android – 开始视频录制时屏幕闪烁并调整大小

此外,只要调用recorder.start(),我的相机预览显示就会调整大小.我不明白为什么会这样.它使预览失真(一切看起来都是压扁和更宽).

我的问题：如何在开始视频录制时阻止闪烁/暂停？如何防止recorder.start()调整预览显示的大小？

每当启用“视频模式”时,立即调用initRecording().一旦用户按下按钮,就会调用startRecording().最后,再次按下该按钮时,将调用stopRecording().不太重要的是,当切换回“图片模式”时,会调用destroyRecorder().

@Override
public void onResume() {

    super.onResume();

    Camera camera = null;
    try {
        camera = Camera.open();
    }
    catch (Exception E) {
        // Camera isn't available
        Toast.makeText( getActivity(),"Camera is not available at this time.",Toast.LENGTH_SHORT ).show();
        getActivity().finish();
        return;
    }

    if ( Build.VERSION.SDK_INT >= Build.VERSION_CODEs.GINGERBREAD ) {
        setCameraDisplayOrientation( camera );
    }
    else {
        camera.setDisplayOrientation( 90 );
    }

    setCamera( camera );
    setCameraZoomDisplay( camera );

    if ( getSurfaceHolder() != null ) {
        startPreview();

        if ( getMode() == MODE_VIDEO ) {
            initRecording();
        }
    }
}

private void setCameraDisplayOrientation( Camera camera ) {

    CameraInfo info = new CameraInfo();
    Camera.getCameraInfo( 0,info );

    int rotation = getActivity().getWindowManager().getDefaultDisplay().getRotation();
    int degrees = 0;
    switch (rotation) {
        case Surface.ROTATION_0:
            degrees = 0;
            break;
        case Surface.ROTATION_90:
            degrees = 90;
            break;
        case Surface.ROTATION_180:
            degrees = 180;
            break;
        case Surface.ROTATION_270:
            degrees = 270;
            break;
    }

    int result = ( info.orientation - degrees + 360 ) % 360;
    camera.setDisplayOrientation( result );
}

private void initRecording() {

    MediaRecorder recorder = new MediaRecorder();
    setRecorder( recorder );

    Camera camera = getCamera();
    camera.unlock();
    recorder.setCamera( camera );

    recorder.setAudiosource( MediaRecorder.Audiosource.MIC );
    recorder.setVideosource( MediaRecorder.Videosource.CAMERa );

    CamcorderProfile cp = CamcorderProfile.get( CamcorderProfile.QUALITY_HIGH );
    recorder.setProfile( cp );

    String extension;
    switch (cp.fileFormat) {
        case MediaRecorder.outputFormat.MPEG_4:
            extension = "mp4";
            break;
        case MediaRecorder.outputFormat.THREE_GPP:
            extension = "3gp";
            break;
        default:
            extension = "tmp";
    }

    setVideoMimeType( MimeTypeMap.getSingleton().getMimeTypeFromExtension( extension ) );

    File toFile = new File( getActivity().getCacheDir(),"tempvideo.tmp" );
    if ( toFile.exists() ) {
        toFile.delete();
    }
    setTempFile( toFile );

    recorder.setOutputFile( toFile.getPath() );
    recorder.setPreviewDisplay( getSurfaceHolder().getSurface() );

    try {
        recorder.prepare();
        setRecorderInitialized( true );
    }
    catch (IllegalStateException E) {
        e.printStackTrace();
    }
    catch (IOException E) {
        e.printStackTrace();
    }
}

private Boolean startRecording() {

    try {
        getRecorder().start();
        setRecording( true );

        ImageView actionImageView = getActionImageView();
        actionImageView.setImageresource( R.drawable.record_red );
    }
    catch (Exception E) {
        getCamera().lock();
    }

    return true;
}

private void stopRecording() {

    MediaRecorder recorder = getRecorder();
    if ( recorder != null && isRecording() ) {
        recorder.stop();
        setRecording( false );
        setRecorderInitialized( false );

        try {
            insertVideo();
        }
        catch (IOException E) {
            e.printStackTrace();
        }

        initRecording();

        ImageView actionImageView = getActionImageView();
        actionImageView.setImageresource( R.drawable.record_green );
    }
}

private void destroyRecorder() {

    MediaRecorder recorder = getRecorder();
    recorder.release();
    setRecorder( null );
    getCamera().lock();
}