1/* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18/* 19 20 Filename: sbr_decode_huff_cw.c 21 22------------------------------------------------------------------------------ 23 REVISION HISTORY 24 25 26 Who: Date: MM/DD/YYYY 27 Description: 28 29------------------------------------------------------------------------------ 30 INPUT AND OUTPUT DEFINITIONS 31 32 SbrHuffman h, pointer to huffman codebook table 33 BIT_BUFFER * hBitBuf pointer to Bitbuffer 34 35 return decoded value 36------------------------------------------------------------------------------ 37 FUNCTION DESCRIPTION 38 39 Decodes one huffman code word 40 41 Reads bits from the bitstream until a valid codeword is found. 42 The table entries are interpreted either as index to the next entry 43 or - if negative - as the codeword. 44 45------------------------------------------------------------------------------ 46 REQUIREMENTS 47 48 49------------------------------------------------------------------------------ 50 REFERENCES 51 52SC 29 Software Copyright Licencing Disclaimer: 53 54This software module was originally developed by 55 Coding Technologies 56 57and edited by 58 - 59 60in the course of development of the ISO/IEC 13818-7 and ISO/IEC 14496-3 61standards for reference purposes and its performance may not have been 62optimized. This software module is an implementation of one or more tools as 63specified by the ISO/IEC 13818-7 and ISO/IEC 14496-3 standards. 64ISO/IEC gives users free license to this software module or modifications 65thereof for use in products claiming conformance to audiovisual and 66image-coding related ITU Recommendations and/or ISO/IEC International 67Standards. ISO/IEC gives users the same free license to this software module or 68modifications thereof for research purposes and further ISO/IEC standardisation. 69Those intending to use this software module in products are advised that its 70use may infringe existing patents. ISO/IEC have no liability for use of this 71software module or modifications thereof. Copyright is not released for 72products that do not conform to audiovisual and image-coding related ITU 73Recommendations and/or ISO/IEC International Standards. 74The original developer retains full right to modify and use the code for its 75own purpose, assign or donate the code to a third party and to inhibit third 76parties from using the code for products that do not conform to audiovisual and 77image-coding related ITU Recommendations and/or ISO/IEC International Standards. 78This copyright notice must be included in all copies or derivative works. 79Copyright (c) ISO/IEC 2002. 80 81------------------------------------------------------------------------------ 82 PSEUDO-CODE 83 84------------------------------------------------------------------------------ 85*/ 86 87 88/*---------------------------------------------------------------------------- 89; INCLUDES 90----------------------------------------------------------------------------*/ 91 92#ifdef AAC_PLUS 93 94 95#include "sbr_decode_huff_cw.h" 96#include "buf_getbits.h" 97 98/*---------------------------------------------------------------------------- 99; MACROS 100; Define module specific macros here 101----------------------------------------------------------------------------*/ 102 103 104/*---------------------------------------------------------------------------- 105; DEFINES 106; Include all pre-processor statements here. Include conditional 107; compile variables also. 108----------------------------------------------------------------------------*/ 109 110/*---------------------------------------------------------------------------- 111; LOCAL FUNCTION DEFINITIONS 112; Function Prototype declaration 113----------------------------------------------------------------------------*/ 114 115/*---------------------------------------------------------------------------- 116; LOCAL STORE/BUFFER/POINTER DEFINITIONS 117; Variable declaration - defined here and used outside this module 118----------------------------------------------------------------------------*/ 119 120/*---------------------------------------------------------------------------- 121; EXTERNAL FUNCTION REFERENCES 122; Declare functions defined elsewhere and referenced in this module 123----------------------------------------------------------------------------*/ 124 125/*---------------------------------------------------------------------------- 126; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 127; Declare variables used in this module but defined elsewhere 128----------------------------------------------------------------------------*/ 129 130/*---------------------------------------------------------------------------- 131; FUNCTION CODE 132----------------------------------------------------------------------------*/ 133 134Int32 sbr_decode_huff_cw(SbrHuffman h, 135 BIT_BUFFER * hBitBuf) 136{ 137 Int32 bits; 138 Char index = 0; 139 140 while (index >= 0) 141 { 142 bits = buf_get_1bit(hBitBuf); 143 index = h[index][bits]; 144 } 145 146 return((Int32)index + 64); /* Add offset */ 147} 148 149#endif 150