From 4a1aa619d2926d2ab11dfd150ca13a2c4860450a Mon Sep 17 00:00:00 2001
From: Nyanmisaka <nst799610810@gmail.com>
Date: Fri, 22 Apr 2022 17:36:36 +0800
Subject: [PATCH] Fix H264 level on safari fmp4

---
 MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index 162a821f5..006fd8861 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -1062,10 +1062,12 @@ namespace MediaBrowser.Controller.MediaEncoding
                 }
                 else if (string.Equals(state.ActualOutputVideoCodec, "h264", StringComparison.OrdinalIgnoreCase))
                 {
-                    // Clients may direct play higher than level 41, but there's no reason to transcode higher.
-                    if (requestLevel >= 41)
+                    // Transcode to level 5.1 and lower for maximum compatibility.
+                    // h264 4k 30fps requires at least level 5.1 otherwise it will break on safari fmp4.
+                    // https://en.wikipedia.org/wiki/Advanced_Video_Coding#Levels
+                    if (requestLevel >= 51)
                     {
-                        return "41";
+                        return "51";
                     }
                 }
             }