Problem when trying to convert images into video

[Mashnunul Huq]

I am trying to rebuild the video I divided into frames. Below is my code:
`using System.Resources;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Xabe.FFmpeg;
using Xabe.FFmpeg.Downloader;
using System.Collections;
using static System.Net.WebRequestMethods;
using System.Runtime.InteropServices;

namespace TestingFFmpeg
{
class Program
{
static void Main(string[] args)
{

        Run().GetAwaiter().GetResult();


    }

    private static async Task Run()
    {
        //First download and install FFmpeg into the folder
        string outputFolder = nameof(TestingFFmpeg) + GetCurrentTime();
        string convertedVideoDir, testOutputFolder, ffmpegFolder;
        CreateTemporaryFolders(outputFolder, out convertedVideoDir, out testOutputFolder, out ffmpegFolder);
        await FFmpegDownloader.GetLatestVersion(FFmpegVersion.Official, ffmpegFolder);
        FFmpeg.SetExecutablesPath(ffmpegFolder);
        Console.WriteLine("FFmpeg is downloaded");

        //Read the video file
        string testFilePath = Path.Combine("C:\\Work and files\\Cloud Computing Project\\TestingOfFFmpeg\\TestingFFmpeg\\TestingFiles", "circle.mp4");
        string fileName = Path.GetFileName(testFilePath);
        Console.WriteLine($"Found the file named {fileName}");

        //Turn Video into images
        Func<string, string> outputFileNameBuilder = (number) => { return convertedVideoDir + "\\fileNameNo" + number + ".png"; };            
        IMediaInfo info = await FFmpeg.GetMediaInfo(testFilePath).ConfigureAwait(false);
        IVideoStream videoStream = info.VideoStreams.First()?.SetCodec(VideoCodec.png);
        IConversionResult conversionResult = await FFmpeg.Conversions.New().AddStream(videoStream).ExtractEveryNthFrame(2, outputFileNameBuilder).SetOutput(convertedVideoDir).Start();

        //Turn images into Video
        List<string> files = Directory.EnumerateFiles(convertedVideoDir).ToList(); 
        IConversion conversion = new Conversion();
        //await imageToVideo.SetInputFrameRate(1).BuildVideoFromImages(files).SetInputFrameRate(1).SetFrameRate(25).SetOutput(Path.Combine(testFilePath, "outputfile.avi")).Start();
        //await FFmpeg.Conversions.New().SetInputFrameRate(1).BuildVideoFromImages(files).SetFrameRate(36).SetPixelFormat(PixelFormat.yuv420p).SetOutput(Path.Combine(testFilePath, "outputfile.mp4")).Start();
        //await FFmpeg.Conversions.New().SetInputFrameRate(1).SetFrameRate(15).BuildVideoFromImages(files).SetOutput(Path.Combine(testFilePath, "outputFile.mp4")).SetPixelFormat(PixelFormat.yuv420p).SetOutputFormat(Format.mp4).SetOverwriteOutput(true).Start();
        await FFmpeg.Conversions.New().BuildVideoFromImages(files).SetFrameRate(15).SetOverwriteOutput(true).SetOutputFormat(Format.mp4).SetVideoBitrate(2600000).SetPixelFormat(PixelFormat.yuv420p).SetOutput(Path.Combine(testFilePath, "outputFile.mp4")).SetOutputFormat(Format.mp4).Start();
    }

    private static void CreateTemporaryFolders(string outputFolder, out string convertedVideoDir, out string testOutputFolder, out string ffmpegFolder)
    {
        MakeDirectoryIfRequired(outputFolder);

        convertedVideoDir = Path.Combine(outputFolder, "Converted");
        MakeDirectoryIfRequired(convertedVideoDir);

        testOutputFolder = Path.Combine(outputFolder, "TEST");
        MakeDirectoryIfRequired(testOutputFolder);

        ffmpegFolder = Path.Combine(outputFolder, "FFmpeg");
        MakeDirectoryIfRequired(ffmpegFolder);
    }

    private static void MakeDirectoryIfRequired(string path)
    {
        if (!Directory.Exists(path))
        {
            Directory.CreateDirectory(path);
        }
    }
    private static string GetCurrentTime()
    {
        var currentTime = DateTime.Now.ToString();
        var timeWithoutSpace = currentTime.Split();
        var timeWithUnderScore = string.Join("_", timeWithoutSpace);
        var timeWithoutColon = timeWithUnderScore.Replace(':', '-');
        var timeWithoutSlash = timeWithoutColon.Replace('/', '-');
        return timeWithoutSlash;
    }

}
}
`
But it is showing this error:
FFmpegNoSuitableOutputFormatFoundException: ffmpeg version 4.4.1-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 11.2.0 (Rev1, Built by MSYS2 project)
configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
[lrc @ 0000016e5d3ed0c0] Format lrc detected only with low score of 5, misdetection possible!
Input #0, lrc, from 'C:\Users\Mashnunul':
Duration: N/A, bitrate: N/A
Stream #0:0: Subtitle: text
[NULL @ 0000016e5d3f02c0] Unable to find a suitable output format for 'Huq'
Huq: Invalid argument

[Mashnunul Huq]

This is the video file I am using

circle.mp4

[HenningF2]

This line looks strange:
IConversionResult conversionResult = await FFmpeg.Conversions.New().AddStream(videoStream).ExtractEveryNthFrame(2, outputFileNameBuilder).SetOutput(convertedVideoDir).Start();

The output is already defined in the ExtractEveryNthFrame method.
Try to delete 'SetOutput'. The directory name should be included in the 'outFileNameBuilder'.