1 /* 2 * Copyright (C) 2009 The Android Open Source Project 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 express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /*------------------------------------------------------------------------------ 18 19 Table of contents 20 21 1. Include headers 22 2. External compiler flags 23 3. Module defines 24 4. Local function prototypes 25 5. Functions 26 h264bsdDecodeNalUnit 27 28 ------------------------------------------------------------------------------*/ 29 30 /*------------------------------------------------------------------------------ 31 1. Include headers 32 ------------------------------------------------------------------------------*/ 33 34 #include "h264bsd_nal_unit.h" 35 #include "h264bsd_util.h" 36 37 /*------------------------------------------------------------------------------ 38 2. External compiler flags 39 -------------------------------------------------------------------------------- 40 41 -------------------------------------------------------------------------------- 42 3. Module defines 43 ------------------------------------------------------------------------------*/ 44 45 /*------------------------------------------------------------------------------ 46 4. Local function prototypes 47 ------------------------------------------------------------------------------*/ 48 49 /*------------------------------------------------------------------------------ 50 51 Function name: h264bsdDecodeNalUnit 52 53 Functional description: 54 Decode NAL unit header information 55 56 Inputs: 57 pStrmData pointer to stream data structure 58 59 Outputs: 60 pNalUnit NAL unit header information is stored here 61 62 Returns: 63 HANTRO_OK success 64 HANTRO_NOK invalid NAL unit header information 65 66 ------------------------------------------------------------------------------*/ 67 68 u32 h264bsdDecodeNalUnit(strmData_t *pStrmData, nalUnit_t *pNalUnit) 69 { 70 71 /* Variables */ 72 73 u32 tmp; 74 75 /* Code */ 76 77 ASSERT(pStrmData); 78 ASSERT(pNalUnit); 79 ASSERT(pStrmData->bitPosInWord == 0); 80 81 /* forbidden_zero_bit (not checked to be zero, errors ignored) */ 82 tmp = h264bsdGetBits(pStrmData, 1); 83 /* Assuming that NAL unit starts from byte boundary > don't have to check 84 * following 7 bits for END_OF_STREAM */ 85 if (tmp == END_OF_STREAM) 86 return(HANTRO_NOK); 87 88 tmp = h264bsdGetBits(pStrmData, 2); 89 pNalUnit->nalRefIdc = tmp; 90 91 tmp = h264bsdGetBits(pStrmData, 5); 92 pNalUnit->nalUnitType = (nalUnitType_e)tmp; 93 94 /* data partitioning NAL units not supported */ 95 if ( (tmp == 2) || (tmp == 3) || (tmp == 4) ) 96 { 97 return(HANTRO_NOK); 98 } 99 100 /* nal_ref_idc shall not be zero for these nal_unit_types */ 101 if ( ( (tmp == NAL_SEQ_PARAM_SET) || (tmp == NAL_PIC_PARAM_SET) || 102 (tmp == NAL_CODED_SLICE_IDR) ) && (pNalUnit->nalRefIdc == 0) ) 103 { 104 return(HANTRO_NOK); 105 } 106 /* nal_ref_idc shall be zero for these nal_unit_types */ 107 else if ( ( (tmp == NAL_SEI) || (tmp == NAL_ACCESS_UNIT_DELIMITER) || 108 (tmp == NAL_END_OF_SEQUENCE) || (tmp == NAL_END_OF_STREAM) || 109 (tmp == NAL_FILLER_DATA) ) && (pNalUnit->nalRefIdc != 0) ) 110 { 111 return(HANTRO_NOK); 112 } 113 114 return(HANTRO_OK); 115 116 } 117 118
