1 files changed, 150 insertions, 0 deletions
diff --git a/isoparser/src/main/java/com/coremedia/iso/boxes/CompositionTimeToSample.java b/isoparser/src/main/java/com/coremedia/iso/boxes/CompositionTimeToSample.java
new file mode 100644
index 0000000..411bfe9
--- /dev/null
+++ b/isoparser/src/main/java/com/coremedia/iso/boxes/CompositionTimeToSample.java
@@ -0,0 +1,150 @@
+package com.coremedia.iso.boxes;
+
+import com.coremedia.iso.IsoTypeReader;
+import com.coremedia.iso.IsoTypeWriter;
+import com.googlecode.mp4parser.AbstractFullBox;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static com.googlecode.mp4parser.util.CastUtils.l2i;
+
+/**
+ * <pre>
+ * aligned(8) class CompositionOffsetBox
+ * extends FullBox(‘ctts’, version = 0, 0) {
+ *  unsigned int(32) entry_count;
+ *  int i;
+ *  if (version==0) {
+ *   for (i=0; i < entry_count; i++) {
+ *    unsigned int(32) sample_count;
+ *    unsigned int(32) sample_offset;
+ *   }
+ *  }
+ *  else if (version == 1) {
+ *   for (i=0; i < entry_count; i++) {
+ *    unsigned int(32) sample_count;
+ *    signed int(32) sample_offset;
+ *   }
+ *  }
+ * }
+ * </pre>
+ * <p/>
+ * This box provides the offset between decoding time and composition time.
+ * In version 0 of this box the decoding time must be less than the composition time, and
+ * the offsets are expressed as unsigned numbers such that
+ * CT(n) = DT(n) + CTTS(n) where CTTS(n) is the (uncompressed) table entry for sample n.
+ * <p/>
+ * In version 1 of this box, the composition timeline and the decoding timeline are
+ * still derived from each other, but the offsets are signed.
+ * It is recommended that for the computed composition timestamps, there is
+ * exactly one with the value 0 (zero).
+ */
+public class CompositionTimeToSample extends AbstractFullBox {
+    public static final String TYPE = "ctts";
+
+    List<Entry> entries = Collections.emptyList();
+
+    public CompositionTimeToSample() {
+        super(TYPE);
+    }
+
+    protected long getContentSize() {
+        return 8 + 8 * entries.size();
+    }
+
+    public List<Entry> getEntries() {
+        return entries;
+    }
+
+    public void setEntries(List<Entry> entries) {
+        this.entries = entries;
+    }
+
+    @Override
+    public void _parseDetails(ByteBuffer content) {
+        parseVersionAndFlags(content);
+        int numberOfEntries = l2i(IsoTypeReader.readUInt32(content));
+        entries = new ArrayList<Entry>(numberOfEntries);
+        for (int i = 0; i < numberOfEntries; i++) {
+            Entry e = new Entry(l2i(IsoTypeReader.readUInt32(content)), content.getInt());
+            entries.add(e);
+        }
+    }
+
+    @Override
+    protected void getContent(ByteBuffer byteBuffer) {
+        writeVersionAndFlags(byteBuffer);
+        IsoTypeWriter.writeUInt32(byteBuffer, entries.size());
+
+        for (Entry entry : entries) {
+            IsoTypeWriter.writeUInt32(byteBuffer, entry.getCount());
+            byteBuffer.putInt(entry.getOffset());
+        }
+
+    }
+
+
+    public static class Entry {
+        int count;
+        int offset;
+
+        public Entry(int count, int offset) {
+            this.count = count;
+            this.offset = offset;
+        }
+
+        public int getCount() {
+            return count;
+        }
+
+        public int getOffset() {
+            return offset;
+        }
+
+        public void setCount(int count) {
+            this.count = count;
+        }
+
+        public void setOffset(int offset) {
+            this.offset = offset;
+        }
+
+        @Override
+        public String toString() {
+            return "Entry{" +
+                    "count=" + count +
+                    ", offset=" + offset +
+                    '}';
+        }
+    }
+
+
+    /**
+     * Decompresses the list of entries and returns the list of composition times.
+     *
+     * @return decoding time per sample
+     */
+    public static int[] blowupCompositionTimes(List<CompositionTimeToSample.Entry> entries) {
+        long numOfSamples = 0;
+        for (CompositionTimeToSample.Entry entry : entries) {
+            numOfSamples += entry.getCount();
+        }
+        assert numOfSamples <= Integer.MAX_VALUE;
+        int[] decodingTime = new int[(int) numOfSamples];
+
+        int current = 0;
+
+
+        for (CompositionTimeToSample.Entry entry : entries) {
+            for (int i = 0; i < entry.getCount(); i++) {
+                decodingTime[current++] = entry.getOffset();
+            }
+        }
+
+        return decodingTime;
+    }
+
+}