Black frames at start if recording is Paused on start

[ranwer-dev]

After this ticket https://github.com/sskodje/ScreenRecorderLib/issues/233, the initial pause option was added. So now if we call ScreenRecorder.Pause(); right after ScreenRecorder.Record(); the recording remains in Pause state which can be resumed later.

But I have seen on Windows 10, that if this Pause option is used, it adds a black screen for 0.5/1 second at the start of recording.

Also sometimes if a partial screen is recorded, it adds fullscreen frames for 0.5/1 second before using the correct area.

How this can be fixed?

https://github.com/sskodje/ScreenRecorderLib/assets/92986100/4ea0c0e5-5d65-48a0-b584-bf8f5311fe2b

[sskodje]

I'm not able to reproduce. Here's a small example code i used to test.

using ScreenRecorderLib;
using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using System.Linq;

    class Program
    {
        static void Main(string[] args)
        {
            var source = DisplayRecordingSource.MainMonitor;
            source.RecorderApi = RecorderApi.WindowsGraphicsCapture;
            var opts = new RecorderOptions
            {
                SourceOptions = new SourceOptions
                {
                    RecordingSources = { { source } }
                }
            };
            Recorder rec = Recorder.CreateRecorder(opts);
            Recorder rec2 = Recorder.CreateRecorder(opts);
            rec.OnRecordingComplete += (source, e) =>
            {
                Console.WriteLine($"Recording complete: {e.FilePath}");
            };
            rec2.OnRecordingComplete += (source, e) =>
            {
                Console.WriteLine($"Recording complete: {e.FilePath}");
            };

            Console.WriteLine("Press ENTER to start recording or ESC to exit");
            while (true)
            {
                ConsoleKeyInfo info = Console.ReadKey(true);
                if (info.Key == ConsoleKey.Enter)
                {
                    break;
                }
                else if (info.Key == ConsoleKey.Escape)
                {
                    return;
                }
            }
            ManualResetEvent completionEvent = new ManualResetEvent(false);
            string timestamp = DateTime.Now.ToString("yyyy-MM-dd HH-mm-ss");
            Console.WriteLine("Starting recording");
            int count = 5;
            Task.Run(async () =>
                {
                    for (int i = 0; i < count; i++)
                    {
                        var currentRecorder = i % 2 == 0 ? rec : rec2;
                        var nextRecorder = i % 2 == 0 ? rec2 : rec;

                        if (currentRecorder.Status == RecorderStatus.Paused)
                        {
                            currentRecorder.Resume();
                        }
                        else
                        {
                            currentRecorder.Record(Path.Combine(Path.GetTempPath(), "ScreenRecorder", timestamp, i + ".mp4"));
                        }

                        await WaitForIdle(nextRecorder);
                        if (i < count)
                        {
                            nextRecorder.Record(Path.Combine(Path.GetTempPath(), "ScreenRecorder", timestamp, i + 1 + ".mp4"));
                            nextRecorder.Pause();
                        }
                        await Task.Delay(5000);
                        currentRecorder.Stop();
                    }
                    completionEvent.Set();
                });

            completionEvent.WaitOne();
            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }

        private static async Task WaitForIdle(Recorder rec)
        {
            if (rec.Status == RecorderStatus.Idle)
            {
                return;
            }
            else
            {
                SemaphoreSlim semaphore = new SemaphoreSlim(0, 1);
                EventHandler<RecordingStatusEventArgs> handler = delegate (object s, RecordingStatusEventArgs args)
                {
                    if (args.Status == RecorderStatus.Idle)
                    {
                        semaphore.Release();
                    }
                };
                rec.OnStatusChanged += handler;
                await semaphore.WaitAsync();
                rec.OnStatusChanged -= handler;
            }
        }
    }

[ranwer-dev]

After updating to the latest master branch, the issue is no more happening.