ref: 828dd5189c28650ab41c2c8d4a8ec1828370a186
dir: /jbig2_arith_iaid.c/
/* Copyright (C) 2001-2018 Artifex Software, Inc. All Rights Reserved. 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. Refer to licensing information at http://www.artifex.com or contact Artifex Software, Inc., 1305 Grant Avenue - Suite 200, Novato, CA 94945, U.S.A., +1(415)492-9861, for further information. */ /* jbig2dec */ /* 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; if (result == NULL) { jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "failed to allocate storage in jbig2_arith_iaid_ctx_new"); return NULL; } result->SBSYMCODELEN = SBSYMCODELEN; result->IAIDx = jbig2_new(ctx, Jbig2ArithCx, ctx_size); if (result->IAIDx == NULL) { jbig2_free(ctx->allocator, result); jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "failed to allocate symbol ID storage in jbig2_arith_iaid_ctx_new"); return NULL; } memset(result->IAIDx, 0, ctx_size); return result; } /* A.3 */ /* Return value: -1 on error, 0 on normal value */ int jbig2_arith_iaid_decode(Jbig2Ctx *ctx, Jbig2ArithIaidCtx *actx, Jbig2ArithState *as, int32_t *p_result) { Jbig2ArithCx *IAIDx = actx->IAIDx; int SBSYMCODELEN = actx->SBSYMCODELEN; int PREV = 1; int D; int i; int code = 0; /* A.3 (2) */ for (i = 0; i < SBSYMCODELEN; i++) { D = jbig2_arith_decode(as, &IAIDx[PREV], &code); if (code) return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "failed to decode IAIDx code"); #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) { if (iax != NULL) { jbig2_free(ctx->allocator, iax->IAIDx); jbig2_free(ctx->allocator, iax); } }