android - Camera X 的 AE 锁无法正常工作

Question

我使用 Camera X 并尝试使用 锁定 AF 和 AE FocusMeteringAction，AF 锁定正常但 AE 没有锁定。可能是什么原因？

camerax_version = "1.1.0-alpha02"

val factory: MeteringPointFactory = previewView.meteringPointFactory
val point: MeteringPoint = factory.createPoint(x, y)
val builder = FocusMeteringAction.Builder(point)
builder.disableAutoCancel()
camerax?.cameraControl?.startFocusAndMetering(builder.build())

代码片段很简单，ListenableFuturefromstartFocusAndMetering()返回一个成功的结果，但是AE仍然是动态的并且没有被锁定。

我期待的结果：然后将应用程序指向明亮的东西（例如太阳或强光），然后锁定曝光。然后将相机远离光线，一切都会变得非常黑暗。这表明相机没有自动调整曝光（因为它被锁定）。

我的实际结果是：曝光调整，图片亮/正常。

将不胜感激任何想法！提前致谢！

Answer 1

It's been a long time but this might be helpful to someone may ended up here.

I don't know if it is possible by using only CameraX apis. But I've achieved the expected behaviour with Camera2 apis. With the below snippet, the AF and AE can be measured and updated with a tap and stays locked afterwards until another tap occures.

private void initTapToFocus() {
    previewView.setOnTouchListener((v, event) -> {
        MeteringPointFactory meteringPointFactory = previewView.getMeteringPointFactory();
        MeteringPoint point = meteringPointFactory.createPoint(event.getX(), event.getY());
        FocusMeteringAction action = new FocusMeteringAction
                .Builder(point, FocusMeteringAction.FLAG_AF)
                .addPoint(point, FocusMeteringAction.FLAG_AE)
                .disableAutoCancel()
                .build();

        //Unlock AE before the tap so it can be updated.
        lockAe(false, () -> doFocusAndMetering(action));
        return true;
    });
}

private void doFocusAndMetering(FocusMeteringAction builder) {
    ListenableFuture<FocusMeteringResult> future = cameraControl.startFocusAndMetering(builder);

    //Lock AE again when measuring completed
    future.addListener(() -> lockAe(true, () -> {}), executor);
}


private void lockAe(boolean lockAe, Runnable doWhenComplete) {
    Camera2CameraControl camera2CameraControl = Camera2CameraControl.from(cameraControl);
    CaptureRequestOptions options = new CaptureRequestOptions.Builder()
            .setCaptureRequestOption(CaptureRequest.CONTROL_AE_LOCK, lockAe)
            .build();
    camera2CameraControl.setCaptureRequestOptions(options).addListener(doWhenComplete, executor);
}