如何在Android中使用ffmpeg反轉視頻？

Question

我想反向播放從圖庫和相機加載的視頻。 視頻使用ffmpeg命令轉換為圖像幀，並且幀轉換為反向視頻。

Answer 1

從https://stackoverflow.com/a/8137637/2930834

• http://ubuntuforums.org/showthread.php?t=1353893

后者如下：

轉儲所有視頻幀

$ ffmpeg -i input.mkv -an -qscale 1 %06d.jpg

轉儲音頻

$ ffmpeg -i input.mkv -vn -ac 2 audio.wav

反向音頻

$ sox -V audio.wav backwards.wav reverse

Cat視頻幀以與FFmpeg相反的順序輸入

$ cat $(ls -t *jpg) | ffmpeg -f image2pipe -vcodec mjpeg -r 25 -i - -i backwards.wav -vcodec libx264 -vpre slow -crf 20 -threads 0 -acodec flac output.mkv

使用Mencoder對PAL dv進行去隔行，並將幀頻從25倍增至50，然后通過管道傳輸到FFmpeg。

$ mencoder input.dv -of rawvideo -ofps 50 -ovc raw -vf yadif=3,format=i420 -nosound -really-quiet -o - | ffmpeg -vsync 0 -f rawvideo -s 720x576 -r 50 -pix_fmt yuv420p -i - -vcodec libx264 -vpre slow -crf 20 -threads 0 video.mkv

還值得檢查，

• https://video.stackexchange.com/a/17739

我還沒試過 希望這可以幫助

Answer 2

1.將視頻分為時長為10秒或更短的段（以下命令為6秒）

String[] complexCommand = {"-i", inputFileAbsolutePath, "-c:v", "libx264", "-crf", "22", "-map", "0", "-segment_time", "6", "-g", "9", "-sc_threshold", "0", "-force_key_frames", "expr:gte(t,n_forced*6)", "-f", "segment", outputFileAbsolutePath};

2. 反轉分段視頻

有聲

String command[] = {"-i", inputFileAbsolutePath, "-vf", "reverse", "-af", "areverse", outputFileAbsolutePath};

沒有音頻

String command[] = {"-i",inputFileAbsolutePath, "-vf", "reverse", outputFileAbsolutePath};

3. 以反向順序串聯反向分割的視頻

有聲

String command[] = {"-i",inputFile1AbsolutePath,"-i",inputFile2AbsolutePath .....,"-i",inputFileNAbsolutePath,"-filter_complex","[0:v0] [0:a0] [1:v1] [1:a1]...[N:vN] concat=n=N:v=1:a=1 [v] [a],"-map","[v]","-map","[a]", outputFileAbsolutePath};

沒有音頻

String command[] = {"-i",inputFile1AbsolutePath,"-i",inputFile2AbsolutePath .....,"-i",inputFileNAbsolutePath,"-filter_complex","[0:0] [1:0] [2:0]...[N:0] concat=n=N:v=1:a=0",outputFileAbsolutePath};

有關詳細說明，請在此處查看此示例代碼

Answer 3

此示例代碼僅是反向視頻，不包括音頻。

build.gradle

compile 'com.writingminds:FFmpegAndroid:0.3.2'

在執行命令之前，您需要先加載二進制文件

FFmpeg ffmpeg = FFmpeg.getInstance(this);

try {
        ffmpeg.loadBinary(new FFmpegLoadBinaryResponseHandler() {
        @Override
        public void onFailure() {

        }

        @Override
        public void onSuccess() {

        }

        @Override
        public void onStart() {

        }

        @Override
        public void onFinish() {

        }
        });
        } catch (FFmpegNotSupportedException e) {
             e.printStackTrace();
       }

加載二進制文件后，您可以執行命令。

String strInputVideoPath = dir.getAbsolutePath()  + "/" + "1543999518815.mp4";
String strRevOutputVideoPath = dir.getAbsolutePath() + "/" + "reverse.mp4";    
String[] cmdRevVid = {"-i",  strInputVideoPath,"-vf","reverse", strRevOutputVideoPath};
            try {
                ffmpeg.execute(cmdRevVid, new ExecuteBinaryResponseHandler(){
                    @Override
                    public void onStart() {

                    }

                    @Override
                    public void onProgress(String message) {

                    }

                    @Override
                    public void onFailure(String message) {

                    }

                    @Override
                    public void onSuccess(String message) {

                        try{



                        }catch (Exception ex){

                        }
                    }

                    @Override
                    public void onFinish() {

                    }
                });

            } catch (FFmpegCommandAlreadyRunningException e) {
                // Handle if FFmpeg is not supported by device
            }

就我而言，我必須做反向視頻和連續視頻本身。 參考文章

String[] cmdFinal = {"-i",  dir.getAbsolutePath()  + "/" + "inputVideo.mp4",
                "-filter_complex", "[0:v]reverse,fifo[r];[0:v][r] concat=n=2:v=1 [v]",
                "-map", "[v]",
                dir.getAbsolutePath() + "/" + "final.mp4"};