From 77fc4d4171927b9c32fa12bbb2c39ead8a4da35b Mon Sep 17 00:00:00 2001
From: puckey <jonathan@puckey.studio>
Date: Tue, 3 Oct 2023 16:49:41 +0200
Subject: [PATCH] Avoid emitting empty metadata.

Using rntp, I was seeing empty values for Event.MetadataTimedReceived like: `{ "raw": [] }`. This commit filters out these empty metadata groups.
---
 SwiftAudioEx/Classes/Observer/AVPlayerItemObserver.swift | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/SwiftAudioEx/Classes/Observer/AVPlayerItemObserver.swift b/SwiftAudioEx/Classes/Observer/AVPlayerItemObserver.swift
index 9736cf7..2ec14d9 100644
--- a/SwiftAudioEx/Classes/Observer/AVPlayerItemObserver.swift
+++ b/SwiftAudioEx/Classes/Observer/AVPlayerItemObserver.swift
@@ -114,6 +114,9 @@ class AVPlayerItemObserver: NSObject {
 
 extension AVPlayerItemObserver: AVPlayerItemMetadataOutputPushDelegate {
     func metadataOutput(_ output: AVPlayerItemMetadataOutput, didOutputTimedMetadataGroups groups: [AVTimedMetadataGroup], from track: AVPlayerItemTrack?) {
-        delegate?.item(didReceiveTimedMetadata: groups)
+        let groupsWithMetadata = groups.filter { !$0.items.isEmpty }
+        if !groupsWithMetadata.isEmpty {
+            delegate?.item(didReceiveTimedMetadata: groupsWithMetadata)
+        }
     }
 }