ScreenRecorder/Program.cs

using System.Windows.Forms;
using ScreenRecorder;

var app = new RecorderForm();
Application.Run(app);

public class RecorderForm : Form
{
    private readonly Button _btnStart;
    private readonly Button _btnStop;
    private readonly Label _lblStatus;
    private readonly Label _lblTimer;
    private readonly Label _lblFps;
    private readonly Label _lblQuality;
    private readonly TrackBar _trackFps;
    private readonly ComboBox _cmbQuality;
    private readonly Label _lblFpsVal;
    private readonly CheckBox _chkHideCursor;
    private readonly System.Windows.Forms.Timer _timer;
    private readonly ProgressBar _progressBar;
    private readonly Label _lblProgress;

    private CaptureService? _capture;
    private DateTime _startTime;
    private string _outputDir = Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
    private string? _lastVideoPath;

    private static string? FindFfmpeg()
    {
        var local = Path.Combine(AppContext.BaseDirectory, "ffmpeg.exe");
        if (File.Exists(local)) return local;
        foreach (var dir in (Environment.GetEnvironmentVariable("PATH") ?? "").Split(';'))
        {
            var p = Path.Combine(dir.Trim(), "ffmpeg.exe");
            if (File.Exists(p)) return p;
        }
        return null;
    }

    // Value: 0=无损H265, 1-100=MJPEG quality, 10/18=H264有损
    private static readonly (string Label, int Value, string FfmpegArgs)[] QualityOptions =
    [
        ("无损 (H.265 CRF 0, yuv444p)",   0,   "-c:v libx265 -preset fast -crf 0 -pix_fmt yuv444p -tag:v hvc1"),
        ("极高画质 (H.264 CRF 10)",        10,  "-c:v libx264 -preset fast -crf 10 -pix_fmt yuv420p"),
        ("高画质 (H.264 CRF 18)",          18,  "-c:v libx264 -preset fast -crf 18 -pix_fmt yuv420p"),
        ("中画质 MJPEG 100",              100,  ""),
        ("低画质 MJPEG 80",                80,  ""),
        ("极低画质 MJPEG 50",              50,  ""),
    ];

    public RecorderForm()
    {
        Text = "屏幕录制";
        Size = new System.Drawing.Size(360, 340);
        FormBorderStyle = FormBorderStyle.FixedSingle;
        MaximizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;

        _lblStatus = new Label
        {
            Text = "就绪",
            Location = new System.Drawing.Point(20, 12),
            Size = new System.Drawing.Size(320, 22),
            Font = new System.Drawing.Font("微软雅黑", 10)
        };
        _lblTimer = new Label
        {
            Text = "00:00:00",
            Location = new System.Drawing.Point(20, 36),
            Size = new System.Drawing.Size(320, 26),
            Font = new System.Drawing.Font("Consolas", 15),
            ForeColor = System.Drawing.Color.DarkBlue
        };

        _lblFps = new Label
        {
            Text = "帧率 (fps):",
            Location = new System.Drawing.Point(20, 74),
            Size = new System.Drawing.Size(80, 20),
            Font = new System.Drawing.Font("微软雅黑", 9)
        };
        _trackFps = new TrackBar
        {
            Minimum = 1, Maximum = 60, Value = 30,
            TickFrequency = 5, SmallChange = 1, LargeChange = 5,
            Location = new System.Drawing.Point(100, 67),
            Size = new System.Drawing.Size(190, 40)
        };
        _lblFpsVal = new Label
        {
            Text = "30",
            Location = new System.Drawing.Point(295, 74),
            Size = new System.Drawing.Size(40, 20),
            Font = new System.Drawing.Font("Consolas", 10),
            ForeColor = System.Drawing.Color.DarkBlue
        };
        _trackFps.ValueChanged += (_, _) => _lblFpsVal.Text = _trackFps.Value.ToString();

        _lblQuality = new Label
        {
            Text = "画质:",
            Location = new System.Drawing.Point(20, 120),
            Size = new System.Drawing.Size(80, 20),
            Font = new System.Drawing.Font("微软雅黑", 9)
        };
        _cmbQuality = new ComboBox
        {
            Location = new System.Drawing.Point(100, 117),
            Size = new System.Drawing.Size(230, 26),
            DropDownStyle = ComboBoxStyle.DropDownList,
            Font = new System.Drawing.Font("微软雅黑", 9)
        };
        foreach (var (label, _, _) in QualityOptions)
            _cmbQuality.Items.Add(label);
        _cmbQuality.SelectedIndex = 0;

        _chkHideCursor = new CheckBox
        {
            Text = "隐藏鼠标光标",
            Location = new System.Drawing.Point(20, 155),
            Size = new System.Drawing.Size(150, 22),
            Font = new System.Drawing.Font("微软雅黑", 9),
            Checked = false
        };

        _btnStart = new Button
        {
            Text = "开始录制",
            Location = new System.Drawing.Point(20, 185),
            Size = new System.Drawing.Size(140, 38),
            BackColor = System.Drawing.Color.ForestGreen,
            ForeColor = System.Drawing.Color.White,
            FlatStyle = FlatStyle.Flat
        };
        _btnStart.Click += BtnStart_Click;

        _btnStop = new Button
        {
            Text = "停止录制",
            Location = new System.Drawing.Point(185, 185),
            Size = new System.Drawing.Size(140, 38),
            BackColor = System.Drawing.Color.Crimson,
            ForeColor = System.Drawing.Color.White,
            FlatStyle = FlatStyle.Flat,
            Enabled = false
        };
        _btnStop.Click += BtnStop_Click;

        _progressBar = new ProgressBar
        {
            Location = new System.Drawing.Point(20, 235),
            Size = new System.Drawing.Size(305, 16),
            Style = ProgressBarStyle.Continuous,
            Minimum = 0, Maximum = 100, Value = 0,
            Visible = false
        };

        _lblProgress = new Label
        {
            Location = new System.Drawing.Point(20, 254),
            Size = new System.Drawing.Size(305, 18),
            Font = new System.Drawing.Font("Consolas", 8),
            ForeColor = System.Drawing.Color.DimGray,
            Text = "",
            Visible = false
        };

        _timer = new System.Windows.Forms.Timer { Interval = 1000 };
        _timer.Tick += (_, _) => _lblTimer.Text = (DateTime.Now - _startTime).ToString(@"hh\:mm\:ss");

        Controls.AddRange(new Control[]
        {
            _lblStatus, _lblTimer,
            _lblFps, _trackFps, _lblFpsVal,
            _lblQuality, _cmbQuality,
            _chkHideCursor,
            _btnStart, _btnStop,
            _progressBar,
            _lblProgress
        });
    }

    private void BtnStart_Click(object? sender, EventArgs e)
    {
        var (_, qualityValue, _) = QualityOptions[_cmbQuality.SelectedIndex];
        var timestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss");
        var videoPath = Path.Combine(_outputDir, $"recording_{timestamp}.avi");
        _lastVideoPath = videoPath;

        // H.264 模式先录无压缩 AVI，之后 ffmpeg 转码
        // MJPEG 模式直接录 MJPEG AVI
        int captureQuality = qualityValue <= 18 ? 101 : qualityValue; // 101 = 无压缩
        _capture = new CaptureService(fps: _trackFps.Value, quality: captureQuality, hideCursor: _chkHideCursor.Checked);
        _capture.Start(videoPath);

        _startTime = DateTime.Now;
        _timer.Start();

        _trackFps.Enabled = false;
        _cmbQuality.Enabled = false;
        _chkHideCursor.Enabled = false;
        _lblStatus.Text = $"录制中 → {Path.GetFileName(videoPath)}";
        _btnStart.Enabled = false;
        _btnStop.Enabled = true;
    }

    private void BtnStop_Click(object? sender, EventArgs e)
    {
        _timer.Stop();
        _capture?.Stop();
        _capture = null;

        _lblTimer.Text = "00:00:00";
        _btnStop.Enabled = false;

        var aviPath = _lastVideoPath;
        var (_, qualityValue, ffmpegArgs) = QualityOptions[_cmbQuality.SelectedIndex];
        bool needFfmpeg = qualityValue <= 18;

        if (aviPath != null && File.Exists(aviPath) && needFfmpeg)
        {
            var ffmpeg = FindFfmpeg();
            if (ffmpeg != null)
            {
                // 先获取视频总时长（秒），用于计算进度百分比
                double totalSeconds = GetAviDuration(ffmpeg, aviPath);

                _lblStatus.Text = "转码中，请稍候...";
                _progressBar.Value = 0;
                _progressBar.Visible = true;
                _lblProgress.Text = "";
                _lblProgress.Visible = true;
                var mp4Path = Path.ChangeExtension(aviPath, ".mp4");

                Task.Run(() =>
                {
                    try
                    {
                        var psi = new System.Diagnostics.ProcessStartInfo
                        {
                            FileName = ffmpeg,
                            Arguments = $"-y -i \"{aviPath}\" {ffmpegArgs} -progress pipe:1 \"{mp4Path}\"",
                            CreateNoWindow = true,
                            UseShellExecute = false,
                            RedirectStandardOutput = true,
                            RedirectStandardError = true
                        };
                        var proc = System.Diagnostics.Process.Start(psi)!;
                        proc.ErrorDataReceived += (_, _) => { }; // 丢弃 stderr 避免阻塞
                        proc.BeginErrorReadLine();

                        // 逐行读取 stdout 进度
                        string? line;
                        while ((line = proc.StandardOutput.ReadLine()) != null)
                        {
                            // 格式: out_time_us=1234567
                            if (line.StartsWith("out_time_us=") &&
                                long.TryParse(line.AsSpan("out_time_us=".Length), out long us) &&
                                totalSeconds > 0)
                            {
                                double done = us / 1_000_000.0;
                                int pct = (int)Math.Min(100, done / totalSeconds * 100);
                                string timeStr = TimeSpan.FromSeconds(done).ToString(@"hh\:mm\:ss");
                                string totalStr = TimeSpan.FromSeconds(totalSeconds).ToString(@"hh\:mm\:ss");
                                Invoke(() =>
                                {
                                    _progressBar.Value = pct;
                                    _lblProgress.Text = $"{timeStr} / {totalStr}  ({pct}%)";
                                });
                            }
                        }

                        proc.WaitForExit();
                        bool ok = proc.ExitCode == 0 && File.Exists(mp4Path);
                        if (ok) File.Delete(aviPath);

                        Invoke(() =>
                        {
                            _progressBar.Visible = false;
                            _lblProgress.Visible = false;
                            _trackFps.Enabled = true;
                            _cmbQuality.Enabled = true;
                            _chkHideCursor.Enabled = true;
                            _btnStart.Enabled = true;
                            if (ok)
                            {
                                _lblStatus.Text = $"已保存至 {_outputDir}";
                                MessageBox.Show($"录制完成：\n{mp4Path}", "完成",
                                    MessageBoxButtons.OK, MessageBoxIcon.Information);
                            }
                            else
                            {
                                _lblStatus.Text = "转码失败，AVI 已保留";
                                MessageBox.Show($"转码失败，AVI 保留在：\n{aviPath}", "提示",
                                    MessageBoxButtons.OK, MessageBoxIcon.Warning);
                            }
                        });
                    }
                    catch (Exception ex)
                    {
                        Invoke(() =>
                        {
                            _progressBar.Visible = false;
                            _lblProgress.Visible = false;
                            _trackFps.Enabled = true;
                            _cmbQuality.Enabled = true;
                            _chkHideCursor.Enabled = true;
                            _btnStart.Enabled = true;
                            _lblStatus.Text = "转码出错";
                            MessageBox.Show($"转码出错：{ex.Message}", "错误",
                                MessageBoxButtons.OK, MessageBoxIcon.Error);
                        });
                    }
                });
                return;
            }
            else
            {
                MessageBox.Show(
                    $"未找到 ffmpeg，无法转码。\nAVI 保留在：\n{aviPath}",
                    "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }
        else if (aviPath != null)
        {
            _lblStatus.Text = $"已保存至 {_outputDir}";
            MessageBox.Show($"录制完成：\n{aviPath}", "完成",
                MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        _trackFps.Enabled = true;
        _cmbQuality.Enabled = true;
        _chkHideCursor.Enabled = true;
        _btnStart.Enabled = true;
    }

    // 用 ffprobe 思路：让 ffmpeg 读文件头获取时长
    private static double GetAviDuration(string ffmpeg, string path)
    {
        try
        {
            var psi = new System.Diagnostics.ProcessStartInfo
            {
                FileName = ffmpeg,
                Arguments = $"-i \"{path}\"",
                CreateNoWindow = true,
                UseShellExecute = false,
                RedirectStandardError = true
            };
            var proc = System.Diagnostics.Process.Start(psi)!;
            string err = proc.StandardError.ReadToEnd();
            proc.WaitForExit();
            // 解析 "Duration: HH:MM:SS.xx"
            var m = System.Text.RegularExpressions.Regex.Match(err,
                @"Duration:\s*(\d+):(\d+):(\d+\.\d+)");
            if (m.Success)
            {
                double h = double.Parse(m.Groups[1].Value);
                double min = double.Parse(m.Groups[2].Value);
                double sec = double.Parse(m.Groups[3].Value);
                return h * 3600 + min * 60 + sec;
            }
        }
        catch { }
        return 0;
    }

    protected override void OnFormClosing(FormClosingEventArgs e)
    {
        _capture?.Dispose();
        base.OnFormClosing(e);
    }
}