Android

Question

我一直在尝试使用 com.android.hardware.Camera 软件包拍摄视频。

似乎 MediaRecorder 无法启动。我想通过 Intent Service 拍摄视频（不在屏幕上预览输出）。这是我的 Intent 主要功能。

private     MediaRecorder   mMediaRecorder;
private     Camera          cam = null;
public static boolean       isRecording = false;
public static boolean       isRunning = false;

public void onCreate() {
    cam = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);
    try {
        cam.unlock();
        mMediaRecorder.setCamera(cam);
        cam.lock();
    } catch (Exception e){
        e.fillInStackTrace();
    }
    isRunning = true;
    // Step 2: Set sources
    mMediaRecorder = new MediaRecorder();
    mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
    mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
    mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
    mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
    // Step 4: Set output file
    String fileName = "/sdcard/" + RandomNameGenerator.setSecureFilename(".video");
    mMediaRecorder.setOutputFile(fileName);
    // Step 6: Prepare configured MediaRecorder
    try {
        mMediaRecorder.prepare();
    } catch (IllegalStateException e) {
        Log.d("DEBUG", "IllegalStateException preparing MediaRecorder: " + e.getMessage());
    } catch (IOException e) {
        Log.d("DEBUG", "IOException preparing MediaRecorder: " + e.getMessage());
    }
    isRecording = true;
    Log.d("SERVICE VIDEO", "IS RECORDING");
    try {
        mMediaRecorder.start();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void onDestroy(){
    isRecording = false;
    if (mMediaRecorder != null) {
        mMediaRecorder.reset();   // clear recorder configuration
        mMediaRecorder.release(); // release the recorder object
        mMediaRecorder = null;
        isRunning = false;
    }
}

这是我启动 Intent 时的日志：

E/MediaRecorder: start failed: -22
W/System.err: java.lang.RuntimeException: start failed.
W/System.err:     at android.media.MediaRecorder.start(Native Method)
W/System.err:     at com.example.nathan.def_calc.VideoRecorder.onCreate(VideoRecorder.java:61)
W/System.err:     at android.app.ActivityThread.handleCreateService(ActivityThread.java:3192)
W/System.err:     at android.app.ActivityThread.-wrap5(ActivityThread.java)
W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1568)
W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
W/System.err:     at android.os.Looper.loop(Looper.java:154)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6121)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)

清单中设置了所有必要的权限。我必须在某处声明一种缓冲区吗？我没有在 API 中找到任何关于我们如何创建视频缓冲区的文档。有人有解决办法吗？

Answer 1

好的，我解决了这个问题，明显的问题是我没有任何视频缓冲区。我发现我需要一个 Surface 对应于 Camera 对象的缓冲区。添加 onCreate():

sft = new SurfaceTexture(0);
sf = new Surface(sft);
mMediaRecorder.setPreviewDisplay(sf);

和

sf.release();
sft.release();

在 onDestroy() 函数中成功了。

Android - 拍摄视频错误-22

Android - taking video error -22

android-intent

video-capture