MultiMon 1.0.0-rc.1

First release candidate of the ground-up rebuild. Self-contained win-x64 build, nothing to install: unzip and run App\MultiMon.Control.exe. The stress harness ships alongside in Stress\.

Pre-release: Windows is code-complete; GA is gated on the hardware acceptance pass (real Intel QuickSync, multi-vendor 4+ screen rig, live audio device-pull). Builds are unsigned, so SmartScreen will warn on first run: choose More info then Run anyway.

Requirements: Windows 10 1809+ / 11 (64-bit), any Direct3D 11 feature-level 11.0 GPU. FFmpeg on PATH only if you want Convert to HAP.

This is the first release candidate of the MultiMon ground-up rebuild. The old WPF + LibVLCSharp
implementation is replaced in its entirety by a persistent Direct3D 11 pipeline.

Added

• Persistent D3D11 pipeline — one ID3D11Device and one IDXGISwapChain1 per monitor, created
  once at application start and reused for the entire session. Entering and leaving perform mode shows
  and hides windows; it never recreates the device, swapchains, shaders, or pipeline state.
• Media Foundation decode — H.264 and HEVC hardware decode via IMFDXGIDeviceManager bound to the
  application's D3D11 device; automatic software-decode fallback when hardware decode is unavailable.
• HAP / HapQ playback — from-scratch vendored MOV atom parser, Snappy chunk decompression, BCn
  (BC1/BC3/BC7) compressed-texture upload, and a HapQ YCoCg-to-RGB pixel shader. No third-party HAP
  library.
• Three perform modes — Span (one source across all monitors, equal share per screen), Individual
  (one source per monitor), and Split (one source divided into a configurable rows-by-columns grid of
  outputs; 4-output default is 2x2; grid is configurable).
• WASAPI audio — raw shared-mode WASAPI per output device, clocked to the QPC-based master
  timeline. Audio track linked to a video slot only when the track is audible.
• Master volume and mute — master level is owned by PerformanceController and persists across
  engine rebuilds and between perform cycles.
• Project I/O — save and load monitor assignments, source bindings, mode, and audio routing as
  .mmproj JSON files (schema version 2).
• Convert to HAP dialog — transcodes a source file to HAP via an external FFmpeg process; surfaces
  probe and metadata faults; progress tracking.
• Identify screens — toggles a numbered Windows-11-style overlay on every monitor; auto-hidden on
  perform entry.
• Device-removed recovery — DeviceRemovedHandler detects DXGI_ERROR_DEVICE_REMOVED on present
  or decode, recreates the device and all resources, and resumes from the master clock. Verified via
  --inject-device-loss.
• Multi-adapter support — single D3D11 device with DXGI cross-adapter present; output windows on a
  secondary adapter are composited via DWM. Verified on an AMD+NVIDIA dual-adapter box.
• Stress harness (MultiMon.Stress) — headless EnterPerform/ExitPerform cycle runner with D3D11
  debug-layer live-object tracking, wedge detection, and flags --cycles, --windows, --fullscreen,
  --mode, --hap, --audio, --inject-device-loss, --force-sw-decode, --pause-after, and
  others.
• File logging — timestamped log lines written to %LOCALAPPDATA%\MultiMon\Logs\ (10-file
  rotation); startup banner captures GPU, monitor inventory, and D3D11 feature level.
• Remote diagnostics — global crash handlers write a [CRASH] stack to the log; present-rate
  watchdog and TogglePause markers assist remote debugging.
• BC7 capability gating — HAP BC7 format is enabled only when the GPU reports
  D3D11_FORMAT_SUPPORT_TEXTURE2D for DXGI_FORMAT_BC7_UNORM; older iGPUs fall back to BC3.
• "Signal" UI theme — immersive dark title bar on both the control window and the HAP dialog.

Fixed

• Multi-output pause freeze (Individual mode) — on a four-output rig, pausing in Individual mode
  froze two to four screens until Escape. Root cause: each MediaFoundationSource exhausted its
  hardware decoder's output-sample pool (depth 8) on pause, causing MF_E_SAMPLEALLOCATOR_EMPTY on
  resume and killing the decode thread. Fix: cap the MF frame-timeline depth to 3.
• Teardown timeout on multi-output rig — the same sample-pool exhaustion left decode threads
  blocked at shutdown, producing a "teardown did not complete within 10s" warning. Resolved by the
  same depth cap.
• Span mode equal-per-screen division — span UV layout now divides equally per screen regardless
  of pixel resolution differences between monitors, matching the intended equal-share-per-screen
  semantic.
• Audio garble after re-perform — fixed clock-reset and WASAPI re-baseline on re-entry to perform
  mode.
• Master volume lost on engine rebuild — master volume and mute were reset to defaults each time
  the audio engine was rebuilt (e.g. on re-perform). Moved master ownership to
  PerformanceController.
• FFmpeg argument injection — FfmpegHapConverter now passes every argument as a discrete element
  via ProcessStartInfo.ArgumentList instead of a hand-quoted concatenated string.
• MFStartup ref-count leak — MfAudioSource now balances MFStartup if its Configure() call
  throws.
• Cross-thread StateChanged — MainViewModel.OnControllerStateChanged marshals to the WPF
  dispatcher before updating bound properties.
• async void Convert_Click unhandled exception — wrapped in try/catch to prevent an escaped
  exception from crashing the application.
• Hotkey registration failure silent — Space and Escape perform hotkeys now notify the user if
  registration fails, matching the behaviour of F11.
• Bounded teardown join — App.OnExit joins the teardown thread with a 10-second timeout and
  calls Environment.Exit(0) if the timeout is reached, preventing a wedged teardown from freezing
  the process at shutdown.
• Present-model wedge under raised system timer — changed from Present(1) to a WAITABLE
  swapchain with Present(0) to eliminate render-loop stalls caused by the 1ms system timer raised
  by Media Foundation and WASAPI.
• HAP/MOV/Snappy untrusted-file OOM — MovHapDemuxer, SnappyDecoder, and HapFrameDecoder now
  reject implausible sizes from file-supplied fields before allocating, preventing a crafted file from
  causing an out-of-memory condition in the decode thread.
• ConvertToHap dialog fault surfacing — probe and metadata failures are now surfaced in the dialog
  instead of silently stalling; metadata parse uses TryParse per field to degrade gracefully.
• Harness windowed-span false positive — windowed test rects are now tiled non-overlapping so the
  span UV clustering produces correct per-output slices.

Known Limitations

• Real-Intel (QuickSync) acceptance run not yet completed; WARP cannot emulate Intel QuickSync. The
  hardware-gated go/no-go gate (multi-vendor 4+ screen rig, real Intel, live audio device-pull) remains
  open. This RC build should not be tagged v1.0.0 until that gate passes.
• The build is unsigned. Windows SmartScreen will show a warning on first run; see README for the
  "More info -> Run anyway" step.
• FFmpeg PATH-walk: the Convert-to-HAP dialog resolves ffmpeg.exe from PATH without filtering
  world-writable directories. Install FFmpeg only from a trusted source.
• Project file media paths (including UNC) are accepted as-is by ProjectService. Only open project
  files you created.
• Per-link audio mixer overrides (track volume set within a perform session) are not persisted to the
  .mmproj file. This is a known feature gap, not a regression.
• Live audio device-pull mid-show: the WASAPI invalidation-rebuild code is implemented and
  harness-verified; a live device-pull confirmation on the multi-output rig is still pending.