Resolves the DX12 mirror stutter and makes dropped frames observable.
Decouple the D3D11On12 copy from the game's present queue. Submitting the
copy on the game's own present queue (the prior approach) ordered it
correctly but stalled the game's presents: GPU back-pressure, plus the
shared keyed-mutex AcquireSync is a CPU-blocking call on the render
thread. Running it on an independent queue avoids the stall but races the
game's render -> stale frames. Do both: run the copy on our own queue and
order it after the frame with an ID3D12Fence the game's present queue
signals (near-free) and our queue waits on. The present queue is still
recovered for late injection via the ExecuteCommandLists hook (now used to
signal the fence, not host the copy). Producer AcquireSync stays
non-blocking (timeout 0) so a busy mutex drops a mirror frame instead of
stalling the game.
Add drop detection (protocol v12 -> v13). The hook counts captures skipped
because the keyed mutex was busy (VideoShare.frames_dropped); the host
counts published frames it never displayed (generation gaps). The Video
panel shows "Frames lost: N/s capture N/s display", red when nonzero.
This confirmed the game-window-vs-mirror behavior is a display-path
artifact (unfocused windows lose VRR/independent flip), not a capture loss.
Add a one-shot present-pattern log: per distinct swapchain (size/format/
buffer index) and per distinct present-flags value, with DXGI_PRESENT_TEST
spelled out as an occlusion probe that draws nothing -- which is why
Miles Morales shows ~2 presents per captured frame (the test present is
counted but produces no frame).
Docs: add the DX12 capture lessons to the README (rotating back buffer,
fence/own-queue, capture-at-Present decoupling from DWM) and drop the now
-moot DX12 overhead future-work item.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The host sampled the shared backbuffer copy through a view typed exactly like the
game's backbuffer. For games whose backbuffer is an *_SRGB format (e.g. Life is
Strange: Before the Storm -- confirmed R8G8B8A8_UNORM_SRGB / fmt 29 via the hook
log), the GPU decoded sRGB->linear on the sample, and the host then wrote those
linear values straight to its plain-UNORM swapchain with no re-encode, so the
mirror came out noticeably darker than the game.
Sample the copy as the plain-UNORM sibling of the format (srgb_to_unorm) so the
bytes pass through unchanged -- matching what WGC already does. The UNORM and
*_SRGB formats share a typeless group, so CopyResource from the producer's sRGB
texture into the host's UNORM copy is allowed. Non-sRGB formats are unaffected.
Adds srgb_format_test locking the mapping. All 6 tests pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add an injected IDXGISwapChain::Present / Present1 hook as a lower-latency,
border-free alternative to WGC. The hook copies the swapchain backbuffer into a
shared keyed-mutex texture (coop_video_<pid>); the host opens it by name and
samples it. New opt-in HookSubsys_Video (protocol v6 -> v7); the Video mirror
panel gains a WGC vs Hooked source toggle that installs/removes the subsystem.
Verified by present_hook_test (drives a real D3D11 swapchain end-to-end and reads
the rendered pixels back through the shared texture) and against Phantom Brave
(D3D9: hook installs cleanly and stays idle, WGC fallback). All 5 tests pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
