Simple PMP reader to parse Picasa's metadata

webkit/fileapi/media/picasa/pmp_constants.h

Index: webkit/fileapi/media/picasa/pmp_constants.h
diff --git a/webkit/fileapi/media/picasa/pmp_constants.h b/webkit/fileapi/media/picasa/pmp_constants.h
new file mode 100644
index 0000000000000000000000000000000000000000..47fc9cae9599a2c7b741a271897341c066605353
--- /dev/null
+++ b/webkit/fileapi/media/picasa/pmp_constants.h
@@ -0,0 +1,70 @@
+// Copyright 2013 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.
+
+#ifndef WEBKIT_FILEAPI_MEDIA_PICASA_PMP_CONSTANTS_H_
+#define WEBKIT_FILEAPI_MEDIA_PICASA_PMP_CONSTANTS_H_
+
+#include "base/basictypes.h"
+
+namespace fileapi {
+
+// PMP file format.
+// Info derived from: http://sbktech.blogspot.com/2011/12/picasa-pmp-format.html
+
+// values look "flipped" because serialized as little-endian
+
+// Total header size: 4+2+2+4+2+2+4 = 20 bytes
+const size_t kPmpHeaderSize = 20;
+
+// [0]  - 4 Bytes - cd cc cc 3f
+const uint8 kPmpMagicO0S4[] = { 0xcd, 0xcc, 0xcc, 0x3f };

[vandebo (ex-Chrome), 2013/03/27 00:06:19]

The 00S4 nomenclature isn't like anything else I've seen in Chrome.

I think you just want something like this:

const int kPmpMagic1Offset = 0
const int kPmpFieldTypeOffset = 4
const int kPmpMagic2Offset = 6
...

const uint32 kPmpMagic1 = 0xCDCCCC3F;
const uint16 kPmpMagic2 = 0x3213
...

[tommycli, 2013/03/27 19:34:30]

Cool that's way better.

+
+// [4]  - 2 Bytes - Field type
+const int kPmpFieldTypeFirstOffset = 4;
+
+// [6]  - 2 Bytes - 32 13
+const uint8 kPmpMagicO6S2[] = { 0x32, 0x13 };
+
+// [8]  - 4 Bytes - 02 00 00 00
+const uint8 kPmpMagicO8S4[] = { 0x02, 0x00, 0x00, 0x00 };
+
+// [12] - 2 bytes - Field type. Same as above.
+const int kPmpFieldTypeSecondOffset = 12;
+
+// [14] - 2 bytes - 32 13
+const uint8 kPmpMagicO14S2[] = { 0x32, 0x13 };
+
+// [16] - 4 bytes - Row count as uint32.
+const int kPmpRowCountOffset = 16;
+
+// [20] - * bytes - Rest of the entries.
+
+// Field types:
+// 0x00 - cstrings

[vandebo (ex-Chrome), 2013/03/27 00:06:19]

Comments below aren't necessary, the code describes what's going on pretty well.
 For things like this, you can indent the values so they all line up.

[tommycli, 2013/03/27 19:34:30]

Done.

+const uint16 kPmpFieldTypeString = 0x00;
+
+// 0x01 - uint32
+const uint16 kPmpFieldTypeUInt32 = 0x01;
+
+// 0x02 - double (Microsoft variant time)
+const uint16 kPmpFieldTypeDouble64 = 0x02;
+
+// 0x03 - uint8
+const uint16 kPmpFieldTypeUInt8 = 0x03;
+
+// 0x04 - uint64
+const uint16 kPmpFieldTypeUInt64 = 0x04;
+
+// 0x05 - uint16 - unhandled
+// const uint16 kPmpFieldTypeUInt16 = 0x05;
+
+// 0x06 - cstrings - unhandled
+// const uint16 kPmpFieldTypeString_06 = 0x06;
+
+// 0x07 - uint32 - unhandled
+// const uint16 kPmpFieldTypeUInt32_07 = 0x07;
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_MEDIA_PICASA_PMP_CONSTANTS_H_