C# 录音录像合成代码

以下是一个简单的 C# 录音录像合成的代码示例：

using System;
using System.IO;
using System.Windows.Forms;
using Accord.Video.FFMPEG;
using NAudio.Wave;

namespace RecordAndMerge
{
    public partial class MainForm : Form
    {
        private WaveInEvent waveIn;
        private VideoFileWriter writer;
        private string audioPath;
        private string videoPath;

        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            waveIn = new WaveInEvent();
            waveIn.WaveFormat = new WaveFormat(44100, 1);
            waveIn.DataAvailable += OnDataAvailable;

            writer = new VideoFileWriter();
            writer.Open("output.avi", Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, 30, VideoCodec.MPEG4);

            audioPath = "output.wav";
            videoPath = "output.avi";
        }

        private void OnDataAvailable(object sender, WaveInEventArgs e)
        {
            writer.WriteVideoFrame(GetScreenshot(), DateTime.Now - startTime);
            File.WriteAllBytes(audioPath, e.Buffer);
        }

        private Bitmap GetScreenshot()
        {
            Bitmap bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
            using (Graphics graphics = Graphics.FromImage(bitmap))
            {
                graphics.CopyFromScreen(0, 0, 0, 0, bitmap.Size);
            }
            return bitmap;
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            waveIn.StartRecording();
            startTime = DateTime.Now;
        }

        private void btnStop_Click(object sender, EventArgs e)
        {
            waveIn.StopRecording();
            writer.Close();

            // 合成音视频
            using (var v = new VideoFileReader())
            using (var a = new AudioFileReader(audioPath))
            using (var combine = new MediaFoundationReader(videoPath))
            using (var output = new MediaFoundationEncoder(combine.WaveFormat, "output.mp4"))
            {
                output.VideoBitrate = v.BitRate;
                output.VideoFramerate = v.FrameRate;
                output.AudioBitrate = a.WaveFormat.AverageBytesPerSecond * 8;
                output.AudioChannels = a.WaveFormat.Channels;
                output.AudioSampleRate = a.WaveFormat.SampleRate;
                output.Initialize();
                combine.CopyTo(output);
                a.CopyTo(output);
                output.Flush();
            }

            // 删除临时文件
            File.Delete(audioPath);
            File.Delete(videoPath);

            MessageBox.Show("合成成功！");
        }

        private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            waveIn.Dispose();
            writer.Dispose();
        }
    }
}

需要使用 NuGet 安装 Accord.Video.FFMPEG 和 NAudio 库。在窗体中添加两个 Button 控件，分别用于开始录制和停止录制。在 MainForm_Load 方法中初始化音频录制和视频写入。在 OnDataAvailable 方法中将录制的音频写入到临时文件中，并将当前屏幕截图写入到视频帧中。在 btnStart_Click 方法中开始录制，并记录开始时间。在 btnStop_Click 方法中停止录制，关闭视频写入器，并使用 Accord 和 NAudio 库合成音视频。最后，删除临时文件，并弹出提示框。你可以根据实际需求进行调整和优化。