Sometimes video fails to decode if H.264 configuration changes mid stream.
The reason is that configuration parser assumes that nal_ref_idc is equal to 11b
while actually some codecs but 01b there. The H.264 spec is somewhat
vague about this but it looks like it allows any non-zero nal_ref_idc for sps/pps.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>