If the frame is filled with the same colour, encoder may produce no data
and the fill value is indicated by zero code length (the rest of symbols
will have 0xFF for code length, meaning invalid).  So such Huffman trees
should be treated specially.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

This prevents truncating output due to an output buffer that is too small for
all blocks. There is no limit on the number of blocks in a packet.

This fixes the requirement for the buffer size to be larger than the number of
samples actually decoded.

This stops decoding before overreads instead of after.

the decoder can handle multiple frames in a packet

For stereo we need to use intermediate planar buffers, but mono does not need
to be deinterleaved so the output buffer can be used directly.

ENOTSUP is not defined on some systems

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Luma slices in YUV420 colourspace should have height in multiple of two since
they have the same line of chrominance data corresponding to pair of them.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This fixes false positives of has_codec_delay_been_guessed() for
streams where not every input picture generates an output picture,
such as interlaced H264.