Merge pull request #416 from drewnoakes/mp4-date-refactor

Refactor date processing
drewnoakes · Jul 22, 2019 · 1f15c79 · 1f15c79
2 parents 6ee77ff + 9edcea9
commit 1f15c79
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Showing 7 changed files with 65 additions and 42 deletions.
diff --git a/Source/com/drew/lang/DateUtil.java b/Source/com/drew/lang/DateUtil.java
@@ -1,12 +1,40 @@
+/*
+ * Copyright 2002-2019 Drew Noakes and contributors
+ *
+ *    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.
+ *
+ * More information about this project is available at:
+ *
+ *    https://drewnoakes.com/code/exif/
+ *    https://github.com/drewnoakes/metadata-extractor
+ */
 package com.drew.lang;
 
+import java.util.Date;
+
 /**
  * @author Drew Noakes http://drewnoakes.com
  */
 public class DateUtil
 {
     private static int[] _daysInMonth365 = new int[] {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
+    /**
+     * The offset (in milliseconds) to add to a MP4 date/time integer value to
+     * align with Java's Epoch.
+     */
+    private static final long EPOCH_1_JAN_1904 = -2082844799175L;
+
     public static boolean isValidDate(int year, int month, int day)
     {
         if (year < 1 || year > 9999 || month < 0 || month > 11)
@@ -29,4 +57,9 @@ public static boolean isValidTime(int hours, int minutes, int seconds)
             && minutes >= 0 && minutes < 60
             && seconds >= 0 && seconds < 60;
     }
+
+    public static Date get1Jan1904EpochDate(long seconds)
+    {
+        return new Date((seconds * 1000) + EPOCH_1_JAN_1904);
+    }
 }
diff --git a/Source/com/drew/metadata/mov/QuickTimeMediaHandler.java b/Source/com/drew/metadata/mov/QuickTimeMediaHandler.java
@@ -21,16 +21,15 @@
 package com.drew.metadata.mov;
 
 import com.drew.imaging.quicktime.QuickTimeHandler;
+import com.drew.lang.DateUtil;
 import com.drew.lang.SequentialByteArrayReader;
 import com.drew.lang.SequentialReader;
 import com.drew.lang.annotations.NotNull;
 import com.drew.lang.annotations.Nullable;
 import com.drew.metadata.Metadata;
 import com.drew.metadata.mov.atoms.Atom;
 import com.drew.metadata.mov.media.QuickTimeMediaDirectory;
-import com.drew.metadata.mp4.Mp4Directory;
 import java.io.IOException;
-import java.util.Date;
 
 /**
  * Classes that extend this class should be from the media dat atom types:
@@ -43,15 +42,16 @@ public abstract class QuickTimeMediaHandler<T extends QuickTimeDirectory> extend
     public QuickTimeMediaHandler(Metadata metadata)
     {
         super(metadata);
+
         if (QuickTimeHandlerFactory.HANDLER_PARAM_CREATION_TIME != null && QuickTimeHandlerFactory.HANDLER_PARAM_MODIFICATION_TIME != null) {
             // Get creation/modification times
             directory.setDate(
                 QuickTimeMediaDirectory.TAG_CREATION_TIME,
-                new Date(QuickTimeHandlerFactory.HANDLER_PARAM_CREATION_TIME * 1000 + Mp4Directory.MP4_EPOCH_OFFSET)
+                DateUtil.get1Jan1904EpochDate(QuickTimeHandlerFactory.HANDLER_PARAM_CREATION_TIME)
             );
             directory.setDate(
                 QuickTimeMediaDirectory.TAG_MODIFICATION_TIME,
-                new Date(QuickTimeHandlerFactory.HANDLER_PARAM_MODIFICATION_TIME * 1000 + Mp4Directory.MP4_EPOCH_OFFSET)
+                DateUtil.get1Jan1904EpochDate(QuickTimeHandlerFactory.HANDLER_PARAM_MODIFICATION_TIME)
             );
         }
     }

diff --git a/Source/com/drew/metadata/mov/atoms/MovieHeaderAtom.java b/Source/com/drew/metadata/mov/atoms/MovieHeaderAtom.java
@@ -20,12 +20,11 @@
  */
 package com.drew.metadata.mov.atoms;
 
+import com.drew.lang.DateUtil;
 import com.drew.lang.Rational;
 import com.drew.lang.SequentialReader;
 import com.drew.metadata.mov.QuickTimeDirectory;
-import com.drew.metadata.mp4.Mp4Directory;
 import java.io.IOException;
-import java.util.Date;
 import static com.drew.metadata.mov.QuickTimeDirectory.*;
 
 /**
@@ -35,20 +34,21 @@
  */
 public class MovieHeaderAtom extends FullAtom
 {
-    long creationTime;
-    long modificationTime;
-    long timescale;
-    long duration;
-    int preferredRate;
-    int preferredVolume;
-    int[] matrixStructure;
-    long previewTime;
-    long previewDuration;
-    long posterTime;
-    long selectionTime;
-    long selectionDuration;
-    long currentTime;
-    long nextTrackID;
+    private long creationTime;
+    private long modificationTime;
+    private long timescale;
+    private long duration;
+    private int preferredRate;
+    private int preferredVolume;
+    // TODO this matrix data is not currently used anywhere
+    private int[] matrixStructure;
+    private long previewTime;
+    private long previewDuration;
+    private long posterTime;
+    private long selectionTime;
+    private long selectionDuration;
+    private long currentTime;
+    private long nextTrackID;
 
     public MovieHeaderAtom(SequentialReader reader, Atom atom) throws IOException
     {
@@ -84,22 +84,22 @@ public MovieHeaderAtom(SequentialReader reader, Atom atom) throws IOException
     public void addMetadata(QuickTimeDirectory directory)
     {
         // Get creation/modification times
-        directory.setDate(TAG_CREATION_TIME, new Date(creationTime * 1000 + Mp4Directory.MP4_EPOCH_OFFSET));
-        directory.setDate(TAG_MODIFICATION_TIME, new Date(modificationTime * 1000 + Mp4Directory.MP4_EPOCH_OFFSET));
+        directory.setDate(TAG_CREATION_TIME, DateUtil.get1Jan1904EpochDate(creationTime));
+        directory.setDate(TAG_MODIFICATION_TIME, DateUtil.get1Jan1904EpochDate(modificationTime));
 
         // Get duration and time scale
         directory.setLong(TAG_DURATION, duration);
         directory.setLong(TAG_TIME_SCALE, timescale);
-        directory.setRational(QuickTimeDirectory.TAG_DURATION_SECONDS, new Rational(duration, timescale));
+        directory.setRational(TAG_DURATION_SECONDS, new Rational(duration, timescale));
 
         // Calculate preferred rate fixed point
         double preferredRateInteger = (preferredRate & 0xFFFF0000) >> 16;
-        double preferredRateFraction = (preferredRate & 0x0000FFFF) / Math.pow(2, 4);
+        double preferredRateFraction = (preferredRate & 0x0000FFFF) / 16.0d;
         directory.setDouble(TAG_PREFERRED_RATE, preferredRateInteger + preferredRateFraction);
 
         // Calculate preferred volume fixed point
         double preferredVolumeInteger = (preferredVolume & 0xFF00) >> 8;
-        double preferredVolumeFraction = (preferredVolume & 0x00FF) / Math.pow(2, 2);
+        double preferredVolumeFraction = (preferredVolume & 0x00FF) / 8.0d;
         directory.setDouble(TAG_PREFERRED_VOLUME, preferredVolumeInteger + preferredVolumeFraction);
 
         directory.setLong(TAG_PREVIEW_TIME, previewTime);

diff --git a/Source/com/drew/metadata/mp4/Mp4Directory.java b/Source/com/drew/metadata/mp4/Mp4Directory.java
@@ -50,12 +50,6 @@ public class Mp4Directory extends Directory {
     public static final int TAG_MINOR_VERSION                           = 2;
     public static final int TAG_COMPATIBLE_BRANDS                       = 3;
 
-    /**
-     * The offset (in milliseconds) to add to a MP4 date/time integer value to
-     * align with Java's Epoch
-     */
-    public static final long MP4_EPOCH_OFFSET;
-
     @NotNull
     protected static final HashMap<Integer, String> _tagNameMap = new HashMap<Integer, String>();
 
@@ -82,11 +76,6 @@ public class Mp4Directory extends Directory {
         _tagNameMap.put(TAG_ROTATION, "Rotation");
 
         _tagNameMap.put(TAG_MEDIA_TIME_SCALE, "Media Time Scale");
-
-        // Calculate the difference between the Java Epoch and the MP4 Epoch
-        Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
-        calendar.set(1904, 0, 1, 0, 0, 0); // January 1, 1904  -  Macintosh/MP4/QuickTime Time Epoch
-        MP4_EPOCH_OFFSET = calendar.getTime().getTime();
     }
 
     public Mp4Directory()

diff --git a/Source/com/drew/metadata/mp4/Mp4MediaHandler.java b/Source/com/drew/metadata/mp4/Mp4MediaHandler.java
@@ -21,6 +21,7 @@
 package com.drew.metadata.mp4;
 
 import com.drew.imaging.mp4.Mp4Handler;
+import com.drew.lang.DateUtil;
 import com.drew.lang.SequentialByteArrayReader;
 import com.drew.lang.SequentialReader;
 import com.drew.lang.annotations.NotNull;
@@ -30,7 +31,6 @@
 import com.drew.metadata.mp4.media.Mp4MediaDirectory;
 
 import java.io.IOException;
-import java.util.Date;
 
 public abstract class Mp4MediaHandler<T extends Mp4MediaDirectory> extends Mp4Handler<T>
 {
@@ -41,11 +41,11 @@ public Mp4MediaHandler(Metadata metadata)
             // Get creation/modification times
             directory.setDate(
                 Mp4MediaDirectory.TAG_CREATION_TIME,
-                new Date(Mp4HandlerFactory.HANDLER_PARAM_CREATION_TIME * 1000 + Mp4Directory.MP4_EPOCH_OFFSET)
+                DateUtil.get1Jan1904EpochDate(Mp4HandlerFactory.HANDLER_PARAM_CREATION_TIME)
             );
             directory.setDate(
                 Mp4MediaDirectory.TAG_MODIFICATION_TIME,
-                new Date(Mp4HandlerFactory.HANDLER_PARAM_MODIFICATION_TIME * 1000 + Mp4Directory.MP4_EPOCH_OFFSET)
+                DateUtil.get1Jan1904EpochDate(Mp4HandlerFactory.HANDLER_PARAM_MODIFICATION_TIME)
             );
             directory.setString(Mp4MediaDirectory.TAG_LANGUAGE_CODE, Mp4HandlerFactory.HANDLER_PARAM_LANGUAGE);
         }

diff --git a/Source/com/drew/metadata/mp4/boxes/MovieHeaderBox.java b/Source/com/drew/metadata/mp4/boxes/MovieHeaderBox.java
@@ -20,6 +20,7 @@
  */
 package com.drew.metadata.mp4.boxes;
 
+import com.drew.lang.DateUtil;
 import com.drew.lang.Rational;
 import com.drew.lang.SequentialReader;
 import com.drew.metadata.mp4.Mp4Directory;
@@ -76,8 +77,8 @@ public MovieHeaderBox(SequentialReader reader, Box box) throws IOException
     public void addMetadata(Mp4Directory directory)
     {
         // Get creation/modification times
-        directory.setDate(Mp4Directory.TAG_CREATION_TIME, new Date(creationTime * 1000 + Mp4Directory.MP4_EPOCH_OFFSET));
-        directory.setDate(Mp4Directory.TAG_MODIFICATION_TIME, new Date(modificationTime * 1000 + Mp4Directory.MP4_EPOCH_OFFSET));
+        directory.setDate(Mp4Directory.TAG_CREATION_TIME, DateUtil.get1Jan1904EpochDate(creationTime));
+        directory.setDate(Mp4Directory.TAG_MODIFICATION_TIME, DateUtil.get1Jan1904EpochDate(modificationTime));
 
         // Get duration and time scale
         directory.setLong(Mp4Directory.TAG_DURATION, duration);

diff --git a/metadata-extractor.iml b/metadata-extractor.iml
@@ -4,12 +4,12 @@
     <output url="file://$MODULE_DIR$/Output/maven/classes" />
     <output-test url="file://$MODULE_DIR$/Output/maven/test-classes" />
     <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/Samples" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/Source" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/Tests" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/.idea" />
       <excludeFolder url="file://$MODULE_DIR$/Output/maven" />
       <excludeFolder url="file://$MODULE_DIR$/Releases" />
+      <excludeFolder url="file://$MODULE_DIR$/Samples" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />