main.cpp

[De functie die is gekoppeld aan deze pagina, DirectShow, is een verouderde functie. Het is vervangen door MediaPlayer, IMFMediaEngineen Audio/Video Capture in Media Foundation. Deze functies zijn geoptimaliseerd voor Windows 10 en Windows 11. Microsoft raadt ten zeerste aan om nieuwe code te gebruiken MediaPlayer, IMFMediaEngine en Audio/Video Capture in Media Foundation in plaats van DirectShow, indien mogelijk. Microsoft stelt voor dat bestaande code die gebruikmaakt van de verouderde API's, indien mogelijk opnieuw worden geschreven om de nieuwe API's te gebruiken.]

Dit onderwerp bevat code voor de zelfstudie Afspelen van audio/video in DirectShow.

// 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 <new>
#include <windows.h>
#include <dshow.h>
#include "playback.h"

#pragma comment(lib, "strmiids")

DShowPlayer *g_pPlayer = NULL;

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
void CALLBACK OnGraphEvent(HWND hwnd, long eventCode, LONG_PTR param1, LONG_PTR param2);
void OnChar(HWND hwnd, wchar_t c);
void OnFileOpen(HWND hwnd);
void OnPaint(HWND hwnd);
void OnSize(HWND hwnd);
void NotifyError(HWND hwnd, PCWSTR pszMessage);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow)
{
    if (FAILED(CoInitializeEx(NULL, COINIT_MULTITHREADED | COINIT_DISABLE_OLE1DDE)))
    {
        NotifyError(NULL, L"CoInitializeEx failed.");
        return 0;
    }

    // Register the window class.
    const wchar_t CLASS_NAME[]  = L"Sample Window Class";
    
    WNDCLASS wc = { };
    wc.lpfnWndProc   = WindowProc;
    wc.hInstance     = hInstance;
    wc.lpszClassName = CLASS_NAME;

    RegisterClass(&wc);

    HWND hwnd = CreateWindowEx(0, CLASS_NAME, L"DirectShow Playback", 
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
        CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    if (hwnd == NULL)
    {
        NotifyError(NULL, L"CreateWindowEx failed.");
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);

    // Run the message loop.

    MSG msg = { };
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_CHAR:
        OnChar(hwnd, (wchar_t)wParam);
        return 0;

    case WM_CREATE:
        g_pPlayer = new (std::nothrow) DShowPlayer(hwnd);
        if (g_pPlayer == NULL)
        {
            return -1;
        }
        return 0;

    case WM_DESTROY:
        delete g_pPlayer;
        PostQuitMessage(0);
        return 0;

    case WM_DISPLAYCHANGE:
        g_pPlayer->DisplayModeChanged();
        break;

    case WM_ERASEBKGND:
        return 1;

    case WM_PAINT:
        OnPaint(hwnd);
        return 0;

    case WM_SIZE:
        OnSize(hwnd);
        return 0;

    case WM_GRAPH_EVENT:
       g_pPlayer->HandleGraphEvent(OnGraphEvent);
       return 0;
    }
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

void OnPaint(HWND hwnd)
{
    PAINTSTRUCT ps;
    HDC hdc;

    hdc = BeginPaint(hwnd, &ps);

    if (g_pPlayer->State() != STATE_NO_GRAPH && g_pPlayer->HasVideo())
    {
        // The player has video, so ask the player to repaint. 
        g_pPlayer->Repaint(hdc);
    }
    else
    {
        FillRect(hdc, &ps.rcPaint, (HBRUSH) (COLOR_WINDOW+1));
    }

    EndPaint(hwnd, &ps);
}

void OnSize(HWND hwnd)
{
    if (g_pPlayer)
    {
        RECT rc;
        GetClientRect(hwnd, &rc);

        g_pPlayer->UpdateVideoWindow(&rc);
    }
}

void CALLBACK OnGraphEvent(HWND hwnd, long evCode, LONG_PTR param1, LONG_PTR param2)
{
    switch (evCode)
    {
    case EC_COMPLETE:
    case EC_USERABORT:
        g_pPlayer->Stop();
        break;

    case EC_ERRORABORT:
        NotifyError(hwnd, L"Playback error.");
        g_pPlayer->Stop();
        break;
    }
}

void OnChar(HWND hwnd, wchar_t c)
{
    switch (c)
    {
    case L'o':
    case L'O':
        OnFileOpen(hwnd);
        break;

    case L'p':
    case L'P':
        if (g_pPlayer->State() == STATE_RUNNING)
        {
            g_pPlayer->Pause();
        }
        else
        {
            g_pPlayer->Play();
        }
        break;
    }
}

void OnFileOpen(HWND hwnd)
{
    OPENFILENAME ofn;
    ZeroMemory(&ofn, sizeof(ofn));

    WCHAR szFileName[MAX_PATH];
    szFileName[0] = L'\0';

    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = hwnd;
    ofn.hInstance = GetModuleHandle(NULL);
    ofn.lpstrFilter = L"All (*.*)/0*.*/0";
    ofn.lpstrFile = szFileName;
    ofn.nMaxFile = MAX_PATH;
    ofn.Flags = OFN_FILEMUSTEXIST;

    HRESULT hr;

    if (GetOpenFileName(&ofn))
    {
        hr = g_pPlayer->OpenFile(szFileName);

        InvalidateRect(hwnd, NULL, FALSE);

        if (SUCCEEDED(hr))
        {
            // If this file has a video stream, notify the video renderer 
            // about the size of the destination rectangle.
            OnSize(hwnd);
        }
        else
        {
            NotifyError(hwnd, TEXT("Cannot open this file."));
        }
    }
}

void NotifyError(HWND hwnd, PCWSTR pszMessage)
{
    MessageBox(hwnd, pszMessage, TEXT("Error"), MB_OK | MB_ICONERROR);
}

Verwante onderwerpen

afspelen van audio/video in DirectShow-

voorbeeld van het afspelen van DirectShow