Home | History | Annotate | Download | only in builder 
      1 /*
      2  * Copyright 2012 Sebastian Annies, Hamburg
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the License);
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an AS IS BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.googlecode.mp4parser.authoring.builder;
     17 
     18 import com.coremedia.iso.boxes.TimeToSampleBox;
     19 import com.googlecode.mp4parser.authoring.Movie;
     20 import com.googlecode.mp4parser.authoring.Track;
     21 
     22 import java.util.Arrays;
     23 import java.util.List;
     24 
     25 /**
     26  * This <code>FragmentIntersectionFinder</code> cuts the input movie in 2 second
     27  * snippets.
     28  */
     29 public class TwoSecondIntersectionFinder implements FragmentIntersectionFinder {
     30 
     31     protected long getDuration(Track track) {
     32         long duration = 0;
     33         for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) {
     34             duration += entry.getCount() * entry.getDelta();
     35         }
     36         return duration;
     37     }
     38 
     39     /**
     40      * {@inheritDoc}
     41      */
     42     public long[] sampleNumbers(Track track, Movie movie) {
     43         List<TimeToSampleBox.Entry> entries = track.getDecodingTimeEntries();
     44 
     45         double trackLength = 0;
     46         for (Track thisTrack : movie.getTracks()) {
     47             double thisTracksLength = getDuration(thisTrack) / thisTrack.getTrackMetaData().getTimescale();
     48             if (trackLength < thisTracksLength) {
     49                 trackLength = thisTracksLength;
     50             }
     51         }
     52 
     53         int fragmentCount = (int)Math.ceil(trackLength / 2) - 1;
     54         if (fragmentCount < 1) {
     55             fragmentCount = 1;
     56         }
     57 
     58         long fragments[] = new long[fragmentCount];
     59         Arrays.fill(fragments, -1);
     60         fragments[0] = 1;
     61 
     62         long time = 0;
     63         int samples = 0;
     64         for (TimeToSampleBox.Entry entry : entries) {
     65             for (int i = 0; i < entry.getCount(); i++) {
     66                 int currentFragment = (int) (time / track.getTrackMetaData().getTimescale() / 2) + 1;
     67                 if (currentFragment >= fragments.length) {
     68                     break;
     69                 }
     70                 fragments[currentFragment] = samples++ + 1;
     71                 time += entry.getDelta();
     72             }
     73         }
     74         long last = samples + 1;
     75         // fill all -1 ones.
     76         for (int i = fragments.length - 1; i >= 0; i--) {
     77             if (fragments[i] == -1) {
     78                 fragments[i] = last ;
     79             }
     80             last = fragments[i];
     81         }
     82         return fragments;
     83 
     84     }
     85 
     86 }
     87