CoopAllTheThings/tools/audio_probe/main.cpp

// coop_audio_probe — standalone harness to bring up the injected audio
// render-hook against a real game without Steam / RPT / the host UI.
//
// Given a target pid it: creates the input SharedBlock and the audio ring the
// hook expects (named by that pid), enables capture, injects coop_hook.dll, then
// polls and prints the hook's status back-channel and the audio ring counters
// for a while. The hook writes a detailed trace to %TEMP%\coop_hook.log.
//
//   coop_audio_probe <pid> [seconds]
//
// Run from the same directory as coop_hook.dll (i.e. bin/<config>/).

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <vector>

#include <windows.h>

#include "coop/audio_ring.hpp"
#include "coop/protocol.hpp"
#include "coop/shared_memory.hpp"

namespace
{

std::wstring dll_path_next_to_self()
{
	wchar_t exe[MAX_PATH] = {};
	GetModuleFileNameW(nullptr, exe, MAX_PATH);
	std::wstring path(exe);
	const size_t slash = path.find_last_of(L"\\/");
	if (slash != std::wstring::npos)
	{
		path.resize(slash + 1);
	}
	return path + L"coop_hook.dll";
}

bool inject(unsigned long pid, const std::wstring& dll_path)
{
	if (GetFileAttributesW(dll_path.c_str()) == INVALID_FILE_ATTRIBUTES)
	{
		std::printf("ERROR: coop_hook.dll not found at the probe's directory.\n");
		return false;
	}
	const DWORD access = PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION |
	                     PROCESS_VM_WRITE | PROCESS_VM_READ;
	HANDLE process = OpenProcess(access, FALSE, pid);
	if (process == nullptr)
	{
		std::printf("ERROR: OpenProcess(%lu) failed (%lu). Run as administrator?\n", pid, GetLastError());
		return false;
	}
	const SIZE_T bytes = (dll_path.size() + 1) * sizeof(wchar_t);
	void* remote = VirtualAllocEx(process, nullptr, bytes, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
	bool ok = false;
	if (remote != nullptr && WriteProcessMemory(process, remote, dll_path.c_str(), bytes, nullptr))
	{
		auto load_library = reinterpret_cast<LPTHREAD_START_ROUTINE>(
		    GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "LoadLibraryW"));
		HANDLE thread = CreateRemoteThread(process, nullptr, 0, load_library, remote, 0, nullptr);
		if (thread != nullptr)
		{
			WaitForSingleObject(thread, INFINITE);
			DWORD exit_code = 0;
			GetExitCodeThread(thread, &exit_code);
			CloseHandle(thread);
			ok = (exit_code != 0);
		}
	}
	if (remote != nullptr)
	{
		VirtualFreeEx(process, remote, 0, MEM_RELEASE);
	}
	CloseHandle(process);
	if (!ok)
	{
		std::printf("ERROR: injection failed (%lu).\n", GetLastError());
	}
	return ok;
}

} // namespace

int wmain(int argc, wchar_t** argv)
{
	if (argc < 2)
	{
		std::printf("usage: coop_audio_probe <pid> [seconds] [ring_delay_ms]\n"
		            "  ring_delay_ms: how long after injecting to create the audio ring\n"
		            "  (default 1500 = reproduces the real app, which creates the ring\n"
		            "  only when audio mirroring is toggled on; 0 = ring before inject).\n");
		return 1;
	}
	const unsigned long pid = std::wcstoul(argv[1], nullptr, 10);
	const int seconds = (argc >= 3) ? std::max(1, _wtoi(argv[2])) : 20;
	const int ring_delay_ms = (argc >= 4) ? std::max(0, _wtoi(argv[3])) : 1500;
	if (pid == 0)
	{
		std::printf("ERROR: invalid pid.\n");
		return 1;
	}

	// 1) Input SharedBlock (the hook's worker exits if it can't connect to this).
	coop::SharedMemory ipc;
	if (!ipc.create(coop::shared_memory_name(pid), sizeof(coop::SharedBlock)))
	{
		std::printf("ERROR: create input mapping failed (%lu).\n", GetLastError());
		return 1;
	}
	auto* block = ipc.as<coop::SharedBlock>();
	block->version = coop::kProtocolVersion;
	block->pad_count = 0;
	block->sequence.store(0, std::memory_order_relaxed);
	block->magic = coop::kProtocolMagic;

	// Enable the hook's file trace (%TEMP%\coop_hook.log) for this debug session.
	{
		wchar_t dir[MAX_PATH] = {};
		if (GetTempPathW(MAX_PATH, dir) != 0)
		{
			const std::wstring sentinel = std::wstring(dir) + L"coop_hook.log.on";
			HANDLE h = CreateFileW(sentinel.c_str(), GENERIC_WRITE, FILE_SHARE_READ, nullptr,
			                       OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
			if (h != INVALID_HANDLE_VALUE)
			{
				CloseHandle(h);
			}
		}
	}

	// Create the audio ring (capture enabled), mirroring AudioMirror::thread_main.
	// By default we do this *after* injecting so the ordering matches the real app
	// (the host creates the ring only when audio mirroring is toggled on, which is
	// after the hook has already been injected and the game's stream registered).
	coop::SharedMemory ring_shm;
	coop::AudioRingHeader* ring = nullptr;
	auto create_ring = [&]() -> bool {
		if (!ring_shm.create(coop::audio_ring_name(pid),
		                     coop::audio_ring_total_size(coop::kAudioRingCapacity)))
		{
			std::printf("ERROR: create audio ring mapping failed (%lu).\n", GetLastError());
			return false;
		}
		ring = ring_shm.as<coop::AudioRingHeader>();
		coop::audio_ring_init(*ring, coop::kAudioRingCapacity);
		ring->capture_enabled.store(1, std::memory_order_release);
		return true;
	};

	if (ring_delay_ms == 0 && !create_ring())
	{
		return 1;
	}

	// Inject.
	std::printf("Injecting coop_hook.dll into pid %lu ...\n", pid);
	if (!inject(pid, dll_path_next_to_self()))
	{
		return 1;
	}

	if (ring_delay_ms > 0)
	{
		std::printf("Injected. Creating audio ring %d ms later (app-ordering)...\n", ring_delay_ms);
		Sleep(static_cast<DWORD>(ring_delay_ms));
		if (!create_ring())
		{
			return 1;
		}
	}
	std::printf("Polling for %d s. Hook trace: %%TEMP%%\\coop_hook.log\n\n", seconds);

	// Poll + print. Drain the ring like the real host would (so it doesn't
	// overrun) and measure peak amplitude to prove we captured real audio.
	const coop::HookStatus& status = block->status;
	std::uint64_t prev_frames[coop::kMaxAudioStreams] = {};
	std::vector<std::uint8_t> drain(coop::kAudioRingCapacity);
	for (int t = 0; t < seconds * 2; ++t)
	{
		Sleep(500);

		// Consume everything available and find the peak sample magnitude.
		double peak = 0.0;
		std::uint32_t got = 0;
		while ((got = coop::audio_ring_pop(*ring, drain.data(), static_cast<std::uint32_t>(drain.size()))) > 0)
		{
			if (ring->format_tag == 3 /*IEEE_FLOAT*/ && ring->bits == 32)
			{
				const auto* f = reinterpret_cast<const float*>(drain.data());
				for (std::uint32_t i = 0; i < got / 4; ++i)
				{
					peak = std::max(peak, static_cast<double>(std::abs(f[i])));
				}
			}
			else if (ring->bits == 16)
			{
				const auto* s = reinterpret_cast<const std::int16_t*>(drain.data());
				for (std::uint32_t i = 0; i < got / 2; ++i)
				{
					peak = std::max(peak, std::abs(s[i]) / 32768.0);
				}
			}
			if (got < drain.size())
			{
				break;
			}
		}

		const std::uint32_t streams = status.audio_streams_seen;
		const std::uint32_t heartbeat = status.heartbeat.load(std::memory_order_relaxed);
		const std::uint64_t produced = ring->frames_produced.load(std::memory_order_relaxed);
		const std::uint64_t overruns = ring->overruns.load(std::memory_order_relaxed);
		const bool fmt_ready = coop::audio_ring_format_ready(*ring);

		std::printf("[%4.1fs] hb=%u streams=%u peak=%.4f ring{fmt=%d %uHz/%uch/%ubit produced=%llu "
		            "overruns=%llu}\n",
		            (t + 1) * 0.5, heartbeat, streams, peak, fmt_ready ? 1 : 0, ring->sample_rate,
		            ring->channels, ring->bits, static_cast<unsigned long long>(produced),
		            static_cast<unsigned long long>(overruns));
		for (std::uint32_t i = 0; i < coop::kMaxAudioStreams && i < streams; ++i)
		{
			const coop::AudioStreamInfo& s = status.audio_streams[i];
			const bool live = s.frames_rendered > prev_frames[i];
			prev_frames[i] = s.frames_rendered;
			std::printf("         stream %u %s %uHz/%uch/%ubit tag=%u frames=%llu %s\n", i,
			            s.is_primary ? "PRIMARY" : "extra  ", s.sample_rate, s.channels, s.bits,
			            s.format_tag, static_cast<unsigned long long>(s.frames_rendered),
			            live ? "<live>" : "");
		}
	}

	std::printf("\nDone. Leaving the hook loaded in the game.\n");
	block->magic = 0; // invalidate so a late hook read won't trust stale data
	return 0;
}