get duration of (most) mp4 files in the own Java tag reader library, mp3 and...

get duration of (most) mp4 files in the own Java tag reader library, mp3 and others still missing and report zeros

app/src/main/java/de/kromke/andreas/audiotags/TagsBase.java

@@ -80,6 +80,11 @@ public abstract class TagsBase
     public int coverPictureType = 0;                    // 0: none or unknown, 1: jpeg, 2: png
     public int tagType = 0;                             // 0: unknown, 1: ID3v1, 2: ID3v2, 10: MP4, 11: Vorbis
 
+    // duration
+    public int timeScale = 1000;                        // units per second
+    public int durationUnits = -1;                      // number of units, -1: unknown
+    public int durationMs = -1;                         // derived: duration in [ms], -1: unknown
+
     // configuration
     public static final boolean doTrim = true;          // remove leading and trailing spaces
     public static final boolean doEmptyAsNull = true;   // set empty strings as null pointer
@@ -384,6 +389,8 @@ public abstract class TagsBase
      *  "n movement" or
      *  "n/m movement"
      *
+     * also calculate duration in [ms]
+     *
      ***********************************************************************************/
     @SuppressWarnings("WeakerAccess")
     public void combineValues()
@@ -431,6 +438,17 @@ public abstract class TagsBase
         }
 
         values[idCombinedMovement] = result;
+
+        // duration
+
+        if ((durationUnits > 0) && (timeScale > 0))
+        {
+            // convert to ms (needs 64 bit arithmetic)
+            long temp = durationUnits;
+            temp *= 1000;
+            temp /= timeScale;
+            durationMs = (int) temp;    // reduce to 32 bits
+        }
     }
 
 
@@ -686,6 +704,18 @@ public abstract class TagsBase
         {
             Log.d(LOG_TAG, "dump() -- tag type = " + tagType);
         }
+
+        if (durationMs > 0)
+        {
+            int duration_s = durationMs / 1000;       // seconds
+            int duration_min = duration_s / 60;
+            duration_s -= 60 * duration_min;
+            Log.d(LOG_TAG, "dump() -- duration is " + durationMs + " ms (" + duration_min + ":" + duration_s + ")");
+        }
+        else
+        {
+            Log.d(LOG_TAG, "dump() -- (duration is unknown)");
+        }
     }
 
 

app/src/main/java/de/kromke/andreas/audiotags/TagsMp4.java

@@ -197,7 +197,7 @@ public class TagsMp4 extends TagsBase
             return safeSkip(boxPayloadSize);
         }
 
-        // some boxes, called "full boxes", have version and flags
+        // some boxes, called "full boxes", have version and flags (four bytes)
         boolean readVersionAndFlags()
         {
             byte[] v = new byte[4];
@@ -209,8 +209,24 @@ public class TagsMp4 extends TagsBase
             boxPayloadSize = boxSize - bytesRead;
             version = v[0] & 0xff;
             flags = getBigEndianInt3(v, 1);
-            Log.d(LOG_TAG, "Mp4Box::check() : " + levelStr + "    version = " + version + ", flags = " + flags);
-            Log.d(LOG_TAG, "Mp4Box::check() : " + levelStr + "    remaining payload size = " + boxPayloadSize);
+            Log.d(LOG_TAG, "Mp4Box::readVersionAndFlags() : " + levelStr + "    version = " + version + ", flags = " + flags);
+            Log.d(LOG_TAG, "Mp4Box::readVersionAndFlags() : " + levelStr + "    remaining payload size = " + boxPayloadSize);
+            return true;
+        }
+
+        boolean readMovieHeader()
+        {
+            byte[] v = new byte[96];
+            bytesRead += v.length;
+            if (!readBytes(v))
+            {
+                return false;
+            }
+            boxPayloadSize = boxSize - bytesRead;
+            timeScale = getBigEndianInt4(v, 8);
+            durationUnits =  getBigEndianInt4(v, 12);
+            Log.d(LOG_TAG, "Mp4Box::readMovieHeader() : " + levelStr + "    timescale = " + timeScale + ", duration = " + durationUnits);
+            Log.d(LOG_TAG, "Mp4Box::readMovieHeader() : " + levelStr + "    remaining payload size = " + boxPayloadSize);
             return true;
         }
 
@@ -451,12 +467,33 @@ public class TagsMp4 extends TagsBase
                 }
             }
             else
+            if (box.boxType.equals("mvhd"))
+            {
+                // header
+                if (!box.readVersionAndFlags())
+                {
+                    return false;
+                }
+                if (!box.readMovieHeader())
+                {
+                    return false;
+                }
+                // skip remaining payload, if any
+                if (!box.skipPayload())
+                {
+                    res = false;
+                    break;
+                }
+            }
+            else
             if (box.boxType.equals("meta"))
             {
+                // header
                 if (!box.readVersionAndFlags())
                 {
                     return false;
                 }
+                // recursion
                 if (!read_container(box))
                 {
                     return false;

app/src/main/java/de/kromke/andreas/safmediascanner/MyTaggerInterface.java

@@ -72,6 +72,17 @@ public class MyTaggerInterface extends TaggerInterface
             // replace numerical genres with text
             tags.replaceNumericalGenres();
 
+            // calculate duration, if possible
+            int duration;
+            if (tags.durationMs > 0)
+            {
+                duration = tags.durationMs;
+            }
+            else
+            {
+                duration = 0;
+                Log.w(LOG_TAG, "readTagsFromUri() : unknown duration");
+            }
             MusicDatabase.AudioFile af = new MusicDatabase.AudioFile();
             af.id = -1;               // add later
             af.track_no = 1000 * tags.getNumericValue(TagsBase.idDiscNo, 0) + tags.getNumericValue(TagsBase.idTrackNo, 0);
@@ -79,7 +90,7 @@ public class MyTaggerInterface extends TaggerInterface
             af.title = tags.values[TagsBase.idCombinedMovement];    // automatically falls back to title, if necessary
             af.album = tags.values[TagsBase.idAlbum];
             af.album_id = -1;               // add later
-            af.duration = 0;                // add later
+            af.duration = duration;
             af.grouping = tags.values[TagsBase.idGrouping];
             af.subtitle = tags.values[TagsBase.idSubtitle];
             af.composer = tags.values[TagsBase.idComposer];