Convert Mp3 to wav

Question

I have a working code to convert wav to m4a.is there anyway convert mp3 to m4a, modifying my existing code. I do not want to use ffmpeg or native code for this. Below function works for wav to m4a conversion, but does not work for mp3 to m4a

public void convertAudio(final String filename) {
    final String AUDIO_RECORDING_FILE_NAME = Config.mp3Audio; // Input PCM file
    final String COMPRESSED_AUDIO_FILE_NAME = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC).getPath()
            + "/convertedmp4.m4a"; // Output MP4/M4A file
    final String COMPRESSED_AUDIO_FILE_MIME_TYPE = "audio/mp4a-latm";
    final int COMPRESSED_AUDIO_FILE_BIT_RATE = 320000; // 64kbps
    final int SAMPLING_RATE = 22050;
    final int BUFFER_SIZE = 22050;
    final int CODEC_TIMEOUT_IN_MS = 5000;
    String LOGTAG = "CONVERT AUDIO";

    try {

        File inputFile = new File(filename);
        FileInputStream fis = new FileInputStream(inputFile);
        File outputFile = new File(COMPRESSED_AUDIO_FILE_NAME);
        if (outputFile.exists()) outputFile.delete();
        MediaMuxer mux = new MediaMuxer(outputFile.getAbsolutePath(), MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
        MediaFormat outputFormat = MediaFormat.createAudioFormat(COMPRESSED_AUDIO_FILE_MIME_TYPE, SAMPLING_RATE, 1);
        outputFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
        outputFormat.setInteger(MediaFormat.KEY_BIT_RATE, COMPRESSED_AUDIO_FILE_BIT_RATE);
        outputFormat.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 16384);
        MediaCodec codec = MediaCodec.createEncoderByType(COMPRESSED_AUDIO_FILE_MIME_TYPE);
        codec.configure(outputFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
        codec.start();
        ByteBuffer[] codecInputBuffers = codec.getInputBuffers(); // Note: Array of buffers
        ByteBuffer[] codecOutputBuffers = codec.getOutputBuffers();
        MediaCodec.BufferInfo outBuffInfo = new MediaCodec.BufferInfo();
        byte[] tempBuffer = new byte[BUFFER_SIZE];
        boolean hasMoreData = true;
        double presentationTimeUs = 0;
        int audioTrackIdx = 0;
        int totalBytesRead = 0;
        int percentComplete = 0;
        do {
            int inputBufIndex = 0;
            while (inputBufIndex != -1 && hasMoreData) {
                inputBufIndex = codec.dequeueInputBuffer(CODEC_TIMEOUT_IN_MS);

                if (inputBufIndex >= 0) {
                    ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
                    dstBuf.clear();

                    int bytesRead = fis.read(tempBuffer, 0, dstBuf.limit());

                    if (bytesRead == -1) { // -1 implies EOS
                        hasMoreData = false;
                        codec.queueInputBuffer(inputBufIndex, 0, 0, (long) presentationTimeUs, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
                    } else {
                        totalBytesRead += bytesRead;
                        dstBuf.put(tempBuffer, 0, bytesRead);
                        codec.queueInputBuffer(inputBufIndex, 0, bytesRead, (long) presentationTimeUs, 0);
                        presentationTimeUs = 1000000l * (totalBytesRead / 2) / SAMPLING_RATE;
                    }
                }
            }
            int outputBufIndex = 0;
            while (outputBufIndex != MediaCodec.INFO_TRY_AGAIN_LATER) {
                outputBufIndex = codec.dequeueOutputBuffer(outBuffInfo, CODEC_TIMEOUT_IN_MS);
                if (outputBufIndex >= 0) {
                    ByteBuffer encodedData = codecOutputBuffers[outputBufIndex];
                    encodedData.position(outBuffInfo.offset);
                    encodedData.limit(outBuffInfo.offset + outBuffInfo.size);
                    if ((outBuffInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0 && outBuffInfo.size != 0) {
                        codec.releaseOutputBuffer(outputBufIndex, false);
                    } else {
                        mux.writeSampleData(audioTrackIdx, codecOutputBuffers[outputBufIndex], outBuffInfo);
                        codec.releaseOutputBuffer(outputBufIndex, false);
                    }
                } else if (outputBufIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                    outputFormat = codec.getOutputFormat();

                    audioTrackIdx = mux.addTrack(outputFormat);
                    mux.start();
                } else if (outputBufIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {

                } else if (outputBufIndex == MediaCodec.INFO_TRY_AGAIN_LATER) {
                    // NO OP
                } else {

                }
            }
            percentComplete = (int) Math.round(((float) totalBytesRead / (float) inputFile.length()) * 100.0);

        } while (outBuffInfo.flags != MediaCodec.BUFFER_FLAG_END_OF_STREAM);
        fis.close();
        mux.stop();
        mux.release();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }


}