www.pudn.com > IPcaptu.rar > asyncrdr.cpp

//==========================================================================; 
// 
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY 
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR 
//  PURPOSE. 
// 
//  Copyright (c) 1992 - 1997  Microsoft Corporation.  All Rights Reserved. 
// 
//--------------------------------------------------------------------------; 
 
 
// 
// Implementation of Io source filter methods and output pin methods for 
// CAsyncReader and CAsyncOutputPin 
// 
#include "stdafx.h" 
 
#include  
#include "asyncio.h" 
#include "asyncrdr.h" 
 
 
// --- CAsyncOutputPin implementation --- 
 
CAsyncOutputPin::CAsyncOutputPin( 
    HRESULT * phr, 
    CAsyncReader *pReader, 
    CAsyncIo *pIo, 
    CCritSec * pLock) 
  : CBasePin( 
	NAME("Async output pin"), 
	pReader, 
	pLock, 
	phr, 
	L"Output", 
	PINDIR_OUTPUT), 
    m_pReader(pReader), 
    m_pIo(pIo) 
{ 
 
} 
 
CAsyncOutputPin::~CAsyncOutputPin() 
{ 
} 
 
STDMETHODIMP 
CAsyncOutputPin::NonDelegatingQueryInterface(REFIID riid, void** ppv) 
{ 
    CheckPointer(ppv,E_POINTER); 
    if (riid == IID_IAsyncReader) { 
        m_bQueriedForAsyncReader = TRUE; 
	return GetInterface((IAsyncReader*) this, ppv); 
    } else { 
	return CBasePin::NonDelegatingQueryInterface(riid, ppv); 
    } 
} 
 
HRESULT 
CAsyncOutputPin::GetMediaType(int iPosition, CMediaType *pMediaType) 
{ 
    if (iPosition < 0) { 
	return E_INVALIDARG; 
    } 
    if (iPosition > 0) { 
	return VFW_S_NO_MORE_ITEMS; 
    } 
    *pMediaType = *m_pReader->LoadType(); 
    return S_OK; 
} 
 
HRESULT 
CAsyncOutputPin::CheckMediaType(const CMediaType* pType) 
{ 
    CAutoLock lck(m_pLock); 
 
    /*  We treat MEDIASUBTYPE_NULL subtype as a wild card */ 
    if ((m_pReader->LoadType()->majortype == pType->majortype) && 
	(m_pReader->LoadType()->subtype == MEDIASUBTYPE_NULL || 
         m_pReader->LoadType()->subtype == pType->subtype)) { 
	    return S_OK; 
    } 
    return S_FALSE; 
} 
 
HRESULT 
CAsyncOutputPin::InitAllocator(IMemAllocator **ppAlloc) 
{ 
    HRESULT hr = NOERROR; 
    *ppAlloc = NULL; 
    CMemAllocator *pMemObject = NULL; 
 
    /* Create a default memory allocator */ 
 
    pMemObject = new CMemAllocator(NAME("Base memory allocator"),NULL, &hr); 
    if (pMemObject == NULL) { 
	return E_OUTOFMEMORY; 
    } 
 
    if (FAILED(hr)) { 
	delete pMemObject; 
	return hr; 
    } 
 
    /* Get a reference counted IID_IMemAllocator interface */ 
 
    hr = pMemObject->QueryInterface(IID_IMemAllocator,(void **)ppAlloc); 
    if (FAILED(hr)) { 
	delete pMemObject; 
	return E_NOINTERFACE; 
    } 
    ASSERT(*ppAlloc != NULL); 
    return NOERROR; 
} 
 
// we need to return an addrefed allocator, even if it is the preferred 
// one, since he doesn't know whether it is the preferred one or not. 
STDMETHODIMP 
CAsyncOutputPin::RequestAllocator( 
    IMemAllocator* pPreferred, 
    ALLOCATOR_PROPERTIES* pProps, 
    IMemAllocator ** ppActual) 
{ 
    // we care about alignment but nothing else 
    if (!pProps->cbAlign || !m_pIo->IsAligned(pProps->cbAlign)) { 
       m_pIo->Alignment(&pProps->cbAlign); 
    } 
    ALLOCATOR_PROPERTIES Actual; 
    HRESULT hr; 
    if (pPreferred) { 
	hr = pPreferred->SetProperties(pProps, &Actual); 
	if (SUCCEEDED(hr) && m_pIo->IsAligned(Actual.cbAlign)) { 
            pPreferred->AddRef(); 
	    *ppActual = pPreferred; 
            return S_OK; 
        } 
    } 
 
    // create our own allocator 
    IMemAllocator* pAlloc; 
    hr = InitAllocator(&pAlloc); 
    if (FAILED(hr)) { 
        return hr; 
    } 
 
    //...and see if we can make it suitable 
    hr = pAlloc->SetProperties(pProps, &Actual); 
    if (SUCCEEDED(hr) && m_pIo->IsAligned(Actual.cbAlign)) { 
        // we need to release our refcount on pAlloc, and addref 
        // it to pass a refcount to the caller - this is a net nothing. 
        *ppActual = pAlloc; 
        return S_OK; 
    } 
 
    // failed to find a suitable allocator 
    pAlloc->Release(); 
 
    // if we failed because of the IsAligned test, the error code will 
    // not be failure 
    if (SUCCEEDED(hr)) { 
        hr = VFW_E_BADALIGN; 
    } 
    return hr; 
} 
 
 
// queue an aligned read request. call WaitForNext to get 
// completion. 
STDMETHODIMP 
CAsyncOutputPin::Request( 
    IMediaSample* pSample, 
    DWORD dwUser)	        // user context 
{ 
    REFERENCE_TIME tStart, tStop; 
    HRESULT hr = pSample->GetTime(&tStart, &tStop); 
    if (FAILED(hr)) { 
	return hr; 
    } 
 
    LONGLONG llPos = tStart / UNITS; 
    LONG lLength = (LONG) ((tStop - tStart) / UNITS); 
 
    LONGLONG llTotal; 
    LONGLONG llAvailable; 
    hr = m_pIo->Length(&llTotal, &llAvailable); 
    if (llPos + lLength > llTotal) { 
 
        // the end needs to be aligned, but may have been aligned 
        // on a coarser alignment. 
        LONG lAlign; 
        m_pIo->Alignment(&lAlign); 
        llTotal = (llTotal + lAlign -1) & ~(lAlign-1); 
 
        if (llPos + lLength > llTotal) { 
            lLength = (LONG) (llTotal - llPos); 
 
            // must be reducing this! 
            ASSERT((llTotal * UNITS) <= tStop); 
            tStop = llTotal * UNITS; 
            pSample->SetTime(&tStart, &tStop); 
        } 
    } 
 
 
 
 
    BYTE* pBuffer; 
    hr = pSample->GetPointer(&pBuffer); 
    if (FAILED(hr)) { 
	return hr; 
    } 
 
    return m_pIo->Request( 
			llPos, 
			lLength, 
                        TRUE, 
			pBuffer, 
			(LPVOID)pSample, 
			dwUser); 
} 
 
// sync-aligned request. just like a request/waitfornext pair. 
STDMETHODIMP 
CAsyncOutputPin::SyncReadAligned( 
                  IMediaSample* pSample) 
{ 
    REFERENCE_TIME tStart, tStop; 
    HRESULT hr = pSample->GetTime(&tStart, &tStop); 
    if (FAILED(hr)) { 
	return hr; 
    } 
 
    LONGLONG llPos = tStart / UNITS; 
    LONG lLength = (LONG) ((tStop - tStart) / UNITS); 
 
    LONGLONG llTotal; 
    LONGLONG llAvailable; 
    hr = m_pIo->Length(&llTotal, &llAvailable); 
    if (llPos + lLength > llTotal) { 
 
        // the end needs to be aligned, but may have been aligned 
        // on a coarser alignment. 
        LONG lAlign; 
        m_pIo->Alignment(&lAlign); 
        llTotal = (llTotal + lAlign -1) & ~(lAlign-1); 
 
        if (llPos + lLength > llTotal) { 
            lLength = (LONG) (llTotal - llPos); 
 
            // must be reducing this! 
            ASSERT((llTotal * UNITS) <= tStop); 
            tStop = llTotal * UNITS; 
            pSample->SetTime(&tStart, &tStop); 
        } 
    } 
 
 
 
 
    BYTE* pBuffer; 
    hr = pSample->GetPointer(&pBuffer); 
    if (FAILED(hr)) { 
	return hr; 
    } 
 
    LONG cbActual; 
    hr = m_pIo->SyncReadAligned( 
			llPos, 
			lLength, 
			pBuffer, 
                        &cbActual 
                        ); 
 
    pSample->SetActualDataLength(cbActual); 
 
    return hr; 
} 
 
 
// 
// collect the next ready sample 
STDMETHODIMP 
CAsyncOutputPin::WaitForNext( 
    DWORD dwTimeout, 
    IMediaSample** ppSample,  // completed sample 
    DWORD * pdwUser)		// user context 
{ 
    LONG cbActual; 
 
    IMediaSample* pSample; 
    HRESULT hr =  m_pIo->WaitForNext( 
			    dwTimeout, 
			    (LPVOID*) &pSample, 
			    pdwUser, 
                            &cbActual 
                            ); 
    if (SUCCEEDED(hr)) { 
        pSample->SetActualDataLength(cbActual); 
    } 
    *ppSample = pSample; 
 
    return hr; 
} 
 
 
// 
// synchronous read that need not be aligned. 
STDMETHODIMP 
CAsyncOutputPin::SyncRead( 
    LONGLONG llPosition,	// absolute Io position 
    LONG lLength,		// nr bytes required 
    BYTE* pBuffer)		// write data here 
{ 
    return m_pIo->SyncRead(llPosition, lLength, pBuffer); 
} 
 
// return the length of the file, and the length currently 
// available locally. We only support locally accessible files, 
// so they are always the same 
STDMETHODIMP 
CAsyncOutputPin::Length( 
    LONGLONG* pTotal, 
    LONGLONG* pAvailable) 
{ 
    HRESULT hr = m_pIo->Length(pTotal, pAvailable); 
    return hr; 
} 
 
STDMETHODIMP 
CAsyncOutputPin::BeginFlush(void) 
{ 
    return m_pIo->BeginFlush(); 
} 
 
STDMETHODIMP 
CAsyncOutputPin::EndFlush(void) 
{ 
    return m_pIo->EndFlush(); 
} 
 
 
 
 
// --- CAsyncReader implementation --- 
 
#pragma warning(disable:4355) 
 
CAsyncReader::CAsyncReader( 
    TCHAR *pName, 
    LPUNKNOWN pUnk, 
    CAsyncStream *pStream, 
    HRESULT *phr) 
  : CBaseFilter( 
      	pName, 
	pUnk, 
	&m_csFilter, 
	CLSID_AsyncReader, 
        NULL 
    ), 
    m_OutputPin( 
	phr, 
	this, 
	&m_Io, 
	&m_csFilter), 
    m_Io(pStream) 
{ 
 
} 
 
CAsyncReader::~CAsyncReader() 
{ 
} 
 
int 
CAsyncReader::GetPinCount() 
{ 
    return 1; 
} 
 
CBasePin * 
CAsyncReader::GetPin(int n) 
{ 
    if ((GetPinCount() > 0) && 
	(n == 0)) { 
	return &m_OutputPin; 
    } else { 
	return NULL; 
    } 
}