feat: add useVideoMetadata hook for aspect ratio calculation

src/features/project/CaptionSettingsStep/useVideoMetadata.ts

@@ -0,0 +1,41 @@
+import { useMemo } from "react"
+
+import api from "@shared/api"
+
+interface UseVideoMetadataResult {
+	aspectRatio: number
+	isLoading: boolean
+	isError: boolean
+}
+
+const DEFAULT_ASPECT_RATIO = 16 / 9
+
+export function useVideoMetadata(fileId: string | null): UseVideoMetadataResult {
+	const { data: mediaFile, isLoading, isError } = api.useQuery(
+		"get",
+		"/api/media/mediafiles/{media_file_id}/",
+		{
+			params: {
+				path: {
+					media_file_id: fileId ?? "",
+				},
+			},
+		},
+		{
+			enabled: !!fileId,
+		}
+	)
+
+	const aspectRatio = useMemo(() => {
+		if (!mediaFile?.width || !mediaFile?.height) {
+			return DEFAULT_ASPECT_RATIO
+		}
+		return mediaFile.width / mediaFile.height
+	}, [mediaFile])
+
+	return {
+		aspectRatio,
+		isLoading,
+		isError,
+	}
+}