spice2x.github.io/src/spice2x/hooks/audio/audio.cpp

#include "audio.h"

#include <vector>

#include <windows.h>
#include <initguid.h>
#include <audioclient.h>
#include <mmdeviceapi.h>

#include "avs/game.h"
#include "hooks/audio/backends/mmdevice/device_enumerator.h"
#include "util/detour.h"
#include "util/logging.h"
#include "util/memutils.h"

#include "audio_private.h"
#include "acm.h"
#include "asio_proxy.h"
#include "xact.h"

#ifdef _MSC_VER
DEFINE_GUID(CLSID_MMDeviceEnumerator,
    0xBCDE0395, 0xE52F, 0x467C,
    0x8E, 0x3D, 0xC4, 0x57, 0x92, 0x91, 0x69, 0x2E);
#endif

// {ef985e71-d5c7-42d4-ba4d-2d073e2e96f4}
DEFINE_GUID(CLSID_DirectSoundI3DL2ReverbDMO,
    0xef985e71, 0xd5c7, 0x42d4,
    0xba, 0x4d, 0x2d, 0x07, 0x3e, 0x2e, 0x96, 0xf4);

// {87fc0268-9a55-4360-95aa-004a1d9de26c}
DEFINE_GUID(CLSID_DirectSoundWavesReverbDMO,
    0x87fc0268, 0x9a55, 0x4360,
    0x95, 0xaa, 0x00, 0x4a, 0x1d, 0x9d, 0xe2, 0x6c);

// function pointers
static decltype(CoCreateInstance) *CoCreateInstance_orig = nullptr;

namespace hooks::audio {

    // public globals
    bool ENABLED = true;
    bool VOLUME_HOOK_ENABLED = true;
    std::optional<DownmixAlgorithm> DOWNMIX_ALGORITHM = std::nullopt;
    float VOLUME_BOOST = 1.0f;
    std::optional<uint32_t> RESAMPLE_RATE = std::nullopt;
    std::optional<uint32_t> EXCLUSIVE_BUFFER_MS = std::nullopt;
    bool WASAPI_COMPATIBILITY_MODE = false;
    bool USE_DUMMY = false;
    WAVEFORMATEXTENSIBLE FORMAT {};
    std::optional<Backend> BACKEND = std::nullopt;
    bool INJECT_FAKE_REALTEK_AUDIO = false;
    std::optional<size_t> ASIO_DRIVER_ID = std::nullopt;
    std::string ASIO_DRIVER_NAME = "";
    bool ASIO_FORCE_UNLOAD_ON_STOP = false;

    std::mutex INITIALIZE_LOCK; // for asio

    IAudioClient *CLIENT = nullptr;
    static std::mutex CLIENT_LOCK;
    static bool CLIENT_STOPPING = false;

    void set_active_client(IAudioClient *client, const char *source) {
        IAudioClient *previous_client = nullptr;
        {
            std::lock_guard lock(CLIENT_LOCK);

            if (CLIENT_STOPPING || CLIENT == client) {
                return;
            }
            if (client) {
                client->AddRef();
            }

            previous_client = CLIENT;
            CLIENT = client;
        }

        if (previous_client) {
            previous_client->Release();
        }

        if (client) {
            log_info(
                "audio",
                "active client selected by {} after successful initialization",
                source);
        }
    }
}

static HRESULT STDAPICALLTYPE CoCreateInstance_hook(
    REFCLSID rclsid,
    LPUNKNOWN pUnkOuter,
    DWORD dwClsContext,
    REFIID riid,
    LPVOID *ppv)
{

    HRESULT ret;

    // ASIO: if we already hold a cached instance for this CLSID, hand back a fresh
    // wrapper over it instead of re-creating the real driver (see asio_proxy.cpp)
    if (ppv != nullptr && hooks::audio::asio::is_asio_creation(rclsid, riid)) {
        if (IUnknown *reused = hooks::audio::asio::wrap_existing(rclsid)) {
            *ppv = reused;
            return S_OK;
        }
    }

    // call original
    ret = CoCreateInstance_orig(rclsid, pUnkOuter, dwClsContext, riid, ppv);
    if (FAILED(ret)) {
        if (IsEqualCLSID(rclsid, CLSID_MMDeviceEnumerator)) {
            log_warning("audio", "CoCreateInstance failed for CLSID_MMDeviceEnumerator, hr={}", FMT_HRESULT(ret));
        } else if (IsEqualCLSID(rclsid, CLSID_DirectSoundI3DL2ReverbDMO)) {
            // deal with reverb DMO missing from dsdmo.dll
            // it usually fails with 0x80040154 (REGDB_E_CLASSNOTREG), but we have also seen 0x8007007e (ERROR_MOD_NOT_FOUND) 
            static std::once_flag printed;
            std::call_once(printed, [ret]() {
                log_warning(
                    "audio",
                    "CoCreateInstance for CLSID_DirectSoundI3DL2ReverbDMO failed with {}, swap with CLSID_DirectSoundWavesReverbDMO...",
                    FMT_HRESULT(ret));
            });
            ret = CoCreateInstance_orig(CLSID_DirectSoundWavesReverbDMO, pUnkOuter, dwClsContext, riid, ppv);
            if (FAILED(ret)) {
                log_warning("audio", "CoCreateInstance(CLSID_DirectSoundWavesReverbDMO...) failed, hr={}", FMT_HRESULT(ret));
            }
        }

        return ret;
    }

    // check if this is the audio device enumerator
    if (IsEqualCLSID(rclsid, CLSID_MMDeviceEnumerator)) {

        // wrap object
        auto mmde = reinterpret_cast<IMMDeviceEnumerator **>(ppv);
        *mmde = new WrappedIMMDeviceEnumerator(*mmde);
    } else if (ppv != nullptr && *ppv != nullptr && hooks::audio::asio::is_asio_creation(rclsid, riid)) {

        // wrap every ASIO driver so calls pass through to the real driver
        *ppv = hooks::audio::asio::wrap(rclsid, *ppv);
    }

    // return original result
    return ret;
}

namespace hooks::audio {
    void init() {
        if (!ENABLED) {
            return;
        }

        log_info("audio", "initializing");
        init_low_latency();
        hooks::audio::acm::init();

        // general hooks
        CoCreateInstance_orig = detour::iat_try("CoCreateInstance", CoCreateInstance_hook);
        if (avs::game::is_model("PAN")) {
            hooks::audio::xact::init();
        }
    }

    void stop() {
        log_info("audio", "stopping");
        IAudioClient *client = nullptr;
        {
            std::lock_guard lock(CLIENT_LOCK);
            CLIENT_STOPPING = true;
            client = CLIENT;
            CLIENT = nullptr;
        }
        if (client) {
            client->Stop();
            client->Release();
        }
        stop_low_latency();

        // release the ASIO drivers we kept pinned for the process lifetime now that we are
        // at a controlled shutdown point (see asio_proxy.cpp)
        hooks::audio::asio::release_all_wrappers();
    }
}