Clips

NostrStreamer/Services/Clips/ClipGenerator.cs

@@ -0,0 +1,34 @@
+using FFMpegCore;
+using NostrStreamer.Database;
+
+namespace NostrStreamer.Services.Clips;
+
+public class ClipGenerator
+{
+    private readonly ILogger<ClipGenerator> _logger;
+    private readonly Config _config;
+
+    public ClipGenerator(ILogger<ClipGenerator> logger, Config config)
+    {
+        _logger = logger;
+        _config = config;
+    }
+
+    public async Task<string> GenerateClip(UserStream stream)
+    {
+        const int clipLength = 20;
+        var path = Path.ChangeExtension(Path.GetTempFileName(), ".mp4");
+        var cmd = FFMpegArguments
+            .FromUrlInput(new Uri(_config.DataHost, $"stream/{stream.Id}.m3u8"),
+                inOpt =>
+                {
+                    inOpt.WithCustomArgument($"-ss -{clipLength}");
+                })
+            .OutputToFile(path, true, o => { o.WithDuration(TimeSpan.FromSeconds(clipLength)); })
+            .CancellableThrough(new CancellationTokenSource(TimeSpan.FromSeconds(60)).Token);
+        
+        _logger.LogInformation("Running command {cmd}", cmd.Arguments);
+        await cmd.ProcessAsynchronously();
+        return path;
+    }
+}

NostrStreamer/Services/Clips/IClipService.cs

@@ -0,0 +1,8 @@
+namespace NostrStreamer.Services.Clips;
+
+public interface IClipService
+{
+    Task<ClipResult?> CreateClip(Guid streamId, string takenBy);
+}
+
+public record ClipResult(Uri Url);

NostrStreamer/Services/Clips/S3ClipService.cs

@@ -0,0 +1,80 @@
+using Amazon.S3;
+using Microsoft.EntityFrameworkCore;
+using NostrStreamer.Database;
+
+namespace NostrStreamer.Services.Clips;
+
+public class S3ClipService : IClipService
+{
+    private readonly ClipGenerator _generator;
+    private readonly AmazonS3Client _client;
+    private readonly Config _config;
+    private readonly StreamerContext _context;
+
+    public S3ClipService(ClipGenerator generator, Config config, StreamerContext context)
+    {
+        _generator = generator;
+        _client = config.S3Store.CreateClient();
+        ;
+        _config = config;
+        _context = context;
+    }
+
+    public async Task<ClipResult?> CreateClip(Guid streamId, string takenBy)
+    {
+        var stream = await _context.Streams
+            .Include(a => a.User)
+            .Include(a => a.Endpoint)
+            .FirstOrDefaultAsync(a => a.Id == streamId);
+
+        if (stream == default)
+        {
+            return default;
+        }
+
+        var tmpClip = await _generator.GenerateClip(stream);
+
+        var clipId = Guid.NewGuid();
+        var s3Path = $"{stream.Id}/clips/{clipId}.mp4";
+
+        await using var fs = new FileStream(tmpClip, FileMode.Open, FileAccess.Read);
+        await _client.PutObjectAsync(new()
+        {
+            BucketName = _config.S3Store.BucketName,
+            Key = s3Path,
+            InputStream = fs,
+            AutoCloseStream = false,
+            AutoResetStreamPosition = false,
+            ContentType = "video/mp4",
+            DisablePayloadSigning = _config.S3Store.DisablePayloadSigning
+        });
+
+        var uri = _client.GetPreSignedURL(new()
+        {
+            BucketName = _config.S3Store.BucketName,
+            Key = s3Path,
+            Expires = DateTime.UtcNow.AddYears(1000)
+        });
+
+        var ub = new UriBuilder(uri)
+        {
+            Scheme = _config.S3Store.PublicHost.Scheme,
+            Host = _config.S3Store.PublicHost.Host,
+            Port = _config.S3Store.PublicHost.Port
+        };
+
+
+        var clipObj = new UserStreamClip()
+        {
+            Id = clipId,
+            UserStreamId = stream.Id,
+            TakenByPubkey = takenBy,
+            Url = ub.Uri.ToString()
+        };
+
+        _context.Clips.Add(clipObj);
+        await _context.SaveChangesAsync();
+
+        return new(ub.Uri);
+    }
+}

NostrStreamer/Services/StreamEventBuilder.cs

@@ -41,7 +41,8 @@ public class StreamEventBuilder
             new("status", status),
             new("p", user.PubKey, "", "host"),
             new("relays", _config.Relays),
-            new("starts", new DateTimeOffset(stream.Starts).ToUnixTimeSeconds().ToString())
+            new("starts", new DateTimeOffset(stream.Starts).ToUnixTimeSeconds().ToString()),
+            new("service", new Uri(_config.ApiHost, "/api/nostr").ToString())
         };
 
         if (status == "live")