如何设置Android相机2预览和捕捉大小？

Question

我正在使用SurfaceView来显示我捕获的预览。我想使用宽度=1080，高度=1920作为预览。在哪里可以设置预览的大小？

我用谷歌搜索了答案，但它们都是相机版本一的。我正在使用android.hardware.camera2。

private void takePreview() {
    try {
        final CaptureRequest.Builder previewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        previewRequestBuilder.addTarget(mSurfaceHolder.getSurface());
        mCameraDevice.createCaptureSession(Arrays.asList(mSurfaceHolder.getSurface(), mImageReader.getSurface()), new CameraCaptureSession.StateCallback() // ③
        {
            @Override
            public void onConfigured(CameraCaptureSession cameraCaptureSession) {
                if (null == mCameraDevice) return;
                mCameraCaptureSession = cameraCaptureSession;
                try {
                    previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
                    previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_ALWAYS_FLASH);
                    previewRequestBuilder.set(CaptureRequest.JPEG_THUMBNAIL_SIZE, new Size(1080,1920));

                    CaptureRequest previewRequest = previewRequestBuilder.build();
                    mCameraCaptureSession.setRepeatingRequest(previewRequest, null, childHandler);
                } catch (CameraAccessException e) {
                    Log.e("takePreview","onConfigured(CameraCaptureSession cameraCaptureSession)",e);
                }
            }
            @Override
            public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {
                Log.e("takePreview","onConfigureFailed");
            }
        }, childHandler);
    } catch (CameraAccessException e) {
        Log.e("takePreview","CameraAccessException");
    }
}

Answer 1

要设置预览大小：mSurfaceTexture。设置默认缓冲区大小（宽度、高度） 函数中选择code>。

要设置捕获（图片）大小：ImageReader。newInstance（宽度、高度、格式、最大尺寸）

Answer 2

看看Google在GitHub上提供的Camama2Basic示例：https://github.com/googlesamples/android-Camera2Basic

在主片段中有一种方法可以为给定的设备选择最佳预览大小。如果你想让你的应用程序更灵活，而不是硬编码大小，这可能是一个更好的方法，但即使你仍然希望坚持设置大小，你也可以看到他们如何使用结果。

总结是，您只需将TextureView的大小设置为您想要的大小。

方法名称为“chooseOptimalSize”，其中包括以下注释/解释：

/**
     * Given {@code choices} of {@code Size}s supported by a camera, choose the smallest one that
     * is at least as large as the respective texture view size, and that is at most as large as the
     * respective max size, and whose aspect ratio matches with the specified value. If such size
     * doesn't exist, choose the largest one that is at most as large as the respective max size,
     * and whose aspect ratio matches with the specified value.
     *
     * @param choices           The list of sizes that the camera supports for the intended output
     *                          class
     * @param textureViewWidth  The width of the texture view relative to sensor coordinate
     * @param textureViewHeight The height of the texture view relative to sensor coordinate
     * @param maxWidth          The maximum width that can be chosen
     * @param maxHeight         The maximum height that can be chosen
     * @param aspectRatio       The aspect ratio
     * @return The optimal {@code Size}, or an arbitrary one if none were big enough
     */

Answer 3

如对createCapture会话的引用中所述：

对于绘制到SurfaceView：创建SurfaceView的曲面后，使用setFixedSize（int，int）将曲面的大小设置为getOutputSizes（SurfaceHolder.class）返回的大小之一，然后通过调用getSurface（）获取曲面。如果应用程序未设置大小，则相机设备会将其舍入到最近支持的小于1080p的大小。