1e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard/* 2e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** Copyright 2003-2010, VisualOn, Inc. 3e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** 4e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** Licensed under the Apache License, Version 2.0 (the "License"); 5e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** you may not use this file except in compliance with the License. 6e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** You may obtain a copy of the License at 7e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** 8e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** http://www.apache.org/licenses/LICENSE-2.0 9e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** 10e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** Unless required by applicable law or agreed to in writing, software 11e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** distributed under the License is distributed on an "AS IS" BASIS, 12e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** See the License for the specific language governing permissions and 14e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard ** limitations under the License. 15e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard */ 16e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard/******************************************************************************* 17e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard File: bitbuffer.c 18e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard 19e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard Content: Bit Buffer Management functions 20e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard 21956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*******************************************************************************/ 22956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 23956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong#include "bitbuffer.h" 24956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 25956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 26956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 27956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: updateBitBufWordPtr 28956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: update Bit Buffer pointer 29956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 30956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 31956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dongstatic void updateBitBufWordPtr(HANDLE_BIT_BUF hBitBuf, 32956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong UWord8 **pBitBufWord, 33956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong Word16 cnt) 34956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 35b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *pBitBufWord += cnt; 36b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 37956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 38956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong if(*pBitBufWord > hBitBuf->pBitBufEnd) { 39b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *pBitBufWord -= (hBitBuf->pBitBufEnd - hBitBuf->pBitBufBase + 1); 40956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong } 41b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 42956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong if(*pBitBufWord < hBitBuf->pBitBufBase) { 43b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *pBitBufWord += (hBitBuf->pBitBufEnd - hBitBuf->pBitBufBase + 1); 44956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong } 45956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 46956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 47956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 48956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 49956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 50956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: CreateBitBuffer 51956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: create and init Bit Buffer Management 52956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 53956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 54956c553ab0ce72f8074ad0fda2ffd66a0305700cJames DongHANDLE_BIT_BUF CreateBitBuffer(HANDLE_BIT_BUF hBitBuf, 55956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong UWord8 *pBitBufBase, 56956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong Word16 bitBufSize) 57956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 58956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong assert(bitBufSize*8 <= 32768); 59956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 60b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pBitBufBase = pBitBufBase; 61b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pBitBufEnd = pBitBufBase + bitBufSize - 1; 62956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 63b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pWriteNext = pBitBufBase; 64956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 65956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong hBitBuf->cache = 0; 66b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 67b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->wBitPos = 0; 68b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->cntBits = 0; 69b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 70b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->size = (bitBufSize << 3); 71b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->isValid = 1; 72956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 73956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong return hBitBuf; 74956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 75956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 76956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 77956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 78956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: DeleteBitBuffer 79956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: uninit Bit Buffer Management 80956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 81956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 82956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dongvoid DeleteBitBuffer(HANDLE_BIT_BUF *hBitBuf) 83956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 84e2e838afcf03e603a41a0455846eaf9614537c16Mans Rullgard if(*hBitBuf) 85b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard (*hBitBuf)->isValid = 0; 86b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *hBitBuf = NULL; 87956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 88956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 89956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 90956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 91956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: ResetBitBuf 92956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: reset Bit Buffer Management 93956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 94956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 95956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dongvoid ResetBitBuf(HANDLE_BIT_BUF hBitBuf, 96956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong UWord8 *pBitBufBase, 97956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong Word16 bitBufSize) 98956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 99b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pBitBufBase = pBitBufBase; 100b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pBitBufEnd = pBitBufBase + bitBufSize - 1; 101b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 102956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 103b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->pWriteNext = pBitBufBase; 104b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 105b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->wBitPos = 0; 106b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->cntBits = 0; 107956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 108956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong hBitBuf->cache = 0; 109956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 110956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 111956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 112956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 113956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: CopyBitBuf 114956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: copy Bit Buffer Management 115956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 116956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 117956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dongvoid CopyBitBuf(HANDLE_BIT_BUF hBitBufSrc, 118956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong HANDLE_BIT_BUF hBitBufDst) 119956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 120b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *hBitBufDst = *hBitBufSrc; 121956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 122956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 123956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 124956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 125956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: GetBitsAvail 126956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: get available bits 127956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 128956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 129956c553ab0ce72f8074ad0fda2ffd66a0305700cJames DongWord16 GetBitsAvail(HANDLE_BIT_BUF hBitBuf) 130956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 131956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong return hBitBuf->cntBits; 132956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 133956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 134956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong/***************************************************************************** 135956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 136956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* function name: WriteBits 137956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* description: write bits to the buffer 138956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong* 139956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong*****************************************************************************/ 140956c553ab0ce72f8074ad0fda2ffd66a0305700cJames DongWord16 WriteBits(HANDLE_BIT_BUF hBitBuf, 1415e9afe434d8207fb0af6e191cca671ab74cfe878Martin Storsjo UWord32 writeValue, 142956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong Word16 noBitsToWrite) 143956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong{ 144956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong Word16 wBitPos; 145956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 146956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong assert(noBitsToWrite <= (Word16)sizeof(Word32)*8); 147956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 148956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong if(noBitsToWrite == 0) 149956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong return noBitsToWrite; 150956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 151b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard hBitBuf->cntBits += noBitsToWrite; 152956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong 153956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong wBitPos = hBitBuf->wBitPos; 154956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong wBitPos += noBitsToWrite; 1553989d5c21ce6d1f3492c9e5484d610d5d66abd9eMartin Storsjo writeValue &= ~(0xffffffff << noBitsToWrite); // Mask out everything except the lowest noBitsToWrite bits 156b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard writeValue <<= 32 - wBitPos; 157956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong writeValue |= hBitBuf->cache; 158b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 159b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard while (wBitPos >= 8) 160956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong { 161956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong UWord8 tmp; 162956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong tmp = (UWord8)((writeValue >> 24) & 0xFF); 163b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 164b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard *hBitBuf->pWriteNext++ = tmp; 165956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong writeValue <<= 8; 166956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong wBitPos -= 8; 167956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong } 168b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 169956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong hBitBuf->wBitPos = wBitPos; 170956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong hBitBuf->cache = writeValue; 171b676a05348e4c516fa8b57e33b10548e6142c3f8Mans Rullgard 172956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong return noBitsToWrite; 173956c553ab0ce72f8074ad0fda2ffd66a0305700cJames Dong} 174