This uses a RGB intermediate, a more optimal solution would be to perform the rematrixing
directly in subsampled YUV, this is quite a bit more complicated though
Fixes Ticket4805
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
+ split color conversion from scaling
- disabled gamma correction, until it's refactored too
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This simplifies allocating and initializing swscale contexts with custom options.
The function is internal currently but could be moved into the public header
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes use of uninitialized memory
Fixes: a96874b9466b6edc660a519c7ad47977_signal_sigsegv_7ffff713351a_744_nc_sample.avi with memlimit 2147483648
Found-by: Samuel Groß, Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes use of uninitialized memory
Fixes: asan_heap-oob_35ca682_1474_cov_3230122439_aletrek_tga_16bit.mov
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fixes out of array read
Fixes: asan_heap-oob_35ca682_1474_cov_3230122439_aletrek_tga_16bit.mov
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fixes out of array read
Fixes: asan_heap-oob_1fb2f9b_3780_cov_3984375136_usf.mkv
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The rationale is that you have a packed format in form
<greyscale sample> <alpha sample> <greyscale sample> <alpha sample>
and shortening greyscale to 'G' might make one thing about Greenscale instead.
An alias pixel format and color space name are provided for compatibility.
Prevent a division by zero down the codepath.
Sample-Id: 00001721-google
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This way all context fields get initialized and can be used without needing to reinit the context
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Both of these dithering methods are from http://pippin.gimp.org/a_dither/ for
GIF they can be considered better than bayer (provides more gray-levels), and
spatial stability - often more than twice as good compression and less visual
flicker than error diffusion methods (the methods also avoids error-shadow
artifacts of diffusion dithers).
These methods are similar to blue/green noise type dither masks; but are
simple enough to generate their mask on the fly. They are still research work
in progress; though more expensive to generate masks (which can be used in a
LUT) like 'void and cluster' and similar methods will yield superior results
Improves rgb -> gray16 conversion
Fixes Ticket3422
The pam and png output files look visually similar, in both cases the
dynamics increase to 0x0 -> 0xfffb.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>