Set error on unrecognized top-level BMFF boxes.

media/mp4/box_reader_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "media/mp4/box_reader.h"
 #include "media/mp4/rcheck.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace media {
 namespace mp4 {
 
 static const uint8 kTestBox[] = {
-  // Test box containing three children
-  0x00, 0x00, 0x00, 0x40, 't', 'e', 's', 't',
+  // Test box containing three children. The FourCCs used for these boxes were
+  // chosen arbitrarily.

[acolwell GONE FROM CHROMIUM, 2012/08/02 20:38:18]

Why did these need to change if they are chosen arbitrarily?

[strobe_, 2012/08/02 21:27:50]

They didn't, I was just removing the test variables since they had to leak into
IsValidTopLevelBox() as well as fourccs.h. I can revert that change if you like?

[acolwell GONE FROM CHROMIUM, 2012/08/02 21:40:25]

Yeah. I think it is best to revert this text since it isn't really arbitrary.
Perhaps s/Test box/Test top level box/ would help as well if your test relies on
this.

+  0x00, 0x00, 0x00, 0x40, 's', 'k', 'i', 'p',
   0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
   0xf9, 0x0a, 0x0b, 0x0c, 0xfd, 0x0e, 0x0f, 0x10,
-  // Ordinary child box
-  0x00, 0x00, 0x00, 0x0c,  'c',  'h',  'l',  'd', 0xde, 0xad, 0xbe, 0xef,
-  // Extended-size child box
-  0x00, 0x00, 0x00, 0x01,  'c',  'h',  'l',  'd',
+  // Ordinary (8-byte header) child box
+  0x00, 0x00, 0x00, 0x0c,  'p',  's',  's',  'h', 0xde, 0xad, 0xbe, 0xef,
+  // Extended-size header child box
+  0x00, 0x00, 0x00, 0x01,  'p',  's',  's',  'h',
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14,
   0xfa, 0xce, 0xca, 0xfe,
-  // Empty box
-  0x00, 0x00, 0x00, 0x08,  'm',  'p',  't',  'y',
+  // Empty free box
+  0x00, 0x00, 0x00, 0x08,  'f',  'r',  'e',  'e',
   // Trailing garbage
   0x00 };
 
 struct EmptyBox : Box {

[acolwell GONE FROM CHROMIUM, 2012/08/02 20:38:18]

Rename this and the ones below to match the new 4ccs?

[strobe_, 2012/08/02 21:27:50]

Done.

   virtual bool Parse(BoxReader* reader) OVERRIDE {
     return true;
   }
-  virtual FourCC BoxType() const OVERRIDE { return FOURCC_MPTY; }
+  virtual FourCC BoxType() const OVERRIDE { return FOURCC_FREE; }
 };
 
 struct ChildBox : Box {
   uint32 val;
 
   virtual bool Parse(BoxReader* reader) OVERRIDE {
     return reader->Read4(&val);
   }
-  virtual FourCC BoxType() const OVERRIDE { return FOURCC_CHLD; }
+  virtual FourCC BoxType() const OVERRIDE { return FOURCC_PSSH; }
 };
 
 struct TestBox : Box {
   uint8 a, b;
   uint16 c;
   int32 d;
   int64 e;
 
   std::vector<ChildBox> kids;
   EmptyBox mpty;
 
   virtual bool Parse(BoxReader* reader) OVERRIDE {
     RCHECK(reader->ReadFullBoxHeader() &&
            reader->Read1(&a) &&
            reader->Read1(&b) &&
            reader->Read2(&c) &&
            reader->Read4s(&d) &&
            reader->Read4sInto8s(&e));
     return reader->ScanChildren() &&
            reader->ReadChildren(&kids) &&
            reader->MaybeReadChild(&mpty);
   }
-  virtual FourCC BoxType() const OVERRIDE { return FOURCC_TEST; }
+  virtual FourCC BoxType() const OVERRIDE { return FOURCC_SKIP; }
 
   TestBox();
   ~TestBox();
 };
 
 TestBox::TestBox() {}
 TestBox::~TestBox() {}
 
 class BoxReaderTest : public testing::Test {
  protected:
@@ skipping 50 matching lines @@
       BoxReader::ReadTopLevelBox(&buf[0], buf.size(), &err));
 
   TestBox box;
   EXPECT_FALSE(box.Parse(reader.get()));
 }
 
 TEST_F(BoxReaderTest, WrongFourCCTest) {
   std::vector<uint8> buf = GetBuf();
   bool err;
 
-  // Use an unknown FourCC both on an outer box and an inner one.
+  // Set an unrecognized top-level FourCC.
   buf[5] = 1;
-  buf[28] = 1;
   scoped_ptr<BoxReader> reader(
       BoxReader::ReadTopLevelBox(&buf[0], buf.size(), &err));
-
-  TestBox box;
-  std::vector<ChildBox> kids;
-  // This should still work; the outer box reader doesn't care about the FourCC,
-  // since it assumes you've already examined it before deciding what to parse.
-  EXPECT_TRUE(box.Parse(reader.get()));
-  EXPECT_EQ(0x74017374, reader->type());
-  // Parsing the TestBox should have left the modified inner box unread, which
-  // we collect here.
-  EXPECT_TRUE(reader->ReadAllChildren(&kids));
-  EXPECT_EQ(1u, kids.size());
-  EXPECT_EQ(0xdeadbeef, kids[0].val);
+  EXPECT_FALSE(reader.get());
+  EXPECT_TRUE(err);
 }
 
 TEST_F(BoxReaderTest, ChildrenTest) {
   std::vector<uint8> buf = GetBuf();
   bool err;
   scoped_ptr<BoxReader> reader(
       BoxReader::ReadTopLevelBox(&buf[0], buf.size(), &err));
 
   EXPECT_TRUE(reader->SkipBytes(16) && reader->ScanChildren());
 
   EmptyBox mpty;
   EXPECT_TRUE(reader->ReadChild(&mpty));
   EXPECT_FALSE(reader->ReadChild(&mpty));
   EXPECT_TRUE(reader->MaybeReadChild(&mpty));
 
   std::vector<ChildBox> kids;
 
   EXPECT_TRUE(reader->ReadAllChildren(&kids));
   EXPECT_EQ(2u, kids.size());
   kids.clear();
   EXPECT_FALSE(reader->ReadChildren(&kids));
   EXPECT_TRUE(reader->MaybeReadChildren(&kids));
 }
 
 }  // namespace mp4
 }  // namespace media