1 files changed, 21 insertions, 0 deletions
diff --git a/Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs b/Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs
index cf42d5f10b..1ac2abcfbf 100644
--- a/Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs
+++ b/Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs
@@ -346,4 +346,25 @@ public static class HlsCodecStringHelpers
 
         return result.ToString();
     }
+
+    /// <summary>
+    /// Gets a Dolby Vision codec string for profiles without a compatible base layer.
+    /// </summary>
+    /// <param name="dvProfile">Dolby Vision profile number.</param>
+    /// <param name="dvLevel">Dolby Vision level number.</param>
+    /// <param name="codec">Video codec name (e.g. "hevc", "av1") to determine the DoVi FourCC.</param>
+    /// <returns>Dolby Vision codec string.</returns>
+    public static string GetDoviString(int dvProfile, int dvLevel, string codec)
+    {
+        // HEVC DoVi uses dvh1, AV1 DoVi uses dav1 (out-of-band parameter sets, recommended by Apple HLS spec Rule 1.10)
+        var fourCc = string.Equals(codec, "av1", StringComparison.OrdinalIgnoreCase) ? "dav1" : "dvh1";
+        StringBuilder result = new StringBuilder(fourCc, 12);
+
+        result.Append('.')
+            .AppendFormat(CultureInfo.InvariantCulture, "{0:D2}", dvProfile)
+            .Append('.')
+            .AppendFormat(CultureInfo.InvariantCulture, "{0:D2}", dvLevel);
+
+        return result.ToString();
+    }
 }