The decoder assumes in various places that the image size
is a multiple of the block size, and there is no obvious
way to support odd sizes. Bailing out early if the header
specifies a bad size avoids various errors later on.
Fixes CVE-2012-0947.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Progressive data is allocated later in decode_sof(), not allocating
that data leads to NULL dereferences.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This prevents sample_rate/data_length from going negative, which
caused various crashes and undefined behaviour further down.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This properly synchronizes frame size changes between threads if
subsequent threads abort decoding before frame size is initialized, i.e.
it prevents the thread after that from ping-ponging back to the original
value.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Starting with version 4.7, gcc properly supports unaligned
memory accesses on ARM. Not using the inline asm with these
compilers results in better code.
Signed-off-by: Mans Rullgard <mans@mansr.com>
With a dereferenced type-cast pointer as memory operand, gcc 4.6
and later will sometimes copy the data to a temporary location,
the address of which is used as the operand value, if it thinks
the target address might be misaligned. Using a pointer to a
packed struct type instead does the right thing.
The 16-bit case is special since the ldrh instruction addressing
modes are limited compared to ldr. The "Uq" constraint produces a
memory reference suitable for an ldrsb instruction, which supports
the same addressing modes as ldrh. However, the restrictions appear
to apply only when the operand addresses a single byte. The memory
reference must thus be split into two operands each targeting one
byte. Finally, the "Uq" constraint is only available in ARM mode.
The Thumb-2 ldrh instruction supports most addressing modes so the
normal "m" constraint can be used there.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The index of the motion vector has to be checked before being
multiplied by 2 for the array index.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
ModeTab.fmode has only 3 elements, so indexing it with ftype
in the initialier for 'size' is invalid when ftype == FT_PPC.
This fixes crashes with gcc 4.8.
Signed-off-by: Mans Rullgard <mans@mansr.com>
SDL only supports s16 sample format and a limited number of channel layouts.
Some versions of SDL on some systems support 4-channel and 6-channel output,
but it's safer overall to downmix any layout with more than 2 channels to
stereo.
The shift parameter was removed from this interface in 7e1ce6a.
This updates the Altivec implementation to match.
Signed-off-by: Mans Rullgard <mans@mansr.com>
To load unaligned vector data in the usual way, explicit vec_ld()
should be used rather than dereferencing a pointer to a vector type.
When the VSX extension is enabled, gcc may compile vector pointer
dereferences using the VSX lxvw4x instruction instead of the lvx
instruction typically used with Altivec/VMX. As the behaviour of
these instructions with unaligned addresses differs, it is important
that only lvx is used here.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Allowing dsputil functions to assume the stride is a multiple of 16
even for smaller block sizes can simplify their implementation.
This appears to be the only place this guarantee is not met.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Non perceptual color model that aims to have an increase effectiveness
in compression like the normal YCbCr while having near-lossless/lossless
mapping to RGB.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This adds a hand-optimized assembly version for get_cabac much like the
existing one, but it works if the table offsets are RIP-relative.
Compared to the non-RIP-relative version this adds 2 lea instructions
and it needs one extra register. get_cabac() gets about 40% faster, for
an overall speedup of about 5%.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
