Fixes tsan warnings in fate-apng:
WARNING: ThreadSanitizer: data race (pid=51230)
Read of size 4 at 0x7d50000042fc by main thread (mutexes: write M1000):
#0 frame_copy_props frame.c:302 (ffmpeg:x86_64+0x1019a35d6)
[..]
Previous write of size 4 at 0x7d50000042fc by thread T1 (mutexes: write M997):
#0 decode_idat_chunk pngdec.c:708 (ffmpeg:x86_64+0x100f5562a)
Fixes a reported (but false) race condition in tsan for fate-apng:
WARNING: ThreadSanitizer: data race (pid=6274)
Read of size 4 at 0x7d680001ec78 by main thread (mutexes: write M1338):
#0 update_thread_context src/libavcodec/pngdec.c:1456 (ffmpeg+0x000000dacf0c)
[..]
Previous write of size 4 at 0x7d680001ec78 by thread T1 (mutexes: write M1335):
#0 decode_idat_chunk src/libavcodec/pngdec.c:737 (ffmpeg+0x000000dae951)
Fixes: runtime error: shift exponent 132 is too large for 32-bit type 'int'
Fixes: 609/clusterfuzz-testcase-4825202619842560
See 11.2.2 IHDR Image header
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This fixes a segmentation fault caused by calling memcpy with NULL as
second argument in handle_p_frame_apng.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
This reverts commit e0c6b32046.
Said commit changed the behavior of the demuxer and decoder in a non
backwards compatible way.
Demuxers should make extradata available at init if possible, and send
new extradata as side data within a packet if needed.
A better fix for the remuxing crash will follow.
Signed-off-by: James Almer <jamrial@gmail.com>
Fixes remuxing apng streams coming from the apng demuxer.
This is a regression since 940b8908b9.
Found-by: James Almer <jamrial@gmail.com>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
The buffer needs s->bpp bytes, at maximum currently 10.
Assert that s->bpp is not larger.
This fixes a stack buffer overflow.
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Use optional sTER chunk defining side-by-side stereo pair
within "Extensions to the PNG 1.2 Specification", version 1.3.0.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Use optional sTER chunk defining side-by-side stereo pair
within "Extensions to the PNG 1.2 Specification", version 1.3.0.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
When compiled with --disable-pthreads, e.g
http://fate.ffmpeg.org/report.cgi?time=20150917015044&slot=alpha-debian-qemu-gcc-4.7,
a bunch of -Wunused-functions are reported due to missing header guards
around threading related functions.
This patch should silence such warnings.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Fixes deadlock with threads
Found-by: Paul B Mahol
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Previously these chunks where parsed again for each frame with threads
but not without leading to a different path and the potential for
inconsistencies
This also removes a related special case from decode_ihdr_chunk()
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Multiple IHDR chunks are forbidden in PNG
Fixes inconsistency and out of array accesses
Fixes: asan_heap-oob_4d5c5a_1738_cov_2638287726_c-m2-8f2b481b7fd9bd745e620b7c01a18df2.png
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Currently restricted to blending pixels that only contain either
0 or 255 in their alpha components
Signed-off-by: Donny Yang <work@kota.moe>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The spec specifies the dispose operation as how the current (i.e., currently
being rendered) frame should be disposed when the next frame is blended onto it
This is contrary to ffmpeg's current behaviour of interpreting the dispose
operation as how the previous (i.e., already rendered) frame should be disposed
This patch fixes ffmpeg's behaviour to match those of the spec, which involved
a rewrite of the blending function
Signed-off-by: Donny Yang <work@kota.moe>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ARGB is not a supported PNG pixel format
Signed-off-by: Donny Yang <work@kota.moe>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
AV_PIX_FMT_GRAY8/16 are considered YUV formats, and the color_range is
not set - so the API user will have to assume limitted range. (Unless
the API user adds a special-case for the PNG decoder.)
Just export the correct range - full range.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
AV_PIX_FMT_MONOBLACK has the AV_PIX_FMT_FLAG_BITSTREAM flag, i.e.
linesize can be smaller than width.
Since x_offset is only check against the width, this can lead to
x_offset * bpp >= image_linesize.
In this case ptr could be set to a position outside the image_buf in
png_handle_row, leading to memory corruption and thus crashes.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
During the loop ret can get changed. Since it is not set on all failure
paths, decode_frame_common can return 0 even though an error occurred.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This check was removed in commit 08aec6f6, but
s->last_picture.f->data[0] is still used in handle_p_frame_apng
unconditionally.
This fixes a segmentation fault.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>