Example usage for android.hardware.camera2 CaptureRequest CONTROL_AE_LOCK

List of usage examples for android.hardware.camera2 CaptureRequest CONTROL_AE_LOCK

Introduction

In this page you can find the example usage for android.hardware.camera2 CaptureRequest CONTROL_AE_LOCK.

Prototype

Key CONTROL_AE_LOCK

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Document

Whether auto-exposure (AE) is currently locked to its latest calculated values.

When set to true (ON), the AE algorithm is locked to its latest parameters, and will not change exposure settings until the lock is set to false (OFF).

Note that even when AE is locked, the flash may be fired if the CaptureRequest#CONTROL_AE_MODE android.control.aeMode is ON_AUTO_FLASH / ON_ALWAYS_FLASH / ON_AUTO_FLASH_REDEYE.

When CaptureRequest#CONTROL_AE_EXPOSURE_COMPENSATION android.control.aeExposureCompensation is changed, even if the AE lock is ON, the camera device will still adjust its exposure value.

If AE precapture is triggered (see CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER android.control.aePrecaptureTrigger ) when AE is already locked, the camera device will not change the exposure time ( CaptureRequest#SENSOR_EXPOSURE_TIME android.sensor.exposureTime ) and sensitivity ( CaptureRequest#SENSOR_SENSITIVITY android.sensor.sensitivity ) parameters.

Usage

From source file:com.android.camera2.its.ItsService.java

private void do3A(JSONObject params) throws ItsException {
    try {/*from   www  .j av a2 s .  c om*/
        // Start a 3A action, and wait for it to converge.
        // Get the converged values for each "A", and package into JSON result for caller.

        // 3A happens on full-res frames.
        Size sizes[] = ItsUtils.getYuvOutputSizes(mCameraCharacteristics);
        int widths[] = new int[1];
        int heights[] = new int[1];
        int formats[] = new int[1];
        widths[0] = sizes[0].getWidth();
        heights[0] = sizes[0].getHeight();
        formats[0] = ImageFormat.YUV_420_888;
        int width = widths[0];
        int height = heights[0];

        prepareCaptureReader(widths, heights, formats, 1);
        List<Surface> outputSurfaces = new ArrayList<Surface>(1);
        outputSurfaces.add(mCaptureReaders[0].getSurface());
        BlockingSessionCallback sessionListener = new BlockingSessionCallback();
        mCamera.createCaptureSession(outputSurfaces, sessionListener, mCameraHandler);
        mSession = sessionListener.waitAndGetSession(TIMEOUT_IDLE_MS);

        // Add a listener that just recycles buffers; they aren't saved anywhere.
        ImageReader.OnImageAvailableListener readerListener = createAvailableListenerDropper(mCaptureCallback);
        mCaptureReaders[0].setOnImageAvailableListener(readerListener, mSaveHandlers[0]);

        // Get the user-specified regions for AE, AWB, AF.
        // Note that the user specifies normalized [x,y,w,h], which is converted below
        // to an [x0,y0,x1,y1] region in sensor coords. The capture request region
        // also has a fifth "weight" element: [x0,y0,x1,y1,w].
        MeteringRectangle[] regionAE = new MeteringRectangle[] {
                new MeteringRectangle(0, 0, width, height, 1) };
        MeteringRectangle[] regionAF = new MeteringRectangle[] {
                new MeteringRectangle(0, 0, width, height, 1) };
        MeteringRectangle[] regionAWB = new MeteringRectangle[] {
                new MeteringRectangle(0, 0, width, height, 1) };
        if (params.has(REGION_KEY)) {
            JSONObject regions = params.getJSONObject(REGION_KEY);
            if (regions.has(REGION_AE_KEY)) {
                regionAE = ItsUtils.getJsonWeightedRectsFromArray(regions.getJSONArray(REGION_AE_KEY), true,
                        width, height);
            }
            if (regions.has(REGION_AF_KEY)) {
                regionAF = ItsUtils.getJsonWeightedRectsFromArray(regions.getJSONArray(REGION_AF_KEY), true,
                        width, height);
            }
            if (regions.has(REGION_AWB_KEY)) {
                regionAWB = ItsUtils.getJsonWeightedRectsFromArray(regions.getJSONArray(REGION_AWB_KEY), true,
                        width, height);
            }
        }

        // If AE or AWB lock is specified, then the 3A will converge first and then lock these
        // values, waiting until the HAL has reported that the lock was successful.
        mNeedsLockedAE = params.optBoolean(LOCK_AE_KEY, false);
        mNeedsLockedAWB = params.optBoolean(LOCK_AWB_KEY, false);

        // By default, AE and AF both get triggered, but the user can optionally override this.
        // Also, AF won't get triggered if the lens is fixed-focus.
        boolean doAE = true;
        boolean doAF = true;
        if (params.has(TRIGGER_KEY)) {
            JSONObject triggers = params.getJSONObject(TRIGGER_KEY);
            if (triggers.has(TRIGGER_AE_KEY)) {
                doAE = triggers.getBoolean(TRIGGER_AE_KEY);
            }
            if (triggers.has(TRIGGER_AF_KEY)) {
                doAF = triggers.getBoolean(TRIGGER_AF_KEY);
            }
        }
        if (doAF && mCameraCharacteristics.get(CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE) == 0) {
            // Send a dummy result back for the code that is waiting for this message to see
            // that AF has converged.
            Logt.i(TAG, "Ignoring request for AF on fixed-focus camera");
            mSocketRunnableObj.sendResponse("afResult", "0.0");
            doAF = false;
        }

        mInterlock3A.open();
        mIssuedRequest3A = false;
        mConvergedAE = false;
        mConvergedAWB = false;
        mConvergedAF = false;
        mLockedAE = false;
        mLockedAWB = false;
        long tstart = System.currentTimeMillis();
        boolean triggeredAE = false;
        boolean triggeredAF = false;

        Logt.i(TAG, String.format("Initiating 3A: AE:%d, AF:%d, AWB:1, AELOCK:%d, AWBLOCK:%d", doAE ? 1 : 0,
                doAF ? 1 : 0, mNeedsLockedAE ? 1 : 0, mNeedsLockedAWB ? 1 : 0));

        // Keep issuing capture requests until 3A has converged.
        while (true) {

            // Block until can take the next 3A frame. Only want one outstanding frame
            // at a time, to simplify the logic here.
            if (!mInterlock3A.block(TIMEOUT_3A * 1000)
                    || System.currentTimeMillis() - tstart > TIMEOUT_3A * 1000) {
                throw new ItsException("3A failed to converge (timeout)");
            }
            mInterlock3A.close();

            // If not converged yet, issue another capture request.
            if ((doAE && (!triggeredAE || !mConvergedAE)) || !mConvergedAWB
                    || (doAF && (!triggeredAF || !mConvergedAF)) || (doAE && mNeedsLockedAE && !mLockedAE)
                    || (mNeedsLockedAWB && !mLockedAWB)) {

                // Baseline capture request for 3A.
                CaptureRequest.Builder req = mCamera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
                req.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF);
                req.set(CaptureRequest.CONTROL_MODE, CaptureRequest.CONTROL_MODE_AUTO);
                req.set(CaptureRequest.CONTROL_CAPTURE_INTENT, CaptureRequest.CONTROL_CAPTURE_INTENT_PREVIEW);
                req.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
                req.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, 0);
                req.set(CaptureRequest.CONTROL_AE_LOCK, false);
                req.set(CaptureRequest.CONTROL_AE_REGIONS, regionAE);
                req.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
                req.set(CaptureRequest.CONTROL_AF_REGIONS, regionAF);
                req.set(CaptureRequest.CONTROL_AWB_MODE, CaptureRequest.CONTROL_AWB_MODE_AUTO);
                req.set(CaptureRequest.CONTROL_AWB_LOCK, false);
                req.set(CaptureRequest.CONTROL_AWB_REGIONS, regionAWB);

                if (mConvergedAE && mNeedsLockedAE) {
                    req.set(CaptureRequest.CONTROL_AE_LOCK, true);
                }
                if (mConvergedAWB && mNeedsLockedAWB) {
                    req.set(CaptureRequest.CONTROL_AWB_LOCK, true);
                }

                // Trigger AE first.
                if (doAE && !triggeredAE) {
                    Logt.i(TAG, "Triggering AE");
                    req.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
                            CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);
                    triggeredAE = true;
                }

                // After AE has converged, trigger AF.
                if (doAF && !triggeredAF && (!doAE || (triggeredAE && mConvergedAE))) {
                    Logt.i(TAG, "Triggering AF");
                    req.set(CaptureRequest.CONTROL_AF_TRIGGER, CaptureRequest.CONTROL_AF_TRIGGER_START);
                    triggeredAF = true;
                }

                req.addTarget(mCaptureReaders[0].getSurface());

                mIssuedRequest3A = true;
                mSession.capture(req.build(), mCaptureResultListener, mResultHandler);
            } else {
                mSocketRunnableObj.sendResponse("3aConverged", "");
                Logt.i(TAG, "3A converged");
                break;
            }
        }
    } catch (android.hardware.camera2.CameraAccessException e) {
        throw new ItsException("Access error: ", e);
    } catch (org.json.JSONException e) {
        throw new ItsException("JSON error: ", e);
    } finally {
        mSocketRunnableObj.sendResponse("3aDone", "");
    }
}