minor changes per suggestions

Jellyfin.Api/Controllers/DynamicHlsController.cs

@@ -1412,7 +1412,7 @@ namespace Jellyfin.Api.Controllers
 
             return string.Format(
                 CultureInfo.InvariantCulture,
-                "{0} {1} -map_metadata -1 -map_chapters -1 -threads {2} {3} {4} {5} -copyts -avoid_negative_ts disabled -max_muxing_queue_size {6} -f hls -max_delay 5000000 -hls_time {7} -individual_header_trailer 0 -hls_segment_type {8} -start_number {9} -hls_segment_filename \"{10}\" -hls_playlist_type vod -hls_list_size 0 -y \"{11}\"",
+                "{0} {1} -map_metadata -1 -map_chapters -1 -threads {2} {3} {4} {5} -copyts -avoid_negative_ts 0 -max_muxing_queue_size {6} -f hls -max_delay 5000000 -hls_time {7} -individual_header_trailer 0 -hls_segment_type {8} -start_number {9} -hls_segment_filename \"{10}\" -hls_playlist_type vod -hls_list_size 0 -y \"{11}\"",
                 inputModifier,
                 _encodingHelper.GetInputArgument(state, encodingOptions),
                 threads,
@@ -1576,7 +1576,9 @@ namespace Jellyfin.Api.Controllers
                     args += " " + gopArg;
                 }
                 else if (string.Equals(codec, "libx264", StringComparison.OrdinalIgnoreCase)
-                    || string.Equals(codec, "libx265", StringComparison.OrdinalIgnoreCase))
+                        || string.Equals(codec, "libx265", StringComparison.OrdinalIgnoreCase)
+                        || string.Equals(codec, "h264_vaapi", StringComparison.OrdinalIgnoreCase)
+                        || string.Equals(codec, "hevc_vaapi", StringComparison.OrdinalIgnoreCase))
                 {
                     args += " " + keyFrameArg;
                 }

Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs

@@ -9,13 +9,38 @@ namespace Jellyfin.Api.Helpers
     /// </summary>
     public static class HlsCodecStringHelpers
     {
+        /// <summary>
+        /// Codec name for MP3.
+        /// </summary>
+        public const string MP3 = "mp4a.40.34";
+
+        /// <summary>
+        /// Codec name for AC-3.
+        /// </summary>
+        public const string AC3 = "mp4a.a5";
+
+        /// <summary>
+        /// Codec name for E-AC-3.
+        /// </summary>
+        public const string EAC3 = "mp4a.a6";
+
+        /// <summary>
+        /// Codec name for FLAC.
+        /// </summary>
+        public const string FLAC = "fLaC";
+
+        /// <summary>
+        /// Codec name for ALAC.
+        /// </summary>
+        public const string ALAC = "alac";
+
         /// <summary>
         /// Gets a MP3 codec string.
         /// </summary>
         /// <returns>MP3 codec string.</returns>
         public static string GetMP3String()
         {
-            return "mp4a.40.34";
+            return MP3;
         }
 
         /// <summary>
@@ -40,6 +65,42 @@ namespace Jellyfin.Api.Helpers
             return result.ToString();
         }
 
+        /// <summary>
+        /// Gets an AC-3 codec string.
+        /// </summary>
+        /// <returns>AC-3 codec string.</returns>
+        public static string GetAC3String()
+        {
+            return AC3;
+        }
+
+        /// <summary>
+        /// Gets an E-AC-3 codec string.
+        /// </summary>
+        /// <returns>E-AC-3 codec string.</returns>
+        public static string GetEAC3String()
+        {
+            return EAC3;
+        }
+
+        /// <summary>
+        /// Gets an FLAC codec string.
+        /// </summary>
+        /// <returns>FLAC codec string.</returns>
+        public static string GetFLACString()
+        {
+            return FLAC;
+        }
+
+        /// <summary>
+        /// Gets an ALAC codec string.
+        /// </summary>
+        /// <returns>ALAC codec string.</returns>
+        public static string GetALACString()
+        {
+            return ALAC;
+        }
+
         /// <summary>
         /// Gets a H.264 codec string.
         /// </summary>
@@ -104,41 +165,5 @@ namespace Jellyfin.Api.Helpers
 
             return result.ToString();
         }
-
-        /// <summary>
-        /// Gets an AC-3 codec string.
-        /// </summary>
-        /// <returns>AC-3 codec string.</returns>
-        public static string GetAC3String()
-        {
-            return "mp4a.a5";
-        }
-
-        /// <summary>
-        /// Gets an E-AC-3 codec string.
-        /// </summary>
-        /// <returns>E-AC-3 codec string.</returns>
-        public static string GetEAC3String()
-        {
-            return "mp4a.a6";
-        }
-
-        /// <summary>
-        /// Gets an FLAC codec string.
-        /// </summary>
-        /// <returns>FLAC codec string.</returns>
-        public static string GetFLACString()
-        {
-            return "fLaC";
-        }
-
-        /// <summary>
-        /// Gets an ALAC codec string.
-        /// </summary>
-        /// <returns>ALAC codec string.</returns>
-        public static string GetALACString()
-        {
-            return "alac";
-        }
     }
 }

MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs

@@ -662,6 +662,10 @@ namespace MediaBrowser.Controller.MediaEncoding
                 if (string.Equals(state.ActualOutputVideoCodec, "hevc", StringComparison.OrdinalIgnoreCase)
                     || string.Equals(state.ActualOutputVideoCodec, "h265", StringComparison.OrdinalIgnoreCase))
                 {
+                    // Transcode to level 5.0 and lower for maximum compatibility
+                    // level 5.0 is suitable for up to 4k 30fps hevc encoding, otherwise let the encoder to handle it
+                    // https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding_tiers_and_levels
+                    // MaxLumaSampleRate = 3840*2160*30 = 248832000 < 267386880,
                     if (requestLevel >= 150)
                     {
                         return "150";
@@ -3293,7 +3297,7 @@ namespace MediaBrowser.Controller.MediaEncoding
 
                 if (state.RunTimeTicks.HasValue && state.BaseRequest.CopyTimestamps)
                 {
-                    args += " -copyts -avoid_negative_ts disabled -start_at_zero";
+                    args += " -copyts -avoid_negative_ts 0 -start_at_zero";
                 }
 
                 if (!state.RunTimeTicks.HasValue)
@@ -3341,7 +3345,7 @@ namespace MediaBrowser.Controller.MediaEncoding
                         args += " -copyts";
                     }
 
-                    args += " -avoid_negative_ts disabled";
+                    args += " -avoid_negative_ts 0";
 
                     if (!(state.SubtitleStream != null && state.SubtitleStream.IsExternal && !state.SubtitleStream.IsTextSubtitleStream))
                     {