add channel slugs (#2823)

* add channel slugs

* safety

CHANGELOG.md

@@ -14,6 +14,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Classic schedule info includes schedule, schedule item, scheduler, filler, playback order, random seed, collection index
   - Block schedule info includes block, block item, playback order, random seed, collection index
   - E.g. items with the same random seed are part of the same shuffle
+- Add channel setting `Slug Seconds`
+  - This controls how many (optional) seconds of black video and silent audio to insert between *every* playout item
+  - This will drift playback from the wall clock as slugs are not scheduled in the playout, but are inserted dynamically during playback
+  - If this feature turns out to be popular, methods to correct the drift may be investigated
 
 ### Changed
 - Move dark/light mode toggle to **Settings** > **UI**

ErsatzTV.Application/Channels/ChannelViewModel.cs

@@ -11,6 +11,7 @@ public record ChannelViewModel(
     string Group,
     string Categories,
     int FFmpegProfileId,
+    double? SlugSeconds,
     ArtworkContentTypeModel Logo,
     ChannelStreamSelectorMode StreamSelectorMode,
     string StreamSelector,

ErsatzTV.Application/Channels/Commands/CreateChannel.cs

@@ -10,6 +10,7 @@ public record CreateChannel(
     string Group,
     string Categories,
     int FFmpegProfileId,
+    double? SlugSeconds,
     ArtworkContentTypeModel Logo,
     ChannelStreamSelectorMode StreamSelectorMode,
     string StreamSelector,

ErsatzTV.Application/Channels/Commands/CreateChannelHandler.cs

@@ -80,6 +80,7 @@ public class CreateChannelHandler(
                 Group = request.Group,
                 Categories = request.Categories,
                 FFmpegProfileId = ffmpegProfileId,
+                SlugSeconds = request.SlugSeconds,
                 PlayoutSource = request.PlayoutSource,
                 PlayoutMode = request.PlayoutMode,
                 MirrorSourceChannelId = request.MirrorSourceChannelId,

ErsatzTV.Application/Channels/Commands/UpdateChannel.cs

@@ -11,6 +11,7 @@ public record UpdateChannel(
     string Group,
     string Categories,
     int FFmpegProfileId,
+    double? SlugSeconds,
     ArtworkContentTypeModel Logo,
     ChannelStreamSelectorMode StreamSelectorMode,
     string StreamSelector,

ErsatzTV.Application/Channels/Commands/UpdateChannelHandler.cs

@@ -52,6 +52,7 @@ public class UpdateChannelHandler(
         c.Group = update.Group;
         c.Categories = update.Categories;
         c.FFmpegProfileId = update.FFmpegProfileId;
+        c.SlugSeconds = update.SlugSeconds;
         c.StreamSelectorMode = update.StreamSelectorMode;
         c.StreamSelector = update.StreamSelector;
         c.PreferredAudioLanguageCode = update.PreferredAudioLanguageCode;

ErsatzTV.Application/Channels/Mapper.cs

@@ -14,6 +14,7 @@ internal static class Mapper
             channel.Group,
             channel.Categories,
             channel.FFmpegProfileId,
+            channel.SlugSeconds,
             GetLogo(channel),
             channel.StreamSelectorMode,
             channel.StreamSelector,

ErsatzTV.Application/Channels/Queries/GetSlugSecondsByChannelNumber.cs

@@ -0,0 +1,3 @@
+namespace ErsatzTV.Application.Channels;
+
+public record GetSlugSecondsByChannelNumber(string ChannelNumber) : IRequest<Option<double>>;

ErsatzTV.Application/Channels/Queries/GetSlugSecondsByChannelNumberHandler.cs

@@ -0,0 +1,17 @@
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Channels;
+
+public class GetSlugSecondsByChannelNumberHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetSlugSecondsByChannelNumber, Option<double>>
+{
+    public async Task<Option<double>> Handle(GetSlugSecondsByChannelNumber request, CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        return await dbContext.Channels
+            .AsNoTracking()
+            .SingleOrDefaultAsync(c => c.Number == request.ChannelNumber, cancellationToken)
+            .Map(c => Optional(c?.SlugSeconds));
+    }
+}

ErsatzTV.Application/Streaming/HlsSessionState.cs

@@ -6,5 +6,7 @@ public enum HlsSessionState
     ZeroAndWorkAhead,
     SeekAndRealtime,
     ZeroAndRealtime,
+    SlugAndWorkAhead,
+    SlugAndRealtime,
     PlayoutUpdated
 }

ErsatzTV.Application/Streaming/HlsSessionWorker.cs

@@ -8,6 +8,7 @@ using System.Timers;
 using Bugsnag;
 using CliWrap;
 using CliWrap.Buffered;
+using ErsatzTV.Application.Channels;
 using ErsatzTV.Application.Playouts;
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
@@ -54,6 +55,7 @@ public class HlsSessionWorker : IHlsSessionWorker
     private Timer _timer;
     private DateTimeOffset _transcodedUntil;
     private string _workingDirectory;
+    private Option<double> _slugSeconds;
 
     public HlsSessionWorker(
         IServiceScopeFactory serviceScopeFactory,
@@ -215,6 +217,10 @@ public class HlsSessionWorker : IHlsSessionWorker
                 new GetPlayoutIdByChannelNumber(_channelNumber),
                 cancellationToken);
 
+            _slugSeconds = await _mediator.Send(
+                new GetSlugSecondsByChannelNumber(_channelNumber),
+                cancellationToken);
+
             // time shift on-demand playout if needed
             foreach (int playoutId in maybePlayoutId)
             {
@@ -382,6 +388,13 @@ public class HlsSessionWorker : IHlsSessionWorker
             // after seeking and NOT completing the item, seek again, transcode method will accelerate if needed
             HlsSessionState.SeekAndWorkAhead when !isComplete => HlsSessionState.SeekAndRealtime,
 
+            // switch back to normal item after slug
+            HlsSessionState.SlugAndWorkAhead => HlsSessionState.ZeroAndWorkAhead,
+            HlsSessionState.SlugAndRealtime => HlsSessionState.ZeroAndRealtime,
+
+            // after completing the item, insert a slug
+            _ when isComplete && _slugSeconds.IsSome => HlsSessionState.SlugAndWorkAhead,
+
             // after seeking and completing the item, start at zero
             HlsSessionState.SeekAndWorkAhead => HlsSessionState.ZeroAndWorkAhead,
 
@@ -456,19 +469,32 @@ public class HlsSessionWorker : IHlsSessionWorker
             _logger.LogDebug("HLS session state: {State}", _state);
 
             DateTimeOffset now = wasSeekAndWorkAhead ? DateTimeOffset.Now : _transcodedUntil;
-            bool startAtZero = _state is HlsSessionState.ZeroAndWorkAhead or HlsSessionState.ZeroAndRealtime;
-
-            var request = new GetPlayoutItemProcessByChannelNumber(
-                _channelNumber,
-                StreamingMode.HttpLiveStreamingSegmenter,
-                now,
-                startAtZero,
-                realtime,
-                _channelStart,
-                ptsOffset,
-                _targetFramerate,
-                IsTroubleshooting: false,
-                Option<int>.None);
+            bool startAtZero = _state is HlsSessionState.ZeroAndWorkAhead or HlsSessionState.ZeroAndRealtime
+                or HlsSessionState.SlugAndWorkAhead or HlsSessionState.SlugAndRealtime;
+
+            bool isSlug = _state is HlsSessionState.SlugAndWorkAhead or HlsSessionState.SlugAndRealtime;
+
+            FFmpegProcessRequest request = isSlug
+                ? new GetSlugProcessByChannelNumber(
+                    _channelNumber,
+                    StreamingMode.HttpLiveStreamingSegmenter,
+                    now,
+                    realtime,
+                    _channelStart,
+                    ptsOffset,
+                    _targetFramerate,
+                    _slugSeconds)
+                : new GetPlayoutItemProcessByChannelNumber(
+                    _channelNumber,
+                    StreamingMode.HttpLiveStreamingSegmenter,
+                    now,
+                    startAtZero,
+                    realtime,
+                    _channelStart,
+                    ptsOffset,
+                    _targetFramerate,
+                    IsTroubleshooting: false,
+                    Option<int>.None);
 
             // _logger.LogInformation("Request {@Request}", request);
 

ErsatzTV.Application/Streaming/Queries/GetSlugProcessByChannelNumber.cs

@@ -0,0 +1,22 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.FFmpeg;
+
+namespace ErsatzTV.Application.Streaming;
+
+public record GetSlugProcessByChannelNumber(
+    string ChannelNumber,
+    StreamingMode Mode,
+    DateTimeOffset Now,
+    bool HlsRealtime,
+    DateTimeOffset ChannelStart,
+    TimeSpan PtsOffset,
+    Option<FrameRate> TargetFramerate,
+    Option<double> SlugSeconds) : FFmpegProcessRequest(
+    ChannelNumber,
+    Mode,
+    Now,
+    StartAtZero: true,
+    HlsRealtime,
+    ChannelStart,
+    PtsOffset,
+    FFmpegProfileId: Option<int>.None);

ErsatzTV.Application/Streaming/Queries/GetSlugProcessByChannelNumberHandler.cs

@@ -0,0 +1,111 @@
+using System.IO.Abstractions;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.FFmpeg;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.FFmpeg;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Streaming;
+
+public class GetSlugProcessByChannelNumberHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IFileSystem fileSystem,
+    IFFmpegProcessService ffmpegProcessService,
+    ILocalStatisticsProvider localStatisticsProvider)
+    : FFmpegProcessHandler<GetSlugProcessByChannelNumber>(dbContextFactory)
+{
+    protected override async Task<Either<BaseError, PlayoutItemProcessModel>> GetProcess(
+        TvContext dbContext,
+        GetSlugProcessByChannelNumber request,
+        Channel channel,
+        string ffmpegPath,
+        string ffprobePath,
+        CancellationToken cancellationToken)
+    {
+        string videoPath = fileSystem.Path.Combine(FileSystemLayout.ResourcesCacheFolder, "slug.mp4");
+
+        bool saveReports = await dbContext.ConfigElements
+            .GetValue<bool>(ConfigElementKey.FFmpegSaveReports, cancellationToken)
+            .Map(result => result.IfNone(false));
+
+        Either<BaseError, MediaVersion> maybeVersion =
+            await localStatisticsProvider.GetStatistics(ffprobePath, videoPath);
+        foreach (var error in maybeVersion.LeftToSeq())
+        {
+            return error;
+        }
+
+        var version = maybeVersion.RightToSeq().Head();
+
+        var mediaItem = new OtherVideo
+        {
+            MediaVersions = [version]
+        };
+
+        TimeSpan duration = version.Duration;
+        foreach (double slugSeconds in request.SlugSeconds)
+        {
+            TimeSpan seconds = TimeSpan.FromSeconds(slugSeconds);
+            if (seconds > TimeSpan.Zero && seconds < duration)
+            {
+                duration = seconds;
+            }
+        }
+
+        DateTimeOffset finish = request.Now.Add(duration);
+
+        PlayoutItemResult playoutItemResult = await ffmpegProcessService.ForPlayoutItem(
+            ffmpegPath,
+            ffprobePath,
+            saveReports,
+            channel,
+            new MediaItemVideoVersion(mediaItem, version),
+            new MediaItemAudioVersion(mediaItem, version),
+            videoPath,
+            videoPath,
+            _ => Task.FromResult<List<Subtitle>>([]),
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            request.Now,
+            finish,
+            request.Now,
+            duration,
+            [],
+            [],
+            channel.FFmpegProfile.VaapiDisplay,
+            channel.FFmpegProfile.VaapiDriver,
+            channel.FFmpegProfile.VaapiDevice,
+            Optional(channel.FFmpegProfile.QsvExtraHardwareFrames),
+            request.HlsRealtime,
+            StreamInputKind.Vod,
+            FillerKind.None,
+            inPoint: TimeSpan.Zero,
+            request.ChannelStartTime,
+            request.PtsOffset,
+            request.TargetFramerate,
+            Option<string>.None,
+            _ => { },
+            canProxy: true,
+            cancellationToken);
+
+        var result = new PlayoutItemProcessModel(
+            playoutItemResult.Process,
+            playoutItemResult.GraphicsEngineContext,
+            duration,
+            finish,
+            isComplete: true,
+            request.Now.ToUnixTimeSeconds(),
+            playoutItemResult.MediaItemId,
+            Optional(channel.PlayoutOffset),
+            !request.HlsRealtime);
+
+        return Right<BaseError, PlayoutItemProcessModel>(result);
+    }
+}

ErsatzTV.Core/Domain/Channel.cs

@@ -17,6 +17,7 @@ public class Channel
     public string Categories { get; set; }
     public int FFmpegProfileId { get; set; }
     public FFmpegProfile FFmpegProfile { get; set; }
+    public double? SlugSeconds { get; set; }
     public int? WatermarkId { get; set; }
     public ChannelWatermark Watermark { get; set; }
     public int? FallbackFillerId { get; set; }

ErsatzTV.Infrastructure.MySql/Migrations/20260215014015_Add_ChannelSlugSeconds.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.MySql.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_ChannelSlugSeconds : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<double>(
+                name: "SlugSeconds",
+                table: "Channel",
+                type: "double",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "SlugSeconds",
+                table: "Channel");
+        }
+    }
+}

ErsatzTV.Infrastructure.MySql/Migrations/TvContextModelSnapshot.cs

@@ -357,6 +357,9 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
                         .HasColumnType("tinyint(1)")
                         .HasDefaultValue(true);
 
+                    b.Property<double?>("SlugSeconds")
+                        .HasColumnType("double");
+
                     b.Property<int>("SongVideoMode")
                         .HasColumnType("int");
 

ErsatzTV.Infrastructure.Sqlite/Migrations/20260215013932_Add_ChannelSlugSeconds.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.Sqlite.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_ChannelSlugSeconds : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<double>(
+                name: "SlugSeconds",
+                table: "Channel",
+                type: "REAL",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "SlugSeconds",
+                table: "Channel");
+        }
+    }
+}

ErsatzTV.Infrastructure.Sqlite/Migrations/TvContextModelSnapshot.cs

@@ -344,6 +344,9 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
                         .HasColumnType("INTEGER")
                         .HasDefaultValue(true);
 
+                    b.Property<double?>("SlugSeconds")
+                        .HasColumnType("REAL");
+
                     b.Property<int>("SongVideoMode")
                         .HasColumnType("INTEGER");
 

ErsatzTV/ErsatzTV.csproj

@@ -119,6 +119,7 @@
           <Generator>ResXFileCodeGenerator</Generator>
           <LastGenOutput>Common.Designer.cs</LastGenOutput>
         </EmbeddedResource>
+        <EmbeddedResource Include="Resources\slug.mp4" />
     </ItemGroup>
 
     <ItemGroup>

ErsatzTV/Pages/ChannelEditor.razor

@@ -154,6 +154,19 @@ else
         }
     </MudSelect>
 </MudStack>
+<MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
+    <div class="d-flex">
+        <MudText>Slug Seconds</MudText>
+    </div>
+    <MudSelect T="double?" @bind-Value="_model.SlugSeconds" For="@(() => _model.SlugSeconds)" HelperText="Seconds of black video and silent audio to insert between *every* playout item">
+        <MudSelectItem Value="@((double?)null)">(none)</MudSelectItem>
+        <MudSelectItem Value="@((double?)0.5)">0.5 seconds</MudSelectItem>
+        <MudSelectItem Value="@((double?)1)">1 second</MudSelectItem>
+        <MudSelectItem Value="@((double?)2)">2 seconds</MudSelectItem>
+        <MudSelectItem Value="@((double?)3)">3 seconds</MudSelectItem>
+        <MudSelectItem Value="@((double?)5)">5 seconds</MudSelectItem>
+    </MudSelect>
+</MudStack>
 <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
     <div class="d-flex">
         <MudText>Stream Selector Mode</MudText>
@@ -376,6 +389,7 @@ else
                         _model.Categories = channelViewModel.Categories;
                         _model.Number = channelViewModel.Number;
                         _model.FFmpegProfileId = channelViewModel.FFmpegProfileId;
+                        _model.SlugSeconds = channelViewModel.SlugSeconds;
 
                         if (channelViewModel.Logo.IsExternalUrl)
                         {

ErsatzTV/Services/RunOnce/ResourceExtractorService.cs

@@ -27,6 +27,7 @@ public class ResourceExtractorService : BackgroundService
         await ExtractResource(assembly, "sequential-schedule.schema.json", stoppingToken);
         await ExtractResource(assembly, "sequential-schedule-import.schema.json", stoppingToken);
         await ExtractResource(assembly, "test.avs", stoppingToken);
+        await ExtractResource(assembly, "slug.mp4", stoppingToken);
 
         await ExtractFontResource(assembly, "Sen.ttf", stoppingToken);
         await ExtractFontResource(assembly, "Roboto-Regular.ttf", stoppingToken);

ErsatzTV/ViewModels/ChannelEditViewModel.cs

@@ -13,6 +13,7 @@ public class ChannelEditViewModel
     public string Categories { get; set; }
     public string Number { get; set; }
     public int FFmpegProfileId { get; set; }
+    public double? SlugSeconds { get; set; }
     public ChannelStreamSelectorMode StreamSelectorMode { get; set; }
     public string StreamSelector { get; set; }
     public string PreferredAudioLanguageCode { get; set; }
@@ -59,6 +60,7 @@ public class ChannelEditViewModel
             Group,
             Categories,
             FFmpegProfileId,
+            SlugSeconds,
             string.IsNullOrWhiteSpace(ExternalLogoUrl)
                 ? Logo
                 : new ArtworkContentTypeModel(ExternalLogoUrl, string.Empty),
@@ -90,6 +92,7 @@ public class ChannelEditViewModel
             Group,
             Categories,
             FFmpegProfileId,
+            SlugSeconds,
             string.IsNullOrWhiteSpace(ExternalLogoUrl)
                 ? Logo
                 : new ArtworkContentTypeModel(ExternalLogoUrl, string.Empty),