下面是合并两个视频和维护的工作命令宽高比

  complexCommand = new String [] { -  y，-i，file1.toString（） ，-i，file2.toString（），-strict，experimental，-filter_complex，
[0：v] scale = iw * min（1920 / iw\\， 1080 / ih）：ih * min（1920 / iw \\\，1080 / ih），pad = 1920：1080：（1920-iw * min（1920 / iw \\\，1080 / ih））/ 2 ：（1080-ih * min（1920 / iw \\\，1080 / ih））/ 2，setar = 1：1 [v0]; [1：v] scale = iw * min（1920 / iw \\ （1080 / ih）：ih * min（1920 / iw \\\，1080 / ih），pad = 1920：1080：（1920-iw * min（1920 / iw \\，1080 / ih）） / 2：（1080-IH *分钟（1920 / iw\\，1080 / 1H））/ 2，setsar = 1：1 [V1]; [V0] [0：一个] [V1] [1：一] concat = n = 2：v = 1：a = 1，
-ab，48000，-ac，2，-ar，22050 ，1920×1080，-vcodec，libx264，-crf，27，-q，4，-preset，ultrafast，rootPath +/output.mp4 }; 
 

I am using following FFMPEG command for merging mp4 videos in android. But video is rotated 90 degree after merging.

I am stuck from two days .If any idea it would be highly appriciated.

Thanks in Advance !

complexCommand = new String[] {
                "ffmpeg",
                "-y",
                "-i",
                recordpath + "Vid1.mp4",
                "-i",
                recordpath + "Vid2.mp4",
                "-strict",
                "experimental",
                "-filter_complex",
                "[0:v]scale=w=640:h=480[v1]; [1:v]scale=w=640:h=480[v2]; [v1][0:a][v2][1:a] concat=n=2:v=1:a=1 [v] [a]",
                "-map", "[v]", "-map", "[a]", "-b", "2097k", "-vcodec",
                "mpeg4","-ab","64k","-ac","2","-ar","22050", recordpath + "Outputnew.mp4"};

Below is the working command for merging two videos and maintaining aspect ratio of both

complexCommand = new String[]{"-y", "-i", file1.toString(), "-i", file2.toString(), "-strict", "experimental", "-filter_complex",
                "[0:v]scale=iw*min(1920/iw\\,1080/ih):ih*min(1920/iw\\,1080/ih), pad=1920:1080:(1920-iw*min(1920/iw\\,1080/ih))/2:(1080-ih*min(1920/iw\\,1080/ih))/2,setsar=1:1[v0];[1:v] scale=iw*min(1920/iw\\,1080/ih):ih*min(1920/iw\\,1080/ih), pad=1920:1080:(1920-iw*min(1920/iw\\,1080/ih))/2:(1080-ih*min(1920/iw\\,1080/ih))/2,setsar=1:1[v1];[v0][0:a][v1][1:a] concat=n=2:v=1:a=1",
                "-ab", "48000", "-ac", "2", "-ar", "22050", "-s", "1920x1080", "-vcodec", "libx264", "-crf", "27", "-q", "4", "-preset", "ultrafast", rootPath + "/output.mp4"};