Merge pull request #15926 from abitofevrything/feat/accurate_hls_seeking

Refactor HLS transcode seeking

MediaBrowser.Model/Configuration/EncodingOptions.cs

@@ -1,6 +1,7 @@
 #pragma warning disable CA1819 // XML serialization handles collections improperly, so we need to use arrays
 
 #nullable disable
+using System.ComponentModel;
 using MediaBrowser.Model.Entities;
 
 namespace MediaBrowser.Model.Configuration;
@@ -60,6 +61,7 @@ public class EncodingOptions
         SubtitleExtractionTimeoutMinutes = 30;
         AllowOnDemandMetadataBasedKeyframeExtractionForExtensions = ["mkv"];
         HardwareDecodingCodecs = ["h264", "vc1"];
+        HlsAudioSeekStrategy = HlsAudioSeekStrategy.DisableAccurateSeek;
     }
 
     /// <summary>
@@ -301,4 +303,10 @@ public class EncodingOptions
     /// Gets or sets the file extensions on-demand metadata based keyframe extraction is enabled for.
     /// </summary>
     public string[] AllowOnDemandMetadataBasedKeyframeExtractionForExtensions { get; set; }
+
+    /// <summary>
+    /// Gets or sets the method used for audio seeking in HLS.
+    /// </summary>
+    [DefaultValue(HlsAudioSeekStrategy.DisableAccurateSeek)]
+    public HlsAudioSeekStrategy HlsAudioSeekStrategy { get; set; }
 }

MediaBrowser.Model/Configuration/HlsAudioSeekStrategy.cs

@@ -0,0 +1,23 @@
+namespace MediaBrowser.Model.Configuration
+{
+    /// <summary>
+    /// An enum representing the options to seek the input audio stream when
+    /// transcoding HLS segments.
+    /// </summary>
+    public enum HlsAudioSeekStrategy
+    {
+        /// <summary>
+        /// If the video stream is transcoded and the audio stream is copied,
+        /// seek the video stream to the same keyframe as the audio stream. The
+        /// resulting timestamps in the output streams may be inaccurate.
+        /// </summary>
+        DisableAccurateSeek = 0,
+
+        /// <summary>
+        /// Prevent audio streams from being copied if the video stream is transcoded.
+        /// The resulting timestamps will be accurate, but additional audio transcoding
+        /// overhead will be incurred.
+        /// </summary>
+        TranscodeAudio = 1,
+    }
+}