slightly increase throttled readrate in segmenter (#2534)

ErsatzTV.Application/Streaming/HlsSessionWorker.cs

@@ -515,7 +515,10 @@ public class HlsSessionWorker : IHlsSessionWorker
                     if (commandResult.ExitCode == 0)
                     {
                         _logger.LogDebug("HLS process has completed for channel {Channel}", _channelNumber);
-                        _logger.LogDebug("Transcoded until: {Until}", processModel.Until);
+                        _logger.LogDebug(
+                            "Transcoded until: {Until} - buffer {Buffer}",
+                            processModel.Until,
+                            DateTimeOffset.Now - processModel.Until);
                         _transcodedUntil = processModel.Until;
                         _state = NextState(_state, processModel);
                         _hasWrittenSegments = true;

ErsatzTV.FFmpeg.Tests/PipelineBuilderBaseTests.cs

@@ -118,7 +118,7 @@ public class PipelineBuilderBaseTests
 
         string command = PrintCommand(videoInputFile, audioInputFile, None, None, None, result);
         command.ShouldBe(
-            "-nostdin -hide_banner -nostats -loglevel error -fflags +genpts+discardcorrupt+igndts -ss 00:00:01 -c:v h264 -readrate 1.0 -i /tmp/whatever.mkv -filter_complex [0:1]aresample=async=1[a] -map 0:0 -map [a] -muxdelay 0 -muxpreload 0 -movflags +faststart -flags cgop -bf 0 -sc_threshold 0 -video_track_timescale 90000 -b:v 2000k -maxrate:v 2000k -bufsize:v 4000k -c:v libx265 -tag:v hvc1 -x265-params log-level=error -c:a aac -b:a 320k -maxrate:a 320k -bufsize:a 640k -ar 48k -f mpegts -mpegts_flags +initial_discontinuity pipe:1");
+            "-nostdin -hide_banner -nostats -loglevel error -fflags +genpts+discardcorrupt+igndts -ss 00:00:01 -c:v h264 -readrate 1.05 -i /tmp/whatever.mkv -filter_complex [0:1]aresample=async=1[a] -map 0:0 -map [a] -muxdelay 0 -muxpreload 0 -movflags +faststart -flags cgop -bf 0 -sc_threshold 0 -video_track_timescale 90000 -b:v 2000k -maxrate:v 2000k -bufsize:v 4000k -c:v libx265 -tag:v hvc1 -x265-params log-level=error -c:a aac -b:a 320k -maxrate:a 320k -bufsize:a 640k -ar 48k -f mpegts -mpegts_flags +initial_discontinuity pipe:1");
     }
 
     [Test]
@@ -217,7 +217,7 @@ public class PipelineBuilderBaseTests
 
         string command = PrintCommand(videoInputFile, audioInputFile, None, None, None, result);
         command.ShouldBe(
-            "-nostdin -hide_banner -nostats -loglevel error -fflags +genpts+discardcorrupt+igndts -ss 00:00:01 -c:v h264 -readrate 1.0 -i /tmp/whatever.mkv -filter_complex [0:1]aresample=async=1[a] -map 0:0 -map [a] -muxdelay 0 -muxpreload 0 -movflags +faststart -flags cgop -bf 0 -sc_threshold 0 -video_track_timescale 90000 -b:v 2000k -maxrate:v 2000k -bufsize:v 4000k -c:v libx265 -tag:v hvc1 -x265-params log-level=error -c:a aac -ac 6 -b:a 320k -maxrate:a 320k -bufsize:a 640k -ar 48k -f mpegts -mpegts_flags +initial_discontinuity pipe:1");
+            "-nostdin -hide_banner -nostats -loglevel error -fflags +genpts+discardcorrupt+igndts -ss 00:00:01 -c:v h264 -readrate 1.05 -i /tmp/whatever.mkv -filter_complex [0:1]aresample=async=1[a] -map 0:0 -map [a] -muxdelay 0 -muxpreload 0 -movflags +faststart -flags cgop -bf 0 -sc_threshold 0 -video_track_timescale 90000 -b:v 2000k -maxrate:v 2000k -bufsize:v 4000k -c:v libx265 -tag:v hvc1 -x265-params log-level=error -c:a aac -ac 6 -b:a 320k -maxrate:a 320k -bufsize:a 640k -ar 48k -f mpegts -mpegts_flags +initial_discontinuity pipe:1");
     }
 
     [Test]

ErsatzTV.FFmpeg/Capabilities/FFmpegKnownOption.cs

@@ -6,15 +6,11 @@ namespace ErsatzTV.FFmpeg.Capabilities;
 [SuppressMessage("ReSharper", "StringLiteralTypo")]
 public record FFmpegKnownOption
 {
-    public static readonly FFmpegKnownOption ReadrateInitialBurst = new("readrate_initial_burst");
-
     private FFmpegKnownOption(string Name) => this.Name = Name;
 
     public string Name { get; }
 
     public static IList<string> AllOptions =>
-        new[]
-        {
-            ReadrateInitialBurst.Name
-        };
+    [
+    ];
 }

ErsatzTV.FFmpeg/InputOption/ReadrateInputOption.cs

@@ -1,54 +1,19 @@
 using System.Globalization;
-using ErsatzTV.FFmpeg.Capabilities;
 using ErsatzTV.FFmpeg.Environment;
-using Microsoft.Extensions.Logging;
 
 namespace ErsatzTV.FFmpeg.InputOption;
 
-public class ReadrateInputOption : IInputOption
+public class ReadrateInputOption(double readRate) : IInputOption
 {
-    private readonly IFFmpegCapabilities _ffmpegCapabilities;
-    private readonly int _initialBurstSeconds;
-    private readonly ILogger _logger;
-
-    public ReadrateInputOption(
-        IFFmpegCapabilities ffmpegCapabilities,
-        int initialBurstSeconds,
-        ILogger logger)
-    {
-        _ffmpegCapabilities = ffmpegCapabilities;
-        _initialBurstSeconds = initialBurstSeconds;
-        _logger = logger;
-    }
-
     public EnvironmentVariable[] EnvironmentVariables => [];
 
     public string[] GlobalOptions => [];
 
-    public string[] InputOptions(InputFile inputFile)
-    {
-        var result = new List<string> { "-readrate", "1.0" };
-
-        if (_initialBurstSeconds > 0)
-        {
-            if (!_ffmpegCapabilities.HasOption(FFmpegKnownOption.ReadrateInitialBurst))
-            {
-                _logger.LogWarning(
-                    "FFmpeg is missing {Option} option; unable to transcode faster than realtime",
-                    FFmpegKnownOption.ReadrateInitialBurst.Name);
-
-                return result.ToArray();
-            }
-
-            result.AddRange(
-            [
-                "-readrate_initial_burst",
-                    _initialBurstSeconds.ToString(CultureInfo.InvariantCulture)
-            ]);
-        }
-
-        return result.ToArray();
-    }
+    public string[] InputOptions(InputFile inputFile) =>
+    [
+        "-readrate",
+        readRate.ToString("0.0####", CultureInfo.InvariantCulture)
+    ];
 
     public string[] FilterOptions => [];
     public string[] OutputOptions => [];

ErsatzTV.FFmpeg/Pipeline/PipelineBuilderBase.cs

@@ -116,7 +116,7 @@ public abstract class PipelineBuilderBase : IPipelineBuilder
         };
 
         concatInputFile.AddOption(new ConcatInputFormat());
-        concatInputFile.AddOption(new ReadrateInputOption(_ffmpegCapabilities, 0, _logger));
+        concatInputFile.AddOption(new ReadrateInputOption(1.0));
         concatInputFile.AddOption(new InfiniteLoopInputOption(HardwareAccelerationMode.None));
 
         foreach (int threadCount in ffmpegState.ThreadCount)
@@ -162,7 +162,7 @@ public abstract class PipelineBuilderBase : IPipelineBuilder
             new EncoderCopyAll()
         };
 
-        concatInputFile.AddOption(new ReadrateInputOption(_ffmpegCapabilities, 0, _logger));
+        concatInputFile.AddOption(new ReadrateInputOption(1.0));
 
         SetMetadataServiceProvider(ffmpegState, pipelineSteps);
         SetMetadataServiceName(ffmpegState, pipelineSteps);
@@ -564,7 +564,7 @@ public abstract class PipelineBuilderBase : IPipelineBuilder
             : SetDecoder(videoInputFile, videoStream, ffmpegState, context);
 
         //SetStillImageInfiniteLoop(videoInputFile, videoStream, ffmpegState);
-        SetRealtimeInput(videoInputFile, ffmpegState, desiredState);
+        SetRealtimeInput(videoInputFile, desiredState);
         SetInfiniteLoop(videoInputFile, videoStream, ffmpegState, desiredState);
         SetFrameRateOutput(desiredState, pipelineSteps);
         SetVideoTrackTimescaleOutput(desiredState, pipelineSteps);
@@ -761,30 +761,16 @@ public abstract class PipelineBuilderBase : IPipelineBuilder
         }
     }
 
-    private void SetRealtimeInput(VideoInputFile videoInputFile, FFmpegState ffmpegState, FrameState desiredState)
+    private void SetRealtimeInput(VideoInputFile videoInputFile, FrameState desiredState)
     {
         if (videoInputFile.StreamInputKind is StreamInputKind.Live || !desiredState.Realtime)
         {
             return;
         }
 
-        AudioFilter filter = _audioInputFile
-            .Map(a => a.DesiredState.NormalizeLoudnessFilter)
-            .IfNone(AudioFilter.None);
-
-        int initialBurst = filter switch
-        {
-            AudioFilter.LoudNorm => 5,
-            _ => 0
-        };
-
-        if (ffmpegState.Finish.Any(finish => finish.TotalSeconds < initialBurst))
-        {
-            return;
-        }
-
-        _audioInputFile.Iter(a => a.AddOption(new ReadrateInputOption(_ffmpegCapabilities, initialBurst, _logger)));
-        videoInputFile.AddOption(new ReadrateInputOption(_ffmpegCapabilities, initialBurst, _logger));
+        double readRate = desiredState.VideoFormat == VideoFormat.Copy ? 1.0 : 1.05;
+        _audioInputFile.Iter(a => a.AddOption(new ReadrateInputOption(readRate)));
+        videoInputFile.AddOption(new ReadrateInputOption(readRate));
     }
 
     protected static void SetStillImageLoop(