Fix acestep-cpp model path resolution and cover mode spawn pipeline

server/src/config/index.ts

@@ -13,11 +13,22 @@ const __dirname  = path.dirname(__filename);
 //   release: <bundle>/server/dist/config/ → ../../.. → <bundle>/
 const APP_ROOT = path.resolve(__dirname, '../../..');
 
+// ── Path helpers ─────────────────────────────────────────────────────────────
+
+/**
+ * Resolves a path relative to APP_ROOT when it is not already absolute.
+ * This prevents relative paths from .env (e.g. `./models`) being interpreted
+ * relative to the server/ working directory instead of the project root.
+ */
+function resolveFromRoot(p: string): string {
+  return path.isAbsolute(p) ? p : path.resolve(APP_ROOT, p);
+}
+
 // ── Binary resolution ───────────────────────────────────────────────────────
 
 /** Resolves the ace-qwen3 LLM binary path (step 1 of the pipeline). */
 function resolveLmBin(): string {
-  if (process.env.ACE_QWEN3_BIN) return process.env.ACE_QWEN3_BIN;
+  if (process.env.ACE_QWEN3_BIN) return resolveFromRoot(process.env.ACE_QWEN3_BIN);
   for (const name of ['ace-qwen3', 'ace-qwen3.exe']) {
     const p = path.join(APP_ROOT, 'bin', name);
     if (existsSync(p)) return p;
@@ -27,7 +38,7 @@ function resolveLmBin(): string {
 
 /** Resolves the dit-vae binary path (step 2 of the pipeline). */
 function resolveDitVaeBin(): string {
-  if (process.env.DIT_VAE_BIN) return process.env.DIT_VAE_BIN;
+  if (process.env.DIT_VAE_BIN) return resolveFromRoot(process.env.DIT_VAE_BIN);
   for (const name of ['dit-vae', 'dit-vae.exe']) {
     const p = path.join(APP_ROOT, 'bin', name);
     if (existsSync(p)) return p;
@@ -39,13 +50,13 @@ function resolveDitVaeBin(): string {
 
 /** Resolves the models directory. */
 function resolveModelsDir(): string {
-  if (process.env.MODELS_DIR) return process.env.MODELS_DIR;
+  if (process.env.MODELS_DIR) return resolveFromRoot(process.env.MODELS_DIR);
   return path.join(APP_ROOT, 'models');
 }
 
 /** Resolves the DiT model (acestep-v15-turbo-*.gguf). */
 function resolveDitModel(modelsDir: string): string {
-  if (process.env.ACESTEP_MODEL) return process.env.ACESTEP_MODEL;
+  if (process.env.ACESTEP_MODEL) return resolveFromRoot(process.env.ACESTEP_MODEL);
   if (!existsSync(modelsDir)) return '';
 
   const preference = [
@@ -73,7 +84,7 @@ function resolveDitModel(modelsDir: string): string {
 
 /** Resolves the causal LM model (acestep-5Hz-lm-*.gguf). */
 function resolveLmModel(modelsDir: string): string {
-  if (process.env.LM_MODEL) return process.env.LM_MODEL;
+  if (process.env.LM_MODEL) return resolveFromRoot(process.env.LM_MODEL);
   if (!existsSync(modelsDir)) return '';
 
   // Prefer 4B Q8_0, then smaller quantisations, then smaller LM sizes
@@ -103,7 +114,7 @@ function resolveLmModel(modelsDir: string): string {
 
 /** Resolves the text-encoder model (Qwen3-Embedding-*.gguf). */
 function resolveTextEncoderModel(modelsDir: string): string {
-  if (process.env.TEXT_ENCODER_MODEL) return process.env.TEXT_ENCODER_MODEL;
+  if (process.env.TEXT_ENCODER_MODEL) return resolveFromRoot(process.env.TEXT_ENCODER_MODEL);
   if (!existsSync(modelsDir)) return '';
 
   for (const name of [
@@ -125,7 +136,7 @@ function resolveTextEncoderModel(modelsDir: string): string {
 
 /** Resolves the VAE model (vae-BF16.gguf). */
 function resolveVaeModel(modelsDir: string): string {
-  if (process.env.VAE_MODEL) return process.env.VAE_MODEL;
+  if (process.env.VAE_MODEL) return resolveFromRoot(process.env.VAE_MODEL);
   if (!existsSync(modelsDir)) return '';
 
   for (const name of ['vae-BF16.gguf', 'vae-Q8_0.gguf']) {
@@ -174,7 +185,7 @@ export const config = {
 
   // SQLite database
   database: {
-    path: process.env.DATABASE_PATH || path.join(APP_ROOT, 'data', 'acestep.db'),
+    path: resolveFromRoot(process.env.DATABASE_PATH || path.join(APP_ROOT, 'data', 'acestep.db')),
   },
 
   // acestep-cpp — spawn mode uses ace-qwen3 + dit-vae directly.
@@ -204,7 +215,7 @@ export const config = {
 
   storage: {
     provider: 'local' as const,
-    audioDir: process.env.AUDIO_DIR || path.join(APP_ROOT, 'public', 'audio'),
+    audioDir: resolveFromRoot(process.env.AUDIO_DIR || path.join(APP_ROOT, 'public', 'audio')),
   },
 
   jwt: {

server/src/services/acestep.ts

@@ -130,9 +130,20 @@ let isProcessingQueue = false;
 // Mode detection
 // ---------------------------------------------------------------------------
 
-function useSpawnMode(): boolean {
-  // Spawn mode requires both ace-qwen3 (LLM) and dit-vae (synthesis) binaries
-  return Boolean(config.acestep.lmBin && config.acestep.ditVaeBin);
+/**
+ * Returns true when the spawn-mode binaries satisfy the requirements for
+ * the given generation parameters.
+ *
+ * - Cover/passthrough (sourceAudioUrl or audioCodes): only dit-vae is needed;
+ *   ace-qwen3 is skipped because the audio codes come from the source audio.
+ * - Text-to-music: both ace-qwen3 (LLM) and dit-vae (synthesis) are required.
+ */
+function useSpawnMode(params?: Pick<GenerationParams, 'sourceAudioUrl' | 'audioCodes'>): boolean {
+  if (!config.acestep.ditVaeBin) return false;
+  // Cover / passthrough: only dit-vae is needed — no LLM step
+  if (params?.sourceAudioUrl || params?.audioCodes) return true;
+  // Text-to-music: need ace-qwen3 too
+  return Boolean(config.acestep.lmBin);
 }
 
 // ---------------------------------------------------------------------------
@@ -259,14 +270,20 @@ async function runViaSpawn(
     if (params.timeSignature)             requestJson.timesignature = params.timeSignature;
     // Passthrough: skip the LLM when audio codes are already provided
     if (params.audioCodes)                requestJson.audio_codes   = params.audioCodes;
+    // Cover/audio-to-audio: strength of the source audio influence on the output
+    if (params.audioCoverStrength !== undefined) requestJson.audio_cover_strength = params.audioCoverStrength;
 
     const requestPath = path.join(tmpDir, 'request.json');
     await writeFile(requestPath, JSON.stringify(requestJson, null, 2));
 
     // ── Step 1: ace-qwen3 — LLM (lyrics + audio codes) ────────────────────
+    // Skipped when:
+    //   • audio_codes are provided (passthrough) — codes are already known
+    //   • sourceAudioUrl is provided (cover/audio-to-audio) — dit-vae derives
+    //     codes directly from the source audio; running ace-qwen3 is not needed
     let enrichedPaths: string[] = [];
 
-    if (!params.audioCodes) {
+    if (!params.audioCodes && !params.sourceAudioUrl) {
       job.stage = 'LLM: generating lyrics and audio codes…';
 
       const lmBin   = config.acestep.lmBin!;
@@ -294,7 +311,8 @@ async function runViaSpawn(
         throw new Error('ace-qwen3 produced no enriched request files');
       }
     } else {
-      // Passthrough: use the original request.json directly (audio_codes present)
+      // Passthrough: use the original request.json directly
+      // (audio codes provided, or source audio supplied for cover/audio-to-audio mode)
       enrichedPaths = [requestPath];
     }
 
@@ -619,7 +637,7 @@ async function processGeneration(
 
   try {
     job.stage = 'Generating music...';
-    if (useSpawnMode()) {
+    if (useSpawnMode(params)) {
       await runViaSpawn(jobId, params, job);
     } else {
       await runViaHttp(jobId, params, job);