MediaRecorder不以代码-38开头

Question

我正在尝试将视频写入socket（使用ParcelFileDescriptor）。但是当调用mediaPlayer.start（）方法时 - 使用此消息发生IllegalStateException - “E / MediaRecorder：start failed：-38”。

文件描述符的代码（程序集调用时，套接字100％正确连接）：

public ParcelFileDescriptor getFileDescriptorToSocket() {
        return ParcelFileDescriptor.fromSocket(socket);
    }

准备录音机：

private boolean prepareMediaRecorder() {
        mediaRecorder = new MediaRecorder();
        camera.unlock();

        mediaRecorder.setCamera(camera);
        // mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
        mediaRecorder.setPreviewDisplay(cameraSurface.getHolder().getSurface());
        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
        mediaRecorder.setVideoSize(320, 240);
        mediaRecorder.setVideoFrameRate(30);
        //mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_720P));
        mediaRecorder.setOutputFile(MainActivity.socketClient.getFileDescriptorToSocket().getFileDescriptor());

        try {
            mediaRecorder.prepare();
        } catch (IllegalStateException ise) {

            // TODO Delete test code
            Log.d(TAG, "Error during MediaRecorder preparing:  " + ise.getMessage());
            ise.printStackTrace();

            releaseMediaRecorder();
            return false;
        } catch (IOException ioe) {

            // TODO Delete test code
            Log.d(TAG, "Error during MediaRecorder preparing:  " + ioe.getMessage());
            ioe.printStackTrace();

            releaseMediaRecorder();
            return false;
        }

返回true;     }

并要求开始录制：

private void startRecording() {
        if (!prepareMediaRecorder()) {

            // TODO Delete test code
            Log.d(TAG, "Error starting recording process");

            finish();
        } else {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        mediaRecorder.start();
                    } catch (Exception e) {
                        // TODO Delete test code
                        Log.d(TAG, "Error in recording thread:  " + e.getMessage());
                        e.printStackTrace();
                    }
                }
            }).start();

            recordingStatus = true;
        }
    }

我应该注意，当我禁用开始录制方法 - 相机工作正常 - 我可以正确看到相机预览表面。