1 files changed, 88 insertions, 0 deletions
diff --git a/src/atom_stsc.cpp b/src/atom_stsc.cpp
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--- /dev/null
+++ b/src/atom_stsc.cpp
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+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (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.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is MPEG4IP.
+ *
+ * The Initial Developer of the Original Code is Cisco Systems Inc.
+ * Portions created by Cisco Systems Inc. are
+ * Copyright (C) Cisco Systems Inc. 2001.  All Rights Reserved.
+ *
+ * Contributor(s):
+ *      Dave Mackie     dmackie@cisco.com
+ */
+
+#include "src/impl.h"
+
+namespace mp4v2 {
+namespace impl {
+
+///////////////////////////////////////////////////////////////////////////////
+
+MP4StscAtom::MP4StscAtom()
+        : MP4Atom("stsc")
+{
+    AddVersionAndFlags();
+
+    MP4Integer32Property* pCount =
+        new MP4Integer32Property("entryCount");
+    AddProperty(pCount);
+
+    MP4TableProperty* pTable = new MP4TableProperty("entries", pCount);
+    AddProperty(pTable);
+
+    pTable->AddProperty(
+        new MP4Integer32Property("firstChunk"));
+    pTable->AddProperty(
+        new MP4Integer32Property("samplesPerChunk"));
+    pTable->AddProperty(
+        new MP4Integer32Property("sampleDescriptionIndex"));
+
+    // As an optimization we add an implicit property to this table,
+    // "firstSample" that corresponds to the first sample of the firstChunk
+    MP4Integer32Property* pSample =
+        new MP4Integer32Property("firstSample");
+    pSample->SetImplicit();
+    pTable->AddProperty(pSample);
+}
+
+void MP4StscAtom::Read()
+{
+    // Read as usual
+    MP4Atom::Read();
+
+    // Compute the firstSample values for later use
+    uint32_t count =
+        ((MP4Integer32Property*)m_pProperties[2])->GetValue();
+
+    MP4Integer32Property* pFirstChunk = (MP4Integer32Property*)
+                                        ((MP4TableProperty*)m_pProperties[3])->GetProperty(0);
+    MP4Integer32Property* pSamplesPerChunk = (MP4Integer32Property*)
+            ((MP4TableProperty*)m_pProperties[3])->GetProperty(1);
+    MP4Integer32Property* pFirstSample = (MP4Integer32Property*)
+                                         ((MP4TableProperty*)m_pProperties[3])->GetProperty(3);
+
+    MP4SampleId sampleId = 1;
+
+    for (uint32_t i = 0; i < count; i++) {
+        pFirstSample->SetValue(sampleId, i);
+
+        if (i < count - 1) {
+            sampleId +=
+                (pFirstChunk->GetValue(i+1) - pFirstChunk->GetValue(i))
+                * pSamplesPerChunk->GetValue(i);
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+}
+} // namespace mp4v2::impl