150 lines
3.3 KiB
C++
150 lines
3.3 KiB
C++
#pragma once
|
|
|
|
#include "Types.h"
|
|
#include "JpgEvent.h"
|
|
#include "Utils.h"
|
|
|
|
namespace Jpeg2000
|
|
{
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
// Bit input-output stream (BitIO)
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
// Вспомогательные функции
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
static int BitIO_ByteOut(BitIO *pBIO)
|
|
{
|
|
pBIO->nBuffer = (pBIO->nBuffer << 8) & 0xffff;
|
|
pBIO->nValidBitsCount = pBIO->nBuffer == 0xff00 ? 7 : 8;
|
|
|
|
if (pBIO->pCurPos >= pBIO->pEnd)
|
|
{
|
|
return 1;
|
|
}
|
|
*pBIO->pCurPos++ = pBIO->nBuffer >> 8;
|
|
return 0;
|
|
}
|
|
|
|
static int BitIO_ByteIn(BitIO *pBIO)
|
|
{
|
|
pBIO->nBuffer = (pBIO->nBuffer << 8) & 0xffff;
|
|
pBIO->nValidBitsCount = pBIO->nBuffer == 0xff00 ? 7 : 8;
|
|
|
|
if (pBIO->pCurPos >= pBIO->pEnd)
|
|
{
|
|
return 1;
|
|
}
|
|
pBIO->nBuffer |= *pBIO->pCurPos++;
|
|
return 0;
|
|
}
|
|
|
|
static void BitIO_PutBit(BitIO *pBIO, int nBit)
|
|
{
|
|
if (0 == pBIO->nValidBitsCount)
|
|
{
|
|
BitIO_ByteOut(pBIO);
|
|
}
|
|
pBIO->nValidBitsCount--;
|
|
pBIO->nBuffer |= nBit << pBIO->nValidBitsCount;
|
|
}
|
|
|
|
static int BitIO_GetBit(BitIO *pBIO)
|
|
{
|
|
if (0 == pBIO->nValidBitsCount)
|
|
{
|
|
BitIO_ByteIn(pBIO);
|
|
}
|
|
pBIO->nValidBitsCount--;
|
|
return (pBIO->nBuffer >> pBIO->nValidBitsCount) & 1;
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
// Основные функции
|
|
//-------------------------------------------------------------------------------------------------------------------------------
|
|
BitIO* BitIO_Create()
|
|
{
|
|
BitIO *pBIO = (BitIO*)Malloc(sizeof(BitIO));
|
|
return pBIO;
|
|
}
|
|
|
|
void BitIO_Destroy(BitIO *pBIO)
|
|
{
|
|
Free(pBIO);
|
|
}
|
|
|
|
int BitIO_WrittenBytesCount(BitIO *pBIO)
|
|
{
|
|
return (pBIO->pCurPos - pBIO->pStart);
|
|
}
|
|
|
|
void BitIO_InitEncoder(BitIO *pBIO, unsigned char *pBuffer, int nLen)
|
|
{
|
|
pBIO->pStart = pBuffer;
|
|
pBIO->pEnd = pBuffer + nLen;
|
|
pBIO->pCurPos = pBuffer;
|
|
pBIO->nBuffer = 0;
|
|
pBIO->nValidBitsCount = 8;
|
|
}
|
|
void BitIO_InitDecoder(BitIO *pBIO, unsigned char *pBuffer, int nLen)
|
|
{
|
|
pBIO->pStart = pBuffer;
|
|
pBIO->pEnd = pBuffer + nLen;
|
|
pBIO->pCurPos = pBuffer;
|
|
pBIO->nBuffer = 0;
|
|
pBIO->nValidBitsCount = 0;
|
|
}
|
|
|
|
void BitIO_Write(BitIO *pBIO, int nValue, int nLen)
|
|
{
|
|
for (int nIndex = nLen - 1; nIndex >= 0; nIndex--)
|
|
{
|
|
BitIO_PutBit(pBIO, (nValue >> nIndex) & 1);
|
|
}
|
|
}
|
|
|
|
int BitIO_Read(BitIO *pBIO, int nLen)
|
|
{
|
|
int nResult = 0;
|
|
for (int nIndex = nLen - 1; nIndex >= 0; nIndex--)
|
|
{
|
|
nResult += BitIO_GetBit(pBIO) << nIndex;
|
|
}
|
|
return nResult;
|
|
}
|
|
|
|
int BitIO_Flush(BitIO *pBIO)
|
|
{
|
|
pBIO->nValidBitsCount = 0;
|
|
|
|
if (BitIO_ByteOut(pBIO))
|
|
{
|
|
return 1;
|
|
}
|
|
if (7 == pBIO->nValidBitsCount)
|
|
{
|
|
pBIO->nValidBitsCount = 0;
|
|
if (BitIO_ByteOut(pBIO))
|
|
{
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
int BitIO_InAlign(BitIO *pBIO)
|
|
{
|
|
pBIO->nValidBitsCount = 0;
|
|
|
|
if ((pBIO->nBuffer & 0xff) == 0xff)
|
|
{
|
|
if (BitIO_ByteIn(pBIO))
|
|
{
|
|
return 1;
|
|
}
|
|
pBIO->nValidBitsCount = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
} |