memfile.h

jpeg and mpeg 编解码技术源代码

#ifndef __MEMFILE_H__
#define __MEMFILE_H__

//  Define an internal filter that wraps the base CBaseReader stuff
//

class CMemStream : public CAsyncStream
{
public:
    CMemStream(LPBYTE pbData, LONGLONG llLength, DWORD dwKBPerSec = INFINITE) :
        m_pbData(pbData),
        m_llLength(llLength),
        m_llPosition(0),
        m_dwKBPerSec(dwKBPerSec)
    {
        m_dwTimeStart = timeGetTime();
    }
	HRESULT SetPointer(LONGLONG llPos);
	HRESULT Read(PBYTE pbBuffer,
                 DWORD dwBytesToRead,
                 BOOL bAlign,
                 LPDWORD pdwBytesRead);
	LONGLONG Size(LONGLONG *pSizeAvailable);

    DWORD Alignment()
    {
        return 1;
    }
    void Lock()
    {
        m_csLock.Lock();
    }
    void Unlock()
    {
        m_csLock.Unlock();
    }

private:
    CCritSec       m_csLock;
    const PBYTE    m_pbData;
    const LONGLONG m_llLength;
    LONGLONG       m_llPosition;
    DWORD          m_dwKBPerSec;
    DWORD          m_dwTimeStart;

public:
	DWORD m_dwSlotNumber;
};

class CMemReader : public CAsyncReader
{
public:

    //  We're not going to be CoCreate'd so we don't need registration
    //  stuff etc
    STDMETHODIMP Register()
    {
        return S_OK;
    }
    STDMETHODIMP Unregister()
    {
        return S_OK;
    }
    CMemReader(CMemStream *pStream, CMediaType *pmt, HRESULT *phr) :
        CAsyncReader(NAME("Mem Reader"), NULL, pStream, phr)
    {
        m_mt = *pmt;
    }
};

#endif //__MEMFILE_H__