The official Ut Video decoder only threads with slices, thus until
now any files encoded by the libavcodec encoder have only been
decodable with a single thread. The default slice count is now
set to subsampled_height / 120.
Also sets slices to 1 for the Ut Video encoder tests to keep them
green.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
With cli usage the decoder might have not set the colorspace during
encoder init, manual colorspace override might be needed in such
cases.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Also, align the mangled RGB planes, which is required for the
SIMD versions of dsputils' median predict.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>