Image Capture: set SENSOR_EXPOSURE_TIME when CONTROL_AE_MODE_OFF

media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.media;
 
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.graphics.ImageFormat;
 import android.graphics.Rect;
@@ skipping 361 matching lines @@
             // https://crbug.com/518807.
         }
 
         // |mExposureMode|, |mFillLightMode| and |mTorch| interact to configure the AE and Flash
         // modes. In a nutshell, FLASH_MODE is only effective if the auto-exposure is ON/OFF,
         // otherwise the auto-exposure related flash control (ON_{AUTO,ALWAYS}_FLASH{_REDEYE) takes
         // priority.  |mTorch| mode overrides any previous |mFillLightMode| flash control.
         if (mExposureMode == AndroidMeteringMode.NONE
                 || mExposureMode == AndroidMeteringMode.FIXED) {
             requestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_OFF);
+
+            // We need to configure by hand the exposure time when AE mode is off.  Set it to the
+            // middle of the allowed range. Further tuning will be done via |mIso|.
+            final CameraCharacteristics cameraCharacteristics =
+                    getCameraCharacteristics(mContext, mId);
+            Range<Long> range = cameraCharacteristics.get(
+                    CameraCharacteristics.SENSOR_INFO_EXPOSURE_TIME_RANGE);
+            requestBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME,
+                    range.getLower() + (range.getUpper() + range.getLower()) / 2 /* nanoseconds*/);
+
         } else {
             requestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON);
             requestBuilder.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, mAeFpsRange);
         }
         switch (mFillLightMode) {
             case AndroidFillLightMode.OFF:
                 requestBuilder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_OFF);
                 break;
             case AndroidFillLightMode.AUTO:
                 // Setting the AE to CONTROL_AE_MODE_ON_AUTO_FLASH[_REDEYE] overrides FLASH_MODE.
@@ skipping 628 matching lines @@
             return false;
         }
         return true;
     }
 
     @Override
     public void deallocate() {
         Log.d(TAG, "deallocate");
     }
 }