www.gusucode.com > VC++远程视频监控系统源代码-源码程序 > VC++远程视频监控系统源代码-源码程序/code/AV8SDK/AV8SDK/Demo/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 <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->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;
}
}