From 6f1b45409051942fbf1d4431de15f40a72a4598a Mon Sep 17 00:00:00 2001
From: Cursor Agent <cursoragent@cursor.com>
Date: Wed, 9 Sep 2026 06:20:35 +0000
Subject: [PATCH] fix(studio): preserve DramaBox auto duration instead of
 clamping it to 1s

setDurationSeconds used a video floor of 1s, so Wizard prepare and the
Advanced slider rewrote the TTS 0=auto sentinel into a one-second clip.

Co-authored-by: ignaciodelcano+dcl <ignaciodelcano+dcl@gmail.com>
---
 ui/src/stores/studioConfigurationSlice.ts | 13 ++++++-
 ui/tests/architectureSlices.test.mjs      | 42 +++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/ui/src/stores/studioConfigurationSlice.ts b/ui/src/stores/studioConfigurationSlice.ts
index 08a95026..a7477788 100644
--- a/ui/src/stores/studioConfigurationSlice.ts
+++ b/ui/src/stores/studioConfigurationSlice.ts
@@ -133,7 +133,18 @@ export function createStudioConfigurationSlice(
     setDurationSeconds: requestedSeconds => {
       const options = get().modelOptions
       const fps = options?.fps ?? 16
-      const minimum = Math.max(1, (options?.frames_minimum || fps) / fps)
+      // DramaBox (and similar TTS models) declare duration_slider.min=0 so
+      // that 0 means "auto-derive from the prompt". The video floor of 1s
+      // must not rewrite that sentinel — Wizard prepare and the Advanced
+      // slider both call this setter with 0.
+      const autoDurationAllowed = Boolean(
+        options?.audio_only
+        && options.duration_slider
+        && options.duration_slider.min === 0,
+      )
+      const minimum = autoDurationAllowed
+        ? 0
+        : Math.max(1, (options?.frames_minimum || fps) / fps)
       const nativeMaximum = options?.frames_maximum ? options.frames_maximum / fps : null
       const maximum = options?.sliding_window || nativeMaximum == null
         ? Number.POSITIVE_INFINITY
diff --git a/ui/tests/architectureSlices.test.mjs b/ui/tests/architectureSlices.test.mjs
index cc04c10f..ba5cb2cf 100644
--- a/ui/tests/architectureSlices.test.mjs
+++ b/ui/tests/architectureSlices.test.mjs
@@ -393,6 +393,48 @@ test('Studio configuration slice owns form state without owning generation execu
   assert.equal('runTool' in studio, false)
 })
 
+test('Studio duration setter keeps TTS auto sentinel at zero', async () => {
+  const { createStudioConfigurationSlice } = await import('../src/stores/studioConfigurationSlice.ts')
+  let state = {
+    params: { prompt: 'Speaker 1: hello', image_mode: 0 },
+    modelOptions: {
+      fps: 16,
+      audio_only: true,
+      duration_slider: { label: 'Target Duration (seconds, 0 = auto)', min: 0, max: 120, increment: 0.5, default: 0 },
+    },
+    h3WindowPlan: null,
+    generationMode: 'audio',
+    savedParamsPerMode: {},
+  }
+  const set = update => {
+    const partial = typeof update === 'function' ? update(state) : update
+    state = { ...state, ...partial }
+  }
+  const studio = createStudioConfigurationSlice({
+    alignFrameCount: frames => frames,
+    resolveResolution: (_options, preset, ratio) => `${preset}:${ratio}`,
+  })(set, () => state)
+  state = { ...state, ...studio }
+
+  state.setDurationSeconds(0)
+  assert.equal(state.durationSeconds, 0)
+  assert.equal(state.params.video_length, 0)
+
+  state.setDurationSeconds(12)
+  assert.equal(state.durationSeconds, 12)
+
+  state.modelOptions = {
+    fps: 24,
+    frames_minimum: 24,
+    frames_maximum: 120,
+    sliding_window: true,
+    audio_only: false,
+    duration_slider: null,
+  }
+  state.setDurationSeconds(0)
+  assert.equal(state.durationSeconds, 1)
+})
+
 test('composed slices bind without as-never casts at the useStore call site', async () => {
   const fs = await import('node:fs/promises')
   const source = await fs.readFile(new URL('../src/stores/useStore.ts', import.meta.url), 'utf8')