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;
+    }
+}