Instead, use a YUV planar format. It doesn't matter, since we use the
format only internally and for "management" purposes. We're only
interested in the physical layout, not what colorspace FFmpeg "forcibly"
associates with it.
Also get rid of using the old and slightly sketchy mp_imgfmt_find()
function. Yep, the IMGFMT_RGB30 now "constructs" the planar format,
instead of using a pixfmt constant. Slightly inconvenient, tricky, and
fragile, but I like it, so bugger off.
This whole thing gets rid of some of the strange plane permutations that
were needed earlier.
According to the definition of the GL format, and the definition in
img_format.h, and the actual output by vo_gpu, the order of components
was probably wrong. It's exceedingly likely that the vo_drm format (for
which this was originally written) has the same layout, so this was
probably a bug from when the zimg wrapper code was refactored.
This is mostly just because of the odd RGB default gamma issue, which
shouldn't have any real impact. This also sets allow_approximate_gamma,
which I hope is fine for normal use cases.
Normally, the Y plane can just be passed directly to zimg, and only the
chroma plane needs to be (de)interleaved. It still needs a copy if the Y
pointer is not aligned, though. (Whether this is actually a problem
depends on the CPU and probably zimg's compiler.)
This requires deciding per plane whether the plane should go through the
repack buffer or not. This logic is active in non-nv12 cases, because
not doing so would require extra code (maybe 2 lines or so).
repack_align is now always called, even if it's planar->planar with all
input aligned, but it won't actually do anything in that case. The
assumption is that zimg won't change behavior if you pass a callback
that does nothing versus passing NULL as callback.
This is for formats like nv12 (including p010, nv24, etc.). Might be
important for hardware decoding. Previously, this would have forced a
libswscale fallback.
The genericism makes this only slightly more complicated. The main
complication is due to the fact that mixing planar and packed stuff is
insane (thanks, Nvidia).
P010 output will actually happily set any of the 6 bit "padding" LSB,
that are normally supposed to be 0 (for unpadded data there is P016).
Scaling happens with 16 bit precision. Not going to bother adding an
extra packer which zeros them out, or with shifting them in
packing/unpacking. Lets just hope nobody notices.
We've set all planes to the same zmask. But for subsampled chroma, the
zmask obviously needs to be smaller. This could lead to out of bounds
memory read and write accesses.
Move the align repacker to a single function, since this is now more
convenient.
This probably covers all packed formats which have byte-aligned
component, no alpha, and no subsampling. Everything else needs more
imgfmt metadata, or something even more complicated. Alpha is primarily
not supported, because zimg requires a second scaler instance for it,
and handling packing/unpacking with it is an unacceptable mess.
Raise swscale and zimg default parameters. This restores screenshot
quality settings (maybe) unset in the commit before. Also expose some
more libswscale and zimg options.
Since these options are also used for VOs like x11 and drm, this will
make x11/drm/etc. much slower. For compensation, provide a profile that
sets the old option values: sw-fast. I'm also enabling zimg here, just
as an experiment.
The core problem is that we have a single set of command line options
which control the settings used for most swscale/zimg uses. This was
done in the previous commit. It cannot differentiate between the VOs,
which need to be realtime and may accept/require lower quality options,
and things like screenshots or vo_image, which can be slower, but should
not sacrifice quality by default.
Should this have two sets of options or something similar to do the
right thing depending on the code which calls libswscale? Maybe. Or
should I just ignore the problem, make it someone else's problem (users
who want to use software conversion VOs), provide a sub-optimal
solution, and call it a day? Definitely, sounds good, pushing to master,
goodbye.
Purpose uncertain. I guess it's slightly better, maybe.
The move of the sws/zimg options from VO opts (vo_opt_list) to the
top-level option list is tricky. VO opts have some helper code in vo.c,
that sends VOCTRL_SET_PANSCAN to the VO on every VO opts change. That's
because updating certain VO options used to be this way (and not just
the panscan option). This isn't needed anymore for sws/zimg options, so
explicitly move them away.
The RGB pack/unpack code in theory supports packed, non-subsampled YUV,
although in practice FFmpeg defines no such formats. (Only one with
alpha, but all alpha input is rejected by the current code.)
This would in theory have failed, because we would have selected a GBRP
format (instead of YUV), which makes no sense and would either have been
rejected by zimg (inconsistent parameters), or lead to broken output
(wrong permutation of planes).
Select the correct format and don't permute the planes in the YUV case.
As suggested by the zimg author. This is mostly related to XYZ support.
It's unclear whether this works. Using the only XYZ test sample we know,
and the next commits to consume the pixfmt, it looks wrong.
This provides a very similar API to sws_utils.h, which can be used to
convert and scale from one mp_image to another.
This commit adds only the code, but does not use it anywhere.
The code is quite preliminary and barely tested. It supports only a few
pixel formats, and will return failure for many others. (Unlike
libswscale, which tries to support anything that FFmpeg knows.)
zimg itself accepts only planar formats. Supporting other formats
requires manual packing/unpacking. (Compared to libswscale, the zimg API
is generally lower level, but allows for more flexibility.) Only BGR0
output was actually tested. It appears to work.
