It does not work correctly and apparently never did. There is no
indication that this (mis)feature is ever used in the wild or even that
any software other than the reference supports it.
Since the code that attempts to support it adds some nontrivial
complexity and has resulted in several bugs in the past, it is better to
just drop it.
Currently, it needs to be initialized by the ER caller (which is
currently either a mpegvideo decoder or h264dec). However, since none of
those decoders use MECmpContext for anything except ER, it makes more
sense to handle it purely inside ER.
When decoding, this field holds the inverse of the framerate that can be
written in the headers for some codecs. Using a field called 'time_base'
for this is very misleading, as there are no timestamps associated with
it. Furthermore, this field is used for a very different purpose during
encoding.
Add a new field, called 'framerate', to replace the use of time_base for
decoding.
This is done to disentangle ER from mpegvideo. In order to use a
classic Picture, callers can use ff_mpeg_set_erpic() or use a custom function
to set the fields. Please note that buffers need to be allocated before
calling ff_er_frame_end().
And use the value from the specification.
Sample-Id: 00000451-google
Found-by: Mateusz j00ru Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Prevents using GetBitContexts with data from previous calls.
Fixes access to freed memory.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
This handles macroblock edges for the chroma components in the same way
as for the luma compoment for 4:4:4 streams. The Spec explicitly states
that the deblocking filter is not applied to edges at the boundary of
the picture.
Signed-off-by: Janne Grunau <janne-libav@jannau.net>
Otherwise the ER code might try to use some already freed references.
Fixes possible access to freed memory.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
Higher modes are not allowed for 16x16/chroma, which is what this
function is used for. Otherwise this function would return 0 (vertical
prediction) for invalid higher modes, which could result in invalid
reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
In this case we may not have a current frame, while first_field being
set implies we do.
Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
There is no point in delaying the check and it avoids bugs with a
half-initialized context.
Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
If it was set before then we can end up trying to decode a slice without
a valid slice header, which can lead to invalid memory access.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
