ref: da420b02de6412f053b759cd04d498762ac62fbe
dir: /jbig2_arith_iaid.c/
/* jbig2dec Copyright (c) 2001 artofcode LLC. This software is provided AS-IS with no warranty, either express or implied. This software is distributed under license and may not be copied, modified or distributed except as expressly authorized under the terms of the license contained in the file LICENSE in this distribution. For information on commercial licensing, go to http://www.artifex.com/licensing/ or contact Artifex Software, Inc., 101 Lucas Valley Road #110, San Rafael, CA 94903, U.S.A., +1(415)492-9861. $Id: $ */ /* Annex A.3 */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "os_types.h" #include <stddef.h> #include <string.h> /* memset() */ #ifdef VERBOSE #include <stdio.h> /* for debug printing only */ #endif #include "jbig2.h" #include "jbig2_priv.h" #include "jbig2_arith.h" #include "jbig2_arith_iaid.h" struct _Jbig2ArithIaidCtx { int SBSYMCODELEN; Jbig2ArithCx *IAIDx; }; Jbig2ArithIaidCtx * jbig2_arith_iaid_ctx_new(Jbig2Ctx *ctx, int SBSYMCODELEN) { Jbig2ArithIaidCtx *result = jbig2_new(ctx, Jbig2ArithIaidCtx, 1); int ctx_size = 1 << SBSYMCODELEN; result->SBSYMCODELEN = SBSYMCODELEN; result->IAIDx = jbig2_alloc(ctx->allocator, ctx_size); memset(result->IAIDx, 0, ctx_size); return result; } /* A.3 */ /* Return value: -1 on error, 0 on normal value */ int jbig2_arith_iaid_decode(Jbig2ArithIaidCtx *ctx, Jbig2ArithState *as, int32_t *p_result) { Jbig2ArithCx *IAIDx = ctx->IAIDx; int SBSYMCODELEN = ctx->SBSYMCODELEN; int PREV = 1; int D; int i; /* A.3 (2) */ for (i = 0; i < SBSYMCODELEN; i++) { D = jbig2_arith_decode(as, &IAIDx[PREV]); #ifdef VERBOSE fprintf(stderr, "IAID%x: D = %d\n", PREV, D); #endif PREV = (PREV << 1) | D; } /* A.3 (3) */ PREV -= 1 << SBSYMCODELEN; #ifdef VERBOSE fprintf(stderr, "IAID result: %d\n", PREV); #endif *p_result = PREV; return 0; } void jbig2_arith_iaid_ctx_free(Jbig2Ctx *ctx, Jbig2ArithIaidCtx *iax) { jbig2_free(ctx->allocator, iax->IAIDx); jbig2_free(ctx->allocator, iax); }