player.cpp
Questo argomento contiene il codice per l'esercitazione Come riprodurre file multimediali con Media Foundation.
// 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) Microsoft Corporation. All rights reserved.
#include "Player.h"
#include <assert.h>
#pragma comment(lib, "shlwapi")
template <class Q>
HRESULT GetEventObject(IMFMediaEvent *pEvent, Q **ppObject)
{
*ppObject = NULL; // zero output
PROPVARIANT var;
HRESULT hr = pEvent->GetValue(&var);
if (SUCCEEDED(hr))
{
if (var.vt == VT_UNKNOWN)
{
hr = var.punkVal->QueryInterface(ppObject);
}
else
{
hr = MF_E_INVALIDTYPE;
}
PropVariantClear(&var);
}
return hr;
}
HRESULT CreateMediaSource(PCWSTR pszURL, IMFMediaSource **ppSource);
HRESULT CreatePlaybackTopology(IMFMediaSource *pSource,
IMFPresentationDescriptor *pPD, HWND hVideoWnd,IMFTopology **ppTopology);
// Static class method to create the CPlayer object.
HRESULT CPlayer::CreateInstance(
HWND hVideo, // Video window.
HWND hEvent, // Window to receive notifications.
CPlayer **ppPlayer) // Receives a pointer to the CPlayer object.
{
if (ppPlayer == NULL)
{
return E_POINTER;
}
CPlayer *pPlayer = new (std::nothrow) CPlayer(hVideo, hEvent);
if (pPlayer == NULL)
{
return E_OUTOFMEMORY;
}
HRESULT hr = pPlayer->Initialize();
if (SUCCEEDED(hr))
{
*ppPlayer = pPlayer;
}
else
{
pPlayer->Release();
}
return hr;
}
HRESULT CPlayer::Initialize()
{
// Start up Media Foundation platform.
HRESULT hr = MFStartup(MF_VERSION);
if (SUCCEEDED(hr))
{
m_hCloseEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
if (m_hCloseEvent == NULL)
{
hr = HRESULT_FROM_WIN32(GetLastError());
}
}
return hr;
}
CPlayer::CPlayer(HWND hVideo, HWND hEvent) :
m_pSession(NULL),
m_pSource(NULL),
m_pVideoDisplay(NULL),
m_hwndVideo(hVideo),
m_hwndEvent(hEvent),
m_state(Closed),
m_hCloseEvent(NULL),
m_nRefCount(1)
{
}
CPlayer::~CPlayer()
{
assert(m_pSession == NULL);
// If FALSE, the app did not call Shutdown().
// When CPlayer calls IMediaEventGenerator::BeginGetEvent on the
// media session, it causes the media session to hold a reference
// count on the CPlayer.
// This creates a circular reference count between CPlayer and the
// media session. Calling Shutdown breaks the circular reference
// count.
// If CreateInstance fails, the application will not call
// Shutdown. To handle that case, call Shutdown in the destructor.
Shutdown();
}
// IUnknown methods
HRESULT CPlayer::QueryInterface(REFIID riid, void** ppv)
{
static const QITAB qit[] =
{
QITABENT(CPlayer, IMFAsyncCallback),
{ 0 }
};
return QISearch(this, qit, riid, ppv);
}
ULONG CPlayer::AddRef()
{
return InterlockedIncrement(&m_nRefCount);
}
ULONG CPlayer::Release()
{
ULONG uCount = InterlockedDecrement(&m_nRefCount);
if (uCount == 0)
{
delete this;
}
return uCount;
}
// Open a URL for playback.
HRESULT CPlayer::OpenURL(const WCHAR *sURL)
{
// 1. Create a new media session.
// 2. Create the media source.
// 3. Create the topology.
// 4. Queue the topology [asynchronous]
// 5. Start playback [asynchronous - does not happen in this method.]
IMFTopology *pTopology = NULL;
IMFPresentationDescriptor* pSourcePD = NULL;
// Create the media session.
HRESULT hr = CreateSession();
if (FAILED(hr))
{
goto done;
}
// Create the media source.
hr = CreateMediaSource(sURL, &m_pSource);
if (FAILED(hr))
{
goto done;
}
// Create the presentation descriptor for the media source.
hr = m_pSource->CreatePresentationDescriptor(&pSourcePD);
if (FAILED(hr))
{
goto done;
}
// Create a partial topology.
hr = CreatePlaybackTopology(m_pSource, pSourcePD, m_hwndVideo, &pTopology);
if (FAILED(hr))
{
goto done;
}
// Set the topology on the media session.
hr = m_pSession->SetTopology(0, pTopology);
if (FAILED(hr))
{
goto done;
}
m_state = OpenPending;
// If SetTopology succeeds, the media session will queue an
// MESessionTopologySet event.
done:
if (FAILED(hr))
{
m_state = Closed;
}
SafeRelease(&pSourcePD);
SafeRelease(&pTopology);
return hr;
}
// Pause playback.
HRESULT CPlayer::Pause()
{
if (m_state != Started)
{
return MF_E_INVALIDREQUEST;
}
if (m_pSession == NULL || m_pSource == NULL)
{
return E_UNEXPECTED;
}
HRESULT hr = m_pSession->Pause();
if (SUCCEEDED(hr))
{
m_state = Paused;
}
return hr;
}
// Stop playback.
HRESULT CPlayer::Stop()
{
if (m_state != Started && m_state != Paused)
{
return MF_E_INVALIDREQUEST;
}
if (m_pSession == NULL)
{
return E_UNEXPECTED;
}
HRESULT hr = m_pSession->Stop();
if (SUCCEEDED(hr))
{
m_state = Stopped;
}
return hr;
}
// Repaint the video window. Call this method on WM_PAINT.
HRESULT CPlayer::Repaint()
{
if (m_pVideoDisplay)
{
return m_pVideoDisplay->RepaintVideo();
}
else
{
return S_OK;
}
}
// Resize the video rectangle.
//
// Call this method if the size of the video window changes.
HRESULT CPlayer::ResizeVideo(WORD width, WORD height)
{
if (m_pVideoDisplay)
{
// Set the destination rectangle.
// Leave the default source rectangle (0,0,1,1).
RECT rcDest = { 0, 0, width, height };
return m_pVideoDisplay->SetVideoPosition(NULL, &rcDest);
}
else
{
return S_OK;
}
}
// Callback for the asynchronous BeginGetEvent method.
HRESULT CPlayer::Invoke(IMFAsyncResult *pResult)
{
MediaEventType meType = MEUnknown; // Event type
IMFMediaEvent *pEvent = NULL;
// Get the event from the event queue.
HRESULT hr = m_pSession->EndGetEvent(pResult, &pEvent);
if (FAILED(hr))
{
goto done;
}
// Get the event type.
hr = pEvent->GetType(&meType);
if (FAILED(hr))
{
goto done;
}
if (meType == MESessionClosed)
{
// The session was closed.
// The application is waiting on the m_hCloseEvent event handle.
SetEvent(m_hCloseEvent);
}
else
{
// For all other events, get the next event in the queue.
hr = m_pSession->BeginGetEvent(this, NULL);
if (FAILED(hr))
{
goto done;
}
}
// Check the application state.
// If a call to IMFMediaSession::Close is pending, it means the
// application is waiting on the m_hCloseEvent event and
// the application's message loop is blocked.
// Otherwise, post a private window message to the application.
if (m_state != Closing)
{
// Leave a reference count on the event.
pEvent->AddRef();
PostMessage(m_hwndEvent, WM_APP_PLAYER_EVENT,
(WPARAM)pEvent, (LPARAM)meType);
}
done:
SafeRelease(&pEvent);
return S_OK;
}
HRESULT CPlayer::HandleEvent(UINT_PTR pEventPtr)
{
HRESULT hrStatus = S_OK;
MediaEventType meType = MEUnknown;
IMFMediaEvent *pEvent = (IMFMediaEvent*)pEventPtr;
if (pEvent == NULL)
{
return E_POINTER;
}
// Get the event type.
HRESULT hr = pEvent->GetType(&meType);
if (FAILED(hr))
{
goto done;
}
// Get the event status. If the operation that triggered the event
// did not succeed, the status is a failure code.
hr = pEvent->GetStatus(&hrStatus);
// Check if the async operation succeeded.
if (SUCCEEDED(hr) && FAILED(hrStatus))
{
hr = hrStatus;
}
if (FAILED(hr))
{
goto done;
}
switch(meType)
{
case MESessionTopologyStatus:
hr = OnTopologyStatus(pEvent);
break;
case MEEndOfPresentation:
hr = OnPresentationEnded(pEvent);
break;
case MENewPresentation:
hr = OnNewPresentation(pEvent);
break;
default:
hr = OnSessionEvent(pEvent, meType);
break;
}
done:
SafeRelease(&pEvent);
return hr;
}
// Release all resources held by this object.
HRESULT CPlayer::Shutdown()
{
// Close the session
HRESULT hr = CloseSession();
// Shutdown the Media Foundation platform
MFShutdown();
if (m_hCloseEvent)
{
CloseHandle(m_hCloseEvent);
m_hCloseEvent = NULL;
}
return hr;
}
/// Protected methods
HRESULT CPlayer::OnTopologyStatus(IMFMediaEvent *pEvent)
{
UINT32 status;
HRESULT hr = pEvent->GetUINT32(MF_EVENT_TOPOLOGY_STATUS, &status);
if (SUCCEEDED(hr) && (status == MF_TOPOSTATUS_READY))
{
SafeRelease(&m_pVideoDisplay);
// Get the IMFVideoDisplayControl interface from EVR. This call is
// expected to fail if the media file does not have a video stream.
(void)MFGetService(m_pSession, MR_VIDEO_RENDER_SERVICE,
IID_PPV_ARGS(&m_pVideoDisplay));
hr = StartPlayback();
}
return hr;
}
// Handler for MEEndOfPresentation event.
HRESULT CPlayer::OnPresentationEnded(IMFMediaEvent *pEvent)
{
// The session puts itself into the stopped state automatically.
m_state = Stopped;
return S_OK;
}
// Handler for MENewPresentation event.
//
// This event is sent if the media source has a new presentation, which
// requires a new topology.
HRESULT CPlayer::OnNewPresentation(IMFMediaEvent *pEvent)
{
IMFPresentationDescriptor *pPD = NULL;
IMFTopology *pTopology = NULL;
// Get the presentation descriptor from the event.
HRESULT hr = GetEventObject(pEvent, &pPD);
if (FAILED(hr))
{
goto done;
}
// Create a partial topology.
hr = CreatePlaybackTopology(m_pSource, pPD, m_hwndVideo,&pTopology);
if (FAILED(hr))
{
goto done;
}
// Set the topology on the media session.
hr = m_pSession->SetTopology(0, pTopology);
if (FAILED(hr))
{
goto done;
}
m_state = OpenPending;
done:
SafeRelease(&pTopology);
SafeRelease(&pPD);
return S_OK;
}
// Create a new instance of the media session.
HRESULT CPlayer::CreateSession()
{
// Close the old session, if any.
HRESULT hr = CloseSession();
if (FAILED(hr))
{
goto done;
}
assert(m_state == Closed);
// Create the media session.
hr = MFCreateMediaSession(NULL, &m_pSession);
if (FAILED(hr))
{
goto done;
}
// Start pulling events from the media session
hr = m_pSession->BeginGetEvent((IMFAsyncCallback*)this, NULL);
if (FAILED(hr))
{
goto done;
}
m_state = Ready;
done:
return hr;
}
// Close the media session.
HRESULT CPlayer::CloseSession()
{
// The IMFMediaSession::Close method is asynchronous, but the
// CPlayer::CloseSession method waits on the MESessionClosed event.
//
// MESessionClosed is guaranteed to be the last event that the
// media session fires.
HRESULT hr = S_OK;
SafeRelease(&m_pVideoDisplay);
// First close the media session.
if (m_pSession)
{
DWORD dwWaitResult = 0;
m_state = Closing;
hr = m_pSession->Close();
// Wait for the close operation to complete
if (SUCCEEDED(hr))
{
dwWaitResult = WaitForSingleObject(m_hCloseEvent, 5000);
if (dwWaitResult == WAIT_TIMEOUT)
{
assert(FALSE);
}
// Now there will be no more events from this session.
}
}
// Complete shutdown operations.
if (SUCCEEDED(hr))
{
// Shut down the media source. (Synchronous operation, no events.)
if (m_pSource)
{
(void)m_pSource->Shutdown();
}
// Shut down the media session. (Synchronous operation, no events.)
if (m_pSession)
{
(void)m_pSession->Shutdown();
}
}
SafeRelease(&m_pSource);
SafeRelease(&m_pSession);
m_state = Closed;
return hr;
}
// Start playback from the current position.
HRESULT CPlayer::StartPlayback()
{
assert(m_pSession != NULL);
PROPVARIANT varStart;
PropVariantInit(&varStart);
HRESULT hr = m_pSession->Start(&GUID_NULL, &varStart);
if (SUCCEEDED(hr))
{
// Note: Start is an asynchronous operation. However, we
// can treat our state as being already started. If Start
// fails later, we'll get an MESessionStarted event with
// an error code, and we will update our state then.
m_state = Started;
}
PropVariantClear(&varStart);
return hr;
}
// Start playback from paused or stopped.
HRESULT CPlayer::Play()
{
if (m_state != Paused && m_state != Stopped)
{
return MF_E_INVALIDREQUEST;
}
if (m_pSession == NULL || m_pSource == NULL)
{
return E_UNEXPECTED;
}
return StartPlayback();
}
// Create a media source from a URL.
HRESULT CreateMediaSource(PCWSTR sURL, IMFMediaSource **ppSource)
{
MF_OBJECT_TYPE ObjectType = MF_OBJECT_INVALID;
IMFSourceResolver* pSourceResolver = NULL;
IUnknown* pSource = NULL;
// Create the source resolver.
HRESULT hr = MFCreateSourceResolver(&pSourceResolver);
if (FAILED(hr))
{
goto done;
}
// Use the source resolver to create the media source.
// Note: For simplicity this sample uses the synchronous method to create
// the media source. However, creating a media source can take a noticeable
// amount of time, especially for a network source. For a more responsive
// UI, use the asynchronous BeginCreateObjectFromURL method.
hr = pSourceResolver->CreateObjectFromURL(
sURL, // URL of the source.
MF_RESOLUTION_MEDIASOURCE, // Create a source object.
NULL, // Optional property store.
&ObjectType, // Receives the created object type.
&pSource // Receives a pointer to the media source.
);
if (FAILED(hr))
{
goto done;
}
// Get the IMFMediaSource interface from the media source.
hr = pSource->QueryInterface(IID_PPV_ARGS(ppSource));
done:
SafeRelease(&pSourceResolver);
SafeRelease(&pSource);
return hr;
}
// Create an activation object for a renderer, based on the stream media type.
HRESULT CreateMediaSinkActivate(
IMFStreamDescriptor *pSourceSD, // Pointer to the stream descriptor.
HWND hVideoWindow, // Handle to the video clipping window.
IMFActivate **ppActivate
)
{
IMFMediaTypeHandler *pHandler = NULL;
IMFActivate *pActivate = NULL;
// Get the media type handler for the stream.
HRESULT hr = pSourceSD->GetMediaTypeHandler(&pHandler);
if (FAILED(hr))
{
goto done;
}
// Get the major media type.
GUID guidMajorType;
hr = pHandler->GetMajorType(&guidMajorType);
if (FAILED(hr))
{
goto done;
}
// Create an IMFActivate object for the renderer, based on the media type.
if (MFMediaType_Audio == guidMajorType)
{
// Create the audio renderer.
hr = MFCreateAudioRendererActivate(&pActivate);
}
else if (MFMediaType_Video == guidMajorType)
{
// Create the video renderer.
hr = MFCreateVideoRendererActivate(hVideoWindow, &pActivate);
}
else
{
// Unknown stream type.
hr = E_FAIL;
// Optionally, you could deselect this stream instead of failing.
}
if (FAILED(hr))
{
goto done;
}
// Return IMFActivate pointer to caller.
*ppActivate = pActivate;
(*ppActivate)->AddRef();
done:
SafeRelease(&pHandler);
SafeRelease(&pActivate);
return hr;
}
// Add a source node to a topology.
HRESULT AddSourceNode(
IMFTopology *pTopology, // Topology.
IMFMediaSource *pSource, // Media source.
IMFPresentationDescriptor *pPD, // Presentation descriptor.
IMFStreamDescriptor *pSD, // Stream descriptor.
IMFTopologyNode **ppNode) // Receives the node pointer.
{
IMFTopologyNode *pNode = NULL;
// Create the node.
HRESULT hr = MFCreateTopologyNode(MF_TOPOLOGY_SOURCESTREAM_NODE, &pNode);
if (FAILED(hr))
{
goto done;
}
// Set the attributes.
hr = pNode->SetUnknown(MF_TOPONODE_SOURCE, pSource);
if (FAILED(hr))
{
goto done;
}
hr = pNode->SetUnknown(MF_TOPONODE_PRESENTATION_DESCRIPTOR, pPD);
if (FAILED(hr))
{
goto done;
}
hr = pNode->SetUnknown(MF_TOPONODE_STREAM_DESCRIPTOR, pSD);
if (FAILED(hr))
{
goto done;
}
// Add the node to the topology.
hr = pTopology->AddNode(pNode);
if (FAILED(hr))
{
goto done;
}
// Return the pointer to the caller.
*ppNode = pNode;
(*ppNode)->AddRef();
done:
SafeRelease(&pNode);
return hr;
}
// Add an output node to a topology.
HRESULT AddOutputNode(
IMFTopology *pTopology, // Topology.
IMFActivate *pActivate, // Media sink activation object.
DWORD dwId, // Identifier of the stream sink.
IMFTopologyNode **ppNode) // Receives the node pointer.
{
IMFTopologyNode *pNode = NULL;
// Create the node.
HRESULT hr = MFCreateTopologyNode(MF_TOPOLOGY_OUTPUT_NODE, &pNode);
if (FAILED(hr))
{
goto done;
}
// Set the object pointer.
hr = pNode->SetObject(pActivate);
if (FAILED(hr))
{
goto done;
}
// Set the stream sink ID attribute.
hr = pNode->SetUINT32(MF_TOPONODE_STREAMID, dwId);
if (FAILED(hr))
{
goto done;
}
hr = pNode->SetUINT32(MF_TOPONODE_NOSHUTDOWN_ON_REMOVE, FALSE);
if (FAILED(hr))
{
goto done;
}
// Add the node to the topology.
hr = pTopology->AddNode(pNode);
if (FAILED(hr))
{
goto done;
}
// Return the pointer to the caller.
*ppNode = pNode;
(*ppNode)->AddRef();
done:
SafeRelease(&pNode);
return hr;
}
//</SnippetPlayer.cpp>
// Add a topology branch for one stream.
//
// For each stream, this function does the following:
//
// 1. Creates a source node associated with the stream.
// 2. Creates an output node for the renderer.
// 3. Connects the two nodes.
//
// The media session will add any decoders that are needed.
HRESULT AddBranchToPartialTopology(
IMFTopology *pTopology, // Topology.
IMFMediaSource *pSource, // Media source.
IMFPresentationDescriptor *pPD, // Presentation descriptor.
DWORD iStream, // Stream index.
HWND hVideoWnd) // Window for video playback.
{
IMFStreamDescriptor *pSD = NULL;
IMFActivate *pSinkActivate = NULL;
IMFTopologyNode *pSourceNode = NULL;
IMFTopologyNode *pOutputNode = NULL;
BOOL fSelected = FALSE;
HRESULT hr = pPD->GetStreamDescriptorByIndex(iStream, &fSelected, &pSD);
if (FAILED(hr))
{
goto done;
}
if (fSelected)
{
// Create the media sink activation object.
hr = CreateMediaSinkActivate(pSD, hVideoWnd, &pSinkActivate);
if (FAILED(hr))
{
goto done;
}
// Add a source node for this stream.
hr = AddSourceNode(pTopology, pSource, pPD, pSD, &pSourceNode);
if (FAILED(hr))
{
goto done;
}
// Create the output node for the renderer.
hr = AddOutputNode(pTopology, pSinkActivate, 0, &pOutputNode);
if (FAILED(hr))
{
goto done;
}
// Connect the source node to the output node.
hr = pSourceNode->ConnectOutput(0, pOutputNode, 0);
}
// else: If not selected, don't add the branch.
done:
SafeRelease(&pSD);
SafeRelease(&pSinkActivate);
SafeRelease(&pSourceNode);
SafeRelease(&pOutputNode);
return hr;
}
// Create a playback topology from a media source.
HRESULT CreatePlaybackTopology(
IMFMediaSource *pSource, // Media source.
IMFPresentationDescriptor *pPD, // Presentation descriptor.
HWND hVideoWnd, // Video window.
IMFTopology **ppTopology) // Receives a pointer to the topology.
{
IMFTopology *pTopology = NULL;
DWORD cSourceStreams = 0;
// Create a new topology.
HRESULT hr = MFCreateTopology(&pTopology);
if (FAILED(hr))
{
goto done;
}
// Get the number of streams in the media source.
hr = pPD->GetStreamDescriptorCount(&cSourceStreams);
if (FAILED(hr))
{
goto done;
}
// For each stream, create the topology nodes and add them to the topology.
for (DWORD i = 0; i < cSourceStreams; i++)
{
hr = AddBranchToPartialTopology(pTopology, pSource, pPD, i, hVideoWnd);
if (FAILED(hr))
{
goto done;
}
}
// Return the IMFTopology pointer to the caller.
*ppTopology = pTopology;
(*ppTopology)->AddRef();
done:
SafeRelease(&pTopology);
return hr;
}
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