Redo clips api

NostrStreamer/Services/Clips/ClipGenerator.cs

@@ -1,5 +1,5 @@
+using System.Text.RegularExpressions;
 using FFMpegCore;
-using NostrStreamer.Database;
 
 namespace NostrStreamer.Services.Clips;
 
@@ -7,28 +7,56 @@ public class ClipGenerator
 {
     private readonly ILogger<ClipGenerator> _logger;
     private readonly Config _config;
+    private readonly HttpClient _client;
 
-    public ClipGenerator(ILogger<ClipGenerator> logger, Config config)
+    public ClipGenerator(ILogger<ClipGenerator> logger, Config config, HttpClient client)
     {
         _logger = logger;
         _config = config;
+        _client = client;
     }
 
-    public async Task<string> GenerateClip(UserStream stream)
+    public async Task<string> CreateClipFromSegments(List<ClipSegment> segments, float start, float length)
     {
-        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)); })
+            .FromConcatInput(segments.Select(a => a.GetPath()),
+                inOpt => { inOpt.Seek(TimeSpan.FromSeconds(start)); })
+            .OutputToFile(path, true, o => { o.WithDuration(TimeSpan.FromSeconds(length)); })
             .CancellableThrough(new CancellationTokenSource(TimeSpan.FromSeconds(60)).Token);
-        
+
         _logger.LogInformation("Running command {cmd}", cmd.Arguments);
         await cmd.ProcessAsynchronously();
         return path;
     }
+
+    public async Task<List<ClipSegment>> GetClipSegments(Guid id)
+    {
+        var ret = new List<ClipSegment>();
+        var playlist = new Uri(_config.DataHost, $"stream/{id}.m3u8");
+
+        var rsp = await _client.GetStreamAsync(playlist);
+        using var sr = new StreamReader(rsp);
+        while (await sr.ReadLineAsync() is { } line)
+        {
+            if (line.StartsWith("#EXTINF"))
+            {
+                var trackPath = await sr.ReadLineAsync();
+                var seg = Regex.Match(trackPath!, @"-(\d+)\.ts");
+                var idx = int.Parse(seg.Groups[1].Value);
+                var clipSeg = new ClipSegment(id, idx);
+                var outPath = clipSeg.GetPath();
+                if (!File.Exists(outPath))
+                {
+                    var segStream = await _client.GetStreamAsync(new Uri(_config.DataHost, trackPath));
+                    await using var fsOut = new FileStream(outPath, FileMode.Create, FileAccess.ReadWrite);
+                    await segStream.CopyToAsync(fsOut);
+                }
+
+                ret.Add(clipSeg);
+            }
+        }
+
+        return ret;
+    }
 }