# note: An ANIM chunk with four bytes of padding after its two fields.
# expect: reject
# anim: ok
# info: reject
# exercises: The ANIM chunk is six bytes of content and the demuxer treats
#   that as a minimum, not a size: it reads the background colour and loop
#   count and then skips whatever else the chunk declares, the same
#   forward-compatibility the VP8X chunk gets. webpinfo takes the other
#   view and requires the length to be exactly six -- "Corrupted ANIM
#   chunk" -- so this is a file the two disagree about.
payload ANIM ffffffff0300deadbeef
frame
frame_duration 100
lossless
width 16
height 16
argb 0xff800000 x256