MJPEG does not have a single quantiser scale, so this does not fit into
the intended API use.
This removes the last use of the long-deprecated QP table API.
SMVJPEG stores frames as slices of a big JPEG image. The decoder is
implemented as a wrapper that instantiates a full internal MJPEG
decoder, then forwards the decoded frames with offset data pointers.
This is unnecessarily complex and fragile, not supporting useful decoder
capabilities like direct rendering.
Re-implement the decoder inside the MJPEG decoder, which is accomplished
by returning each decoded frame multiple times, setting cropping
information appropriately on each instance.
One peculiar aspect of the previous design is that since
- the smvjpeg decoder returns one frame per input packet
- there are multiple frames in each packets (the aformentioned slices)
the demuxer needs to return each packet multiple times.
This is now also eliminated - the demuxer now returns each packet
exactly once, with the duration set to the number of frames it decodes
to.
This also removes one of the last remaining internal uses of the old
video decoding API.
ff_init_vlc_from_lengths() can be used to offload the computation
of the codes; it also allows to omit the check whether the codes
are already properly ordered (they are).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This affected all decoders that used ff_mjpeg_decode_init() as init
function; and it also affected decoders that open jpeg decoders via
ff_codec_open2_recursive() as well as MxPEG.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Now that the correct number of codes is used, it is no longer necessary
to initialize the lengths of the codes at all any more as the length of
the actually used codes is set later anyway.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
It is always zero; it referred to the INIT_VLC_USE_STATIC flag which has
been removed in 595324e143.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Commit bbc0d0c1fe made the mjpeg decoder
use default Huffman tables when none are given, yet when initializing
the default Huffman tables, it did not use the correct number of entries
of the arrays used to initialize the tables, but instead it used the
biggest entry + 1 (as if it were a continuous array 0..biggest entry).
This worked because the ff_init_vlc_sparse() (and its predecessors)
always skipped entries with a length of zero and the length of the
corresponding elements was always initialized to zero with only the
sizes of the actually existing elements being set to a size > 0 lateron.
Yet since commit 1249698e1b this is no
longer so, as build_vlc() actually read the array containing the values
itself. This implies that the wrong length now leads to a read beyond
the end of the given array; this could lead to crashs (but usually
doesn't); it is detectable by ASAN* and this commit fixes it.
*: AddressSanitizer: global-buffer-overflow on address xy
...
xy is located 0 bytes to the right of global variable 'avpriv_mjpeg_val_ac_luminance'
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Commit 1249698e1b made
ff_mjpeg_decode_dht() call build_vlc() with a wrong (too hight)
number of codes. The reason it worked is that the lengths of the extraneous
entries is initialized to zero and ff_init_vlc_sparse() ignores codes
with a length of zero. But using a too high number of codes was
nevertheless bad, because a) the assert in build_vlc() could have been
triggered (namely if the real amount of codes is 256) and b) the loop in
build_vlc() uses initialized data (leading to Valgrind errors [1]).
Furthermore, the old code spend CPU cycles in said loop although the
result won't be used anyway.
[1]: http://fate.ffmpeg.org/report.cgi?slot=x86_64-archlinux-gcc-valgrind&time=20201008025137
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This has been forgotten in d5a3a20d.
Found via PVS-Studio (see ticket #8156).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: out of array write
Fixes: 17088/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEGLS_fuzzer-5654877765632000
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Also, ensure no false positives when determining DNG bayer images, by
setting them in tiff.c instead of relying on a heuristic. There's no
way to determine this just from the JPEG data, so we have to pass this
information from outside the MJPEG decoder.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Main image data in DNGs is usually comprised of tiles, each of which is a Huffman-encoded lossless JPEG.
Tested for ljpeg regressions with:
`ffmpeg -f lavfi -i testsrc=d=1 -vcodec ljpeg test.avi`
`ffmpeg test.avi out.avi`
The modified code in ljpeg_decode_rgb_scan runs without issues.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
These may be used by hwaccel decoders when the standard tables are not
otherwise available. At the same time, clean up that code into an array
so it's a little less repetitive.
Fixes: out of array access
Fixes: 9225/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEGLS_fuzzer-5684770334834688
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: signed integer overflow: 32768 + 2147450880 cannot be represented in type 'int'
Fixes: 7885/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_THP_fuzzer-5298834394578944
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This is needed by later hwaccel code to tell which encoding process was
used for a particular frame, because hardware decoders may only support a
subset of possible methods.
Fixes: runtime error: signed integer overflow: -65535 * 65312 cannot be represented in type 'int'
Fixes: 4900/clusterfuzz-testcase-minimized-5769019744321536
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
JPEGs store embedded profiles under the APP2 marker, signified
with a "ICC_PROFILE" null-terminated string header, and can be
split across multiple APP2 markers, out of order.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Fixes: runtime error: signed integer overflow: -16711425 + -2130772346 cannot be represented in type 'int'
Fixes: 2533/clusterfuzz-testcase-minimized-5372857678823424
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Anton Khirnov
Andreas Rheinhardt
James Almer
Paul B Mahol
Michael Niedermayer
Mark Thompson
Nick Renieris
Zhong Li
Carl Eugen Hoyos
Vittorio Giovara
Philip Langdale
Martin Vignali
Derek Buitenhuis