Fixed audio/video sync. Single ffprobe call.

ISegmentProcessor.cs

@@ -6,5 +6,5 @@ namespace splitter;
 
 public interface ISegmentProcessor
 {
-    Task ProcessSegment( string inputFile, string outputFile, double start, double length, string[] ffmpegPassthroughParameters);
+    Task ProcessSegment( string inputFile, string outputFile, double start, double length, int videoWidth, int videoHeight, double fps, string[] ffmpegPassthroughParameters);
 }

SimpleSplitter.cs

@@ -9,17 +9,7 @@ namespace splitter;
 
 public class SimpleSplitter(int segmentNo, ILogger logger) : LoggingBase(logger, segmentNo), ISegmentProcessor
 {
-    public async Task ProcessSegment(string inputFile, string outputFile, double start, double length, string[] passthrough)
+    public async Task ProcessSegment(string inputFile, string outputFile, double start, double length, int videoWidth, int videoHeight, double fps, string[] passthrough)
-    {
-        RunFFmpegSegment(inputFile, outputFile, start, length, passthrough);
-    }
-
-    private void RunFFmpegSegment(
-        string inputFile,
-        string outputFile,
-        double start,
-        double length,
-        string[] passthrough)
     {
         var pass = passthrough.Length > 0 ? string.Join(" ", passthrough) : "";
 

SpectreConsoleLogger.cs

@@ -25,8 +25,10 @@ public sealed class SpectreConsoleLogger : ILogger, IDisposable
     private readonly Dictionary<int, ProgressEntry> _progress = new();
 
     private readonly CancellationTokenSource _cts = new();
-    private Task? _uiTask;
+    private Task?                            _uiTask;
-    private Task? _inputTask;
+    private Task?                            _inputTask;
+    private int                              _numberOfProcesses = 1;
+    private const int                        _maxLogEntries = 500;
 
     // Public configuration
     public string Title { get; set; } = string.Empty;
@@ -51,14 +53,6 @@ public sealed class SpectreConsoleLogger : ILogger, IDisposable
         }
     }
 
-    private int _numberOfProcesses = 1;
-
-    private const int MaxLogEntries = 500;
-
-    public SpectreConsoleLogger()
-    {
-        NumberOfProcesses = 1;
-    }
 
     // ---- ILogger ----
 
@@ -93,8 +87,8 @@ public sealed class SpectreConsoleLogger : ILogger, IDisposable
     {
         lock (_sync)
         {
-            if (_logs.Count >= MaxLogEntries)
+            if (_logs.Count >= _maxLogEntries)
-                _logs.RemoveRange(0, _logs.Count - MaxLogEntries + 1);
+                _logs.RemoveRange(0, _logs.Count - _maxLogEntries + 1);
 
             _logs.Add(new LogEntry(
                 DateTime.Now,
@@ -137,7 +131,7 @@ public sealed class SpectreConsoleLogger : ILogger, IDisposable
                         ctx.UpdateTarget(BuildRoot());
                         await Task.Delay(100, token);
                     }
-                    catch ( Exception ex )
+                    catch ( Exception )
                     {
                         break;
                     }

TrackingSplitter.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.Globalization;
+using System.IO;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using OpenCvSharp;
@@ -9,21 +10,16 @@ namespace splitter;
 
 public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
 {
-    private readonly int  _cropWidth;
-    private readonly int  _cropHeight;
-    private readonly bool _debugOverlay;
-    private readonly bool _plainText;
-
     private readonly IObjectDetector _detector;
-    private readonly SingleJob     _cmd;
+    private readonly SingleJob       _cmd;
 
-    public TrackingSplitter(int segmentNo, int cropWidth, int cropHeight, bool debugOverlay, bool plainText, IObjectDetector detector, SingleJob cmd, ILogger logger) 
+    public TrackingSplitter(
-        : base(logger, segmentNo)
+        int  progressLine,
+        IObjectDetector detector,
+        SingleJob cmd,
+        ILogger logger)
+        : base(logger, progressLine)
     {
-        _cropWidth    = cropWidth;
-        _cropHeight   = cropHeight;
-        _debugOverlay = debugOverlay;
-        _plainText    = plainText;
         _detector     = detector;
         _cmd          = cmd;
     }
@@ -34,146 +30,287 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
             d.Dispose();
     }
 
-    public async Task ProcessSegment(string inputFile, string outputFile, double start, double length, string[] ffmpegPassthroughParameters)
+    public async Task ProcessSegment(
+        string inputFile,
+        string outputFile,
+        double start,
+        double length,
+        int videoWidth, int videoHeight, double fps,
+        string[] ffmpegPassthroughParameters)
     {
-        using var capture = new VideoCapture(inputFile);
+        var name = Path.GetFileNameWithoutExtension(outputFile);
-        if (!capture.IsOpened())
+
+        // 1) Probe source video
+        if (videoWidth <= 0 || videoHeight <= 0 || fps <= 0)
         {
-            LogError($"{Path.GetFileName(inputFile)}: Cannot open video");
+            LogError($"{name}: ffprobe failed to get metadata");
             return;
         }
 
-        var name     = Path.GetFileNameWithoutExtension(outputFile);
+        if (_cmd.Crop == null)
-        var skip     = TimeSpan.FromSeconds(start);
+        {
-        var duration = TimeSpan.FromSeconds(length);
+            LogError($"{name}: Crop parameters are required");
+            return;
+        }
 
-        capture.Set(VideoCaptureProperties.PosMsec, start);
+        var encWidth  = _cmd.Debug ? videoWidth  : _cmd.Crop.Value.width;
+        var encHeight = _cmd.Debug ? videoHeight : _cmd.Crop.Value.height;
 
-        var videoWidth  = (int)capture.Get(VideoCaptureProperties.FrameWidth);
+        LogInfo($"{name}: src={videoWidth}x{videoHeight} @ {fps:F3}fps, seg=[{start:F3},{length:F3}] enc={encWidth}x{encHeight}");
-        var videoHeight = (int)capture.Get(VideoCaptureProperties.FrameHeight);
-        var fps         = capture.Get(VideoCaptureProperties.Fps);
-        var totalFrames = (int)(length * fps);
 
-        var originalCropWidth  = _cropWidth;
+        // 2) Start FFmpeg decode (video only → raw BGR24 to stdout)
-        var originalCropHeight = _cropHeight;
+        var decode = StartFfmpegDecode(inputFile, start, length);
+        using var decodeStdout = decode.StandardOutput.BaseStream;
 
-        LogInfo($"{Path.GetFileName(outputFile)}:: [TrackingSplitter] skip={skip}, duration={duration}, fps={fps}, totalFrames={totalFrames}");
+        // 3) Start FFmpeg encode (video from stdin + audio from original)
-
+        var encode = StartFfmpegEncode(
-        var encWidth  = _debugOverlay ? videoWidth  : originalCropWidth;
-        var encHeight = _debugOverlay ? videoHeight : originalCropHeight;
-
-        var ffmpeg = StartFfmpegNvenc(
             inputFile,
             outputFile,
+            start,
+            length,
             encWidth,
             encHeight,
             fps,
-            skip,
             ffmpegPassthroughParameters);
 
-        using var stdin = ffmpeg.StandardInput.BaseStream;
+        using var encodeStdin = encode.StandardInput.BaseStream;
 
-        using var frame     = new Mat();
+        // Separate input/output sizes and buffers
-        using var outputBgr = new Mat(encHeight, encWidth, MatType.CV_8UC3);
+        var inBytes  = videoWidth * videoHeight * 3;
+        var outBytes = encWidth   * encHeight   * 3;
 
-        var frameBytes  = encWidth * encHeight * 3;
+        var inBuffer  = new byte[inBytes];
-        var videoBuffer = new byte[frameBytes];
+        var outBuffer = new byte[outBytes];
+
+        using var frameMat = new Mat(videoHeight, videoWidth, MatType.CV_8UC3);
+        using var outMat   = new Mat(encHeight, encWidth, MatType.CV_8UC3);
 
         var kalman = new KalmanTracker();
-        // initial reset is now done inside CameraController
-
         var camera = new CameraController(
             videoWidth,
             videoHeight,
-            originalCropWidth,
+            _cmd.Crop.Value.width,
-            originalCropHeight,
+            _cmd.Crop.Value.height,
             kalman,
-            _cmd
+            _cmd);
-            );
 
-        var startTime = DateTime.UtcNow;
+        var startTime   = DateTime.UtcNow;
+        var totalFrames = (int)Math.Round(length * fps);
+        var frameIndex  = 0;
 
-        for (var i = 0; i < totalFrames; i++)
+        while (frameIndex < totalFrames)
         {
-            if (!capture.Read(frame) || frame.Empty())
+            frameIndex++;
+
+            var read = ReadExact(decodeStdout, inBuffer, 0, inBytes);
+            if (read != inBytes)
                 break;
 
-            Rect?    objectBox    = null;
+            // input frame → Mat
-            Point2f? objectCenter = null;
+            Marshal.Copy(inBuffer, 0, frameMat.Data, inBytes);
 
-            var objects = _detector.DetectAll(frame, videoWidth, videoHeight);
+            var objects = _detector.DetectAll(frameMat, videoWidth, videoHeight);
             var primary = SelectTrackedObject(objects, kalman.LastMeasurement);
 
             camera.Update(primary);
+            var roi = camera.Roi;
 
-            objectBox = camera.ObjectBox;
+            if (_cmd.Debug)
-            objectCenter = camera.ObjectCenter;
-
-            var smoothedCenter = camera.SmoothedCenter;
-            var cameraCenter   = camera.CameraCenter;
-            var state          = camera.State;
-            var lostFrames     = camera.LostFrames;
-            var roi            = camera.Roi;
-
-            if (_debugOverlay)
             {
-                if (objectBox.HasValue)
+                DrawDebug(frameMat, objects, camera, kalman);
-                {
+                frameMat.CopyTo(outMat);
-                    var fb = objectBox.Value;
-                    Cv2.Rectangle(frame,
-                        new Rect(fb.X, fb.Y, fb.Width, fb.Height),
-                        Scalar.LimeGreen, 2);
-                }
-
-                Cv2.Circle(frame,
-                    new Point((int)smoothedCenter.X, (int)smoothedCenter.Y),
-                    6, Scalar.LimeGreen, -1);
-
-                Cv2.Rectangle(frame, roi,
-                    objectCenter.HasValue ? Scalar.Yellow : Scalar.Red, 3);
-
-                DrawText(frame, $"Faces: {objects.Count}", 20, 40, Scalar.White);
-                DrawText(frame, $"LostFrames: {lostFrames}", 20, 70, Scalar.White);
-                DrawText(frame, $"Noise: {kalman.CurrentNoise:F3}", 20, 130, Scalar.White);
-                DrawText(frame, $"Camera: {cameraCenter.X:F1},{cameraCenter.Y:F1}", 20, 160, Scalar.White);
-            }
-
-            if (_debugOverlay)
-            {
-                frame.CopyTo(outputBgr);
-                Marshal.Copy(outputBgr.Data, videoBuffer, 0, frameBytes);
-                stdin.Write(videoBuffer, 0, frameBytes);
             }
             else
             {
-                using var cropped = new Mat(frame, roi);
+                using var cropped = new Mat(frameMat, roi);
-                cropped.CopyTo(outputBgr);
+                cropped.CopyTo(outMat);
-
-                Marshal.Copy(outputBgr.Data, videoBuffer, 0, frameBytes);
-                stdin.Write(videoBuffer, 0, frameBytes);
             }
 
+            // output Mat → outBuffer
+            Marshal.Copy(outMat.Data, outBuffer, 0, outBytes);
+            encodeStdin.Write(outBuffer, 0, outBytes);
+
             var elapsed         = DateTime.UtcNow - startTime;
-            var progress        = (double)i / totalFrames;
+            var progress        = totalFrames > 0 ? (double)frameIndex / totalFrames : 0.0;
-            var speed           = i > 0 ? (i / elapsed.TotalSeconds)/fps : 0.0;
+            var speed           = elapsed.TotalSeconds > 0 ? (frameIndex / elapsed.TotalSeconds) / fps : 0.0;
-            var remainingFrames = totalFrames - i;
+            var remainingFrames = Math.Max(totalFrames - frameIndex, 0);
-            var etaSeconds      = speed > 0 ? remainingFrames / speed : 0;
+            var etaSeconds      = speed > 0 ? remainingFrames / speed : 0.0;
             var eta             = TimeSpan.FromSeconds(etaSeconds);
 
             DrawProgress(name, progress, eta, speed);
         }
 
-        stdin.Flush();
+        encodeStdin.Flush();
-        stdin.Close();
 
-        await ffmpeg.WaitForExitAsync();
+        // loop finished
+
+        encodeStdin.Flush();
+        encodeStdin.Close();          // must happen before waiting encode
+
+        await encode.WaitForExitAsync();
+
+        // belt-and-braces: if decode is still alive, kill it
+        try { if (!decode.HasExited) decode.Kill(entireProcessTree: true); } catch { }
+        try { if (!decode.HasExited) await decode.WaitForExitAsync(); } catch { }
 
         ClearProgress();
 
-        if (ffmpeg.ExitCode != 0)
+
-            LogError($"{Path.GetFileName(outputFile)}: Segment {name} FFmpeg encoding failed");
+        if (encode.ExitCode != 0)
+            LogError($"{name}: FFmpeg encoding failed");
         else
-            LogInfo($"{Path.GetFileName(outputFile)}: Segment {name} processing completed");
+            LogInfo($"{name}: Segment processing completed");
+    }
+
+
+    // ---------- FFmpeg decode / encode ----------
+
+    private Process StartFfmpegDecode(string inputFile, double start, double length)
+    {
+        var ss = start.ToString("0.###", CultureInfo.InvariantCulture);
+        var t  = length.ToString("0.###", CultureInfo.InvariantCulture);
+
+        var args =
+    $"-i \"{inputFile}\" -ss {ss} -t {t} " +
+    "-an -sn " +
+    "-vf format=bgr24 " +
+    "-f rawvideo -";
+
+        var psi = new ProcessStartInfo
+        {
+            FileName               = "ffmpeg",
+            Arguments              = args,
+            RedirectStandardOutput = true,
+            RedirectStandardError  = true,
+            UseShellExecute        = false,
+            CreateNoWindow         = true
+        };
+
+        var p = new Process { StartInfo = psi };
+        p.Start();
+
+        var fileName = Path.GetFileName(inputFile);
+
+        if (_cmd.PlainText)
+        {
+            _ = Task.Run(() =>
+            {
+                try
+                {
+                    string? line;
+                    while ((line = p.StandardError.ReadLine()) != null)
+                        if (_cmd.PlainText)
+                            LogInfo($"[ffmpeg-decode] {fileName}: {line}");
+                }
+                catch { }
+            });
+        }
+
+        return p;
+    }
+
+    private Process StartFfmpegEncode(
+        string inputFile,
+        string outputFile,
+        double start,
+        double length,
+        int width,
+        int height,
+        double fps,
+        string[] passthrough)
+    {
+        var pass   = passthrough.Length > 0 ? string.Join(" ", passthrough) : "";
+        var fpsStr = fps.ToString("0.###", CultureInfo.InvariantCulture);
+        var ss     = start.ToString("0.###", CultureInfo.InvariantCulture);
+        var t      = length.ToString("0.###", CultureInfo.InvariantCulture);
+
+        var args =
+            "-y " +
+            $"-f rawvideo -pix_fmt bgr24 -s {width}x{height} -r {fpsStr} -i - " +
+            $"-ss {ss} -i \"{inputFile}\" " +
+            "-map 0:v:0 -map 1:a:0? -shortest " +
+            "-c:v h264_nvenc -preset p4 -b:v 8M -pix_fmt yuv420p " +
+            "-c:a aac -b:a 192k " +
+            pass + $" \"{outputFile}\"";
+
+
+
+        var psi = new ProcessStartInfo
+        {
+            FileName              = "ffmpeg",
+            Arguments             = args,
+            RedirectStandardInput = true,
+            RedirectStandardError = true,
+            UseShellExecute       = false,
+            CreateNoWindow        = true
+        };
+
+        var p = new Process { StartInfo = psi };
+        p.Start();
+
+        var fileName = Path.GetFileName(outputFile);
+
+        _ = Task.Run(() =>
+        {
+            try
+            {
+                string? line;
+                while ((line = p.StandardError.ReadLine()) != null)
+                {
+                    if (_cmd.PlainText)
+                        LogInfo($"[ffmpeg-encode] {fileName}: {line}");
+                }
+            }
+            catch { }
+        });
+
+        return p;
+    }
+
+    // ---------- helpers ----------
+
+    private static int ReadExact(Stream s, byte[] buffer, int offset, int count)
+    {
+        var total = 0;
+        while (total < count)
+        {
+            var read = s.Read(buffer, offset + total, count - total);
+            if (read <= 0)
+                break;
+            total += read;
+        }
+        return total;
+    }
+
+    private void DrawDebug(
+        Mat frame,
+        System.Collections.Generic.List<(Rect box, Point2f center)> objects,
+        CameraController camera,
+        KalmanTracker kalman)
+    {
+        if (camera.ObjectBox.HasValue)
+        {
+            var fb = camera.ObjectBox.Value;
+            Cv2.Rectangle(frame, fb, Scalar.LimeGreen, 2);
+        }
+
+        Cv2.Circle(frame,
+            new Point((int)camera.SmoothedCenter.X, (int)camera.SmoothedCenter.Y),
+            6, Scalar.LimeGreen, -1);
+
+        Cv2.Rectangle(frame, camera.Roi,
+            camera.ObjectCenter.HasValue ? Scalar.Yellow : Scalar.Red, 3);
+
+        DrawText(frame, $"Faces: {objects.Count}", 20, 40, Scalar.White);
+        DrawText(frame, $"LostFrames: {camera.LostFrames}", 20, 70, Scalar.White);
+        DrawText(frame, $"Noise: {kalman.CurrentNoise:F3}", 20, 130, Scalar.White);
+        DrawText(frame, $"Camera: {camera.CameraCenter.X:F1},{camera.CameraCenter.Y:F1}", 20, 160, Scalar.White);
+    }
+
+    private static void DrawText(Mat img, string text, int x, int y, Scalar color)
+    {
+        Cv2.PutText(img, text, new Point(x, y),
+            HersheyFonts.HersheySimplex, 0.6, color, 2);
     }
 
     private (Rect box, Point2f center)? SelectTrackedObject(
@@ -185,7 +322,6 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
 
         if (!previousCenter.HasValue)
         {
-            // Largest area
             var bestIndex = 0;
             var bestArea  = float.MinValue;
 
@@ -204,8 +340,7 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
         }
         else
         {
-            // Closest to previous center
+            var prev      = previousCenter.Value;
-            var prev = previousCenter.Value;
             var bestIndex = 0;
             var bestDist2 = float.MaxValue;
 
@@ -226,64 +361,4 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
             return foundObjects[bestIndex];
         }
     }
-
-    private Process StartFfmpegNvenc(
-        string srcFileName,
-        string destFileName,
-        int width,
-        int height,
-        double fps,
-        TimeSpan skip,
-        string[] passthrough)
-    {
-        var pass        = passthrough.Length > 0 ? string.Join(" ", passthrough) : "";
-        var skipSeconds = skip.TotalSeconds.ToString("0.###", CultureInfo.InvariantCulture);
-        var fpsStr      = fps.ToString("0.###", CultureInfo.InvariantCulture);
-
-        var args =
-            "-y " +
-            $"-f rawvideo -pix_fmt bgr24 -s {width}x{height} -r {fpsStr} -i - " +
-            $"-ss {skipSeconds} -i \"{srcFileName}\" " +
-            "-map 0:v:0 -map 1:a:0? -shortest " +
-            "-c:v h264_nvenc -preset p4 -b:v 8M -pix_fmt yuv420p " +
-            "-c:a aac -b:a 192k " +
-            pass + $" \"{destFileName}\"";
-
-        var psi = new ProcessStartInfo
-        {
-            FileName               = "ffmpeg",
-            Arguments              = args,
-            RedirectStandardInput  = true,
-            RedirectStandardError  = true,
-            RedirectStandardOutput = true,
-            UseShellExecute        = false,
-            CreateNoWindow         = true
-        };
-
-        var process = new Process { StartInfo = psi };
-        process.Start();
-
-        _ = Task.Run(() =>
-        {
-            try
-            {
-                string? line;
-                while ((line = process.StandardError.ReadLine()) != null)
-                {
-                    if (_plainText)
-                        Console.WriteLine($"[ffmpeg] {line}");
-                }
-            }
-            catch { }
-        });
-
-        return process;
-    }
-
-    private static void DrawText(Mat img, string text, int x, int y, Scalar color)
-    {
-        Cv2.PutText(img, text, new Point(x, y),
-            HersheyFonts.HersheySimplex, 0.6, color, 2);
-    }
-
 }

splitter.cs

@@ -16,6 +16,9 @@ static class Program
         int TotalSegments,
         double SegmentStart,
         double SegmentLength,
+        int VideoWidth,
+        int VideoHeight,
+        double VideoFps,
         Func<int, ISegmentProcessor> ProcessorFactory
         );
 
@@ -38,7 +41,6 @@ static class Program
             var logger = new SpectreConsoleLogger
             {
                 Title = "Splitter",
-                NumberOfProcesses = cmd.Master.SingleThreaded ? 1 : Math.Max(1, Environment.ProcessorCount / 2) + 1
             };
             _logger = logger;
 
@@ -89,7 +91,7 @@ static class Program
         job.Mask ??= $"{baseName}_seg%03d.mp4";
         LogInfo($"{baseName}: Reading duration via ffprobe...");
 
-        var duration = GetDuration(job.InputFile);
+        (double duration, int width, int height, double fps) = ProbeVideo(job.InputFile);
         if (duration <= 0)
         {
             LogError($"{baseName}: Could not read duration.");
@@ -115,20 +117,17 @@ static class Program
         }
 
         if (cmd.Master.EstimateOnly)
-        {
             LogInfo("=== ESTIMATE MODE ===");
-            LogInfo($"{baseName}: Total duration: {duration:F2}s");
-            LogInfo($"{baseName}: Target duration: {target:F2}s");
-            LogInfo($"{baseName}: Segments: {segments}");
-            LogInfo(job.ForceFixed
-                ? $"{baseName}: Fixed segment length: {segmentLength:F2}s (last may be shorter)"
-                : $"{baseName}: Equalized segment length: {segmentLength:F2}s");
-            return [];
-        }
 
-        LogInfo($"{baseName}: Duration: {duration:F2}s");
+        LogInfo($"{baseName}: Duration {duration:F2}s, {width}x{height} @ {fps:F3}fps");
+        LogInfo($"{baseName}: Target duration: {target:F2}s");
         LogInfo($"{baseName}: Segments: {segments}");
-        LogInfo($"{baseName}: Equal segment length: {segmentLength:F3}s");
+        LogInfo(job.ForceFixed
+            ? $"{baseName}: Fixed segment length: {segmentLength:F2}s (last may be shorter)"
+            : $"{baseName}: Equalized segment length: {segmentLength:F2}s");
+
+        if (cmd.Master.EstimateOnly)
+            return [];
 
         Func<int, ISegmentProcessor> processorFactory;
         if (job.Crop != null)
@@ -141,7 +140,7 @@ static class Program
                     "body" => new YoloOnnxObjectDetector(_logger),
                     _      => throw new InvalidOperationException($"Unknown detector: {job.Detect}")
                 };
-                return new TrackingSplitter(i, job.Crop.Value.width, job.Crop.Value.height, cmd.Master.Debug, cmd.Master.PlainText, detector, job, _logger);
+                return new TrackingSplitter(i, detector, job, _logger);
             };
         }
         else
@@ -160,7 +159,10 @@ static class Program
                     SegmentLength    : (i == segments - 1)
                         ? Math.Max(0.1, duration - i * segmentLength)
                                      : segmentLength,
-                    ProcessorFactory : processorFactory
+                    ProcessorFactory : processorFactory,
+                    VideoWidth       : width,
+                    VideoHeight      : height,
+                    VideoFps         : fps
                 )
             )
             .ToList();
@@ -195,28 +197,6 @@ static class Program
     // ffprobe
     // -----------------------------
 
-    static double GetDuration(string inputFile)
-    {
-        var psi = new ProcessStartInfo
-        {
-            FileName               = "ffprobe",
-            Arguments              = $"-v error -show_entries format=duration -of csv=p=0 \"{inputFile}\"",
-            RedirectStandardOutput = true,
-            UseShellExecute        = false,
-            CreateNoWindow         = true
-        };
-
-        using var proc = Process.Start(psi) ?? throw new Exception("Failed to start ffprobe.");
-        var output = proc.StandardOutput.ReadToEnd();
-        proc.WaitForExit();
-
-        if (output != null &&
-            double.TryParse(output, NumberStyles.Any, CultureInfo.InvariantCulture, out var duration))
-            return duration;
-
-        return -1;
-    }
-
     // -----------------------------
     // Multi-threaded splitting
     // -----------------------------
@@ -252,15 +232,7 @@ static class Program
                     while (!freeSlots.TryDequeue(out slot))
                         await Task.Yield();
 
-                    await ProcessSegment(
+                    await ProcessSegment(job,slot + 1);
-                        job.ProcessorFactory,
-                        job.Job.InputFile,
-                        job.OutputFileName,
-                        job.Job.Passthrough,
-                        slot + 1,                     // <-- slot instead of SegmentIndex (+1 for totals)
-                        job.SegmentStart,
-                        job.SegmentLength
-                    );
 
                     var processed = Interlocked.Increment(ref processedSegments);
                     var elapsed   = sw.Elapsed;
@@ -291,25 +263,25 @@ static class Program
     {
         foreach (var job in jobs)
         {
-            await ProcessSegment(
+            await ProcessSegment(job, 0);
-                job.ProcessorFactory,
-                job.Job.InputFile,
-                job.OutputFileName,
-                job.Job.Passthrough,
-                job.SegmentIndex,
-                job.SegmentStart,
-                job.SegmentLength
-                );
         }
 
     }
 
-    private static async Task ProcessSegment(Func<int, ISegmentProcessor> processorFactory, string inputFile, string outputFileName, string[] passthrough, int index, double start, double length)
+    private static async Task ProcessSegment(SingleTask t, int slot)
     {
-        var processor = processorFactory(index);
+        var processor = t.ProcessorFactory(slot);
         try
         {
-            await processor.ProcessSegment(inputFile, outputFileName, start, length, passthrough);
+            await processor.ProcessSegment(
+                t.Job.InputFile,
+                t.OutputFileName,
+                t.SegmentStart,
+                t.SegmentLength,
+                t.VideoWidth,
+                t.VideoHeight,
+                t.VideoFps,
+                t.Job.Passthrough);
         }
         finally
         {
@@ -345,4 +317,73 @@ static class Program
         return Path.Combine(folder, fileName);
     }
 
+    public static (double duration, int width, int height, double fps) ProbeVideo(string inputFile)
+    {
+        var args =
+        "-v error " +
+        "-select_streams v:0 " +
+        "-show_entries format=duration " +
+        "-show_entries stream=width,height,avg_frame_rate " +
+        "-of default=noprint_wrappers=1:nokey=0 " +   // <-- IMPORTANT: include keys
+        $"\"{inputFile}\"";
+
+        var psi = new ProcessStartInfo
+        {
+            FileName               = "ffprobe",
+            Arguments              = args,
+            RedirectStandardOutput = true,
+            RedirectStandardError  = true,
+            UseShellExecute        = false,
+            CreateNoWindow         = true
+        };
+
+        using var p = new Process { StartInfo = psi };
+        p.Start();
+
+        var duration = -1.0;
+        var width    = 0;
+        var height   = 0;
+        var fps      = 0.0;
+
+        while (!p.StandardOutput.EndOfStream)
+        {
+            var line = p.StandardOutput.ReadLine()?.Trim();
+            if (string.IsNullOrWhiteSpace(line))
+                continue;
+
+            if (line.StartsWith("duration="))
+            {
+                var v = line.Substring("duration=".Length);
+                double.TryParse(v, NumberStyles.Any, CultureInfo.InvariantCulture, out duration);
+            }
+            else if (line.StartsWith("width="))
+            {
+                var v = line.Substring("width=".Length);
+                int.TryParse(v, NumberStyles.Integer, CultureInfo.InvariantCulture, out width);
+            }
+            else if (line.StartsWith("height="))
+            {
+                var v = line.Substring("height=".Length);
+                int.TryParse(v, NumberStyles.Integer, CultureInfo.InvariantCulture, out height);
+            }
+            else if (line.StartsWith("avg_frame_rate="))
+            {
+                var v = line.Substring("avg_frame_rate=".Length);
+                var parts = v.Split('/');
+                if (parts.Length == 2 &&
+                    double.TryParse(parts[0], NumberStyles.Float, CultureInfo.InvariantCulture, out var num) &&
+                    double.TryParse(parts[1], NumberStyles.Float, CultureInfo.InvariantCulture, out var den) &&
+                    den != 0)
+                {
+                    fps = num / den;
+                }
+            }
+        }
+
+        p.WaitForExit();
+
+        return (duration, width, height, fps);
+    }
+
+
 }