Question

我的问题很简单：

如何以1：1的比例获得Android android.hardware.Camera2并且不像Instagram那样变形？

我使用GoogeSamples项目android-Camera2Basic进行了测试。但是当我以1：1的比例更改预览时，图像会变形。有没有人对此有所了解？

Answer 1

感谢@CommonsWare。

我使用负边距（顶部和底部）跟随你的建议并且它有效。

为此，我只是以这种方式更新AutoFitTextureView GoogeSamples项目android-Camera2Basic：

public class AutoFitTextureView extends TextureView {

    //...
    private boolean mWithMargin = false;

    //...

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        int margin = (height - width) / 2;

        if(!mWithMargin) {
            mWithMargin = true;
            ViewGroup.MarginLayoutParams margins = ViewGroup.MarginLayoutParams.class.cast(getLayoutParams());
            margins.topMargin = -margin;
            margins.bottomMargin = -margin;
            margins.leftMargin = 0;
            margins.rightMargin = 0;
            setLayoutParams(margins);
        }

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

Answer 2

像这样创建自定义纹理视图：

public class AutoFitTextureView extends TextureView {

    private int mCameraWidth = 0;
    private int mCameraHeight = 0;
    private boolean mSquarePreview = false;

    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);
    }

    public void setAspectRatio(int width, int height, boolean squarePreview) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Size cannot be negative.");
        }
        mCameraWidth = width;
        mCameraHeight = height;
        mSquarePreview = squarePreview;
        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 == mCameraWidth || 0 == mCameraHeight) {
            setMeasuredDimension(width, height);
        } else {
            /**
             * Vertical orientation
             */
            if (width < height) {
                if (mSquarePreview) {
                    setTransform(squareTransform(width, height));
                    setMeasuredDimension(width, width);
                } else {
                    setMeasuredDimension(width, width * mCameraHeight / mCameraWidth);
                }
            }
            /**
             * Horizontal orientation
             */
            else {
                if (mSquarePreview) {
                    setTransform(squareTransform(width, height));
                    setMeasuredDimension(height, height);
                } else {
                    setMeasuredDimension(height * mCameraWidth / mCameraHeight, height);
                }
            }
        }
    }

    private Matrix setupTransform(int sw, int sh, int dw, int dh) {
        Matrix matrix = new Matrix();
        RectF src = new RectF(0, 0, sw, sh);
        RectF dst = new RectF(0, 0, dw, dh);
        RectF screen = new RectF(0, 0, dw, dh);

        matrix.postRotate(-90, screen.centerX(), screen.centerY());
        matrix.mapRect(dst);

        matrix.setRectToRect(src, dst, Matrix.ScaleToFit.CENTER);
        matrix.mapRect(src);

        matrix.setRectToRect(screen, src, Matrix.ScaleToFit.FILL);
        matrix.postRotate(-90, screen.centerX(), screen.centerY());

        return matrix;
    }

    private Matrix squareTransform(int viewWidth, int viewHeight) {
        Matrix matrix = new Matrix();

        if (viewWidth < viewHeight) {
            MyLogger.log(AutoFitTextureView.class, "Horizontal");
            matrix.setScale(1, (float) mCameraHeight / (float) mCameraWidth, viewWidth / 2, viewHeight / 2);
        } else {
            MyLogger.log(AutoFitTextureView.class, "Vertical");
            matrix.setScale((float) mCameraHeight / (float) mCameraWidth, 1, viewWidth / 2, viewHeight / 2);
        }

        return matrix;
    }
}

为activity / fragment中的纹理视图调用setAspectRatio。

if (mVideoSize.width > mVideoSize.height) {
    mTextureView.setAspectRatio(mVideoSize.height, mVideoSize.width, true);
} else {
    mTextureView.setAspectRatio(mVideoSize.width, mVideoSize.height, true);
}
mCamera.setPreviewTexture(mTextureView.getSurfaceTexture());
mCamera.startPreview();

Answer 3

我用布局做到了这一点，谷歌代码可以保持原样，并根据用户界面自动设置1：1预览。

    <android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_above="@id/footer"
    android:layout_below="@id/header">

    <com.example.android.camera2video.AutoFitTextureView
        android:id="@+id/texture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintDimensionRatio="w,1:1"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        />

</android.support.constraint.ConstraintLayout>

将AutoFitTextureView放入ConstraintLayout然后

previewSize = chooseOptimalSize(map.getOutputSizes(SurfaceTexture.class), width, height, videoSize); 做所有的魔法

Answer 4

对于寻找此内容的任何人，我都尝试过above answer。添加边距以隐藏Textureview的一部分以使其看起来像正方形，在预览中看起来不错。但是在保存图像时，还应该从输出图像中删除隐藏区域。

一种更简单的解决方案是显示完整的textureview并在其上叠加其他布局以使其看起来像正方形。您可以轻松地从输出中裁剪图像。

您可以找到示例代码here

如何获得像Instagram一样的1：1比例的Android Camera2？

4 个答案: