Implementation example of C# calling FFmpeg to operate audio and video

namespace FFmpegAudioAndVideoMerge
{
    class Program
    {
        static void Main(string[] args)
        {
            var physicalPath = "E:\\FFmpegAudioAndVideoMerge\\FFmpegAudioAndVideoMerge\\files\\";

            //Video Merge            VideoCombine(physicalPath + "video1.mp4", physicalPath + "video2.mp4", physicalPath + "merageVideoyy.mp4");

            //Audio merge            var audioMergeList = new List<string>();
            (physicalPath + "music1.mp3");
            (physicalPath + "music2.mp3");
            (physicalPath + "music3.mp3");
            AudioMerge(physicalPath, audioMergeList);

            //Combine audio and video into video            AudioAndVideoMerge(physicalPath);
        }

        #region Video Merge        /// <summary>
        /// Video merge        /// </summary>
        /// <param name="video1">Merge video 1</param>        /// <param name="video2">Merge Video 2</param>        /// <param name="saveFilePath">Save file name</param>        /// &lt;returns&gt;&lt;/returns&gt;
        public static void VideoCombine(string video1, string video2, string saveFilePath)
        {
            string strTmp1 = video1 + ".ts";
            string strTmp2 = video2 + ".ts";
            string strCmd1 = " -i " + video1 + " -c copy -bsf:v h264_mp4toannexb -f mpegts " + strTmp1 + " -y ";
            string strCmd2 = " -i " + video2 + " -c copy -bsf:v h264_mp4toannexb -f mpegts " + strTmp2 + " -y ";

            string videoMerge = " -i \"concat:" + strTmp1 + "|" +
                strTmp2 + "\" -c copy -bsf:a aac_adtstoasc -movflags +faststart " + saveFilePath + " -y ";

            //1. Convert file types. Since not all types of video files support direct merging, you need to convert the format first            CommandManager(strCmd1);
            CommandManager(strCmd2);

            //2. Video merge            CommandManager(videoMerge);
        }
        #endregion

        #region Audio Merge        /// &lt;summary&gt;
        /// Audio merge        /// &lt;/summary&gt;
        public static void AudioMerge(string physicalPath, List&lt;string&gt; mergeFile)
        {
            //Mix multiple audios into one audio file output /#amix
            //ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT

            //Merge two audios            //ffmpeg -i input1.mp3 -i input2.mp3 -filter_complex amerge -ac 2 - c:a libmp3lame -q:a 4 output.mp3

            //Get audio in video            //ffmpeg -i input.mp4 -vn -y -acodec copy output.m4a

            //Remove the audio from the video            //ffmpeg -i input.mp4 -an output.mp4

            // /simadi/p/
            // ffmpeg -i "concat:123.mp3|124.mp3" -acodec copy output.mp3
            // Explanation: -i represents input parameters            // contact: 123.mp3 | 124.mp3 represents the audio file that needs to be connected to -acodec copy output.mp3 Recode and copy to a new file
            string mergeCommandStr = $"-i \"concat:{("|", ())}\" -acodec copy {physicalPath}AudioMerge.mp3  -y";
            CommandManager(mergeCommandStr);
        }
        #endregion

        #region audio and video merge into video        /// &lt;summary&gt;
        /// Merge audio and video into video        /// &lt;/summary&gt;
        /// <param name="physicalPath">PhysicalPath</param>        public static void AudioAndVideoMerge(string physicalPath)
        {
            //1. There is no audio in the video file.            //ffmpeg -i video.mp4 -i  -c:v copy -c:a aac -strict experimental output.mp4
            //string mergeCommandStr = $"-i {physicalPath}video2.mp4 -i {physicalPath}music1.mp3 -c:v copy -c:a aac -strict experimental {physicalPath}output.mp4  -y";

            //video.mp4 is the video and audio to be merged respectively, and output.mp4 is the audio and video file output after the merge.            //2. The following command is to replace the audio in video with audio ffmpeg -i video.mp4 -i -c:v copy -c:a aac -strict experimental -map 0:v:0 -map 1:a: 0 output.mp4            string mergeCommandStr = $"-i {physicalPath}video3.mp4 -i {physicalPath}AudioMerge.mp3 -c:v copy -c:a aac -strict experimental -map 0:v:0 -map 1:a:0 {physicalPath}AudioAndVideoMerge.mp4  -y";

            //3. C++ audio and video merging (if there is no audio in the video file)            //"ffmpeg -i /tmp/mergeMp3/392118469203595327/  -i /tmp/mergeMp3/392118469203595327/bg.mp4 -c copy -bsf:a aac_adtstoasc /tmp/mergeMp3/392118469203595327/392118469203595327.mp4 -y"
            //string mergeCommandStr3 = $"-i {physicalPath}video5.mp4  -i {physicalPath}AudioMerge.mp3 -c copy -bsf:a aac_adtstoasc {physicalPath}AudioAndVideoMerge1.mp4 -y";

            CommandManager(mergeCommandStr);
        }
        #endregion


        /// &lt;summary&gt;
        /// implement        /// C# Process process call /zh-cn/dotnet/api/?view=net-5.0        /// &lt;/summary&gt;
        /// <param name="commandStr">Execute the command</param>        public static void CommandManager(string commandStr)
        {
            try
            {
                using (Process process = new Process())
                {
                     = "D:\\FFmpeg\\bin\\";//The name of the program to be executed (properties, get or set the application or document to be started. The FileName property does not need to represent an executable file. It can be any file type whose extension has been associated with the application installed on the system.)                     = " " + commandStr;//Command line parameters passed when starting the process                     = false;
                     = false;//May accept input information from the calling program                     = false;//The output information is obtained by the calling program                     = false;//Redirection standard error output                     = false;//The program window is not displayed                    ();//Start the program                    ();//Waiting for the program to execute and exit the process (avoiding the process occupying files or the synthetic file has not been generated yet)*                }
            }
            catch (Exception e)
            {
                ();
            }
        }
    
}
}