web: use metadata when processing media locally

web/src/lib/util.ts

@@ -1,3 +1,5 @@
+import { CobaltFileMetadataKeys, type CobaltFileMetadata } from "$lib/types/api";
+
 export const formatFileSize = (size: number | undefined) => {
     size ||= 0;
 
@@ -12,3 +14,15 @@ export const formatFileSize = (size: number | undefined) => {
     const unit = units[units.length - 1] + "B";
     return `${roundedSize} ${unit}`;
 }
+
+export const ffmpegMetadataArgs = (metadata: CobaltFileMetadata) =>
+    Object.entries(metadata).flatMap(([name, value]) => {
+        if (CobaltFileMetadataKeys.includes(name) && typeof value === "string") {
+            return [
+                '-metadata',
+                // eslint-disable-next-line no-control-regex
+                `${name}=${value.replace(/[\u0000-\u0009]/g, "")}`
+            ]
+        }
+        return [];
+    });