Skip to main content

Application Flow

Phase 0 — the launcher (src/MovieMaker/main.cpp)​

// src/MovieMaker/main.cpp (reconstructed shape)
int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int) {
    // 1. Resolve this executable's directory.
    // 2. LoadLibraryExW("WLXPhotoBase.dll") — optional bootstrap of the base DLL,
    //    guarded by its own __try/__except.
    // 3. LoadLibraryExW("MovieMakerCore.dll") from the exe dir (with a
    //    LOAD_LIBRARY_AS_DATAFILE fallback).
    // 4. GetProcAddress("MovieMakerMain").
    // 5. Register the Vectored Exception Handler for MSVC C++ exception codes
    //    (0xe06d7363 magic + subcodes 0x19930520/21/22 and the
    //    undocumented 0x01994000). [Quirk #1] — installed only at this point,
    //    so DLL loading above happens without the VEH active.
    // 6. Call MovieMakerMain(argc, argv) (__cdecl) inside
    //    __except(EXCEPTION_EXECUTE_HANDLER); remove the VEH afterwards.
}

The launcher does not use COM activation for the engine — MovieMakerCore.dll's CLSID is literally all zeros (Quirk #3), so the only way in is LoadLibrary + GetProcAddress.

Phase 1 — engine bootstrap (src/MovieMakerCore/dllmain.cpp)​

MovieMakerMain initializes the engine before any UI exists:

  • COM apartment setup and the WMMR::CoInitializer guard.
  • D3D11 device creation — hardware with WARP fallback, deliberately using the single-threaded flag (Quirk #9).
  • WIC imaging factory (windowscodecs) for thumbnail/decode paths.
  • Media Foundation startup (MFStartup).
  • The single-instance mutex Global\WindowsLiveMovieMaker_Sundance_SingleInstance, created in MovieMakerMain before subsystem init (Quirk #2); SundanceAppMain::AcquireSingleInstanceMutex later takes a second mutex, Global\WindowsLiveMovieMaker_SundanceApp, during initialization.
  • Delay-load hooks for the optional legacy DLLs (WLXPhotoSqm, DmxBici, wlidcli, uxcore) so their absence cannot crash startup (Quirk #11).

Phase 2 — SundanceApp (SundanceApp/SundanceAppMain.cpp)​

CSundanceApp builds the application skeleton:

  1. ProjectManager — creates the in-memory MovieProject, wires dirty-state tracking and auto-save (via AutoSaveManager).
  2. ImportController / ExportController — media import and export/publish pipelines.
  3. MediaBrowser + ThumbnailCache — media browsing surface with background thumbnail generation.
  4. UndoManager — transaction-based undo/redo stack with clipboard integration (ClipboardManager owns both the system clipboard chain and the internal clipboard).
  5. CommandLineParser — startup switches (project files, safemode).
  6. PlaybackController / TimelineController — hook the storyboard model to the preview.

The main window is a DirectUI host: SundanceNativeHwndHost bridges native HWNDs into the DirectUI element tree, and SundanceAppDataContext (IDispatch) feeds data-bound UI.

Phase 3 — the Ribbon (UI/Ribbon/)​

The Windows Ribbon Framework (uiribbon.h) is initialized with 67 command handlers and a full UpdateState / ComputeCommandEnabled pass. The MRU (most-recently-used) project list is backed by a site registry with its own registry "Count" query semantics. Ribbon markup ships as UIFILE resources in MovieMakerLang.dll (RT_UIFILE_RIBBON = 10000).

Phase 4 — storyboard model (StoryboardManager/)​

A MovieProject is created (empty or from a .wlmp file via the Serialization reader). The model is:

  • MovieProject → TimelineTracks (0 = video, higher = audio etc.)
  • Each track holds MovieExtents (clips) with Extents arithmetic for layout/overlap.
  • Templates define the 23 effects / 7 themes; Theme applies visual themes by patching project XML.
  • Transport (StoryboardManager/Transport/) drives playback: TransportBase plus a CommandBin of transport commands.

Phase 5 — rendering loop (HMREngine/ + Preview/)​

  • PreviewPresenter (Preview/PreviewPresenter.cpp) owns the D3D11 preview surface.
  • HMREngine::Engine runs the render loop: scene-graph traversal (RenderingList, depth-capped at 512), text rendering via DirectWrite, mesh/texture resources through DXResources.
  • Media frames reach textures through HMRAVSource::TextureInterop (MF ↔ DX11 sharing), with VideoProc handling DXVA2/XVideoProc conversion (via the dxva2stubs.cpp compatibility layer).
  • Pattern meshes (HMREngine/PatternMesh/) render the video transitions; the 92 transition/effect animation classes live in WLXPipetran (Quirk #18).

Phase 6 — publishing (Publishing/)​

PublishJob runs the background encode/upload pipeline. In the current reconstruction the render/encode stage produces verified test frames, not real video — a documented stub category (see Stub Design). WLXTranscode.exe and WLXCodecHost.exe participate out-of-process where the original used them.

Message flow after startup​

Every user-visible action follows the same shape: UI behavior → controller → model mutation (inside an undo transaction) → transport/render invalidation.