Concatenate two audio files and play resulting file

Question

I am really facing problem from last couple of days but I am not able to find the exact solution please help me.

I want to merge two .mp3 or any audio file and play final single one mp3 file. But when I am combine two file the final file size is ok but when I am trying to play it just play first file, I have tried this with SequenceInputStream or byte array but I am not able to get exact result please help me.

My code is the following:

public class MerginFileHere extends Activity {
public ArrayList<String> audNames;
byte fileContent[];
byte fileContent1[];
FileInputStream ins,ins1;
FileOutputStream fos = null;
String combined_file_stored_path = Environment
        .getExternalStorageDirectory().getPath()
        + "/AudioRecorder/final.mp3";

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    audNames = new ArrayList<String>();
    String file1 = Environment.getExternalStorageDirectory().getPath()
            + "/AudioRecorder/one.mp3";

    String file2 = Environment.getExternalStorageDirectory().getPath()
            + "/AudioRecorder/two.mp3";

    File file = new File(Environment.getExternalStorageDirectory()
            .getPath() + "/AudioRecorder/" + "final.mp3");

    try {
        file.createNewFile();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    audNames.add(file1);
    audNames.add(file2);

    Button btn = (Button) findViewById(R.id.clickme);
    btn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            createCombineRecFile();
        }
    });
}

public void createCombineRecFile() {
    // String combined_file_stored_path = // File path in String to store
    // recorded audio

    try {
        fos = new FileOutputStream(combined_file_stored_path, true);
    } catch (FileNotFoundException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

        try {
            File f = new File(audNames.get(0));
            File f1 = new File(audNames.get(1));
            Log.i("Record Message", "File Length=========>>>" + f.length()+"------------->"+f1.length());


            fileContent = new byte[(int) f.length()];
            ins = new FileInputStream(audNames.get(0));
            int r = ins.read(fileContent);// Reads the file content as byte

            fileContent1 = new byte[(int) f1.length()];
            ins1 = new FileInputStream(audNames.get(1));
            int r1 = ins1.read(fileContent1);// Reads the file content as byte
                                            // from the list.






            Log.i("Record Message", "Number Of Bytes Readed=====>>>" + r);

            //fos.write(fileContent1);// Write the byte into the combine file.


            byte[] combined = new byte[fileContent.length + fileContent1.length];

            for (int i = 0; i < combined.length; ++i)
            {
                combined[i] = i < fileContent.length ? fileContent[i] : fileContent1[i - fileContent.length];
            }
            fos.write(combined);
            //fos.write(fileContent1);*



        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    try {
        fos.close();
        Log.v("Record Message", "===== Combine File Closed =====");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

Answer 1

I already published an app with this function... try my method using SequenceInputStream, in my app I just merge 17 MP3 files in one and play it using the JNI Library MPG123, but I tested the file using MediaPlayer without problems.

This code isn't the best, but it works...

private void mergeSongs(File mergedFile,File...mp3Files){
        FileInputStream fisToFinal = null;
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(mergedFile);
            fisToFinal = new FileInputStream(mergedFile);
            for(File mp3File:mp3Files){
                if(!mp3File.exists())
                    continue;
                FileInputStream fisSong = new FileInputStream(mp3File);
                SequenceInputStream sis = new SequenceInputStream(fisToFinal, fisSong);
                byte[] buf = new byte[1024];
                try {
                    for (int readNum; (readNum = fisSong.read(buf)) != -1;)
                        fos.write(buf, 0, readNum);
                } finally {
                    if(fisSong!=null){
                        fisSong.close();
                    }
                    if(sis!=null){
                        sis.close();
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            try {
                if(fos!=null){
                    fos.flush();
                    fos.close();
                }
                if(fisToFinal!=null){
                    fisToFinal.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    } 

Answer 2

Mp3 files are some frames.

You can concatenate these files by appending the streams to each other if and only if the bit rate and sample rate of your files are same.

If not, the first file plays because it has truly true encoding but the second file can not decode to an true mp3 file.

Suggestion: convert your files with some specific bit rate and sample rate, then use your function.