将一些声音数据添加到现有的 mp3 文件 Android，lame 编码器

Question

所以，这就是 mp3 在 android 中从麦克风编码到文件的方式：

private void startBufferedWrite(final File file) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                output = null;
                try {
                    output = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
                    while (mIsRecording) {
                        int readSize = mRecorder.read(buffer, 0, buffer.length);
                        if (readSize > 0) {
                            int bytesEncoded = androidLame.encode(buffer, buffer, readSize, mp3buffer);
                            if (bytesEncoded > 0) {
                                try {
                                    output.write(mp3buffer, 0, bytesEncoded);
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }
                        }
                    }
                } catch (IOException e) {
                    Log.e("Error writing file : ", e.getMessage());
                }
            }
        }).start();
    }

上面的一切都正常工作，并提供一个新的 mp3 文件，可以从音频播放器正常播放

现在我刚从 InputStream 读取那个 mp3 文件并获取文件字节数组：

private void old_mp3_to_new_mp3(final File mp3, final File mp3_new) throws IOException {
        try {
            int size = 4;
            byte[] rawData = new byte[(int) mp3.length()];
            RandomAccessFile input = new RandomAccessFile(mp3, "rw");
            byte[] header = new byte[size];
            input.read(header, 0, size);
            //noinspection ResultOfMethodCallIgnored
            input.read(rawData);
            input.close();
            byte[] bytes = new byte[100000]; //create random bytes to write to mp3 as Random audio ???
            new Random().nextBytes(bytes);
            FileOutputStream output = new FileOutputStream(mp3_encrypted);
            FileChannel channel = output.getChannel();
            channel.write(ByteBuffer.wrap(header));
            channel.write(ByteBuffer.wrap(rawData));
            channel.write(ByteBuffer.wrap(bytes)); // if comment this line the mp3 new file is generated ok but it's the same with recording, but if wanted to write new random bytes the mp3 is generated but the file says that is corrupted...
            output.close();
            //noinspection ResultOfMethodCallIgnored
            mp3.delete();
            callbackListener.perfundoi_shkrimi_dhe_enkriptimi(mp3_encrypted);
        } catch (Exception ignored) {
            callbackListener.perfundoi_shkrimi_dhe_enkriptimi(mp3_encrypted);
        }
    }

那么如何将一些新的音频数据添加到现有的 mp3 文件中，或者是否有任何选项可以将旧字节 + 新字节编码为新的 mp3 文件以连接在一起？

有关导致问题的部分的更多信息，请阅读评论是第二个代码。

换句话说：

mic -> mp3 ; mp3 file -> bytes + new_bytes -> mp3;

那么，我们是否可以在不重新编码的情况下修改现有的 mp3 文件字节声音数据？

Answer 1

试试这个：

String wavFile1 = "C:\1.mp3";
String wavFile2 = "C:\2.mp3";
FileInputStream fistream1 = new FileInputStream(wavFile1);  // first source file
FileInputStream fistream2 = new FileInputStream(wavFile2);//second source file
SequenceInputStream sistream = new SequenceInputStream(fistream1, fistream2);
FileOutputStream fostream = new FileOutputStream("D://merge1.mp3");//destinationfile

int temp;

while( ( temp = sistream.read() ) != -1)
{
    // System.out.print( (char) temp ); // to print at DOS prompt
    fostream.write(temp);   // to write to file
}
fostream.close();
sistream.close();
fistream1.close();
fistream2.close();

Reference

Answer 2

让我试着回答你的问题：

So how to add some new audio data to existing mp3 file, or maybe there is any options to encode old bytes + new bytes to new mp3 file to join together ?

如果 "add some audio" 你的意思是在 mp3 上添加或添加其他音频数据，答案是肯定的，你可以在不重新编码的情况下做到这一点

您将使用的 class 是 MediaMuxer 您可以在 https://developer.android.com/reference/android/media/MediaMuxer
找到有用的信息 https://bigflake.com/mediacodec/

将一些声音数据添加到现有的 mp3 文件 Android，lame 编码器

Add some sound data to existing mp3 file Android,lame encoder

java

mp3

android

lame

android-studio