fix(export): compute requiredEndSec for decode termination handling

Add requiredEndSec calculation to properly handle early decode termination by using the last segment's end time. This addresses issues with export processing on Windows platforms.

src/lib/exporter/streamingDecoder.ts

@@ -253,6 +253,8 @@ export class StreamingVideoDecoder {
 			this.computeSegments(this.metadata.duration, trimRegions),
 			speedRegions,
 		);
+		const requiredEndSec = segments[segments.length - 1]?.endSec ?? 0;
+
 		const segmentOutputFrameCounts = segments.map((segment) =>
 			Math.ceil(((segment.endSec - segment.startSec) / segment.speed) * targetFrameRate),
 		);
@@ -510,11 +512,13 @@ if (shouldFailDecodeEndedEarly({
     const decodedAtLabel = lastDecodedFrameSec === null ? "no decoded frame" : `${lastDecodedFrameSec.toFixed(3)}s`;
     const decodeGapSec = lastDecodedFrameSec === null ? Infinity : requiredEndSec - lastDecodedFrameSec;
 
-    // On Windows, tolerate a small decode gap (<= 3 seconds) to work around driver quirks.
-    // For severe failures (no frames at all, or a large gap), still throw.
-    if (isWindows && lastDecodedFrameSec !== null && decodeGapSec <= 3.0) {
+    // On Windows, tolerate a small decode gap: up to 10% of required duration, capped at 3 seconds.
+    const maxToleratedGap = Math.min(3.0, requiredEndSec * 0.1);
+
+    if (isWindows && lastDecodedFrameSec !== null && decodeGapSec <= maxToleratedGap) {
         console.warn(
-            `[StreamingVideoDecoder] Decode ended early on Windows with a small gap (${decodeGapSec.toFixed(2)}s) – proceeding anyway.`,
+            `[StreamingVideoDecoder] Decode ended early on Windows with a gap of ${decodeGapSec.toFixed(2)}s ` +
+            `(max tolerated: ${maxToleratedGap.toFixed(2)}s) – proceeding anyway.`,
         );
     } else {
         throw new Error(
@@ -522,6 +526,8 @@ if (shouldFailDecodeEndedEarly({
         );
     }
 }
+	}
+
 	private computeSegments(
 		totalDuration: number,
 		trimRegions?: TrimRegion[],