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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.camera.util;
import android.hardware.camera2.CaptureResult;
import android.location.Location;
import android.os.Build;
import com.android.camera.debug.DebugPropertyHelper;
import com.android.camera.exif.ExifInterface;
import com.android.camera.exif.Rational;
import com.android.camera.one.v2.camera2proxy.CaptureResultProxy;
import com.android.camera.processing.imagebackend.TaskImageContainer;
import com.google.common.base.Optional;
import java.text.DecimalFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
/**
* Exif utility functions.
*/
public class ExifUtil {
private static final double LOG_2 = Math.log(2); // natural log of 2
private final ExifInterface mExif;
/**
* Construct a new ExifUtil object.
* @param exif The EXIF object to populate.
*/
public ExifUtil(ExifInterface exif) {
mExif = exif;
}
/**
* Populate the EXIF object with info pulled from a given capture result.
*
* @param image A {@link TaskImageContainer.TaskImage} from which to extract info from.
* @param captureResult A {@link CaptureResultProxy} from which to extract info from.
* @param location optionally a location that should be added to the EXIF.
*/
public void populateExif(Optional<TaskImageContainer.TaskImage> image,
Optional<CaptureResultProxy> captureResult,
Optional<Location> location) {
addExifVersionToExif();
addTimestampToExif();
addMakeAndModelToExif();
if (image.isPresent()) {
addImageDataToExif(image.get());
}
if (captureResult.isPresent()) {
addCaptureResultToExif(captureResult.get());
}
if (location.isPresent()) {
addLocationToExif(location.get());
}
}
/**
* Adds the given location to the EXIF object.
*
* @param location The location to add.
*/
public void addLocationToExif(Location location) {
final Long ALTITUDE_PRECISION = 1L; // GPS altitude isn't particularly accurate (determined empirically)
mExif.addGpsTags(location.getLatitude(), location.getLongitude());
mExif.addGpsDateTimeStampTag(location.getTime());
if (location.hasAltitude()) {
double altitude = location.getAltitude();
addExifTag(ExifInterface.TAG_GPS_ALTITUDE, rational(altitude, ALTITUDE_PRECISION));
short altitudeRef = altitude < 0 ? ExifInterface.GpsAltitudeRef.SEA_LEVEL_NEGATIVE
: ExifInterface.GpsAltitudeRef.SEA_LEVEL;
addExifTag(ExifInterface.TAG_GPS_ALTITUDE_REF, altitudeRef);
}
}
private void addExifVersionToExif() {
addExifTag(ExifInterface.TAG_EXIF_VERSION, ExifInterface.EXIF_VERSION);
}
private void addTimestampToExif() {
final Long MS_TO_S = 1000L; // Milliseconds per second
final String subSecondFormat = "000";
Long timestampMs = System.currentTimeMillis();
TimeZone timezone = Calendar.getInstance().getTimeZone();
mExif.addDateTimeStampTag(ExifInterface.TAG_DATE_TIME, timestampMs, timezone);
mExif.addDateTimeStampTag(ExifInterface.TAG_DATE_TIME_DIGITIZED, timestampMs, timezone);
mExif.addDateTimeStampTag(ExifInterface.TAG_DATE_TIME_ORIGINAL, timestampMs, timezone);
Long subSeconds = timestampMs % MS_TO_S;
String subSecondsString = new DecimalFormat(subSecondFormat).format(subSeconds);
addExifTag(ExifInterface.TAG_SUB_SEC_TIME, subSecondsString);
addExifTag(ExifInterface.TAG_SUB_SEC_TIME_ORIGINAL, subSecondsString);
addExifTag(ExifInterface.TAG_SUB_SEC_TIME_DIGITIZED, subSecondsString);
}
private void addMakeAndModelToExif() {
if (DebugPropertyHelper.isRedactExifEnabled()) {
addExifTag(ExifInterface.TAG_MAKE, "CAM_YY");
addExifTag(ExifInterface.TAG_MODEL, "CAM_XX");
} else {
addExifTag(ExifInterface.TAG_MAKE, Build.MANUFACTURER);
addExifTag(ExifInterface.TAG_MODEL, Build.MODEL);
}
}
private void addImageDataToExif(TaskImageContainer.TaskImage image) {
mExif.setTag(mExif.buildTag(ExifInterface.TAG_PIXEL_X_DIMENSION, image.width));
mExif.setTag(mExif.buildTag(ExifInterface.TAG_PIXEL_Y_DIMENSION, image.height));
mExif.setTag(mExif.buildTag(ExifInterface.TAG_IMAGE_WIDTH, image.width));
mExif.setTag(mExif.buildTag(ExifInterface.TAG_IMAGE_LENGTH, image.height));
mExif.setTag(mExif.buildTag(ExifInterface.TAG_ORIENTATION,
ExifInterface.getOrientationValueForRotation(image.orientation.getDegrees())));
}
private void addCaptureResultToExif(CaptureResultProxy result) {
final Long NS_TO_S = 1000000000L; // Nanoseconds per second
final Long SHUTTER_SPEED_VALUE_PRECISION = 1000L;
final Long F_NUMBER_PRECISION = 100L;
final Long APERTURE_VALUE_PRECISION = 100L;
final Long FOCAL_LENGTH_PRECISION = 1000L; // micrometer precision
// Exposure time
Long exposureTimeNs = result.get(CaptureResult.SENSOR_EXPOSURE_TIME);
addExifTag(ExifInterface.TAG_EXPOSURE_TIME, ratio(exposureTimeNs, NS_TO_S));
// Shutter speed value (APEX unit, see Jeita EXIF 2.2 spec Annex C).
if (exposureTimeNs != null) {
Double exposureTime = (double) exposureTimeNs / NS_TO_S;
Double shutterSpeedValue = -log2(exposureTime);
addExifTag(ExifInterface.TAG_SHUTTER_SPEED_VALUE, rational(shutterSpeedValue, SHUTTER_SPEED_VALUE_PRECISION));
}
// ISO
addExifTag(ExifInterface.TAG_ISO_SPEED_RATINGS, result.get(CaptureResult.SENSOR_SENSITIVITY));
// F-stop number
Float fNumber = result.get(CaptureResult.LENS_APERTURE);
addExifTag(ExifInterface.TAG_F_NUMBER, rational(fNumber, F_NUMBER_PRECISION));
// Aperture value (APEX unit, see Jeita EXIF 2.2 spec Annex C).
if (fNumber != null) {
Double apertureValue = 2 * log2(fNumber);
addExifTag(ExifInterface.TAG_APERTURE_VALUE, rational(apertureValue, APERTURE_VALUE_PRECISION));
}
// Focal length
Float focalLength = result.get(CaptureResult.LENS_FOCAL_LENGTH);
addExifTag(ExifInterface.TAG_FOCAL_LENGTH, rational(focalLength, FOCAL_LENGTH_PRECISION));
// Flash mode
Integer flashMode = result.get(CaptureResult.FLASH_MODE);
if (flashMode == CaptureResult.FLASH_MODE_OFF) {
addExifTag(ExifInterface.TAG_FLASH, ExifInterface.Flash.DID_NOT_FIRE);
} else {
addExifTag(ExifInterface.TAG_FLASH, ExifInterface.Flash.FIRED);
}
// White balance
Integer whiteBalanceMode = result.get(CaptureResult.CONTROL_AWB_MODE);
if (whiteBalanceMode == CaptureResult.CONTROL_AWB_MODE_OFF) {
addExifTag(ExifInterface.TAG_WHITE_BALANCE, ExifInterface.WhiteBalance.MANUAL);
} else {
addExifTag(ExifInterface.TAG_WHITE_BALANCE, ExifInterface.WhiteBalance.AUTO);
}
}
private void addExifTag(int tagId, Object val) {
if (val != null) {
mExif.setTag(mExif.buildTag(tagId, val));
}
}
private Rational ratio(Long numerator, Long denominator) {
if (numerator != null && denominator != null) {
return new Rational(numerator, denominator);
}
return null;
}
private Rational rational(Float value, Long precision) {
if (value != null && precision != null) {
return new Rational((long) (value * precision), precision);
}
return null;
}
private Rational rational(Double value, Long precision) {
if (value != null && precision != null) {
return new Rational((long) (value * precision), precision);
}
return null;
}
private Double log2(Float value) {
if (value != null) {
return Math.log(value) / LOG_2;
}
return null;
}
private Double log2(Double value) {
if (value != null) {
return Math.log(value) / LOG_2;
}
return null;
}
}
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