Question

我正在制作视频到音频转换器应用程序，但需要帮助才能使用ffmpeg将视频转换为音频。我检查了许多答案和网站，但它们的答案不容易理解，我对用于转换的命令感到困惑。将视频转换为音频的正确命令是什么，我是否以正确的方式执行该命令？

public class VideoConvertActivity extends AppCompatActivity {

    private VideoView videoView;
    private Button convertButton;
    private String filePath;
    private FFmpeg ffmpeg;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_video_convert);

        videoView = findViewById(R.id.videoviewID);
        convertButton = findViewById(R.id.convertbuttonID);

        ffmpeg = FFmpeg.getInstance(VideoConvertActivity.this);

// in variable video i'm getting the path of video path from previous activity through intent and that video will have to convert to audio file
        Intent extras = getIntent();
        final String video = extras.getStringExtra("video");

        videoView.setVideoPath(video);
        videoView.start();

        convertButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                try {

                    File moviesDir = Environment.getExternalStoragePublicDirectory(
                            Environment.DIRECTORY_MUSIC
                    );

                    String filePrefix = "convert_audio";
                    String fileExtn = ".mp3";
                    File dest = new File(moviesDir, filePrefix + fileExtn);

                    int fileNo = 0;
                    while (dest.exists()) {
                        fileNo++;
                        dest = new File(moviesDir, filePrefix + fileNo + fileExtn);
                    }
                    filePath = dest.getAbsolutePath();

                    // to execute "ffmpeg -version" command you just need to pass "-version"
                    String[] command = {"-y", "-i", video, "-vn", "-ar", "44100", "-ac", "2", "-b:a", "256k", "-f", "mp3", filePath};
                    ffmpeg.execute(command, new ExecuteBinaryResponseHandler() {

                        @Override
                        public void onStart() {
                            Toast.makeText(VideoConvertActivity.this,"Started",Toast.LENGTH_LONG).show();
                        }

                        @Override
                        public void onProgress(String message) {
                            Toast.makeText(VideoConvertActivity.this,"Progress",Toast.LENGTH_LONG).show();
                        }

                        @Override
                        public void onFailure(String message) {
                            Toast.makeText(VideoConvertActivity.this,"Failed",Toast.LENGTH_LONG).show();
                        }

                        @Override
                        public void onSuccess(String message) {
                            Toast.makeText(VideoConvertActivity.this,"Succeed",Toast.LENGTH_LONG).show();
                        }

                        @Override
                        public void onFinish() {
                            Toast.makeText(VideoConvertActivity.this,"Finished",Toast.LENGTH_LONG).show();
                        }
                    });
                } catch (FFmpegCommandAlreadyRunningException e) {
                    // Handle if FFmpeg is already running
                }

                 Toast.makeText(VideoConvertActivity.this,"Converted Successfully",Toast.LENGTH_SHORT).show();

            }
        });

    }

}

Answer 1

Main不是一个地方，您不应该放置while循环，否则会引起问题。由于main是一个循环，因此您应该使用线程在后台执行某些操作，而不中断程序的流程。在这种情况下，如果可以。

以下是玩家的示例，因此您可以了解其工作方式： https://developer.android.com/guide/topics/media/exoplayer

如果您几个小时后仍无法解决，请看看我能为您做些什么。

Answer 2

任何建议您将其放入command变量

的转换

如此赞美

String[] command = {"-y", "-i", video, "-vn", "-ar", "44100", "-ac", "2", "-b:a", "256k", "-f", "mp3", filePath};

使用这个

ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn music.mp3

或者您也可以像将命令设置为数组一样格式化命令：

   String[] command = {"-y", "-i", video, "-f", "mp3", "-ab", "192000", "-vn", filePath};

Answer 3

我在清单中授予了读取权限，但忘记了给予写入权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

如何使用FFMPEG将视频文件转换为音频文件？

3 个答案: