如何使用 LocalSocket 修复“MediaRecorder.start()”上的“java.lang.IllegalStateException”答案

【问题标题】：How to fix 'java.lang.IllegalStateException' on 'MediaRecorder.start()' using LocalSocket如何使用 LocalSocket 修复“MediaRecorder.start()”上的“java.lang.IllegalStateException”
【发布时间】：2019-11-24 15:06:44
【问题描述】：

我正在尝试开发一个圆形录像机，我需要将录制的视频保存在缓冲区中以恢复某个时刻的最后 X 分钟。问题是当我运行 MediaRecorder 对象的“start()”方法时：

mMediaRecorder.start();

出现以下错误：

java.lang.IllegalStateException android.media.MediaRecorder.start（本机方法）在 picture.wikinova.com.odc.CameraActivity$MediaPrepareTask.doInBackground(CameraActivity.java:298) 在 picture.wikinova.com.odc.CameraActivity$MediaPrepareTask.doInBackground(CameraActivity.java:289) 在 android.os.AsyncTask$2.call(AsyncTask.java:333) 在 java.util.concurrent.FutureTask.run(FutureTask.java:266) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 在 java.lang.Thread.run(Thread.java:764)

当我使用 'File' 作为 MediaRecorder 的 outputFile 时不会发生该错误，但当我尝试使用 LocalSocket 恢复内存中的视频缓冲区时会发生此错误。

这是我创建 LocalServerSocket 并捕获视频的代码

         mLocalServerSocket = new LocalServerSocket("sockt_ip");
            } catch (Exception e) {
                e.printStackTrace();
            }
            LocalSocket mLocalClientSocket = null;
            mLocalClientSocket = mLocalServerSocket.accept();
            InputStream in = mLocalClientSocket.getInputStream();
            byte[] buffer = new byte[1024];
            String retorno = "";
            int len = 0;
            while ((len = in.read(buffer)) >= 0) {
                for (int i = 0; i < len; i++) {
                  retorno += buffer[i];
                }

             }

这是我创建 MediaRecorder 并设置输出文件的代码

CamcorderProfile profile = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
        profile.videoFrameWidth = optimalSize.width;
        profile.videoFrameHeight = optimalSize.height;

        parameters.setPreviewSize(profile.videoFrameWidth, profile.videoFrameHeight);
        mCamera.setParameters(parameters);
        try {
            mCamera.setPreviewTexture(mPreview.getSurfaceTexture());
        } catch (IOException e) {
            Log.e(TAG, "Surface texture is unavailable or unsuitable" + e.getMessage());
            return false;
        }


        mMediaRecorder = new MediaRecorder();

        mCamera.unlock();
        mMediaRecorder.setCamera(mCamera);


        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
        mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);



        mMediaRecorder.setProfile(profile);

        LocalSocket outSocket = new LocalSocket();
        try {
            outSocket.connect(new LocalSocketAddress("sockt_ip"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        mMediaRecorder.setOutputFile(outSocket.getFileDescriptor());


        mMediaRecorder.prepare();
        mMediaRecorder.start();

我已经测试了套接字连接。我在

中写了一些文字

LocalSocket outSocket

并在

中收到

InputStream in = mLocalClientSocket.getInputStream();
byte[] buffer = new byte[1024];

问题是我将套接字 FileDescriptor 设置为 mediaRecorder 的 outputFile 的部分，但我不知道可以是什么。

【问题讨论】：

标签： java android mediarecorder localsocket

【解决方案1】：

使用下面的代码

    CamcorderProfile profile = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
            profile.videoFrameWidth = optimalSize.width;
            profile.videoFrameHeight = optimalSize.height;

            parameters.setPreviewSize(profile.videoFrameWidth, profile.videoFrameHeight);
            mCamera.setParameters(parameters);
            try {
                mCamera.setPreviewTexture(mPreview.getSurfaceTexture());
            } catch (IOException e) {
                Log.e(TAG, "Surface texture is unavailable or unsuitable" + e.getMessage());
                return false;
            }


            mMediaRecorder = new MediaRecorder();

            mCamera.unlock();
            mMediaRecorder.setCamera(mCamera);


            mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
            mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);



            mMediaRecorder.setProfile(profile);

            LocalSocket outSocket = new LocalSocket(LocalSocket.SOCKET_STREAM);
            try {
                outSocket.connect(new LocalSocketAddress("sockt_ip"));
            } catch (Exception e) {
                e.printStackTrace();
            }
            mMediaRecorder.setOutputFile(outSocket.getFileDescriptor());


            mMediaRecorder.prepare();
            mMediaRecorder.start();

【讨论】：

【解决方案2】：

尝试使用new LocalSocket(LocalSocket.SOCKET_STREAM) 而不是new LocalSocket() 创建您的LocalSocket。

如果你没有如上所示设置你的socket类型，LocalSocketImpl，也就是LocalSocket封装的实际系统socket，准确的报错了IllegalStateException，唯一的一个在该类中：

public void create (int sockType) throws IOException {
    // no error if socket already created
    // need this for LocalServerSocket.accept()
    if (fd == null) {
        int osType;
        switch (sockType) {
            case LocalSocket.SOCKET_DGRAM:
                osType = OsConstants.SOCK_DGRAM;
                break;
            case LocalSocket.SOCKET_STREAM:
                osType = OsConstants.SOCK_STREAM;
                break;
            case LocalSocket.SOCKET_SEQPACKET:
                osType = OsConstants.SOCK_SEQPACKET;
                break;
            default:
                throw new IllegalStateException("unknown sockType");
        }
        try {
            fd = Os.socket(OsConstants.AF_UNIX, osType, 0);
            mFdCreatedInternally = true;
        } catch (ErrnoException e) {
            e.rethrowAsIOException();
        }
    }
}

之所以应该是SOCKET_STREAM，是因为LocalServerSocket内部的LocalSocketImpl也使用了该类型。

【讨论】：