Android：如何从麦克风同时播放音乐和录音？

Question

我正在尝试让应用程序可以同时录制来自麦克风内置的麦克风和来自Android设备的音乐。但我的实施使声音质量太糟糕了。来自Android设备的音乐声音太大，我听不到我的声音。我的代码在这里：

            try 
            {
            recorder = new MediaRecorder();
            recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
            recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
            recorder.setOutputFile(commonHeader.getOutputFilePath());
            recorder.setOnErrorListener(errorListener);
            recorder.setOnInfoListener(infoListener);
                recorder.prepare();
                recorder.start(); // Recording is now started
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();

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

            }


            mplayer = new MediaPlayer();
            try {
                mplayer.setDataSource((String)downloadedData.get(1));

            } catch (IllegalArgumentException e) {

                // TODO Auto-generated catch block
                e.printStackTrace();

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

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

            }

            try {
                mplayer.prepare();
                mplayer.start();


            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                recFailed=true;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                recFailed=true;
            }
            if(recFailed==true)
            {
                stopRec();
                showErrorMsg();
            }

任何人都可以告诉我如何改善音质？