From 32efb47601d3ce4174f61a66181d9e4665288c92 Mon Sep 17 00:00:00 2001
From: theopeuchlestrade <83510973+theopeuchlestrade@users.noreply.github.com>
Date: Mon, 5 Oct 2026 19:19:10 -0400
Subject: Backport pull request #18300 from jellyfin/release-12.z

Use hvc1 for Dolby Vision profile 8

Original-merge: 173ee6947286d36cdb0ba86bbe9676770c57e27b

Merged-by: crobibero <cody@robibe.ro>

Backported-by: Cody Robibero <cody@robibe.ro>
---
 Jellyfin.Api/Controllers/DynamicHlsController.cs   | 13 ++++++++--
 .../Controllers/DynamicHlsControllerTests.cs       | 29 ++++++++++++++++++++++
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/Jellyfin.Api/Controllers/DynamicHlsController.cs b/Jellyfin.Api/Controllers/DynamicHlsController.cs
index dc0a6b2da9..6df76de0b4 100644
--- a/Jellyfin.Api/Controllers/DynamicHlsController.cs
+++ b/Jellyfin.Api/Controllers/DynamicHlsController.cs
@@ -1777,6 +1777,16 @@ public class DynamicHlsController : BaseJellyfinApiController
         return args;
     }
 
+    /// <summary>
+    /// Selects the HEVC Dolby Vision sample entry tag.
+    /// </summary>
+    /// <param name="stream">The video stream.</param>
+    /// <returns>The MP4 sample entry tag.</returns>
+    internal static string GetDolbyVisionHevcCodecTag(MediaStream stream)
+    {
+        return stream.DvProfile == 8 ? "hvc1" : "dvh1";
+    }
+
     /// <summary>
     /// Gets the video arguments for transcoding.
     /// </summary>
@@ -1819,8 +1829,7 @@ public class DynamicHlsController : BaseJellyfinApiController
             {
                 if (isActualOutputVideoCodecHevc)
                 {
-                    // Use hvc1 for 8.4. This is what Dolby uses for its official sample streams. Tagging with dvh1 would break some players with strict tag checking like Apple Safari.
-                    var codecTag = state.VideoStream.VideoRangeType == VideoRangeType.DOVIWithHLG ? "hvc1" : "dvh1";
+                    var codecTag = GetDolbyVisionHevcCodecTag(state.VideoStream);
                     args += $" -tag:v:0 {codecTag} -strict -2";
                 }
                 else if (isActualOutputVideoCodecAv1)
diff --git a/tests/Jellyfin.Api.Tests/Controllers/DynamicHlsControllerTests.cs b/tests/Jellyfin.Api.Tests/Controllers/DynamicHlsControllerTests.cs
index 5f5f273f12..a9f85739bc 100644
--- a/tests/Jellyfin.Api.Tests/Controllers/DynamicHlsControllerTests.cs
+++ b/tests/Jellyfin.Api.Tests/Controllers/DynamicHlsControllerTests.cs
@@ -3,6 +3,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Api.Controllers;
 using MediaBrowser.Controller.MediaEncoding;
+using MediaBrowser.Model.Entities;
 using Microsoft.Extensions.Logging.Abstractions;
 using Xunit;
 
@@ -10,6 +11,34 @@ namespace Jellyfin.Api.Tests.Controllers
 {
     public class DynamicHlsControllerTests
     {
+        [Theory]
+        [InlineData(8, 1, "smpte2084", false, "hvc1")]
+        [InlineData(8, 1, "smpte2084", true, "hvc1")]
+        [InlineData(8, 2, "bt709", false, "hvc1")]
+        [InlineData(8, 4, "arib-std-b67", false, "hvc1")]
+        [InlineData(8, 6, "smpte2084", false, "hvc1")]
+        [InlineData(5, 0, "smpte2084", false, "dvh1")]
+        [InlineData(7, 6, "smpte2084", false, "dvh1")]
+        [InlineData(null, null, "smpte2084", false, "dvh1")]
+        public void GetDolbyVisionHevcCodecTag_SelectsTagForProfile(int? profile, int? compatibilityId, string transfer, bool hdr10Plus, string expected)
+        {
+            var stream = new MediaStream
+            {
+                Codec = "hevc",
+                Type = MediaStreamType.Video,
+                RpuPresentFlag = 1,
+                BlPresentFlag = 1,
+                ColorSpace = "bt2020nc",
+                ColorPrimaries = "bt2020",
+                ColorTransfer = transfer,
+                DvProfile = profile,
+                DvBlSignalCompatibilityId = compatibilityId,
+                Hdr10PlusPresentFlag = hdr10Plus
+            };
+
+            Assert.Equal(expected, DynamicHlsController.GetDolbyVisionHevcCodecTag(stream));
+        }
+
         [Theory]
         [MemberData(nameof(GetSegmentLengths_Success_TestData))]
         public void GetSegmentLengths_Success(long runtimeTicks, int segmentlength, double[] expected)
-- 
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