From 04a13efd6a16385eaf5ea5d374da4cf733dd8090 Mon Sep 17 00:00:00 2001
From: Walker <wfrankenberg@mux.com>
Date: Wed, 11 Feb 2026 11:12:14 -1000
Subject: [PATCH 1/2] refactor: simplify thumbnail URL step

---
 src/primitives/thumbnails.ts | 42 +++++++++++++++++++-----------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/primitives/thumbnails.ts b/src/primitives/thumbnails.ts
index 60f288f2..8d9487e5 100644
--- a/src/primitives/thumbnails.ts
+++ b/src/primitives/thumbnails.ts
@@ -30,37 +30,39 @@ export async function getThumbnailUrls(
 ): Promise<string[]> {
   "use step";
   const { interval = 10, width = 640, shouldSign = false, maxSamples, credentials } = options;
-  let timestamps: number[] = [];
+  const timestamps: number[] = [];
 
+  // Calculate expected number of timestamps before generating
+  let expectedCount: number;
   if (duration <= 50) {
-    const spacing = duration / 6;
-    for (let i = 1; i <= 5; i++) {
-      timestamps.push(Math.round(i * spacing));
-    }
+    expectedCount = 5;
   } else {
-    for (let time = 0; time < duration; time += interval) {
-      timestamps.push(time);
-    }
+    expectedCount = Math.floor(duration / interval) + 1;
   }
 
-  // Apply maxSamples cap if specified and we have more timestamps than the limit
-  if (maxSamples !== undefined && timestamps.length > maxSamples) {
-    const newTimestamps: number[] = [];
+  // If maxSamples is set and would be exceeded, generate evenly-spaced samples directly
+  if (maxSamples !== undefined && expectedCount > maxSamples) {
+    timestamps.push(0); // Always include first frame
 
-    // Always include first frame
-    newTimestamps.push(0);
-
-    // If maxSamples >= 2, add evenly distributed middle frames and last frame
     if (maxSamples >= 2) {
       const spacing = duration / (maxSamples - 1);
       for (let i = 1; i < maxSamples - 1; i++) {
-        newTimestamps.push(spacing * i);
+        timestamps.push(spacing * i);
+      }
+      timestamps.push(duration); // Always include last frame
+    }
+  } else {
+    // Generate timestamps based on duration and interval
+    if (duration <= 50) {
+      const spacing = duration / 6;
+      for (let i = 1; i <= 5; i++) {
+        timestamps.push(Math.round(i * spacing));
+      }
+    } else {
+      for (let time = 0; time < duration; time += interval) {
+        timestamps.push(time);
       }
-      // Always include last frame
-      newTimestamps.push(duration);
     }
-
-    timestamps = newTimestamps;
   }
 
   const baseUrl = `https://image.mux.com/${playbackId}/thumbnail.png`;

From 98b5894ae7cf7b76257289858b228b23af78ad8a Mon Sep 17 00:00:00 2001
From: Walker <wfrankenberg@mux.com>
Date: Wed, 11 Feb 2026 11:30:02 -1000
Subject: [PATCH 2/2] add hardcode

---
 src/primitives/thumbnails.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/primitives/thumbnails.ts b/src/primitives/thumbnails.ts
index 8d9487e5..fed144dd 100644
--- a/src/primitives/thumbnails.ts
+++ b/src/primitives/thumbnails.ts
@@ -1,6 +1,9 @@
 import { signUrl } from "@mux/ai/lib/url-signing";
 import type { WorkflowCredentialsInput } from "@mux/ai/types";
 
+const MIN_DURATION = 50;
+const MIN_SAMPLES = 2;
+
 export interface ThumbnailOptions {
   /** Interval between thumbnails in seconds (default: 10) */
   interval?: number;
@@ -34,7 +37,7 @@ export async function getThumbnailUrls(
 
   // Calculate expected number of timestamps before generating
   let expectedCount: number;
-  if (duration <= 50) {
+  if (duration <= MIN_DURATION) {
     expectedCount = 5;
   } else {
     expectedCount = Math.floor(duration / interval) + 1;
@@ -44,7 +47,7 @@ export async function getThumbnailUrls(
   if (maxSamples !== undefined && expectedCount > maxSamples) {
     timestamps.push(0); // Always include first frame
 
-    if (maxSamples >= 2) {
+    if (maxSamples >= MIN_SAMPLES) {
       const spacing = duration / (maxSamples - 1);
       for (let i = 1; i < maxSamples - 1; i++) {
         timestamps.push(spacing * i);
@@ -53,7 +56,7 @@ export async function getThumbnailUrls(
     }
   } else {
     // Generate timestamps based on duration and interval
-    if (duration <= 50) {
+    if (duration <= MIN_DURATION) {
       const spacing = duration / 6;
       for (let i = 1; i <= 5; i++) {
         timestamps.push(Math.round(i * spacing));