From: Lukáš Lalinský <lalinsky@gmail.com>
Date: Tue, 10 Jan 2012 16:18:20 +0000 (+0100)
Subject: Reverse the version check, similarly to what mp4v2 does
X-Git-Tag: v1.7.2~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cce6ad46c912c4137131c97f67136a3d11881726;p=taglib

Reverse the version check, similarly to what mp4v2 does
---

diff --git a/taglib/mp4/mp4properties.cpp b/taglib/mp4/mp4properties.cpp
index a62bda99..c1f8d47c 100644
--- a/taglib/mp4/mp4properties.cpp
+++ b/taglib/mp4/mp4properties.cpp
@@ -91,15 +91,24 @@ MP4::Properties::Properties(File *file, MP4::Atoms *atoms, ReadStyle style)
 
   file->seek(mdhd->offset);
   data = file->readBlock(mdhd->length);
-  if(data[8] == 0) {
-    unsigned int unit = data.mid(20, 4).toUInt();
-    unsigned int length = data.mid(24, 4).toUInt();
-    d->length = length / unit;
-  }
-  else {
+  uint version = data[8];
+  if(version == 1) {
+    if (data.size() < 36 + 8) {
+      debug("MP4: Atom 'trak.mdia.mdhd' is smaller than expected");
+      return;
+    }
     long long unit = data.mid(28, 8).toLongLong();
     long long length = data.mid(36, 8).toLongLong();
-    d->length = int(length / unit);
+    d->length = unit ? int(length / unit) : 0;
+  }
+  else {
+    if (data.size() < 24 + 4) {
+      debug("MP4: Atom 'trak.mdia.mdhd' is smaller than expected");
+      return;
+    }
+    unsigned int unit = data.mid(20, 4).toUInt();
+    unsigned int length = data.mid(24, 4).toUInt();
+    d->length = unit ? length / unit : 0;
   }
 
   MP4::Atom *atom = trak->find("mdia", "minf", "stbl", "stsd");