Normalize imeta MIME casing

js/nostr/nip71.js

@@ -177,7 +177,8 @@ function buildImetaTags(variants) {
     const dim = stringFromInput(variant.dim);
     const url = stringFromInput(variant.url);
     const x = stringFromInput(variant.x);
-    const mime = stringFromInput(variant.m);
+    const rawMime = stringFromInput(variant.m);
+    const mime = rawMime ? rawMime.toLowerCase() : "";
     const duration = formatNonNegativeNumber(variant.duration, {
       allowFloat: true,
     });

js/services/videoNotePayload.js

@@ -85,7 +85,7 @@ function normalizeImetaVariant(variant) {
   }
   const normalized = {};
   const m = normalizeString(variant.m);
-  if (m) normalized.m = m;
+  if (m) normalized.m = m.toLowerCase();
   const dim = normalizeString(variant.dim);
   if (dim) normalized.dim = dim;
   const url = normalizeString(variant.url);

tests/nip71-base-event-tags.test.mjs

@@ -86,3 +86,21 @@ test("30078 events carry nip71 metadata tags and hydrate fallback metadata", ()
   assert.deepEqual(video.nip71.references, ["https://example.com/info"]);
   assert.equal(video.nip71Source?.eventId, "event-123");
 });
+
+test("imeta tags lower-case mime values", () => {
+  const metadataInput = {
+    imeta: [
+      { m: "VIDEO/MP4", url: "https://cdn.example/video.mp4" },
+      { m: "APPLICATION/DASH+XML" },
+    ],
+  };
+
+  const tags = buildNip71MetadataTags(metadataInput);
+  const mimeEntries = tags
+    .filter((tag) => tag[0] === "imeta")
+    .map((tag) => tag.find((value) => typeof value === "string" && value.startsWith("m ")))
+    .filter(Boolean)
+    .map((entry) => entry.slice(2));
+
+  assert.deepEqual(mimeEntries, ["video/mp4", "application/dash+xml"]);
+});

tests/nip71-builder.test.mjs

@@ -145,7 +145,7 @@ test("buildNip71VideoEvent assembles rich metadata", () => {
   assert.deepEqual(imetaTags[1], [
     "imeta",
     "url https://cdn.example/video-hls.m3u8",
-    "m application/x-mpegURL",
+    "m application/x-mpegurl",
     "duration 45.789",
     "bitrate 2200000",
   ]);

tests/nostr/nip71.test.js

@@ -92,7 +92,7 @@ test("buildNip71MetadataTags normalizes structured fields", () => {
     tags.some(
       (tag) =>
         tag[0] === "p" &&
-        tag[1] === "A".repeat(64) &&
+        tag[1] === "a".repeat(64) &&
         tag[2] === "wss://relay.example",
     ),
   );