refactor(editor): extract MP4 export routing

src/components/video-editor/VideoEditor.tsx

@@ -88,6 +88,7 @@ import {
 } from "@/utils/aspectRatioUtils";
 import { ExtensionIcon } from "./ExtensionIcon";
 import { calculateMp4ExportDimensions, calculateMp4SourceDimensions } from "./exportDimensions";
+import { resolveMp4ExportRouting } from "./mp4ExportRouting";
 import { useNvidiaCudaExportOptIn } from "./useNvidiaCudaExportOptIn";
 
 const PhCursorFill = (props: { className?: string; weight?: "fill" | "regular" }) => (
@@ -4135,25 +4136,24 @@ export default function VideoEditor() {
 					const selectedMp4FrameRate = smokeExportConfig.enabled
 						? (smokeExportConfig.fps ?? settings.mp4FrameRate ?? mp4FrameRate)
 						: (settings.mp4FrameRate ?? mp4FrameRate);
-					const pipelineModel = smokeExportConfig.enabled
-						? (smokeExportConfig.pipelineModel ?? "modern")
-						: (settings.pipelineModel ?? exportPipelineModel);
-					const useExperimentalNativeExport =
-						pipelineModel === "modern" &&
-						(smokeExportConfig.enabled ? smokeExportConfig.useNativeExport : true);
-					const useExperimentalNvidiaCudaExport =
-						useExperimentalNativeExport &&
-						experimentalNvidiaCudaExport &&
-						nvidiaCudaExportAvailable;
-					const backendPreference =
-						pipelineModel === "legacy"
-							? "webcodecs"
-							: smokeExportConfig.enabled
-								? (smokeExportConfig.backendPreference ??
-									(smokeExportConfig.useNativeExport ? "breeze" : "webcodecs"))
-								: useExperimentalNativeExport
-									? "auto"
-									: (settings.backendPreference ?? exportBackendPreference);
+					const {
+						pipelineModel,
+						useExperimentalNativeExport,
+						useExperimentalNvidiaCudaExport,
+						backendPreference,
+					} = resolveMp4ExportRouting({
+						smokeExportConfig: {
+							enabled: smokeExportConfig.enabled,
+							pipelineModel: smokeExportConfig.pipelineModel,
+							useNativeExport: smokeExportConfig.useNativeExport,
+							backendPreference: smokeExportConfig.backendPreference,
+						},
+						settings,
+						exportPipelineModel,
+						exportBackendPreference,
+						experimentalNvidiaCudaExport,
+						nvidiaCudaExportAvailable,
+					});
 					const supportedSourceDimensions =
 						await ensureSupportedMp4SourceDimensions(selectedMp4FrameRate);
 					const { width: exportWidth, height: exportHeight } =

src/components/video-editor/mp4ExportRouting.test.ts

@@ -0,0 +1,99 @@
+import { describe, expect, it } from "vitest";
+
+import { resolveMp4ExportRouting } from "./mp4ExportRouting";
+
+const baseOptions = {
+	smokeExportConfig: {
+		enabled: false,
+		useNativeExport: false,
+	},
+	settings: {},
+	exportPipelineModel: "modern" as const,
+	exportBackendPreference: "breeze" as const,
+	experimentalNvidiaCudaExport: false,
+	nvidiaCudaExportAvailable: false,
+};
+
+describe("resolveMp4ExportRouting", () => {
+	it("uses the modern native auto route for normal MP4 exports by default", () => {
+		expect(resolveMp4ExportRouting(baseOptions)).toEqual({
+			pipelineModel: "modern",
+			useExperimentalNativeExport: true,
+			useExperimentalNvidiaCudaExport: false,
+			backendPreference: "auto",
+		});
+	});
+
+	it("forces WebCodecs and disables native export for the legacy pipeline", () => {
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				settings: { pipelineModel: "legacy", backendPreference: "breeze" },
+			}),
+		).toEqual({
+			pipelineModel: "legacy",
+			useExperimentalNativeExport: false,
+			useExperimentalNvidiaCudaExport: false,
+			backendPreference: "webcodecs",
+		});
+	});
+
+	it("keeps smoke exports on WebCodecs unless smoke native export is requested", () => {
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				smokeExportConfig: {
+					enabled: true,
+					useNativeExport: false,
+				},
+			}),
+		).toEqual({
+			pipelineModel: "modern",
+			useExperimentalNativeExport: false,
+			useExperimentalNvidiaCudaExport: false,
+			backendPreference: "webcodecs",
+		});
+
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				smokeExportConfig: {
+					enabled: true,
+					useNativeExport: true,
+				},
+			}),
+		).toEqual({
+			pipelineModel: "modern",
+			useExperimentalNativeExport: true,
+			useExperimentalNvidiaCudaExport: false,
+			backendPreference: "breeze",
+		});
+	});
+
+	it("only enables NVIDIA CUDA when native export is active and the device is available", () => {
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				experimentalNvidiaCudaExport: true,
+				nvidiaCudaExportAvailable: true,
+			}).useExperimentalNvidiaCudaExport,
+		).toBe(true);
+
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				settings: { pipelineModel: "legacy" },
+				experimentalNvidiaCudaExport: true,
+				nvidiaCudaExportAvailable: true,
+			}).useExperimentalNvidiaCudaExport,
+		).toBe(false);
+
+		expect(
+			resolveMp4ExportRouting({
+				...baseOptions,
+				experimentalNvidiaCudaExport: true,
+				nvidiaCudaExportAvailable: false,
+			}).useExperimentalNvidiaCudaExport,
+		).toBe(false);
+	});
+});

src/components/video-editor/mp4ExportRouting.ts

@@ -0,0 +1,57 @@
+import type {
+	ExportBackendPreference,
+	ExportPipelineModel,
+	ExportSettings,
+} from "@/lib/exporter";
+import type { SmokeExportConfig } from "./smokeExportConfig";
+
+export type Mp4ExportRouting = {
+	pipelineModel: ExportPipelineModel;
+	useExperimentalNativeExport: boolean;
+	useExperimentalNvidiaCudaExport: boolean;
+	backendPreference: ExportBackendPreference;
+};
+
+export function resolveMp4ExportRouting({
+	smokeExportConfig,
+	settings,
+	exportPipelineModel,
+	exportBackendPreference,
+	experimentalNvidiaCudaExport,
+	nvidiaCudaExportAvailable,
+}: {
+	smokeExportConfig: Pick<
+		SmokeExportConfig,
+		"enabled" | "pipelineModel" | "useNativeExport" | "backendPreference"
+	>;
+	settings: Pick<ExportSettings, "pipelineModel" | "backendPreference">;
+	exportPipelineModel: ExportPipelineModel;
+	exportBackendPreference: ExportBackendPreference;
+	experimentalNvidiaCudaExport: boolean;
+	nvidiaCudaExportAvailable: boolean;
+}): Mp4ExportRouting {
+	const pipelineModel = smokeExportConfig.enabled
+		? (smokeExportConfig.pipelineModel ?? "modern")
+		: (settings.pipelineModel ?? exportPipelineModel);
+	const useExperimentalNativeExport =
+		pipelineModel === "modern" &&
+		(smokeExportConfig.enabled ? smokeExportConfig.useNativeExport : true);
+	const useExperimentalNvidiaCudaExport =
+		useExperimentalNativeExport && experimentalNvidiaCudaExport && nvidiaCudaExportAvailable;
+	const backendPreference =
+		pipelineModel === "legacy"
+			? "webcodecs"
+			: smokeExportConfig.enabled
+				? (smokeExportConfig.backendPreference ??
+					(smokeExportConfig.useNativeExport ? "breeze" : "webcodecs"))
+				: useExperimentalNativeExport
+					? "auto"
+					: (settings.backendPreference ?? exportBackendPreference);
+
+	return {
+		pipelineModel,
+		useExperimentalNativeExport,
+		useExperimentalNvidiaCudaExport,
+		backendPreference,
+	};
+}