improve segmenter v2 hevc compliance with fmp4 (#1684)

CHANGELOG.md

@@ -45,6 +45,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 - Use ffmpeg 7 in all docker images 
 - Show health checks at top of home page; scroll release notes if needed
+- Improve `HLS Segmenter V2` compliance by serving fmp4 segments when `hevc` video format is selected
+  - > 1.5. The container format for HEVC video MUST be fMP4.
 
 ## [0.8.6-beta] - 2024-04-03
 ### Added

ErsatzTV.Application/Streaming/Commands/StartFFmpegSessionHandler.cs

@@ -107,7 +107,6 @@ public class StartFFmpegSessionHandler : IRequestHandler<StartFFmpegSession, Eit
         {
             "segmenter-v2" => new HlsSessionWorkerV2(
                 _serviceScopeFactory,
-                _configElementRepository,
                 _localFileSystem,
                 _sessionWorkerV2Logger,
                 targetFramerate,

ErsatzTV.Application/Streaming/HlsSessionWorkerV2.cs

@@ -5,11 +5,9 @@ using System.Timers;
 using CliWrap;
 using CliWrap.Buffered;
 using ErsatzTV.Core;
-using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Metadata;
-using ErsatzTV.Core.Interfaces.Repositories;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Timer = System.Timers.Timer;
@@ -21,7 +19,6 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
     private readonly SemaphoreSlim _slim = new(1, 1);
 
     //private static int _workAheadCount;
-    private readonly IConfigElementRepository _configElementRepository;
     private readonly string _host;
     private readonly ILocalFileSystem _localFileSystem;
     private readonly ILogger<HlsSessionWorkerV2> _logger;
@@ -32,7 +29,6 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
     private CancellationTokenSource _cancellationTokenSource;
     private string _channelNumber;
     private bool _disposedValue;
-    private bool _hasWrittenSegments;
     private DateTimeOffset _lastAccess;
     private Option<PlayoutItemProcessModel> _lastProcessModel;
     private IServiceScope _serviceScope;
@@ -42,7 +38,6 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
 
     public HlsSessionWorkerV2(
         IServiceScopeFactory serviceScopeFactory,
-        IConfigElementRepository configElementRepository,
         ILocalFileSystem localFileSystem,
         ILogger<HlsSessionWorkerV2> logger,
         Option<int> targetFramerate,
@@ -51,7 +46,6 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
     {
         _serviceScope = serviceScopeFactory.CreateScope();
         _mediator = _serviceScope.ServiceProvider.GetRequiredService<IMediator>();
-        _configElementRepository = configElementRepository;
         _localFileSystem = localFileSystem;
         _logger = logger;
         _targetFramerate = targetFramerate;
@@ -298,8 +292,6 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
 
         foreach (PlayoutItemProcessModel processModel in result.RightToSeq())
         {
-            _hasWrittenSegments = true;
-
             _logger.LogDebug("Next playout item process will transcode until {Until}", processModel.Until);
 
             _transcodedUntil = processModel.Until;
@@ -366,45 +358,4 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
 
         return result;
     }
-
-    private async Task<long> GetPtsOffset(string channelNumber, CancellationToken cancellationToken)
-    {
-        await _slim.WaitAsync(cancellationToken);
-        try
-        {
-            long result = 0;
-
-            // if we haven't yet written any segments, start at zero
-            if (!_hasWrittenSegments)
-            {
-                return result;
-            }
-
-            Either<BaseError, PtsAndDuration> queryResult = await _mediator.Send(
-                new GetLastPtsDuration(channelNumber),
-                cancellationToken);
-
-            foreach (BaseError error in queryResult.LeftToSeq())
-            {
-                _logger.LogWarning("Unable to determine last pts offset - {Error}", error.ToString());
-            }
-
-            foreach ((long pts, long duration) in queryResult.RightToSeq())
-            {
-                result = pts + duration + 1;
-            }
-
-            return result;
-        }
-        finally
-        {
-            _slim.Release();
-        }
-    }
-
-    private async Task<int> GetWorkAheadLimit() =>
-        await _configElementRepository.GetValue<int>(ConfigElementKey.FFmpegWorkAheadSegmenters)
-            .Map(maybeCount => maybeCount.Match(identity, () => 1));
-
-    private sealed record Segment(string File, int SequenceNumber);
 }

ErsatzTV.Core/FFmpeg/FFmpegLibraryProcessService.cs

@@ -651,10 +651,14 @@ public class FFmpegLibraryProcessService : IFFmpegProcessService
 
         Option<string> hlsPlaylistPath = Path.Combine(FileSystemLayout.TranscodeFolder, channel.Number, "live.m3u8");
 
-        Option<string> hlsSegmentTemplate = Path.Combine(
-            FileSystemLayout.TranscodeFolder,
-            channel.Number,
-            "live%06d.ts");
+        Option<string> hlsSegmentTemplate = videoFormat switch
+        {
+            // hls/hevc needs mp4
+            VideoFormat.Hevc => Path.Combine(FileSystemLayout.TranscodeFolder, channel.Number, "live%06d.m4s"),
+
+            // hls is otherwise fine with ts
+            _ => Path.Combine(FileSystemLayout.TranscodeFolder, channel.Number, "live%06d.ts")
+        };
 
         var desiredState = new FrameState(
             playbackSettings.RealtimeOutput,

ErsatzTV.FFmpeg/OutputFormat/OutputFormatConcatHls.cs

@@ -18,21 +18,38 @@ public class OutputFormatConcatHls : IPipelineStep
     public string[] InputOptions(InputFile inputFile) => Array.Empty<string>();
     public string[] FilterOptions => Array.Empty<string>();
 
-    public string[] OutputOptions =>
-    [
-        //"-g", $"{gop}",
-        //"-keyint_min", $"{FRAME_RATE * OutputFormatHls.SegmentSeconds}",
-        "-force_key_frames", $"expr:gte(t,n_forced*{OutputFormatHls.SegmentSeconds}/2)",
-        "-f", "hls",
-        //"-hls_segment_type", "fmp4",
-        //"-hls_init_time", "2",
-        "-hls_time", $"{OutputFormatHls.SegmentSeconds}",
-        "-hls_list_size", "25", // burst of 45 means ~12 segments, so allow that plus a handful
-        "-segment_list_flags", "+live",
-        "-hls_segment_filename", _segmentTemplate,
-        "-hls_flags", "delete_segments+program_date_time+omit_endlist+discont_start+independent_segments",
-        _playlistPath
-    ];
+    public string[] OutputOptions
+    {
+        get
+        {
+            string segmentType = "mpegts";
+            string hlsFlags = "delete_segments+program_date_time+omit_endlist+discont_start+independent_segments";
+
+            // check for fmp4 output
+            if (_segmentTemplate.Contains("m4s"))
+            {
+                segmentType = "fmp4";
+                hlsFlags = "delete_segments+program_date_time+omit_endlist";
+            }
+
+            return
+            [
+                //"-g", $"{gop}",
+                //"-keyint_min", $"{FRAME_RATE * OutputFormatHls.SegmentSeconds}",
+                "-force_key_frames", $"expr:gte(t,n_forced*{OutputFormatHls.SegmentSeconds}/2)",
+                "-f", "hls",
+                "-hls_segment_type", segmentType,
+                //"-hls_init_time", "2",
+                "-hls_playlist_type", "event",
+                "-hls_time", $"{OutputFormatHls.SegmentSeconds}",
+                "-hls_list_size", "25", // burst of 45 means ~12 segments, so allow that plus a handful
+                "-segment_list_flags", "+live",
+                "-hls_segment_filename", _segmentTemplate,
+                "-hls_flags", hlsFlags,
+                _playlistPath
+            ];
+        }
+    }
 
     public FrameState NextState(FrameState currentState) => currentState;
 }

ErsatzTV/Startup.cs

@@ -529,9 +529,9 @@ public class Startup
                     ChannelWriter<IFFmpegWorkerRequest> writer = app.ApplicationServices
                         .GetRequiredService<ChannelWriter<IFFmpegWorkerRequest>>();
                     writer.TryWrite(new TouchFFmpegSession(ctx.File.PhysicalPath));
-                }
+                },
                 // to serve m4s
-                // ServeUnknownFileTypes = true
+                ServeUnknownFileTypes = true
             });
 
         app.MapWhen(