Allow video speed to change over time

schemas/videoasset.yaml

@@ -109,16 +109,27 @@
           type: string
         speed:
           description: >-
-            Adjust the playback speed of the video clip between 0 (paused) and 10 (10x normal speed) where 1 is normal
-            speed (defaults to 1). Adjusting the speed will also adjust the duration of the clip and may require you to
-            adjust the Clip length. For example, if you set speed to 0.5, the clip will need to be 2x as long to play
-            the entire video (i.e. original length / 0.5). If you set speed to 2, the clip will need to be half as long
-            to play the entire video (i.e. original length / 2).
-          type: number
-          format: float
-          minimum: 0
-          maximum: 10
-          example: 1
+            Adjust the playback speed of the video clip. Use a number for a constant speed or an array of
+            [Tween](./#tocs_tween) objects to change speed over time, for example easing from normal speed up to 3x.
+          oneOf:
+            - type: number
+              description: >-
+                The playback speed between 0 (paused) and 10 (10x normal speed) where 1 is normal speed (defaults to
+                1). Adjusting the speed will also adjust the duration of the clip and may require you to adjust the
+                Clip length. For example, if you set speed to 0.5, the clip will need to be 2x as long to play the
+                entire video (i.e. original length / 0.5). If you set speed to 2, the clip will need to be half as
+                long to play the entire video (i.e. original length / 2).
+              format: float
+              minimum: 0
+              maximum: 10
+              example: 1
+            - type: array
+              description: >-
+                An array of [Tween](./#tocs_tween) objects that change the playback speed over time. A speed of 0
+                holds the current frame. The clip length is not adjusted, so set it to cover the footage you want to
+                play.
+              items:
+                $ref: "./tween.yaml#/Tween"
         crop:
           $ref: "./crop.yaml#/Crop"
         chromaKey:

tests/smoke.cjs

@@ -206,6 +206,20 @@ async function run() {
     assert.strictEqual(result.src, "https://example.com/video.mp4");
   });
 
+  check("Parse videoAsset with animated speed", () => {
+    const result = zodCjs.videoAssetSchema.parse({
+      type: "video",
+      src: "https://example.com/video.mp4",
+      speed: [{ from: 1, to: 3, start: 0, length: 1, interpolation: "bezier", easing: "easeInOut" }],
+    });
+    assert.strictEqual(result.speed.length, 1);
+  });
+
+  check("Parse videoAsset with numeric speed (existing shape)", () => {
+    const result = zodCjs.videoAssetSchema.parse({ type: "video", src: "https://example.com/video.mp4", speed: 2 });
+    assert.strictEqual(result.speed, 2);
+  });
+
   check("Parse audioAsset with src only (existing shape)", () => {
     const result = zodCjs.audioAssetSchema.parse({
       type: "audio",