92 lines
2.0 KiB
C
Executable File
92 lines
2.0 KiB
C
Executable File
/*
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jbig2dec
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Copyright (C) 2001 Artifex Software, Inc.
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This software is provided AS-IS with no warranty,
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either express or implied.
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This software is distributed under license and may not
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be copied, modified or distributed except as expressly
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authorized under the terms of the license contained in
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the file LICENSE in this distribution.
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For further licensing information refer to http://artifex.com/ or
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contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861.
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*/
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/* Annex A.3 */
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "os_types.h"
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#include <stddef.h>
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#include <string.h> /* memset() */
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#ifdef VERBOSE
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#include <stdio.h> /* for debug printing only */
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#endif
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#include "jbig2.h"
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#include "jbig2_priv.h"
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#include "jbig2_arith.h"
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#include "jbig2_arith_iaid.h"
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struct _Jbig2ArithIaidCtx {
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int SBSYMCODELEN;
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Jbig2ArithCx *IAIDx;
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};
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Jbig2ArithIaidCtx *
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jbig2_arith_iaid_ctx_new(Jbig2Ctx *ctx, int SBSYMCODELEN)
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{
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Jbig2ArithIaidCtx *result = jbig2_new(ctx, Jbig2ArithIaidCtx, 1);
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int ctx_size = 1 << SBSYMCODELEN;
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result->SBSYMCODELEN = SBSYMCODELEN;
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result->IAIDx = jbig2_alloc(ctx->allocator, ctx_size);
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memset(result->IAIDx, 0, ctx_size);
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return result;
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}
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/* A.3 */
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/* Return value: -1 on error, 0 on normal value */
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int
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jbig2_arith_iaid_decode(Jbig2ArithIaidCtx *ctx, Jbig2ArithState *as,
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int32_t *p_result)
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{
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Jbig2ArithCx *IAIDx = ctx->IAIDx;
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int SBSYMCODELEN = ctx->SBSYMCODELEN;
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int PREV = 1;
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int D;
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int i;
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/* A.3 (2) */
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for (i = 0; i < SBSYMCODELEN; i++)
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{
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D = jbig2_arith_decode(as, &IAIDx[PREV]);
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#ifdef VERBOSE
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fprintf(stderr, "IAID%x: D = %d\n", PREV, D);
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#endif
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PREV = (PREV << 1) | D;
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}
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/* A.3 (3) */
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PREV -= 1 << SBSYMCODELEN;
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#ifdef VERBOSE
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fprintf(stderr, "IAID result: %d\n", PREV);
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#endif
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*p_result = PREV;
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return 0;
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}
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void
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jbig2_arith_iaid_ctx_free(Jbig2Ctx *ctx, Jbig2ArithIaidCtx *iax)
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{
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jbig2_free(ctx->allocator, iax->IAIDx);
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jbig2_free(ctx->allocator, iax);
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}
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