93 lines
1.6 KiB
C++
93 lines
1.6 KiB
C++
// ByteSwap.cpp
|
|
|
|
#include "StdAfx.h"
|
|
|
|
#include "../../Common/MyCom.h"
|
|
|
|
#include "../ICoder.h"
|
|
|
|
#include "../Common/RegisterCodec.h"
|
|
|
|
namespace NCompress {
|
|
namespace NByteSwap {
|
|
|
|
class CByteSwap2:
|
|
public ICompressFilter,
|
|
public CMyUnknownImp
|
|
{
|
|
public:
|
|
MY_UNKNOWN_IMP1(ICompressFilter);
|
|
INTERFACE_ICompressFilter(;)
|
|
};
|
|
|
|
class CByteSwap4:
|
|
public ICompressFilter,
|
|
public CMyUnknownImp
|
|
{
|
|
public:
|
|
MY_UNKNOWN_IMP1(ICompressFilter);
|
|
INTERFACE_ICompressFilter(;)
|
|
};
|
|
|
|
STDMETHODIMP CByteSwap2::Init() { return S_OK; }
|
|
|
|
STDMETHODIMP_(UInt32) CByteSwap2::Filter(Byte *data, UInt32 size)
|
|
{
|
|
const UInt32 kStep = 2;
|
|
if (size < kStep)
|
|
return 0;
|
|
size &= ~(kStep - 1);
|
|
|
|
const Byte *end = data + (size_t)size;
|
|
|
|
do
|
|
{
|
|
Byte b0 = data[0];
|
|
data[0] = data[1];
|
|
data[1] = b0;
|
|
data += kStep;
|
|
}
|
|
while (data != end);
|
|
|
|
return size;
|
|
}
|
|
|
|
STDMETHODIMP CByteSwap4::Init() { return S_OK; }
|
|
|
|
STDMETHODIMP_(UInt32) CByteSwap4::Filter(Byte *data, UInt32 size)
|
|
{
|
|
const UInt32 kStep = 4;
|
|
if (size < kStep)
|
|
return 0;
|
|
size &= ~(kStep - 1);
|
|
|
|
const Byte *end = data + (size_t)size;
|
|
|
|
do
|
|
{
|
|
Byte b0 = data[0];
|
|
Byte b1 = data[1];
|
|
data[0] = data[3];
|
|
data[1] = data[2];
|
|
data[2] = b1;
|
|
data[3] = b0;
|
|
data += kStep;
|
|
}
|
|
while (data != end);
|
|
|
|
return size;
|
|
}
|
|
|
|
REGISTER_FILTER_CREATE(CreateFilter2, CByteSwap2())
|
|
REGISTER_FILTER_CREATE(CreateFilter4, CByteSwap4())
|
|
|
|
REGISTER_CODECS_VAR
|
|
{
|
|
REGISTER_FILTER_ITEM(CreateFilter2, CreateFilter2, 0x20302, "Swap2"),
|
|
REGISTER_FILTER_ITEM(CreateFilter4, CreateFilter4, 0x20304, "Swap4")
|
|
};
|
|
|
|
REGISTER_CODECS(ByteSwap)
|
|
|
|
}}
|