c# 使用ffmpeg 计算音频时长 并对音频格式进行转换

c# 使用ffmpeg 计算音频时长  并对音频格式进行转换

1.计算音频的时长

    /// <summary>
    /// 计算音频的时间 单位：秒
    /// </summary>
    /// <param name="FileName"></param>
    /// <returns></returns>
    private static double VideoTime(string FileName)
    {
        // ffmpeg 的路径
        string ffmpegPath = @"G:\FFmpegSpace\ffmpeg-master-latest-win64-gpl\bin\ffmpeg.exe";

        //  构建 FFmpeg 命令
        string command = $"-i \"{FileName}\"";

        // 创建进程并执行 FFmpeg 命令
        Process process = new Process();
        process.StartInfo.FileName = ffmpegPath;
        process.StartInfo.Arguments = command;
        process.StartInfo.RedirectStandardError = true;
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.CreateNoWindow = true;
        process.Start();

        // 读取 FFmpeg 输出信息
        string output = process.StandardError.ReadToEnd();
        process.WaitForExit();

        // 解析输出信息以获取时长
        string durationMarker = "Duration: ";
        int durationIndex = output.IndexOf(durationMarker) + durationMarker.Length;
        int durationLength = output.IndexOf(",", durationIndex) - durationIndex;
        string durationString = output.Substring(durationIndex, durationLength);
        TimeSpan duration = TimeSpan.Parse(durationString);
        double minutes = duration.TotalSeconds;

        // 打印音频时长
        Console.WriteLine($"本次上传的音频时长为: {minutes}" + "秒");

        return minutes;
    }

2.对音频进行格式转换

  /// <summary>
    /// 把非wav格式的转换成wav 并且确保采样率为16K
    /// </summary>
    /// <param name="inputFilePath"></param>
    /// <param name="outputFilePath"></param>
    /// <returns></returns>
    private static string WavChangeType(string inputFilePath, string outputFilePath)
    {
        try
        {
            // FFmpeg 可执行文件路径 需要替换自己电脑上的路径
            string ffmpegPath = @"G:\FFmpegSpace\ffmpeg-master-latest-win64-gpl\bin\ffmpeg.exe";

            //  构建 FFmpeg 命令  并且确保采样率为16K
            string command = $"-i \"{inputFilePath}\" -ar  16000 \"{outputFilePath}\"";



            // 创建进程并执行 FFmpeg 命令
            Process process = new Process();
            process.StartInfo.FileName = ffmpegPath;
            process.StartInfo.Arguments = command;
            process.StartInfo.RedirectStandardError = true;
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.CreateNoWindow = true;
            process.Start();


            string output = process.StandardError.ReadToEnd();
            process.WaitForExit();

            try
            {
                if (process.ExitCode == 0)
                {
                    Console.WriteLine("音频成功转换为wav格式!!!");
                }
                else
                {
                    Console.WriteLine("音频类型转换失败" + output);
                }
            }
            catch (Exception e)
            {

                Console.WriteLine("音频类型转换失败" + e.Message);
            }


        }
        catch (Exception e)
        {

            Console.WriteLine("音频类型转换失败" + e.Message);
        }

        //G:\appaa\ConsoleApp6\bin\Debug\net6.0\20231027113519.wav
        var filePath = outputFilePath;
        return filePath;

    }