fix: Broken actions due to deprecation of download-artifact v2

This was required to be updated already in April as v2 is now
fully unsupported by github

.github/workflows/build-tag.yaml

@@ -49,7 +49,7 @@ jobs:
     steps:
       # This already extracts the contents of the artifact
       - name: "Download artifact"
-        uses: "actions/download-artifact@v2"
+        uses: "actions/download-artifact@v4"
         with:
           name: bemanitools-${{ github.sha }}
 

CHANGELOG.md

@@ -7,8 +7,27 @@ given in tags. The pipeline will pick this up and cuts out the relevant section
 
 ### Features
 
+- Major overhaul of [IIDX sync and performance settings](doc/iidxhook/iidx-syncbook.md)
+  documentation. Supports users in configuring their systems to run any IIDX version with proper
+  display timings, smooth frame rates and sync game-play
+- Add `iidxio-async.dll` wrapper/shim library to drive another iidxio in a dedicated IO thread, see
+  [documentation](doc/iidxhook/iidxio-async.md) for details 
+- Add `nvgpu` tool to configure NVIDIA GPUs and create a custom timing profile, see
+  [documentation](doc/tools/nvgpu.md) for details
+- Add `d3d9-frame-graph-hook.dll` that can be added as a hook to
+  either `launcher.exe` or `inject.exe` to display a graph of the frame times of the game's render
+  for debugging and performance analysis
+- feat: Add `d3d9-monitor-check` tool to run different music game relevant monitor tests including
+  a re-implementation of the infamous IIDX “monitor check” as a separate tool for testing and
+  debugging. See [documentation](doc/tools/d3d9-monitor-check.md) for details
+
 ### Fixes
 
+- iidxhook9: Work around reverb issue from Windows 26100.3476
+- iidxhook9: fix camhook for new style camera detection
+  - `cam.port_layout` added to .conf files of iidx 27 to 30
+- In general, a lot of internal cleanup
+
 ## 5.48
 
 ### Features

doc/dev/journal/2025-02-09-iidx-engine.md

@@ -0,0 +1,319 @@
+# IIDX engine overview and how game-play is impacted by hardware and software
+
+Date: 2025-02-09 Author: icex2
+
+This document provides information and explains the following:
+
+* A sort-of taxonomy of the different major IIDX game engine versions
+* How the core game-play part of the engine works regarding
+  * Threading model
+  * Main render loop
+  * Timing and synchronization
+
+The goal is to capture key knowledge about how the game's engine works to enable a better
+understanding for developing bemanitools and how certain features can impact performance and
+synchronization during game-play.
+
+This document is not claiming to be complete or 100% accurate. It is based on my own personal
+research and understanding of the IIDX game engine. It is very likely that some of the information
+is wrong or misunderstood. Feel free to raise any questions or concerns in an issue as I want
+this document to be as accurate as possible.
+
+## Taxonomy of IIDX game engine versions
+
+With every version, there have been numerous changes and improvements to the game engine. The
+following is a rough taxonomy that is focused on cabinet and hardware changes. As these are likely
+the main driver for key changes to the software and game engine, they create fairly distinct
+stages throughout the different versions of the game. The key attributes to be considered here are:
+
+* Main PCB
+* IO board
+* Monitor
+
+All of these had significant impact on key software features appearing or changing.
+
+### Twinkle hardware era: 1st Style to 8th Style
+
+* [Twinkle PCB](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#twinkle)
+* [Original rear projection monitor](https://github.com/shizmob/arcade-docs/blob/main/konami/products.md#iidx-rear-projection-monitor)
+* Homogenous hardware and software
+
+### 1st gen PC-based upgrade only: 9th Style
+
+* 9th Style came as an upgrade kit only to existing twinkle-based cabinet hardware
+* [KNM-845G3-A02 PCB](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#knm-845g3-a02)
+* [C02 EZUSB FX USB IO board](https://github.com/shizmob/arcade-docs/blob/main/konami/io.md#gec02-pwbaa)
+* Magnetic card readers connected to ezusb IO board
+
+### 1st gen PC-based with dedicated cabinet: 10th Style to DistorteD (13)
+
+* From here on, old cabinets that received the "Twinkle hardware" upgrade kit could always receive software only
+  upgrades
+* [CRT monitor](https://github.com/shizmob/arcade-docs/blob/main/konami/products.md#iidx-crt-monitor) with new dedicated
+  cabinets
+* [D01 EZUSB FX USB IO board](https://github.com/shizmob/arcade-docs/blob/main/konami/io.md#d01-io)
+* Slotted card readers starting version 13
+
+### 2nd gen PC: GOLD (14) to Lincle (19)
+
+* [FAB-e945-KN205](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#fab-e945-kn205)
+* All prior cabinet configurations can be upgraded with a PCB and software upgrade
+* New LCD monitor starting version 15
+  * Further variants of the LCD monitor appear starting version 18
+* [IO2 EZUSB FX2 USB IO board](https://github.com/shizmob/arcade-docs/blob/main/konami/io.md#usbio2) introduced with
+  version 14
+* Switch to wave pass readers on version 19
+
+### 3rd gen PC: Tricoro (20) to Sinobuz (24)
+
+* All prior cabinet configurations can be upgraded with a PCB and software upgrade
+* [ADE-HM65](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#hm65)
+* Game engine supports HD mode (720p)
+* Many new LCD monitor variants appear with every new version
+
+### 4th gen PC: CANNON BALLERS (25) to RESIDENT (30)
+
+* All prior cabinet configurations can be upgraded with a PCB and software upgrade
+* [ADE-6291](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#ade-6291)
+* [BIO2 IO board](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#hm65)
+  * Upgrade cabinets required the [BIO2 sub-IO board](https://github.com/shizmob/arcade-docs/blob/main/konami/io.md#bio2-ldj-sub-io)
+* Drop of SD mode support starting version 27
+* Supporting 120 hz monitors starting version 27
+* Many new LCD monitor variants appear with every new version
+  * 42" 120 hz for lightning cabinets starting version 27
+  * 42" 60 hz for non-lightning cabinets starting version 25
+
+### 5th gen PC: RESIDENT (30) to EPOLIS (31)
+
+* All prior cabinet configurations can be upgraded with a PCB and software upgrade
+* [C300-xonarae](https://github.com/shizmob/arcade-docs/blob/main/konami/boards.md#c300-xonarae)
+* Game engine supports FHD mode (1080p)
+
+## Threading model and core responsibilities in PC-based games
+
+Since the early days of 9th Style to today (as of time of writing this: EPOLIS), the threading model
+hasn't changed significantly:
+
+* Main and rendering thread
+  * Runs your typical D3D9 render loop
+    * Using D3D9ex starting version 27
+  * Starting and managing other threads
+  * Any file and game asset loading
+  * Handles all the core game logic of the different screens starting from the initial boot screen
+    to the core game-play screen
+* IO thread
+  * Polls the main IO hardware and synchronizes the in-memory input and output state with the
+    hardware
+  * Executes commands issued by the main thread to the IO board such as dongle or card reader
+    commands (ezusb generation of IO only)
+* Card reader thread (not applicable to versions 9 to 12)
+  * Runs the protocol to read/write the hardware of the readers
+  * Async execution of higher level commands issued by the main thread to the card reader hardware,
+    e.g. card read, card eject etc.
+* Audio thread
+  * Streaming of audio data to the sound API
+    * DirectSound for versions 9 to 26
+    * WASAPI for versions 27 to 30 for non-lighting cabinets with ADE-6291 hardware
+    * ASIO for versions 27 and newer for lighting cabinets
+    * ASIO for version 30/31 and newer for non-lighting cabinets with C300-xonarae hardware
+  * Async execution of higher level commands issued by the main thread to the audio backend, e.g.
+    play audio, stop audio, etc.
+* Network thread
+  * Network plumbing with the xrpc protocol
+  * Async execution of request-response commands issued by the main thread
+
+## Main and rendering thread
+
+With the game having transitioning to different screens throughout it's lifecycle, the main render
+loop might contain different logic such as asset loading. The following focuses on the main
+game-play screen, only. Common rendering logic still applies to other screens.
+
+This follows your typical D3D9 single threaded rendering loop which boils down to the following:
+
+* Begin the scene (`BeginScene`)
+* Set the render target (`SetRenderTarget`)
+* Clear the back buffer (`Clear`)
+* Run engine step. This includes and is mixed with
+  * IO input evaluation
+  * Game engine state and (re-) drawing the scene
+  * Commands to the audio playback, e.g. play key sounds
+  * Setting IO outputs
+* End the scene (`EndScene`)
+* Target a minimum frame time
+  * Introduced with version 11
+  * Sleep (`Sleep` or `SleepEx`) to fill up the frame up to either 13 ms or 14 ms (depending on the
+    version)
+  * This was likely introduced to not have the game run at hundreds of FPS if v-sync was disabled
+    (probably when running in window mode for development/testing purposes)
+* Swapping the back buffers (`Present`)
+  * D3D9 is configured with v-sync enabled by default and targets 60 hz
+  * With this configuration, the call to `Present` fills up the remaining frame time to target the
+    configured 60 hz refresh rate
+
+### Rendering resolutions
+
+The game engine went through a couple of different rendering resolutions:
+
+* 640x240: version 1 to 8 (all twinkle hardware)
+* 640x480: version 9 to 19 (1st and 2nd gen PC-based)
+* 1280x720 (HD mode) and 640x480 (SD mode): version 20 to 27 (3rd and 4th gen PC-based)
+* 1280x720 (HD mode) only for version 28 to 29 (4th gen PC-based)
+* 1280x720 (HD mode) and 1920x1080 (FHD mode) for version 30 (4th gen PC-based)
+* 1920x1080 (FHD mode) only for version 30+ (5th gen PC-based)
+
+## Core engine timing and synchronization
+
+The following outlines and explains the core engine concepts related to timing and synchronization.
+
+### The origins, twinkle hardware
+
+* It appears that the game has been on the same codebase since it's inception.
+* This can be reasoned by the following observations
+  * 9th style as the first PC-based game very buggy on initial release 
+  * 9th style threading model very clunky with various thread settings showing they tried to
+    prioritize different processing on a single core CPU 
+  * Coming from twinkle hardware that is a realtime system vs. a Windows XP system
+    * Fixed playstation 1 based hardware with a refresh rate of
+      [59.8260978565 hz](https://github.com/mamedev/mame/blob/bf9df04e005697788ae988ef5aea91a1878fd631/src/devices/video/psx.cpp#L435)
+    * No need to assume getting anything else if the resource budget per frame is not exceeded
+    * All sub-systems were driven synchronously to that fixed time step
+    * No need for the engine to synchronize audio during the song. When the song is started
+      correctly, it stayed sync throughout the song
+* Observations and assumptions
+  * It appears the developers struggled a lot with the significant platform shift to PC as indicated
+    by various core engine improvements throughout the years still
+  * Switches of hardware generations further complicated the situation as these forced them to further
+    drift away from how the game engine was initially designed on the twinkle system
+
+### Frame time/timing and engine step
+
+* The game's engine step and timing is frame based
+* The main render loop defines the minimum valid timing window for the game engine to be able to
+  evaluate
+  * 60 hz/fps = 16.667 ms (rounded to three decimal places)
+  * 120 hz/fps = 8.333 ms (rounded to three decimal places), only relevant for lightning cabinets with their 120 hz
+    screen/mode
+* Depending on the GPU hardware and configuration, the GPU might drive the screen not exactly at
+  perfectly 60 hz/fps = 16.667 ms
+* As outlined in the [main render loop](#main-and-rendering-thread), the `Present` call is the
+  key function call to determine the frame time for the game engine
+* Just having v-sync enabled and telling D3D9 to **target** 60 hz, it still depends on how the GPU
+  driver is implemented and how the GPU driver's implementation of D3D9 executes on the `Present`
+  call
+* This is primarily determined by how the GPU driver is operating and driving connected display
+  hardware
+* The following factors can contribute to that either directly or indirectly
+  * Different monitor types analog vs. digital (CRT vs. LCD)
+  * Different monitor connections VGA vs. DVI/HDMI/DP
+  * Different GPU drivers
+  * Different GPU hardware and vendors
+  * Different GPU settings
+
+### Monitor check screen
+
+The monitor check screen was introduced with version 14. This was a solution to the problem of not
+guaranteeing a single fixed refresh rate throughout different GPU and monitor combinations. See
+a detailed explanation in the previous sub-subsection about
+[what influences the frame time](#frame-timetiming-and-engine-step) of the game.
+
+The goal of the monitor check is to measure the frame time of the main render loop and use the
+results for [driving the core engine step](#engine-step-and-synchronization).
+
+The monitor check evolved slightly as different GPU and monitor hardware, and GPU drivers yielded
+varying refresh rates that determined the frame times of the main game loop.
+
+Actual values are outlined further down in the [engine step time](#engine-step-time) section.
+
+There are two main versions of the monitor check, all of them have always been part of the boot
+process:
+
+* 14
+  * Measures a total of 3000 frames
+  * If total time this took < 50004 ms -> so average of 16.668 ms per frame =  59.9952 hz
+    * S-Video mode -> 59.95 hz (also shows S-VIDEO when the monitor check completes)
+    * Otherwise VGA mode -> 60.05 hz
+  * If VGA is determined, the game patches the chart event data when loading
+    * `event_timestamp * 0.99817199 + 0.40000001` 
+  * When S-Video no charts are patched and the timing data in the chart is used as is
+* 15 to 18
+  * Identical to 14 except that chart patching now happens in milliseconds instead of frames
+  * VGA mode: `16.65279`
+  * S-Video mode: `16.680567`
+  * `event_timestamp * (1.0 / frame_time) + 0.40000001)`
+* 19
+  * Identical to previous version
+  * Monitor check screen shows current FPS on the last revision of that version. However, it doesn't
+    use the value shown there by any means. Assuming this was added before the introduction of the
+    new monitor check on 20.
+* 20 to 26
+  * Runs on boot or when switching monitor modes SD vs. HD 
+  * Measures only 1200 frames
+  * Takes the average refresh rate of 1200 frames
+  * Applies the measured avg. frame time directly to the charts before song
+* 27 to 30 
+  * Frame rate measuring identical to prior versions
+  * Added additional logic after the frame time measurements for handling of 120 hz displays 
+  * Includes checking the monitor and if the framerate matches as expected
+* 30/31 LDJ-010 upgrade
+  * Added NvDisplayConfigLDJ tool which runs on system start and configures a custom timing in the
+    NVIDIA GPU driver to ensure a fixed monitor refresh rate
+* 31
+  * Same code as before
+  * Consider the first 460 frames of the measurement as warm-up frames
+  * Discard these for the actual measurement to get more stable frame times
+  * Use a base avg. value of 119.982 for the 120 hz monitors and 59.9 for 60 hz monitors. Further
+    frames measured are counted towards the average with the given base value
+
+### Engine core game-play with visual and audio synchronization
+
+#### Chart data
+
+* Chart data encodes note timing and timing window information
+* Chart data consists of *note events* encoding a timestamp and note information such as type
+  and key-sound information
+* Timing windows are defined per chart
+* Most infamous example: GAMBOL (7Key/Another)
+* Game engine timestamp evaluation and note event timestamp encoding
+  * 9 to 14: Refresh rate in hz
+  * 15 to 31: Milliseconds (equivalent to assuming 1000 fps)
+* Fundamentally, that doesn't change game play experience as it's just a different way of
+  evaluating the timestamps since refresh rate in hz/frame rate in fps can be converted lossless to
+  frame time in ms
+
+#### Engine step time
+
+The engine uses the following source for frame rate/time to drive internal logic on the following
+versions
+
+* 9 to 13: Hardcoded 59.95 hz
+* 14: Either 59.95 hz or 60.05 hz determined by which value is determined to be closer to the
+  measured one during the monitor check screen on startup
+* 15 to 19: 59.95 hz or 60.05 hz
+  * Monitor check on startup measures the frame time and picks the value closest to what's been
+    measured
+  * Monitor check result can be overridden with the *Output Type* setting in the operator menu
+    * *S-Video* to force to 59.95 hz
+    * *VGA* to force to 60.05 hz
+* 20 to 31: Monitor check on boot determines the frame time and uses the result throughout the
+  entire game session
+
+#### Engine step and synchronization
+
+Per frame engine step advancing and synchronization during game-play
+
+* Game-play needs synchronization of the following aspects
+  * Drawn content on the screen
+  * Background audio playback track
+  * Key sound effects
+* The game engine synchronizes these only at the start of a song
+  * It takes known/determined refresh rate/frame time as the fixed time for every frame cycle
+    throughout the entire song
+  * It starts playback of the background audio track together with playback of the chart data
+  * With every engine step/frame it advances internal calculations by that fixed amount of time.
+    Thus, the game engine expects this to be constant/stable throughout an entire song
+  * The chart data is advanced every frame by the engine
+  * Key sound events are turned into audio playback on command as the chart advances
+  * No re-synchronization or check-pointing between main rendering thread and audio is happening
+    throughout the song
+* Remark: The above does not consider any kind of offsetting and timing adjustments for the sake
+  of keeping this simple and focus on the absolute core concepts 

doc/iidxhook/iidx-syncbook.md

@@ -0,0 +1,224 @@
+# IIDX "Syncbook": A guide to ensuring sync and performant gameplay
+
+This is a guide applicable to all IIDX versions that are native Windows PC-based. The goal is to 
+enable proper configuration of those games to ensure the game engine "runs in-sync" with any of its
+IO (visual GPU/display output, audio output, user input) resulting in high and stable performance
+for smooth game-play.
+
+This document won't go into the implementation details of the game engine. Please refer to the
+[IIDX engine details journal](../dev/journal/2025-02-09-iidx-engine.md) for a more in-depth
+information.
+
+## Understanding the problems and options to address them
+
+First, let's understand what the key problems are and how they contribute to different issues
+that impact game-play.
+
+### Song de-syncing
+
+Symptom: Throughout playing a song, the audio is de-syncing even it was fine when the song started.
+
+Cause: The game engine is fundamentally designed to run on a fixed and consistent frame
+rate/time per engine step. A mismatch of expected frame time by the game engine and actually delivered
+frame time by the GPU driver. This can come either as a stable frame time that just mismatches in
+general or (highly) fluctuating frame times.
+
+* G-sync on modern displays causes known fluctuations because it adjusts dynamically the monitor
+  refresh rate
+* V-sync not correctly configured/enforced or even vsync-off override in driver is causing
+  inconsistent frame times
+* Incorrect display timings causing refresh rate fluctuations resulting in inconsistent frame times
+
+Stable frame times but not having the correct ones that the game engine expects is a different
+problem that can be addressed by:
+
+* Knowing the refresh rates expected by the game engine of the different game versions
+* Configuring your GPU driver's display timings to match the expected frame times
+* Or, patch the game's chart data with your custom display timings so the game engine gets uses
+  *your* "correct" frame times
+  * Note: Offline patching the chart data doesn't work for several game versions as the monitor
+    check does override this data, but not as flexible as required
+  * Use the chart patch feature of bemanitools instead
+
+### Micro-stuttering and non-smooth note scrolling
+
+This is a trickier problem as it can be caused by a few different things.
+
+* GPU related
+  * Fluctuating refresh rates result in fluctuating frame times in the main game loop
+  * GPU power configuration in non-performance mode (e.g. "power saving") causes processing latency
+    due to sleep states
+* Display related
+  * Display firmware buggy and/or internal scalers that expect to run at very specific refresh rates
+    and cannot adapt to any custom display timings enforced by the GPU
+  * A known example is the official
+    [PENDUAL LCD monitor](https://github.com/shizmob/arcade-docs/blob/6ac99975cdb2bf668362f65fa9fa3ffb2127308b/konami/product/GULDJ-JI.md#notes-and-known-issues) that does not v-sync correctly to any other refresh-rate than 60.000 hz
+* CPU related
+  * CPU power configuration on Windows in non-performance mode (e.g. "power saving") causes
+    processing latency due to sleep states
+  * Correct CPU C-states configuration in BIOS/UEFI
+    * These cannot be configured in Windows and are separate from Windows's power configuration
+* Other stuff running in the background of the system causing fluctuations
+  * (Synchronous) Disk I/O heavy applications stealing CPU time
+  * Or any other process creating a considerable amount of CPU or GPU load
+
+## Configuration guide for different game versions
+
+### Measuring monitor refresh rate
+
+Let's start with configuring the system to meet the game engine's expectation regarding the
+target monitor refresh rate and requiring vsync.
+
+First, use the [d3d9-monitor-check tool](../tools/d3d9-monitor-check.md) to measure the currently
+configured refresh rate of your monitor. Note that your monitor might yield different timings on
+different resolutions and different game versions run on
+[different rendering resolutions](../dev/journal/2025-02-09-iidx-engine.md#rendering-resolutions).
+
+For example, the game version is 31 with the rendering resolution of 1920x1080 in FHD mode that you
+want to target:
+
+```bat
+d3d9-monitor-check.exe cmdline refresh-rate-test 1920 1080 60
+```
+
+The test shows the current monitor refresh rate and the average refresh rate over the course of
+the test. Check that the avg. refresh rate is stable during the measuring phase (during warm-up,
+it's ok if it fluctuates).
+
+This test allows you to determine/check:
+
+* Refresh rate/frame time fluctuations: if you see (high) fluctuations on the first or second
+  decimal place
+* What's your current target refresh rate the GPU is driving your monitor at
+* If vsync isn't overridden by some other driver setting as you want to see a refresh rate around
+  the 60 hz mark
+
+### Measuring vsync issues
+
+Some displays or the GPU configuration might lead to vsync issues which can be detected with the
+`d3d9-monitor-check.exe` tool as well.
+
+```bat
+d3d9-monitor-check.exe cmdline vsync-test 1920 1080 60
+```
+
+This runs a test with a VSYNC text that alternates red and cyan colors. If the text appears grey
+all the time, everything's fine. If you spot brief red or cyan text either occasionally or
+periodically, your current configuration has vsync issues resulting in skipped frames or old
+frames displaying longer.
+
+### Configuration
+
+The following are recommended configurations for the different game versions. If any of these
+don't work as expected, you have to troubleshoot and tweak these potentially. Please refer to the
+[guidelines above](#configuration-guide-for-different-game-versions) to understand how to use
+the tooling and test your changes.
+
+#### Recommended configuration with NVIDIA GPU and driver
+
+We want to achieve the following configuration on the GPU driver:
+
+* Turn-off g-sync if you have a monitor that supports it
+* Disable power saving mode on GPU driver
+* V-sync is not forced off
+* Run the display on a target refresh rate of `59.950 hz` which has been determined to be
+  [the most compatible across all PC-based versions](../dev/journal/2025-02-09-iidx-engine.md#engine-step-time).
+
+##### Turn-off g-sync
+
+Create a new GPU profile for IIDX, if it doesn't exist yet:
+
+```bat
+nvgpu.exe profile create iidx
+```
+
+Add the application names when the profile needs to be applied:
+
+```bat
+:: For iidx versions 9 to 17
+nvgpu.exe profile application-add iidx bm2dx.exe
+:: For iidx versions 18+
+nvgpu.exe profile application-add iidx launcher.exe
+```
+
+Disable G-SYNC for the profile:
+
+```bat
+nvgpu.exe profile gsync-disable iidx
+```
+
+##### Disable power saving mode
+
+Set GPU power state to maximum for the profile (assumes you have a 
+[GPU profile called `iidx` already created](#turn-off-g-sync)):
+
+```bat
+nvgpu.exe profile gpu-power-state-max iidx
+```
+
+##### Configure and verify target refresh rate of 59.950 hz and vsync
+
+Get display ID of your primary display:
+
+```bat
+nvgpu.exe display primary-display-id
+```
+
+Copy the hex-value of the display ID and use it in the following commands.
+
+Test the custom display timing first, e.g. for versions that run in 1920x1080
+(Replace `<DISPLAY_ID> ` with the primary display ID you got):
+
+```bat
+nvgpu.exe display custom-resolution-test <DISPLAY_ID> 1920 1080 59.95 10
+```
+
+This will test it for 10 seconds and then revert. If the result looked good, i.e. the screen didn't
+go blank or the display output was garbage, apply it:
+
+```bat
+nvgpu.exe display custom-resolution-set <DISPLAY_ID> 1920 1080 59.95
+```
+
+Test and verify the configuration is applied and works correctly:
+
+```bat
+d3d9-monitor-check.exe cmdline refresh-rate-test 1920 1080 60
+```
+
+Test if the enforced refresh rate is compatible with your display and vsync is working correctly:
+
+```bat
+d3d9-monitor-check.exe cmdline vsync-test 1920 1080 60
+```
+
+##### Alternative refresh rate configuration
+
+If for some reason your display doesn't support 59.950 hz properly, i.e. display artifacts or vsync
+issues, you can use any other 60 hz compatible refresh rate, e.g. anything between 59.900 hz and
+60.100 hz that your display supports properly.
+
+Follow the same steps [as above](#configure-and-verify-target-refresh-rate-of-59950-hz-and-vsync) 
+but use a different refresh rate, e.g. 60.000 hz.
+
+Verify using the `d3d9-monitor-check.exe` with the outlined steps if you need to play around to find
+a refresh rate that works for your setup.
+
+For the game versions 9 to 19, you have to use the chart patch feature of bemanitools to patch
+the charts to your custom refresh rate. Otherwise, the game engine will run on your configured
+refresh rate, but it will take the non-matching refresh rate from the chart data which causes
+song de-syncing.
+
+For example, to configure a refresh rate of 60.000 hz in the iidxhook config file:
+
+```text
+gfx.monitor_check=60.000
+```
+
+##### ATI/AMD
+
+Currently, there is no tooling provided by bemanitools to configure the AMD GPU driver. The basic
+concepts of what needs to be configured still applies as outlined in the NVIDIA sections above
+though, e.g. through AMD's GPU control panel.
+
+Further steps and instructions TBD

doc/iidxhook/iidxhook1.md

@@ -146,16 +146,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
-- Use iidxhook's frame rate limiter feature (see further below) to software lock the refresh rate.
-  This might be necessary on Windows 7 and newer for D3D8 games, e.g. iidx 9 to 12, which seem to
-  ignore GPU side v-sync.
-- Use iidxhook's auto timebase feature (see further below) or set a pre-determined value to cut down
-  start-up times.
 
 ### The game still stutters (randomly) and drifts off-sync
 
@@ -173,9 +164,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-- Make sure your machine's refresh rate is stable
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-- If you don't get a close to 59.94hz refresh rate, use the software monitor check/auto timebase
-  that's built into iidxhook (refer to help/config file)
 
 ## The game crashes instantly (10th, RED, HAPPY SKY)
 
@@ -233,6 +222,8 @@ file) or use a CLVSD.ax codec which has the debugger checks removed.
 
 ## I used the auto timebase option and/or limited my refresh rate but the songs are still going offsync
 
+Refer to the [iidx-syncbook](iidx-syncbook.md) if you haven't already.
+
 There aren't many options left. The old games were developed for specific hardware and are not
 guaranteed to work well on (especially) newer hardware. Multiple monitor setups can also have a bad
 impact on a stable refresh rate. Try a setup with just a single monitor you want to use for gameplay

doc/iidxhook/iidxhook2.md

@@ -115,16 +115,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
-- Use iidxhook's frame rate limiter feature (see further below) to software lock the refresh rate.
-  This might be necessary on Windows 7 and newer for D3D8 games, e.g. iidx 9 to 12, which seem to
-  ignore GPU side v-sync.
-- Use iidxhook's auto timebase feature (see further below) or set a pre-determined value to cut down
-  start-up times.
 
 ### The game still stutters (randomly) and drifts off-sync
 
@@ -142,9 +133,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-- Make sure your machine's refresh rate is stable
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-- If you don't get a close to 59.94hz refresh rate, use the software monitor check/auto timebase
-  that's built into iidxhook (refer to help/config file)
 
 ## The game crashes instantly
 
@@ -192,6 +181,8 @@ CLVSD.ax codec which has the debugger checks removed.
 
 ## I used the auto timebase option and/or limited my refresh rate but the songs are still going offsync
 
+Refer to the [iidx-syncbook](iidx-syncbook.md) if you haven't already.
+
 There aren't many options left. The old games were developed for specific hardware and are not
 guaranteed to work well on (especially) newer hardware. Multiple monitor setups can also have a bad
 impact on a stable refresh rate. Try a setup with just a single monitor you want to use for gameplay

doc/iidxhook/iidxhook3.md

@@ -132,16 +132,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
-- Use iidxhook's frame rate limiter feature (see further below) to software lock the refresh rate.
-  This might be necessary on Windows 7 and newer for D3D8 games, e.g. iidx 9 to 12, which seem to
-  ignore GPU side v-sync.
-- Use iidxhook's auto timebase feature (see further below) or set a pre-determined value to cut down
-  start-up times.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -154,15 +145,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-The built-in monitor check just determines if the game should sync to either 59.94 hz (S-Video
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-setting) or 60.04 hz (VGA setting). If you don't have a setup that runs on (as close as possible)
-these values:
-
-- Make sure your machine's refresh rate is stable, e.g. 60.00x hz.
-- If you don't get a close to 59.94hz (S-Video setting) or 60.04 hz (VGA setting) refresh rate, go
-  an set the output mode in the operator menu to "VGA" to enforce the game to run chart syncing on
-  60.04 hz refresh rate (even if your setup does not have that value). Next, use the software
-  monitor check/auto timebase that's built into iidxhook (refer to cmd help/configfile).
 
 ## My game runs too fast
 
@@ -205,6 +188,8 @@ CLVSD.ax codec which has the debugger checks removed.
 
 ## I used the auto timebase option and/or limited my refresh rate but the songs are still going offsync
 
+Refer to the [iidx-syncbook](iidx-syncbook.md) if you haven't already.
+
 There aren't many options left. The old games were developed for specific hardware and are not
 guaranteed to work well on (especially) newer hardware. Multiple monitor setups can also have a bad
 impact on a stable refresh rate. Try a setup with just a single monitor you want to use for gameplay

doc/iidxhook/iidxhook4.md

@@ -143,16 +143,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
-- Use iidxhook's frame rate limiter feature (see further below) to software lock the refresh rate.
-  This might be necessary on Windows 7 and newer for D3D8 games, e.g. iidx 9 to 12, which seem to
-  ignore GPU side v-sync.
-- Use iidxhook's auto timebase feature (see further below) or set a pre-determined value to cut down
-  start-up times.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -165,15 +156,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-The built-in monitor check just determines if the game should sync to either 59.94 hz (S-Video
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-setting) or 60.04 hz (VGA setting). If you don't have a setup that runs on (as close as possible)
-these values:
-
-- Make sure your machine's refresh rate is stable, e.g. 60.00x hz.
-- If you don't get a close to 59.94hz (S-Video setting) or 60.04 hz (VGA setting) refresh rate, go
-  an set the output mode in the operator menu to "VGA" to enforce the game to run chart syncing on
-  60.04 hz refresh rate (even if your setup does not have that value). Next, use the software
-  monitor check/auto timebase that's built into iidxhook (refer to cmd help/configfile).
 
 ## My game runs too fast
 
@@ -211,6 +194,8 @@ CLVSD.ax codec which has the debugger checks removed.
 
 ## I used the auto timebase option and/or limited my refresh rate but the songs are still going offsync
 
+Refer to the [iidx-syncbook](iidx-syncbook.md) if you haven't already.
+
 There aren't many options left. The old games were developed for specific hardware and are not
 guaranteed to work well on (especially) newer hardware. Multiple monitor setups can also have a bad
 impact on a stable refresh rate. Try a setup with just a single monitor you want to use for gameplay

doc/iidxhook/iidxhook5.md

@@ -143,16 +143,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
-- Use iidxhook's frame rate limiter feature (see further below) to software lock the refresh rate.
-  This might be necessary on Windows 7 and newer for D3D8 games, e.g. iidx 9 to 12, which seem to
-  ignore GPU side v-sync.
-- Use iidxhook's auto timebase feature (see further below) or set a pre-determined value to cut down
-  start-up times.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -165,11 +156,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-From this version onwards (if you use the very final data of Lincle), the game comes with a built-in
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-auto timebase option ("monitor check" on startup) which dynamically, detects the refresh rate of
-your current setup. Thus, BT5's timebase option is not included from this hook version onwards,
-anymore. Ensure that refresh rate displayed is very stable, e.g. 60.00x hz, and the game should be
-able to provide you with a smooth and sync game experience.
 
 ## My game runs too fast
 

doc/iidxhook/iidxhook6.md

@@ -155,11 +155,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -172,11 +168,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-From this version onwards (or Lincle very final revision), the game comes with a built-in auto
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-timebase option ("monitor check" on startup) which dynamically, detects the refresh rate of your
-current setup. Thus, BT5's timebase option is not included from this hook version onwards, anymore.
-Ensure that refresh rate displayed is very stable, e.g. 60.00x hz, and the game should be able to
-provide you with a smooth and sync game experience.
 
 ## My game runs too fast
 

doc/iidxhook/iidxhook7.md

@@ -159,11 +159,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -176,11 +172,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-From IIDX 20 (or Lincle very final revision) onwards, the game comes with a built-in auto timebase
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-option ("monitor check" on startup) which dynamically, detects the refresh rate of your current
-setup. Thus, BT5's timebase option is not included from this hook version onwards, anymore. Ensure
-that refresh rate displayed is very stable, e.g. 60.00x hz, and the game should be able to provide
-you with a smooth and sync game experience.
 
 ## My game runs too fast
 

doc/iidxhook/iidxhook8.md

@@ -158,11 +158,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -175,11 +171,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-From IIDX 20 (or Lincle very final revision) onwards, the game comes with a built-in auto timebase
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-option ("monitor check" on startup) which dynamically, detects the refresh rate of your current
-setup. Thus, BT5's timebase option is not included from this hook version onwards, anymore. Ensure
-that refresh rate displayed is very stable, e.g. 60.00x hz, and the game should be able to provide
-you with a smooth and sync game experience.
 
 ## My game runs too fast
 

doc/iidxhook/iidxhook9.md

@@ -212,11 +212,7 @@ This can be related to various issues:
 start "" /relatime "gamestart.bat"
 ```
 
-- Enforce v-sync enabled in your GPU settings.
+Also refer to the [iidx-syncbook](iidx-syncbook.md).
-- Ensure that you have a constant refresh rate around the 60 hz (59.9xx or 60.0xx) that is not
-  jumping around. Use the timebase feature of one of the newer games to check that or enable
-  iidxhook's timebase and check the log output for the determined value. Run this a few times and
-  check if the results differ.
 
 ## "NETWORK WARNING" instead of "NETWORK OK"
 
@@ -229,11 +225,7 @@ This can be caused by:
 
 ## My songs are offsync
 
-From IIDX 20 (or Lincle very final revision) onwards, the game comes with a built-in auto timebase
+Refer to the [iidx-syncbook](iidx-syncbook.md).
-option ("monitor check" on startup) which dynamically, detects the refresh rate of your current
-setup. Thus, BT5's timebase option is not included from this hook version onwards, anymore. Ensure
-that refresh rate displayed is very stable, e.g. 60.00x hz, and the game should be able to provide
-you with a smooth and sync game experience.
 
 ## My game runs too fast
 

doc/tools/d3d9-monitor-check.md

@@ -1,25 +1,26 @@
 # D3D9 Monitor Check
 
-A separate application to run the infamous IIDX “monitor check” without having to run the actual
+A separate application providing various music game relevant tests, e.g. the infamous IIDX “monitor
-game. The tool can be used to test measure the current avg. monitor refresh rate or debug/check if
+check” without having to run the actual game. The tool can be used to debug and test your monitor
-that value is fluctuating for some reason.
+regarding refresh rate calibration (custom monitor timings), v-sync issues or ghosting issues.
-
-The final avg. value that is provided at the end of the test can be used as input for other tooling
-or settings (e.g. patching charts to a different refresh rate on older games with bemanitools).
 
 Simply run the tool without any arguments to get a full synopsis with usage instructions.
 
-## "Accuracy" remarks
+## "Accuracy" remarks refresh rate test/monitor check
 
 The tool has been tested on an actual cabinet with `nvgpu` setting different custom timings. The
 accuracy seems to be even higher than what IIDX’s monitor check is actually showing. For example,
 with a custom timing of 59.900 hz, this tool yields fairly accurate and stable avg. 59.902 hz.
 
-The monitor check of IIDX 29 shows results of 59.8981 hz to 59.8997 hz on screen. As these are the
+The monitor check of IIDX 29 showed results of 59.8981 hz to 59.8997 hz on screen. As these are the
 only visible values to the user, determining a specific (avg.) value that can be used as input for
 other tooling or settings (e.g. patching charts to a different refresh rate on older games with
 bemanitools) is difficult. This doesn't mean that the game's monitor checks are actually
-inaccurate or wrong. Modern games with a built-in monitor check (starting IIDX 20) are syncing up
+inaccurate or wrong. Once the check is finished it uses the
+[avg. value it determined](../dev/journal/2025-02-09-iidx-engine.md) to patch the chart data
+correctly. The value displayed to the user is just the floating value.
+
+Thus, modern games with a built-in monitor check (starting IIDX 20) are syncing up
 fine and don't need any further patching or modifications.
 
 For older games, picking a value that is not as close as possible to an accurate avg. value can

doc/tools/nvgpu.md

@@ -18,61 +18,8 @@ cannot be measured on application level.
 
 Simply run the tool without any arguments to get a full synopsis of available commands.
 
-## Example usage for modern IIDX
+## Example usage for IIDX
 
-### Custom GPU profile
+Refer to the dedicated [iidx-syncbook](../iidxhook/iidx-syncbook.md) documentation for details on
-
+how to use `nvgpu` to configure your system to run IIDX versions with proper display timings, smooth
-The following creates a custom profile to address potential performance concerns such as not 100% smooth scrolling and
+frame rates and sync game-play.
-micro stuttering.
-
-* Create a custom profile: `nvgpu profile create launcher`
-* Add the launcher application to the profile: `nvgpu profile application-add launcher launcher.exe`
-  * This will apply to any (IIDX) game running with `launcher.exe`
-* Set GPU power state to maximum for the profile: `nvgpu profile gpu-power-state-max launcher`
-
-### Custom timing
-
-* Run the game and observe the monitor check screen (requires IIDX 20+)
-* Take note of the refresh rate of the monitor that is determined by the game
-* Exit the game
-* Run `nvgpu display list` to get the display ID of the monitor you want to change use that ID in the following commands
-* Run `nvgpu display custom-resolution-test` with your display ID and monitor settings to test the custom configuration
-  first
-  * For example, for IIDX 31 which runs in native 1920x1080 with a monitor also having that as its native resolution,
-    having the monitor id `0x12345678` and the monitor check yielding a value of ~`59.9345`, run 
-    `nvgpu display custom-resolution-test 1920 1080 59.9345`
-  * Observe if the test is successful and the display doesn't turn blank or displays a glitched image for ~10 seconds
-* Run `nvgpu display custom-resolution-set` with the previously tested settings to apply the custom display mode
-  * For example, `nvgpu display custom-resolution-set 0x12345678 1920 1080 59.9345`
-
-## Example usage for legacy IIDX
-
-Legacy IIDX concerns any game prior to IIDX 20 that introduced the monitor check screen. The game engine was expecting
-a the display/GPU/driver to perform at specific refresh rate timings in order to provide correct timing and audio
-playback for the game. To this date (i.e. IIDX 31), the game engine never re-syncs audio playback during gameplay.
-Therefore any flaky and incorrect timing will result in audio desynchronization either early on or throughout a song.
-
-### Custom GPU profile
-
-The following creates a custom profile to address potential performance concerns such as not 100% smooth scrolling and
-micro stuttering.
-
-* Create a custom profile: `nvgpu profile create bm2dx`
-* Add the launcher application to the profile: `nvgpu profile application-add bm2dx bm2dx.exe`
-  * This will apply to any (IIDX) game running with an executable named `bm2fx.exe`
-* Set GPU power state to maximum for the profile: `nvgpu profile gpu-power-state-max bm2dx`
-
-### Custom timing
-
-* Use a modern game and it to observe the monitor check screen (requires IIDX 20+)
-* Take note of the refresh rate of the monitor that is determined by the game
-* Exit the game
-* Run `nvgpu display list` to get the display ID of the monitor you want to change use that ID in the following commands
-* Run `nvgpu display custom-resolution-test` with your display ID and monitor settings to test the custom configuration
-  first
-  * For example, for IIDX 31 which runs in native 1920x1080 with a monitor also having that as its native resolution,
-    having the monitor id `0x12345678` and the monitor check yielding a value of ~`59.9345`, run 
-    `nvgpu display custom-resolution-test 1920 1080 59.9345`
-  * Observe if the test is successful and the display doesn't turn blank or displays a glitched image for ~10 seconds
-* Run `nvgpu display custom-resolution-set` with the previously tested settings to apply the custom display mode
-  * For example, `nvgpu display custom-resolution-set 0x12345678 1920 1080 59.9345`

src/main/iidxhook9/Module.mk

@@ -30,4 +30,5 @@ libs_iidxhook9      := \
 src_iidxhook9       := \
     config-io.c \
     fs-hook.c \
+    reverbfix.c \
     dllmain.c \

src/main/iidxhook9/dllmain.c

@@ -27,6 +27,7 @@
 
 #include "iidxhook9/config-io.h"
 #include "iidxhook9/fs-hook.h"
+#include "iidxhook9/reverbfix.h"
 
 #include "camhook/cam.h"
 #include "camhook/config-cam.h"
@@ -165,6 +166,8 @@ static bool my_dll_entry_init(char *sidcode, struct property_node *param)
         iidxhook9_fs_hooks_init();
     }
 
+    reverbfixhook_init();
+
     rs232_hook_init();
     rs232_hook_limit_hooks();
 

src/main/iidxhook9/fs-hook.c

@@ -34,6 +34,15 @@ static void *my_avs_fs_mount(const char *dest, const char *src, const char *fs_t
 
         return real_avs_fs_mount(dest, dev_folder_drive, fs_type, options);
     }
+    if (src[0] == 'e' && src[1] == ':' && src[2] == '/' && src[3] == '\0') {
+        const char* dev_folder_drive = "dev/vfs/drive_e/";
+        log_misc("Redirecting %s to %s", src, dev_folder_drive);
+
+        CreateDirectoryA("dev/vfs/", NULL);
+        CreateDirectoryA("dev/vfs/drive_e/", NULL);
+
+        return real_avs_fs_mount(dest, dev_folder_drive, fs_type, options);
+    }
 
     return real_avs_fs_mount(dest, src, fs_type, options);
 }

src/main/iidxhook9/reverbfix.c

@@ -0,0 +1,56 @@
+#define LOG_MODULE "reverbfix-hook"
+
+// clang-format off
+// Don't format because the order is important here
+#include <windows.h>
+#include <initguid.h>
+// clang-format on
+
+#include <combaseapi.h>
+
+#include <stdio.h>
+
+#include "hook/com-proxy.h"
+#include "hook/table.h"
+
+#include "iidxhook9/reverbfix.h"
+
+#include "util/log.h"
+
+DEFINE_GUID(GUID_DSFX_STANDARD_I3DL2REVERB, 0xEF985E71,0xD5C7,0x42D4,0xBA,0x4D,0x2D,0x07,0x3E,0x2E,0x96,0xF4);
+DEFINE_GUID(GUID_DSFX_WAVES_REVERB,         0x87FC0268,0x9A55,0x4360,0x95,0xAA,0x00,0x4A,0x1D,0x9D,0xE2,0x6C);
+
+static HRESULT my_CoCreateInstance(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv);
+
+static HRESULT (*real_CoCreateInstance)(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv);
+
+static const struct hook_symbol reverbfix_ole_syms[] = {
+    {.name = "CoCreateInstance",
+     .patch = my_CoCreateInstance,
+     .link = (void **) &real_CoCreateInstance},
+};
+
+static HRESULT my_CoCreateInstance(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv)
+{
+    HRESULT result = real_CoCreateInstance(rclsid, pUnkOuter, dwClsContext, riid, ppv);
+    if (result == REGDB_E_CLASSNOTREG) {
+        if (IsEqualGUID(rclsid, &GUID_DSFX_STANDARD_I3DL2REVERB)) {
+            // replace effect used by REVERB EX with REVERB, based on CDmoSoundFx classes
+            result = real_CoCreateInstance(&GUID_DSFX_WAVES_REVERB, pUnkOuter, dwClsContext, riid, ppv);
+
+            log_info("DSFX_STANDARD_I3DL2REVERB class missing, replaced with DSFX_WAVES_REVERB");
+        }
+    }
+
+    return result;
+}
+
+void reverbfixhook_init()
+{
+    hook_table_apply(
+        NULL, "Ole32.dll", reverbfix_ole_syms, lengthof(reverbfix_ole_syms));
+    log_info("Inserted reverbfix hook");
+}

src/main/iidxhook9/reverbfix.h

@@ -0,0 +1,6 @@
+#ifndef REVERBFIXHOOK_H
+#define REVERBFIXHOOK_H
+
+void reverbfixhook_init();
+
+#endif