In 16x8 motion compensation, for lower 16x8 region, the input to mpeg_motion() for motion_y was "motion_y + 16", which causes wrong rounding. For 4:2:0, chroma scaling for y is dividing by two and rounding toward zero. When motion_y < 0 and motion_y + 16 > 0, the rounding direction of "motion_y" and "motion_y + 16" is different and rounding "motion_y + 16" would be incorrect.
We should input "motion_y" as is to round correctly. I add "is_16x8" flag to do that.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes integer overflow and out of array read
Fixes: asan_heap-oob_1fb2f9b_3780_cov_3984375136_usf.mkv
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The most interesting parts are initialization in ff_MPV_common_init() and
uninitialization in ff_MPV_common_end().
ff_mpeg_unref_picture and ff_thread_release_buffer have additional NULL
checks for Picture.f, because these functions can be called on
uninitialized or partially initialized Pictures.
NULL pointer checks are added to ff_thread_release_buffer() stub function.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Several decoders disable those anyway and they are not measurably faster
on x86. They might be somewhat faster on other platforms due to missing
emu edge SIMD, but the gain is not large enough (and those decoders
relevant enough) to justify the added complexity.
Allow supporting files for which the image stride is smaller than
the maximum block size + number of subpel mc taps, e.g. a 64x64 VP9
file or a 16x16 VP8 file with -fflags +emu_edge.
Fixes out of array reads
Fixes part of: MSVR 440 (the other issues seem to have been fixed already)
Found-by: Jeremy Brown (jerbrown) of ReSP
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This allows supporting files for which the image stride is smaller than
the max. block size + number of subpel mc taps, e.g. a 64x64 VP9 file
or a 16x16 VP8 file with -fflags +emu_edge.
Currently all uses of the emu edge code as well as the code itself
assume int linesize
changing some but not changing all would introduce a security issue
once all use this typedef a simple search and replace can be
done to switch them all to ptrdiff_t
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This makes sure that linesize * start_y doesn't overflow, so that
emulated_edge_mc can get back the original value if needed.
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
If a reference is unavailable use a field from the current
picture
Fixes null pointer dereference
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The gmc functions access more pixels than there is allocated memory.
Fixes out of array reads
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Move some functions from dsputil. The idea is that videodsp contains
functions that are useful for a large and varied set of video decoders.
Currently, it contains emulated_edge_mc() and prefetch().
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
These arguments are either constants or copies of MpegEncContext
fields just as easily accessed within the function.
Signed-off-by: Mans Rullgard <mans@mansr.com>
These functions do not benefit from being inlined. They are large,
and there are no opportunities for constant propagation.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The main benefit of inlining this function is from constant
propagation for the 'field_based' argument. Instead of inlining
all calls, create two versions of the function for field_based
values of 0 and 1.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This file defines a single, huge function, MPV_motion(), which
although being declared inline is not actually inlined by the
compiler (for good reason). There is thus no sense in defining
this function in a header file, resulting in multiple copies of
it in the final library.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Nekopanda
Michael Niedermayer
Michael Niedermayer
Diego Biurrun
Vittorio Giovara
Luca Barbato
wm4
Anton Khirnov
Ronald S. Bultje
Ronald S. Bultje
Martin Storsjö
Mans Rullgard
Janne Grunau