The render-hook only installed IAudioClient/IAudioRenderClient hooks
reactively, when it saw the game call IMMDevice::Activate -> GetService.
But we attach to a game that is already running and playing audio, so its
render client was created before injection: those calls never fire again,
no primary stream is ever registered, nothing is captured, and the host
always falls back to process loopback (the echo). Every game tested did so.
Fix: at anchor time, build our own probe IAudioClient + IAudioRenderClient
with raw calls and hook GetBuffer/ReleaseBuffer (plus Initialize/GetService)
on their vtables. Every instance of a COM coclass shares one vtable, so this
patches the shared vtables and intercepts the game's pre-existing render
client too. The first render client seen actively releasing buffers is
adopted as primary on the audio thread (try-lock, one-time) using the device
mix format as its assumed format (we never saw its Initialize). Streams
created after injection still register via the reactive path with their real
format.
Also fixes a self-deadlock: installing the Activate hook before the probe's
own device->Activate call re-entered hk_Activate -> install_audioclient_hooks,
which blocked on the setup mutex the installer already held, freezing the
worker (and any game thread that later called Activate -> crash). The probe
objects are now created raw, before any hook is installed.
Validated against Phantom Brave (injected while already playing): the
pre-existing 48 kHz/2ch/float render client is detected and registered as
primary, real non-silent audio reaches the ring (peak tracks the game's
levels), and a draining consumer sees zero overruns.
Tooling for iterating on real games without Steam/RPT/the host UI:
- tools/audio_probe: creates the IPC block + audio ring, injects the hook,
drains the ring and prints stream/format/peak/overrun diagnostics by pid.
- hook/src/debug_log: opt-in file trace (%TEMP%\coop_hook.log), enabled by
the COOP_HOOK_LOG env var or the %TEMP%\coop_hook.log.on sentinel the probe
drops; off in normal use.
All four tests still pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
End-to-end plumbing of the render-hook audio path.
Hook (coop_hook.dll):
- CMake: build audio_hook.cpp, link ole32/mmdevapi, NTDDI_WIN10_CO.
- dllmain: CoInitializeEx(MTA) on the worker thread; install the audio hooks
even before the ring exists (so streams are counted); open the host's
coop_audio_<pid> ring when it appears and attach it (enabling capture+silence);
remove_audio_hooks on clean detach.
Host (coop_host.exe):
- AudioMirror now creates the shared audio ring (owns capture_enabled) and tries
the Hooked path first: waits ~1s for the hook to publish a format, then
re-renders the game's frames from the ring with AUTOCONVERTPCM (no echo, since
the hook silences the game locally).
- Automatic fallback: if the ring can't be created, no format arrives in time,
or the render client won't initialize, it disables capture (so the game stays
audible) and reverts to the existing process-loopback path (echo, no regress).
- Exposes Source (Hooked/Loopback/None) for the upcoming panel indicator.
Loopback render loop kept intact as run_loopback. Manual end-to-end (M5) and the
panel UI (M4) are next.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Surfaced by a game (Life is Strange: Before the Storm) that ignores
controller input when it lacks true OS focus even though it still polls
XInput. To find the focus-gated detection path, instrument the hook.
Protocol v3 status back-channel now reports:
- per-slot XInputGetState and XInputGetCapabilities counters (replacing the
single aggregate), so the overlay shows exactly which slots the game polls
and how fast;
- focus-API call counts (GetForegroundWindow/GetActiveWindow/GetFocus) to see
whether the game consults the APIs we spoof;
- input-path diagnostics: whether the process registered Raw Input for a
gamepad usage and whether it set RIDEV_INPUTSINK (background delivery), and
whether a DirectInput dll is loaded.
Host overlay gains a per-slot poll table and an "Input path" section. The DLL
refreshes input diagnostics each worker tick via GetRegisteredRawInputDevices.
hook_selftest updated for per-slot counters; passes.
This is diagnostic-only: once a real run shows which path LiS uses, the
targeted focus fix (e.g. forcing RIDEV_INPUTSINK or DI background coop) follows.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two problems surfaced in testing: (1) no way to tell whether the injected
hook was actually the input source, and (2) the final design needs the tool
window focused for Steam RPT capture, which would pause/silence games that
react to focus loss. Both are addressed here.
- Focus spoofing (hook/focus_spoof): find the game's main window, subclass it
to rewrite/swallow WM_ACTIVATE/ACTIVATEAPP/NCACTIVATE/KILLFOCUS, and inline-
hook GetForegroundWindow/GetActiveWindow/GetFocus to always report the game
as active. The game keeps running and polling while unfocused.
- Status back-channel (protocol v2): the DLL reports attached/focus-spoof
flags, game pid/hwnd, a heartbeat, and a cumulative XInputGetState counter.
The host overlay turns the counter into a live poll rate, so "is the hook
working" is directly observable.
- Synthetic test-input toggle in the host: forwards a known automated pattern
(stick circle + periodic A) to prove forwarding independent of the physical
pad.
- hook_selftest extended to assert the status channel; passes.
Documented the windowed/borderless requirement and the new observable test
flow in the README.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The host can now inject coop_hook.dll into a running game and forward
controller state to it over shared memory, so the game reads the host's
(eventually the guest's) input and nothing else.
- hook/: coop_hook.dll. DllMain spawns a worker that opens the shared-memory
channel (named by the game's pid) and installs SafetyHook inline hooks on
XInputGetState/GetStateEx/GetCapabilities/SetState. Detours synthesize state
from shared memory; unmanaged slots report disconnected, hiding physical pads.
- host/: process picker (Toolhelp32), CreateRemoteThread(LoadLibraryW) injector
with an IsWow64Process2 bitness guard, IPC server publishing pads each frame,
and an ImGui Injection panel wiring it together.
- tests/: hook_selftest exercises the IPC seqlock + hook detours in-process
(no game/controller needed); passes.
Build: SafetyHook wired in (COOP_BUILD_HOOK=ON), Zydis via FetchContent.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
