asyncrdr.cpp

Mpeg流的网络客户端实时播放

//------------------------------------------------------------------------------
// File: AsyncRdr.cpp
//
// Desc: DirectShow sample code - base library with I/O functionality.
//       This file implements I/O source filter methods and output pin 
//       methods for CAsyncReader and CAsyncOutputPin.
//
// Copyright (c) 1992-2001 Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------

#include "stdafx.h"
#include <streams.h>
#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
                        );

    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();
}


STDMETHODIMP
CAsyncOutputPin::Connect(
    IPin * pReceivePin,
    const AM_MEDIA_TYPE *pmt   // optional media type
)
{
    return m_pReader->Connect(pReceivePin, pmt);
}


// --- 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;
    }
}