Android相机 – 录制视频时预览放大

我一直试图弄清楚一段时间,但由于某种原因,当我开始使用相机录制视频时,预览放大.我从以下示例中获取以下代码：

@Override
public void surfaceChanged(SurfaceHolder holder,int format,int width,int height) {
    Camera.Parameters myParameters = mCamera.getParameters();
    List<Camera.Size> sizes = myParameters.getSupportedPreviewSizes();
    Camera.Size myBestSize = getBestPreviewSize(sizes,width,height);

    if (myBestSize != null) {
        myParameters.setPreviewSize(myBestSize.width,myBestSize.height);
        myParameters.setVideoStabilization(false);
        mCamera.setParameters(myParameters);
        mCamera.startPreview();
        mCamera.unlock();
    }
}

private Camera.Size getBestPreviewSize(List<Camera.Size> sizes,int height) {
    final double ASPECT_TOLERANCE = 0.05;
    double targetRatio = (double) width / height;

    if (sizes == null) return null;

    Camera.Size optimalSize = null;

    double minDiff = Double.MAX_VALUE;

    int targetHeight = height;

    // Find size
    for (Camera.Size size : sizes) {
        double ratio = (double) size.width / size.height;
        if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
        if (Math.abs(size.height - targetHeight) < minDiff) {
            optimalSize = size;
            minDiff = Math.abs(size.height - targetHeight);
        }
    }

    if (optimalSize == null) {
        minDiff = Double.MAX_VALUE;
        for (Camera.Size size : sizes) {
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
    }
    return optimalSize;
}

但录制视频时,预览仍会放大.我尝试手动将预览大小设置为1280×720,但是它在我测试的所有设备上都不起作用,有些显示黑色的SurfaceView.

录制视频时有什么办法阻止预览放大吗？ StackOverflow中的这些解决方案都不会似乎有效.

编辑：我尝试使用自己的onMesaure方法创建了一个自定义的SurfaceView,但是当我启动MediaRecorder时,我收到一个-19错误. (不顾赏金中的-16)

解决方法

我对您所谈论的缩放类型感到困惑,可能是一个软件缩放,或者可能是自动对焦,所以我会提出不同的潜在提示,导致最终的解决方案：

>实现mCamera.setZoomchangelistener,例如：

mCamera.setZoomchangelistener(new Camera.OnZoomchangelistener() {
    @Override public void onZoomChange(int i,boolean b,Camera camera) {
        Log.e("StackOverflow","Zoom just changed !");
        // Inspect things from here
    }
});

>禁用平滑缩放：

mCamera.stopSmoothZoom(); // My device doesn't support it,but maybe your device does

>检查所有的相机Camera.Parameters：

Log.e("StackOverflow","All Camera parameters :");
for(String s : mCamera.getParameters().flatten().split(";"))
    Log.e("StackOverflow",s + "\n");

>然后切换可以缩放相关的任何东西,例如：

Camera.Parameters parameters = mCamera.getParameters();
parameters.setZoom(100); // My device support some values in the range 100 | 400
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_INFINITY);
parameters.setVideoStabilization(false);

// Don't forget to add the new parameters to the camera :
mCamera.setParameters(parameters);

问候