使用 Android camera2 获取全屏预览

Question

我正在使用新的 camera2 API 构建自定义相机。我的代码基于 Google here 提供的代码示例。

我找不到全屏预览相机的方法。在代码示例中，他们使用比例优化来适应所有屏幕，但只占用屏幕高度的 3/4 左右。

这是我的AutoFitTextureView 代码：

public class AutoFitTextureView extends TextureView {

private int mRatioWidth = 0;
private int mRatioHeight = 0;

public AutoFitTextureView(Context context) {
    this(context, null);
}

public AutoFitTextureView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

public AutoFitTextureView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}

/**
 * Sets the aspect ratio for this view. The size of the view will be measured based on the ratio
 * calculated from the parameters. Note that the actual sizes of parameters don't matter, that
 * is, calling setAspectRatio(2, 3) and setAspectRatio(4, 6) make the same result.
 *
 * @param width  Relative horizontal size
 * @param height Relative vertical size
 */
public void setAspectRatio(int width, int height) {
    if (width < 0 || height < 0) {
        throw new IllegalArgumentException("Size cannot be negative.");
    }
    mRatioWidth = width;
    mRatioHeight = height;
    requestLayout();
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    int width = MeasureSpec.getSize(widthMeasureSpec);
    int height = MeasureSpec.getSize(heightMeasureSpec);

    if (0 == mRatioWidth || 0 == mRatioHeight) {
        setMeasuredDimension(width, height);
    } else {
        if (width < height * mRatioWidth / mRatioHeight) {
            setMeasuredDimension(width, width * mRatioHeight / mRatioWidth);
        } else {
            setMeasuredDimension(height * mRatioWidth / mRatioHeight, height);
        }
    }
}

}

非常感谢您的帮助。

Answer 1

您应该更改测量的宽度和高度以覆盖全屏，而不是像下面那样适合屏幕。

发件人：

if (width < height * mRatioWidth / mRatioHeight) 

到

if (width > height * mRatioWidth / mRatioHeight)

对我来说效果很好。

Answer 2

这是您问题的解决方案。在这个line 中，纵横比设置为 3/4。我更改了 chooseVideSize 方法来为 MediaRecorder 选择具有高清分辨率的视频大小。

    private static Size chooseVideoSize(Size[] choices) {
        for (Size size : choices) {
            // Note that it will pick only HD video size, you should create more robust solution depending on screen size and available video sizes
            if (1920 == size.getWidth() && 1080 == size.getHeight()) {
                return size;
            }
        }
        Log.e(TAG, "Couldn't find any suitable video size");
        return choices[choices.length - 1];
    }

然后我更正this method 以根据视频大小纵横比选择预览大小，下面是结果。

private static Size chooseOptimalSize(Size[] choices, int width, int height, Size aspectRatio) {
    // Collect the supported resolutions that are at least as big as the preview Surface
    List<Size> bigEnough = new ArrayList<Size>();
    int w = aspectRatio.getWidth();
    int h = aspectRatio.getHeight();
    double ratio = (double) h / w;
    for (Size option : choices) {
        double optionRatio = (double) option.getHeight() / option.getWidth();
        if (ratio == optionRatio) {
            bigEnough.add(option);
        }
    }

    // Pick the smallest of those, assuming we found any
    if (bigEnough.size() > 0) {
        return Collections.min(bigEnough, new CompareSizesByArea());
    } else {
        Log.e(TAG, "Couldn't find any suitable preview size");
        return choices[1];
    }
}

希望对你有帮助！