This was broken by 4e528206bc - the webp
decoder was assuming that it could set the output pixfmt of the vp8
decoder directly, but after that change it no longer could because
ff_get_format() was used instead. This adds an internal get_format()
callback to webp use of the vp8 decoder to override the pixfmt
appropriately.
This avoids the danger that get_bits.h might get indirectly #included before
BITSTREAM_READER_LE is defined.
Also sort headers into canonical order where appropriate.
Every chunk needs at least 8 bytes for chunk_type and chunk_size.
Prevent a possible infinite loop.
CC: libav-stable@libav.org
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
According to the WebP Lossless Bitstream Specification
"each transform is allowed to be used only once".
If a transform is more than once this can lead to memory
corruption.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
According to the WebP Lossless Bitstream Specification the highest
allowed value for a prefix code is 39.
If prefix_code is too large, the calculated extra_bits has an invalid
value and triggers an assertion in get_bits.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
The vlc reader cannot handle 0-bit huffman codes. For most
situations WebP uses the "simple" huffman coding for this case,
but that will only handle symbols up to 255. For the LZ77 distance
codes, larger symbol values are needed, so it can happen in rare
cases that a normal huffman table is used that only has a single
symbol.
Mark Thompson
Diego Biurrun
Alexandra Hájková
Vittorio Giovara
Andreas Cadhalpun
Justin Ruggles
Anton Khirnov