69*7dd7cddfSDavid du Colombier  * Convenience routines for allocating quantization and Huffman tables.
70*7dd7cddfSDavid du Colombier  * (Would jutils.c be a more reasonable place to put these?)
71*7dd7cddfSDavid du Colombier  */
72*7dd7cddfSDavid du Colombier 
73*7dd7cddfSDavid du Colombier GLOBAL(JQUANT_TBL *)
74*7dd7cddfSDavid du Colombier jpeg_alloc_quant_table (j_common_ptr cinfo)
75*7dd7cddfSDavid du Colombier {
76*7dd7cddfSDavid du Colombier   JQUANT_TBL *tbl;
77*7dd7cddfSDavid du Colombier 
78*7dd7cddfSDavid du Colombier   tbl = (JQUANT_TBL *)
79*7dd7cddfSDavid du Colombier     (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
80*7dd7cddfSDavid du Colombier   tbl->sent_table = FALSE;	/* make sure this is false in any new table */
81*7dd7cddfSDavid du Colombier   return tbl;
82*7dd7cddfSDavid du Colombier }
83*7dd7cddfSDavid du Colombier 
84*7dd7cddfSDavid du Colombier 
85*7dd7cddfSDavid du Colombier GLOBAL(JHUFF_TBL *)
86*7dd7cddfSDavid du Colombier jpeg_alloc_huff_table (j_common_ptr cinfo)
87*7dd7cddfSDavid du Colombier {
88*7dd7cddfSDavid du Colombier   JHUFF_TBL *tbl;
89*7dd7cddfSDavid du Colombier 
90*7dd7cddfSDavid du Colombier   tbl = (JHUFF_TBL *)
91*7dd7cddfSDavid du Colombier     (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
92*7dd7cddfSDavid du Colombier   tbl->sent_table = FALSE;	/* make sure this is false in any new table */
93*7dd7cddfSDavid du Colombier   return tbl;
94*7dd7cddfSDavid du Colombier }
95