doubleTag.oga and broken-file.ogg were created by Brian Wolff and is released into the public domain

VP9-tractor.webm is from http://base-n.de/webm/VP9%20Sample.html and was encoded from a public domain
file located at http://media.xiph.org/video/derf/y4m/

bear-vp9-opus.webm comes from the chromnium project at the url
http://code.metager.de/source/raw/chromium/media/test/data/bear-vp9-opus.webm
which has the following copyright notice:

1 	// Copyright 2014 The Chromium Authors. All rights reserved.
2 	//
3 	// Redistribution and use in source and binary forms, with or without
4 	// modification, are permitted provided that the following conditions are
5 	// met:
6 	//
7 	// * Redistributions of source code must retain the above copyright
8 	// notice, this list of conditions and the following disclaimer.
9 	// * Redistributions in binary form must reproduce the above
10 	// copyright notice, this list of conditions and the following disclaimer
11 	// in the documentation and/or other materials provided with the
12 	// distribution.
13 	// * Neither the name of Google Inc. nor the names of its
14 	// contributors may be used to endorse or promote products derived from
15 	// this software without specific prior written permission.
16 	//
17 	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.