[86b99f7] | 1 | /* |
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| 2 | * jcomapi.c |
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| 3 | * |
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| 4 | * Copyright (C) 1994-1997, Thomas G. Lane. |
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| 5 | * This file is part of the Independent JPEG Group's software. |
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| 6 | * For conditions of distribution and use, see the accompanying README file. |
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| 7 | * |
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| 8 | * This file contains application interface routines that are used for both |
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| 9 | * compression and decompression. |
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| 10 | */ |
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| 11 | |
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| 12 | #define JPEG_INTERNALS |
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| 13 | #include "jinclude.h" |
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| 14 | #include "jpeglib.h" |
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| 15 | |
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| 16 | |
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| 17 | /* |
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| 18 | * Abort processing of a JPEG compression or decompression operation, |
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| 19 | * but don't destroy the object itself. |
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| 20 | * |
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| 21 | * For this, we merely clean up all the nonpermanent memory pools. |
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| 22 | * Note that temp files (virtual arrays) are not allowed to belong to |
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| 23 | * the permanent pool, so we will be able to close all temp files here. |
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| 24 | * Closing a data source or destination, if necessary, is the application's |
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| 25 | * responsibility. |
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| 26 | */ |
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| 27 | |
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| 28 | GLOBAL(void) |
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| 29 | jpeg_abort (j_common_ptr cinfo) |
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| 30 | { |
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| 31 | int pool; |
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| 32 | |
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| 33 | /* Do nothing if called on a not-initialized or destroyed JPEG object. */ |
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| 34 | if (cinfo->mem == NULL) |
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| 35 | return; |
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| 36 | |
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| 37 | /* Releasing pools in reverse order might help avoid fragmentation |
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| 38 | * with some (brain-damaged) malloc libraries. |
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| 39 | */ |
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| 40 | for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) { |
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| 41 | (*cinfo->mem->free_pool) (cinfo, pool); |
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| 42 | } |
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| 43 | |
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| 44 | /* Reset overall state for possible reuse of object */ |
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| 45 | if (cinfo->is_decompressor) { |
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| 46 | cinfo->global_state = DSTATE_START; |
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| 47 | /* Try to keep application from accessing now-deleted marker list. |
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| 48 | * A bit kludgy to do it here, but this is the most central place. |
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| 49 | */ |
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| 50 | ((j_decompress_ptr) cinfo)->marker_list = NULL; |
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| 51 | } else { |
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| 52 | cinfo->global_state = CSTATE_START; |
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| 53 | } |
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| 54 | } |
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| 55 | |
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| 56 | |
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| 57 | /* |
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| 58 | * Destruction of a JPEG object. |
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| 59 | * |
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| 60 | * Everything gets deallocated except the master jpeg_compress_struct itself |
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| 61 | * and the error manager struct. Both of these are supplied by the application |
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| 62 | * and must be freed, if necessary, by the application. (Often they are on |
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| 63 | * the stack and so don't need to be freed anyway.) |
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| 64 | * Closing a data source or destination, if necessary, is the application's |
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| 65 | * responsibility. |
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| 66 | */ |
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| 67 | |
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| 68 | GLOBAL(void) |
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| 69 | jpeg_destroy (j_common_ptr cinfo) |
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| 70 | { |
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| 71 | /* We need only tell the memory manager to release everything. */ |
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| 72 | /* NB: mem pointer is NULL if memory mgr failed to initialize. */ |
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| 73 | if (cinfo->mem != NULL) |
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| 74 | (*cinfo->mem->self_destruct) (cinfo); |
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| 75 | cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */ |
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| 76 | cinfo->global_state = 0; /* mark it destroyed */ |
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| 77 | } |
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| 78 | |
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| 79 | |
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| 80 | /* |
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| 81 | * Convenience routines for allocating quantization and Huffman tables. |
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| 82 | * (Would jutils.c be a more reasonable place to put these?) |
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| 83 | */ |
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| 84 | |
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| 85 | GLOBAL(JQUANT_TBL *) |
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| 86 | jpeg_alloc_quant_table (j_common_ptr cinfo) |
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| 87 | { |
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| 88 | JQUANT_TBL *tbl; |
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| 89 | |
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| 90 | tbl = (JQUANT_TBL *) |
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| 91 | (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL)); |
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| 92 | tbl->sent_table = FALSE; /* make sure this is false in any new table */ |
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| 93 | return tbl; |
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| 94 | } |
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| 95 | |
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| 96 | |
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| 97 | GLOBAL(JHUFF_TBL *) |
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| 98 | jpeg_alloc_huff_table (j_common_ptr cinfo) |
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| 99 | { |
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| 100 | JHUFF_TBL *tbl; |
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| 101 | |
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| 102 | tbl = (JHUFF_TBL *) |
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| 103 | (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL)); |
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| 104 | tbl->sent_table = FALSE; /* make sure this is false in any new table */ |
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| 105 | return tbl; |
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| 106 | } |
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