The underlying integer type of an enumeration is
implementation-defined (see C11, 6.7.2.2 (4)); GCC defaults
to unsigned if there are no negative values like for all enums
from pixfmt.h except enum AVPixelFormat.
This means that tests like "if (csp >= AVCOL_SPC_NB)" for
invalid colorspaces need not work as expected (namely if
enum AVColorSpace is signed). It also means that testing
for such an enum variable to be >= 0 may be tautologically
true. Clang emits a -Wtautological-unsigned-enum-zero-compare
warning for this.
Fix both of these issues by casting to unsigned.
Also do the same in libswscale/format.c.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The existing av_csp_trc_func_from_id() mostly implements the OETF, except for
PQ. As such, we are currently missing a precise definition of an ITU-R EOTF.
Introduce the new functions av_csp_itu_eotf() and av_csp_itu_eotf_inv(), to fill
this void. Note that this is not possible in all cases, e.g. AVCOL_TRC_LOG which
has no corresponding EOTF definition in any ITU-R standard.
Note that we cannot implement the proper HLG and SMPTE 428 OOTFs without access
to all three color channels, because they are not independent per channel. As a
result, we need to define them on double[3] instead of double (*func)(double).
libavutil/color_utils contains some avpriv_ symbols that map
enum AVTransferCharacteristic values to gamma-curve approximations and
to the actual transfer functions to invert them (i.e. -> linear).
There's two issues with this:
(1) avpriv is evil and should be avoided whenever possible
(2) libavutil/csp.h exposes a public API for handling color that
already handles primaries and matricies
I don't see any reason this API has to be private, so this commit takes
the functionality from avutil/color_utils and merges it into avutil/csp
with an exposed av_ API rather than the previous avpriv_ API.
Every reference to the previous API has been updated to point to the
new one. color_utils.h has been deleted as well. This should not break
any applications as it only contained avpriv_ symbols in the first
place, so nothing in that header could be referenced by other
applications.
Signed-off-by: Leo Izen <leo.izen@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This commit moves some of the functionality from avfilter/colorspace
into avutil/csp and exposes it as a public API so it can be used by
libavcodec and/or libavformat. It also converts those structs from
double values to AVRational to make regression testing easier and
more consistent.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
