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| author | Niklas Haas <git@haasn.dev> | 2022-04-09 19:58:55 +0200 |
|---|---|---|
| committer | Niklas Haas <git@haasn.dev> | 2022-04-23 21:51:55 +0200 |
| commit | b9a25963f7232433c9370ac369fb668ac0d5cb53 (patch) | |
| tree | f4bc25c8eccccc4061239f1730263aa4ee7df17b /configure | |
| parent | 072dd047f0e7830bbc51c893bed91d8ba5e4f788 (diff) | |
| download | ffmpeg-b9a25963f7232433c9370ac369fb668ac0d5cb53.tar.gz | |
lavfi: add ICC profile support via lcms2
This introduces an optional dependency on lcms2 into FFmpeg. lcms2 is a
widely used library for ICC profile handling, which apart from being
used in almost all major image processing programs and video players,
has also been deployed in browsers. As such, it's both widely available
and well-tested.
Add a few helpers to cover our major use cases. This commit merely
introduces the helpers (and configure check), even though nothing uses
them yet.
It's worth pointing out that the reason the cmsToneCurves for each
AVCOL_TRC are cached inside the context, is because constructing a
cmsToneCurve requires evaluating the curve at 4096 (by default) grid
points and constructing a LUT. So, we ideally only want to do this once
per curve. This matters for e.g. ff_icc_profile_detect_transfer, which
essentially compares a profile against all of these generated LUTs.
Re-generating the LUTs for every iteration would be unnecessarily
wasteful.
The same consideration does not apply to e.g. cmsCreate*Profile, which
is a very lightweight operation just involving struct allocation and
setting a few pointers.
The cutoff value of 0.01 was determined by experimentation. The lowest
"false positive" delta I saw in practice was 0.13, and the largest
"false negative" delta was 0.0008. So a value of 0.01 sits comfortaby
almost exactly in the middle.
Signed-off-by: Niklas Haas <git@haasn.dev>
Diffstat (limited to 'configure')
| -rwxr-xr-x | configure | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -215,6 +215,7 @@ External library support: --disable-iconv disable iconv [autodetect] --enable-jni enable JNI support [no] --enable-ladspa enable LADSPA audio filtering [no] + --enable-lcms2 enable ICC profile support via LittleCMS 2 [no] --enable-libaom enable AV1 video encoding/decoding via libaom [no] --enable-libaribb24 enable ARIB text and caption decoding via libaribb24 [no] --enable-libass enable libass subtitles rendering, @@ -1814,6 +1815,7 @@ EXTERNAL_LIBRARY_LIST=" gnutls jni ladspa + lcms2 libaom libass libbluray @@ -6510,6 +6512,7 @@ enabled gmp && require gmp gmp.h mpz_export -lgmp enabled gnutls && require_pkg_config gnutls gnutls gnutls/gnutls.h gnutls_global_init enabled jni && { [ $target_os = "android" ] && check_headers jni.h && enabled pthreads || die "ERROR: jni not found"; } enabled ladspa && require_headers "ladspa.h dlfcn.h" +enabled lcms2 && require_pkg_config lcms2 "lcms2 >= 2.13" lcms2.h cmsCreateContext enabled libaom && require_pkg_config libaom "aom >= 1.0.0" aom/aom_codec.h aom_codec_version enabled libaribb24 && { check_pkg_config libaribb24 "aribb24 > 1.0.3" "aribb24/aribb24.h" arib_instance_new || { enabled gpl && require_pkg_config libaribb24 aribb24 "aribb24/aribb24.h" arib_instance_new; } || |