Add perf tradeoff mode to image extractor (#12744)

Emby.Server.Implementations/ConfigurationOptions.cs

@@ -21,6 +21,7 @@ namespace Emby.Server.Implementations
             { BindToUnixSocketKey, bool.FalseString },
             { SqliteCacheSizeKey, "20000" },
             { FfmpegSkipValidationKey, bool.FalseString },
+            { FfmpegImgExtractPerfTradeoffKey, bool.FalseString },
             { DetectNetworkChangeKey, bool.TrueString }
         };
     }

MediaBrowser.Controller/Extensions/ConfigurationExtensions.cs

@@ -39,6 +39,11 @@ namespace MediaBrowser.Controller.Extensions
         /// </summary>
         public const string FfmpegAnalyzeDurationKey = "FFmpeg:analyzeduration";
 
+        /// <summary>
+        /// The key for the FFmpeg image extraction performance tradeoff option.
+        /// </summary>
+        public const string FfmpegImgExtractPerfTradeoffKey = "FFmpeg:imgExtractPerfTradeoff";
+
         /// <summary>
         /// The key for the FFmpeg path option.
         /// </summary>
@@ -107,6 +112,14 @@ namespace MediaBrowser.Controller.Extensions
         public static bool GetFFmpegSkipValidation(this IConfiguration configuration)
             => configuration.GetValue<bool>(FfmpegSkipValidationKey);
 
+        /// <summary>
+        /// Gets a value indicating whether the server should trade off for performance during FFmpeg image extraction.
+        /// </summary>
+        /// <param name="configuration">The configuration to read the setting from.</param>
+        /// <returns><c>true</c> if the server should trade off for performance during FFmpeg image extraction, otherwise <c>false</c>.</returns>
+        public static bool GetFFmpegImgExtractPerfTradeoff(this IConfiguration configuration)
+            => configuration.GetValue<bool>(FfmpegImgExtractPerfTradeoffKey);
+
         /// <summary>
         /// Gets a value indicating whether playlists should allow duplicate entries from the <see cref="IConfiguration"/>.
         /// </summary>

MediaBrowser.MediaEncoding/Encoder/MediaEncoder.cs

@@ -650,6 +650,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         {
             ArgumentException.ThrowIfNullOrEmpty(inputPath);
 
+            var useTradeoff = _config.GetFFmpegImgExtractPerfTradeoff();
+
             var outputExtension = targetFormat?.GetExtension() ?? ".jpg";
 
             var tempExtractPath = Path.Combine(_configurationManager.ApplicationPaths.TempDirectory, Guid.NewGuid() + outputExtension);
@@ -684,7 +686,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
             // Use ffmpeg to sample 100 (we can drop this if required using thumbnail=50 for 50 frames) frames and pick the best thumbnail. Have a fall back just in case.
             // mpegts need larger batch size otherwise the corrupted thumbnail will be created. Larger batch size will lower the processing speed.
-            var enableThumbnail = useIFrame && !string.Equals("wtv", container, StringComparison.OrdinalIgnoreCase);
+            var enableThumbnail = !useTradeoff && useIFrame && !string.Equals("wtv", container, StringComparison.OrdinalIgnoreCase);
             if (enableThumbnail)
             {
                 var useLargerBatchSize = string.Equals("mpegts", container, StringComparison.OrdinalIgnoreCase);
@@ -718,6 +720,11 @@ namespace MediaBrowser.MediaEncoding.Encoder
                 args = string.Format(CultureInfo.InvariantCulture, "-ss {0} ", GetTimeParameter(offset.Value)) + args;
             }
 
+            if (useIFrame && useTradeoff)
+            {
+                args = "-skip_frame nokey " + args;
+            }
+
             if (!string.IsNullOrWhiteSpace(container))
             {
                 var inputFormat = EncodingHelper.GetInputFormat(container);