diff --git a/src/lib/exporter/gifExporter.ts b/src/lib/exporter/gifExporter.ts
index 747e34e..58ed693 100644
--- a/src/lib/exporter/gifExporter.ts
+++ b/src/lib/exporter/gifExporter.ts
@@ -174,11 +174,11 @@ export class GifExporter {
 			});
 
 			// Calculate effective duration and frame count (excluding trim regions)
-			const effectiveDuration = this.streamingDecoder.getEffectiveDuration(
+			const { effectiveDuration, totalFrames } = this.streamingDecoder.getExportMetrics(
+				this.config.frameRate,
 				this.config.trimRegions,
 				this.config.speedRegions,
 			);
-			const totalFrames = Math.ceil(effectiveDuration * this.config.frameRate);
 
 			// Calculate frame delay in milliseconds (gif.js uses ms)
 			const frameDelay = Math.round(1000 / this.config.frameRate);
diff --git a/src/lib/exporter/streamingDecoder.ts b/src/lib/exporter/streamingDecoder.ts
index ee67576..c028832 100644
--- a/src/lib/exporter/streamingDecoder.ts
+++ b/src/lib/exporter/streamingDecoder.ts
@@ -536,11 +536,24 @@ export class StreamingVideoDecoder {
 		return segments;
 	}
 
-	getEffectiveDuration(trimRegions?: TrimRegion[], speedRegions?: SpeedRegion[]): number {
+	getExportMetrics(
+		targetFrameRate: number,
+		trimRegions?: TrimRegion[],
+		speedRegions?: SpeedRegion[],
+	): { effectiveDuration: number; totalFrames: number } {
 		if (!this.metadata) throw new Error("Must call loadMetadata() first");
 		const trimSegments = this.computeSegments(this.metadata.duration, trimRegions);
-		const speedSegments = this.splitBySpeed(trimSegments, speedRegions);
-		return speedSegments.reduce((sum, seg) => sum + (seg.endSec - seg.startSec) / seg.speed, 0);
+		const segments = this.splitBySpeed(trimSegments, speedRegions);
+		return {
+			effectiveDuration: segments.reduce(
+				(sum, seg) => sum + (seg.endSec - seg.startSec) / seg.speed,
+				0,
+			),
+			totalFrames: segments.reduce(
+				(sum, seg) => sum + Math.ceil(((seg.endSec - seg.startSec) / seg.speed) * targetFrameRate),
+				0,
+			),
+		};
 	}
 
 	private splitBySpeed(
diff --git a/src/lib/exporter/videoExporter.ts b/src/lib/exporter/videoExporter.ts
index d0affd1..dcfcc3e 100644
--- a/src/lib/exporter/videoExporter.ts
+++ b/src/lib/exporter/videoExporter.ts
@@ -157,11 +157,11 @@ export class VideoExporter {
 			this.muxer = muxer;
 			await muxer.initialize();
 
-			const effectiveDuration = streamingDecoder.getEffectiveDuration(
+			const { effectiveDuration, totalFrames } = streamingDecoder.getExportMetrics(
+				this.config.frameRate,
 				this.config.trimRegions,
 				this.config.speedRegions,
 			);
-			const totalFrames = Math.ceil(effectiveDuration * this.config.frameRate);
 			const readEndSec = Math.max(videoInfo.duration, videoInfo.streamDuration ?? 0) + 0.5;
 
 			console.log("[VideoExporter] Original duration:", videoInfo.duration, "s");