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
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 to justify the added complexity.
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 to justify the added complexity.
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.
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
The decoder currently sets CODEC_FLAG_EMU_EDGE and relies on
get_buffer2() to always provide buffers with linesize == 2 * width.
This is wrong, since we place no such restriction on get_buffer2()
implementations.
Fix this by decoding into internal buffers and copying them to output
frames. Since this is a very obscure decoder, the performance hit should
not be an issue.
The decoder currently sets CODEC_FLAG_EMU_EDGE and relies on
get_buffer2() to always provide buffers with linesize == 2 * width.
This is wrong, since we place no such restriction on get_buffer2()
implementations.
Fix this by decoding into internal buffers and copying them to output
frames. Since this is a very obscure decoder, the performance hit should
not be an issue.
Specifically, when the corresponding input channel exists and its matrix
column is all-zero (which is necessary for zeroing the output), the
matrix column must be removed from the matrix.
This is not done currently, so the mixing code would end up using
uninitialized pointers from stack.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
This should make it easier to catch problems where some of those
pointers are used uninitialized, since reading from NULL should always
crash, while random numbers from stack can turn out to be valid
pointers, so random memory may be silently overwritten.
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
The code cannot handle there being none, but that should not happen for
valid files.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
It has been checking the number of bits in the offset instead of the
actual offset.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
Otherwise the generic code will unref them, which can then result in
last_picture_ptr == current_picture_ptr, which causes deadlocks at least
in rv40.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
This is a temporary workaround to allow deprecating
avcodec_get_frame_defaults(). The proper solution will be using a
properly allocated AVFrame in Picture.
This is a temporary workaround to allow deprecating
avcodec_get_frame_defaults(). The proper solution will be using a
properly allocated AVFrame in Picture.
Strictly speaking it is not correct to call it on refcounted frames, in
any case it is unnecessary, since filtered_frame is always unreferenced
after poll_filter() returns.
Use only proper AVFrame API (no assigning of whole frames, since that
hardcodes sizeof(AVFrame) into lavc).
Make a copy of the side data, so the caller can use av_frame_unref/free
on non-refcounted frames, eliminating the need for
avcodec_get_frame_defaults()/avcodec_free_frame().
Not just on failure. This is the same thing that is done in the audio
path and should prevent leaks in decoders that allocate a frame, but
then end up not writing into it.
The encoder uses almost none of the mpegvideo infrastructure, only some
fields from MpegEncContext.
The FATE results change because now an all-zero quant matrix is written
into the file. Since it is not used for anything for ljpeg, this should
not be a problem.
This code was originally added in
5f1948111a to h263 to set decoded frame
pts to some random numbers (removed in
a1c5cc429d) and then cargo culted to other
decoders.
The code is left in h263dec for now, since some part of the decoder
(apparently OBMC) relies on the specific previous frame to be reused.
Anton Khirnov
