From 05da56fdc825267b685bf306072574644694212f Mon Sep 17 00:00:00 2001
From: Azeru <pixelpro548@gmail.com.com>
Date: Sat, 11 Apr 2026 17:45:23 +0100
Subject: [PATCH] fix(export): relax early decode termination on Windows

On Windows, tolerate small decode gaps (<=3 seconds) to work around driver quirks, allowing export to complete with available frames.
---
 electron/ipc/handlers.ts             | 12 ++++++
 src/lib/exporter/streamingDecoder.ts | 56 +++++++++++++++-------------
 2 files changed, 42 insertions(+), 26 deletions(-)

diff --git a/electron/ipc/handlers.ts b/electron/ipc/handlers.ts
index 9a5a6c0..6eb2d48 100644
--- a/electron/ipc/handlers.ts
+++ b/electron/ipc/handlers.ts
@@ -638,6 +638,18 @@ export function registerIpcHandlers(
 			return null;
 		}
 	});
+
+/**
+ * Handles saving an exported video file.
+ * Shows a save dialog, normalizes the file path for the current OS,
+ * ensures the directory exists, and writes the video data.
+ * @param _ - Unused event parameter.
+ * @param videoData - The exported video as an ArrayBuffer.
+ * @param fileName - Suggested filename for the save dialog.
+ * @returns Object with success status, optional file path, and error details.
+ */
+
+
 	ipcMain.handle("save-exported-video", async (_, videoData: ArrayBuffer, fileName: string) => {
 		try {
 			// Determine file type from extension
diff --git a/src/lib/exporter/streamingDecoder.ts b/src/lib/exporter/streamingDecoder.ts
index bed103b..cb5bf7b 100644
--- a/src/lib/exporter/streamingDecoder.ts
+++ b/src/lib/exporter/streamingDecoder.ts
@@ -217,7 +217,15 @@ export class StreamingVideoDecoder {
 
 		return this.metadata;
 	}
-
+/**
+ * Decodes all video frames from the loaded source and invokes a callback for each.
+ * Handles trimming and speed adjustments, and resamples to the target frame rate.
+ * On Windows, early decode termination is tolerated to work around driver quirks.
+ * @param targetFrameRate - Desired output frame rate.
+ * @param trimRegions - Array of time regions to keep (others discarded).
+ * @param speedRegions - Array of speed adjustments for specific time ranges.
+ * @param onFrame - Async callback receiving each decoded VideoFrame.
+ */
 	async decodeAll(
 		targetFrameRate: number,
 		trimRegions: TrimRegion[] | undefined,
@@ -491,33 +499,29 @@ export class StreamingVideoDecoder {
 		}
 		this.decoder = null;
 
-		const requiredEndSec = segments.length > 0 ? segments[segments.length - 1].endSec : 0;
-		const isWindows = typeof navigator !== "undefined" && /Windows/.test(navigator.userAgent);
+	const isWindows = typeof navigator !== "undefined" && /Windows/.test(navigator.userAgent);
 
-		if (
-			shouldFailDecodeEndedEarly({
-				cancelled: this.cancelled,
-				lastDecodedFrameSec,
-				requiredEndSec,
-				streamDurationSec: this.metadata.streamDuration,
-			})
-		) {
-			const decodedAtLabel =
-				lastDecodedFrameSec === null ? "no decoded frame" : `${lastDecodedFrameSec.toFixed(3)}s`;
-
-			if (isWindows) {
-				console.warn(
-					`[StreamingVideoDecoder] Decode ended early on Windows at ${decodedAtLabel} (needed ${requiredEndSec.toFixed(3)}s) – proceeding anyway.`,
-				);
-				// Do not throw on Windows; allow export to complete with the frames we have.
-			} else {
-				throw new Error(
-					`Video decode ended early at ${decodedAtLabel} (needed ${requiredEndSec.toFixed(3)}s).`,
-				);
-			}
-		}
-	}
+if (shouldFailDecodeEndedEarly({
+    cancelled: this.cancelled,
+    lastDecodedFrameSec,
+    requiredEndSec,
+    streamDurationSec: this.metadata.streamDuration,
+})) {
+    const decodedAtLabel = lastDecodedFrameSec === null ? "no decoded frame" : `${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) {
+        console.warn(
+            `[StreamingVideoDecoder] Decode ended early on Windows with a small gap (${decodeGapSec.toFixed(2)}s) – proceeding anyway.`,
+        );
+    } else {
+        throw new Error(
+            `Video decode ended early at ${decodedAtLabel} (needed ${requiredEndSec.toFixed(3)}s).`,
+        );
+    }
+}
 	private computeSegments(
 		totalDuration: number,
 		trimRegions?: TrimRegion[],