[FFmpeg-cvslog] lavfi/vf_libplacebo: add contrast recovery options

[Niklas Haas]

ffmpeg | branch: master | Niklas Haas <git at haasn.dev> | Sat Jul  8 12:54:49 2023 +0200| [13e989901468b2e53a7d3a099511aae6987c7b00] | committer: Niklas Haas

lavfi/vf_libplacebo: add contrast recovery options

New upstream option. Enabled by default in the high-quality preset
upstream, so enable it by default here.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=13e989901468b2e53a7d3a099511aae6987c7b00
---

 doc/filters.texi            | 13 +++++++++++++
 libavfilter/vf_libplacebo.c |  8 ++++++++
 2 files changed, 21 insertions(+)

diff --git a/doc/filters.texi b/doc/filters.texi
index 95b04cea1a..54cc5ba820 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -16664,6 +16664,19 @@ output color volumes. Disabled by default.
 Size of the tone-mapping LUT, between @code{2} and @code{1024}. Defaults to
 @code{256}. Note that this figure is squared when combined with
 @code{peak_detect}.
+
+ at item contrast_recovery
+Contrast recovery strength. If set to a value above @code{0.0}, the source
+image will be divided into high-frequency and low-frequency components, and a
+portion of the high-frequency image is added back onto the tone-mapped output.
+May cause excessive ringing artifacts for some HDR sources, but can improve the
+subjective sharpness and detail left over in the image after tone-mapping.
+Defaults to @code{0.30}.
+
+ at item contrast_smoothness
+Contrast recovery lowpass kernel size. Defaults to @code{3.5}. Increasing or
+decreasing this will affect the visual appearance substantially. Has no effect
+when @code{contrast_recovery} is disabled.
 @end table
 
 @subsubsection Dithering
diff --git a/libavfilter/vf_libplacebo.c b/libavfilter/vf_libplacebo.c
index 10a79ac950..031265b637 100644
--- a/libavfilter/vf_libplacebo.c
+++ b/libavfilter/vf_libplacebo.c
@@ -219,6 +219,8 @@ typedef struct LibplaceboContext {
     float tonemapping_param;
     int inverse_tonemapping;
     int tonemapping_lut_size;
+    float contrast_recovery;
+    float contrast_smoothness;
 
 #if FF_API_LIBPLACEBO_OPTS
     /* for backwards compatibility */
@@ -431,6 +433,10 @@ static int update_settings(AVFilterContext *ctx)
         .tone_mapping_param = s->tonemapping_param,
         .inverse_tone_mapping = s->inverse_tonemapping,
         .lut_size = s->tonemapping_lut_size,
+#if PL_API_VER >= 285
+        .contrast_recovery = s->contrast_recovery,
+        .contrast_smoothness = s->contrast_smoothness,
+#endif
     );
 
     set_gamut_mode(&s->color_map_params, gamut_mode);
@@ -1398,6 +1404,8 @@ static const AVOption libplacebo_options[] = {
     { "tonemapping_param", "Tunable parameter for some tone-mapping functions", OFFSET(tonemapping_param), AV_OPT_TYPE_FLOAT, {.dbl = 0.0}, 0.0, 100.0, .flags = DYNAMIC },
     { "inverse_tonemapping", "Inverse tone mapping (range expansion)", OFFSET(inverse_tonemapping), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DYNAMIC },
     { "tonemapping_lut_size", "Tone-mapping LUT size", OFFSET(tonemapping_lut_size), AV_OPT_TYPE_INT, {.i64 = 256}, 2, 1024, DYNAMIC },
+    { "contrast_recovery", "HDR contrast recovery strength", OFFSET(contrast_recovery), AV_OPT_TYPE_FLOAT, {.dbl = 0.30}, 0.0, 3.0, DYNAMIC },
+    { "contrast_smoothness", "HDR contrast recovery smoothness", OFFSET(contrast_smoothness), AV_OPT_TYPE_FLOAT, {.dbl = 3.50}, 1.0, 32.0, DYNAMIC },
 
 #if FF_API_LIBPLACEBO_OPTS
     /* deprecated options for backwards compatibility, defaulting to -1 to not override the new defaults */