Change-Id: Ic7725e279d2263515e5312c152c58e1644eb2495

Change-Id: I784ea2b9fabbec1e99d02e97209981ff1b18ac82

Change-Id: I18e0a9e00731c23a2bdd1a978c8cb38f71e9029d

Change-Id: I0395ffa107651a773fd11d12682ab9372f76a90b

Change-Id: I1c6a275278788dfdc630ed436d2c770acfcbd097

A large collection of example files may be found at
 http://media.xiph.org/video/derf/
This also fixes a bug in ivfenc for uncompressed IVF input, which previously
 appeared not to skip past the file header the second time it opened the file.
I don't actually have an IVF file with which to test this fix, however.

Change-Id: Id69a1e11a3fa16c4a4fa8944e880bcea090cd52b