The new reference.pnm is a freely licensed replacement. The photo has been taken by Reinhard Tartler on August 28 2014, and is licensed under the expat license as stated at http://www.jclark.com/xml/copying.txt
Over-counting occurs if framerate is not set. Signed-off-by: Anton Khirnov <anton@khirnov.net>
Do not fall back on the codec timebase, since that can be anything for VFR video.