From 37ac9b6abebc8051e325af8fe15b1f63c61131f9 Mon Sep 17 00:00:00 2001
From: Skyler Lehmkuhl <skycooler@gmail.com>
Date: Fri, 6 Mar 2026 06:37:25 -0500
Subject: [PATCH] Fix NAM runtime errors on linux

---
 nam-ffi/build.rs                          | 15 +++-
 nam-ffi/capi-override/NeuralAudioCApi.cpp | 83 +++++++++++++++++++++++
 nam-ffi/capi-override/NeuralAudioCApi.h   | 50 ++++++++++++++
 3 files changed, 146 insertions(+), 2 deletions(-)
 create mode 100644 nam-ffi/capi-override/NeuralAudioCApi.cpp
 create mode 100644 nam-ffi/capi-override/NeuralAudioCApi.h

diff --git a/nam-ffi/build.rs b/nam-ffi/build.rs
index 778ca6a..a3703b1 100644
--- a/nam-ffi/build.rs
+++ b/nam-ffi/build.rs
@@ -13,6 +13,19 @@ fn main() {
     let wrapper_dir = Path::new(&manifest_dir).join("cmake");
     let neural_audio_dir = Path::new(&manifest_dir).join("../vendor/NeuralAudio");
 
+    // Copy our patched CAPI files over the submodule versions before building.
+    // The upstream submodule uses `wchar_t*` on all platforms; our patch makes
+    // Linux/macOS use `const char*` instead, matching what the Rust FFI sends.
+    let capi_dir = neural_audio_dir.join("NeuralAudioCAPI");
+    let override_dir = Path::new(&manifest_dir).join("capi-override");
+    for filename in &["NeuralAudioCApi.h", "NeuralAudioCApi.cpp"] {
+        let src = override_dir.join(filename);
+        let dst = capi_dir.join(filename);
+        std::fs::copy(&src, &dst)
+            .unwrap_or_else(|e| panic!("Failed to copy {} override: {}", filename, e));
+        println!("cargo:rerun-if-changed=capi-override/{}", filename);
+    }
+
     let mut cfg = cmake::Config::new(&wrapper_dir);
     // Force single-config generator on Unix to avoid libraries landing in Release/ subdirs
     if !cfg!(target_os = "windows") {
@@ -50,6 +63,4 @@ fn main() {
         _ => {}
     }
 
-    println!("cargo:rerun-if-changed=../vendor/NeuralAudio/NeuralAudioCAPI/NeuralAudioCApi.h");
-    println!("cargo:rerun-if-changed=../vendor/NeuralAudio/NeuralAudioCAPI/NeuralAudioCApi.cpp");
 }
diff --git a/nam-ffi/capi-override/NeuralAudioCApi.cpp b/nam-ffi/capi-override/NeuralAudioCApi.cpp
new file mode 100644
index 0000000..c385586
--- /dev/null
+++ b/nam-ffi/capi-override/NeuralAudioCApi.cpp
@@ -0,0 +1,83 @@
+#include "NeuralAudioCApi.h"
+#include "NeuralModel.h"
+
+struct NeuralModel
+{
+    NeuralAudio::NeuralModel* model;
+};
+
+#ifdef _WIN32
+NeuralModel* CreateModelFromFile(const wchar_t* modelPath)
+#else
+NeuralModel* CreateModelFromFile(const char* modelPath)
+#endif
+{
+    NeuralModel* model = new NeuralModel();
+
+    model->model = NeuralAudio::NeuralModel::CreateFromFile(modelPath);
+
+    return model;
+}
+
+void DeleteModel(NeuralModel* model)
+{
+    delete model->model;
+    delete model;
+}
+
+void SetLSTMLoadMode(int loadMode)
+{
+	NeuralAudio::NeuralModel::SetLSTMLoadMode((NeuralAudio::EModelLoadMode)loadMode);
+}
+
+void SetWaveNetLoadMode(int loadMode)
+{
+	NeuralAudio::NeuralModel::SetWaveNetLoadMode((NeuralAudio::EModelLoadMode)loadMode);
+}
+
+void SetAudioInputLevelDBu(float audioDBu)
+{
+	NeuralAudio::NeuralModel::SetAudioInputLevelDBu(audioDBu);
+}
+
+void SetDefaultMaxAudioBufferSize(int maxSize)
+{
+	NeuralAudio::NeuralModel::SetDefaultMaxAudioBufferSize(maxSize);
+}
+
+int GetLoadMode(NeuralModel* model)
+{
+	return model->model->GetLoadMode();
+}
+
+bool IsStatic(NeuralModel* model)
+{
+	return model->model->IsStatic();
+}
+
+void SetMaxAudioBufferSize(NeuralModel* model, int maxSize)
+{
+	model->model->SetMaxAudioBufferSize(maxSize);
+}
+
+float GetRecommendedInputDBAdjustment(NeuralModel* model)
+{
+	return model->model->GetRecommendedInputDBAdjustment();
+}
+
+float GetRecommendedOutputDBAdjustment(NeuralModel* model)
+{
+	return model->model->GetRecommendedOutputDBAdjustment();
+}
+
+float GetSampleRate(NeuralModel* model)
+{
+	return model->model->GetSampleRate();
+}
+
+void Process(NeuralModel* model, float* input, float* output, size_t numSamples)
+{
+    model->model->Process(input, output, numSamples);
+}
+
+
diff --git a/nam-ffi/capi-override/NeuralAudioCApi.h b/nam-ffi/capi-override/NeuralAudioCApi.h
new file mode 100644
index 0000000..4e62f08
--- /dev/null
+++ b/nam-ffi/capi-override/NeuralAudioCApi.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef _MSC_VER
+#define NA_EXTERN extern __declspec(dllexport)
+#else
+#define NA_EXTERN extern
+#endif
+
+struct NeuralModel;
+
+
+#ifdef _WIN32
+NA_EXTERN NeuralModel* CreateModelFromFile(const wchar_t* modelPath);
+#else
+NA_EXTERN NeuralModel* CreateModelFromFile(const char* modelPath);
+#endif
+
+NA_EXTERN void DeleteModel(NeuralModel* model);
+
+NA_EXTERN void SetLSTMLoadMode(int loadMode);
+
+NA_EXTERN void SetWaveNetLoadMode(int loadMode);
+
+NA_EXTERN void SetAudioInputLevelDBu(float audioDBu);
+
+NA_EXTERN void SetDefaultMaxAudioBufferSize(int maxSize);
+
+NA_EXTERN int GetLoadMode(NeuralModel* model);
+
+NA_EXTERN bool IsStatic(NeuralModel* model);
+
+NA_EXTERN void SetMaxAudioBufferSize(NeuralModel* model, int maxSize);
+
+NA_EXTERN float GetRecommendedInputDBAdjustment(NeuralModel* model);
+
+NA_EXTERN float GetRecommendedOutputDBAdjustment(NeuralModel* model);
+
+NA_EXTERN float GetSampleRate(NeuralModel* model);
+
+NA_EXTERN void Process(NeuralModel* model, float* input, float* output, size_t numSamples);
+
+#ifdef __cplusplus
+}
+#endif
\ No newline at end of file