diff --git a/meson.build b/meson.build
index 3c1e5f9ac4be322b97081bb697c74c5937615609..0f55f354ac101a4c07a0976afad6b76640766ea7 100644
--- a/meson.build
+++ b/meson.build
@@ -2,7 +2,7 @@ project('libplacebo', ['c', 'cpp'],
license: 'LGPL2.1+',
default_options: ['c_std=c99', 'cpp_std=c++11', 'warning_level=2'],
meson_version: '>=0.49',
- version: '2.67.0',
+ version: '2.68.0',
)
# Version number
diff --git a/src/include/libplacebo/shaders/colorspace.h b/src/include/libplacebo/shaders/colorspace.h
index e9fed237f8d56df52c675ec18b87a60dd1a2c6ef..562ef92180ce99925f595dab422d8401bfbcac00 100644
--- a/src/include/libplacebo/shaders/colorspace.h
+++ b/src/include/libplacebo/shaders/colorspace.h
@@ -194,6 +194,10 @@ enum pl_tone_mapping_algorithm {
// as an aditional scaling coefficient to make the image (linearly)
// brighter or darker. Defaults to 1.0.
PL_TONE_MAPPING_LINEAR,
+
+ // EETF from the ITU-R Report BT.2390, a hermite spline roll-off with
+ // linear segment. Not configurable.
+ PL_TONE_MAPPING_BT_2390,
};
struct pl_color_map_params {
@@ -204,7 +208,7 @@ struct pl_color_map_params {
// Algorithm and configuration used for tone-mapping. For non-tunable
// algorithms, the `param` is ignored. If the tone mapping parameter is
// left as 0.0, the tone-mapping curve's preferred default parameter will
- // be used. The default algorithm is PL_TONE_MAPPING_HABLE.
+ // be used. The default algorithm is PL_TONE_MAPPING_BT_2390.
enum pl_tone_mapping_algorithm tone_mapping_algo;
float tone_mapping_param;
diff --git a/src/shaders/colorspace.c b/src/shaders/colorspace.c
index 722722ac60d7c540f23f7563cb8adab8f756cde1..3331f075d7d6065715e44454898c001f78745768 100644
--- a/src/shaders/colorspace.c
+++ b/src/shaders/colorspace.c
@@ -751,9 +751,18 @@ bool pl_shader_detect_peak(struct pl_shader *sh,
return true;
}
+static inline float pq_delinearize(float x)
+{
+ x *= PL_COLOR_SDR_WHITE / 10000.0;
+ x = powf(x, PQ_M1);
+ x = (PQ_C1 + PQ_C2 * x) / (1.0 + PQ_C3 * x);
+ x = pow(x, PQ_M2);
+ return x;
+}
+
const struct pl_color_map_params pl_color_map_default_params = {
.intent = PL_INTENT_RELATIVE_COLORIMETRIC,
- .tone_mapping_algo = PL_TONE_MAPPING_HABLE,
+ .tone_mapping_algo = PL_TONE_MAPPING_BT_2390,
.desaturation_strength = 0.75,
.desaturation_exponent = 1.50,
.desaturation_base = 0.18,
@@ -791,11 +800,13 @@ static void pl_shader_tone_map(struct pl_shader *sh, struct pl_color_space src,
}
}
- // Rescale the input in order to bring it into a representation where
- // 1.0 represents the dst_peak. This is because all of the tone mapping
- // algorithms are defined in such a way that they map to the range [0.0, 1.0].
+ // Rescale the input in order to bring it into a representation where 1.0
+ // represents the dst_peak. This is because (almost) all of the tone
+ // mapping algorithms are defined in such a way that they map to the range
+ // [0.0, 1.0].
+ bool need_norm = params->tone_mapping_algo != PL_TONE_MAPPING_BT_2390;
float dst_range = dst.sig_peak * dst.sig_scale;
- if (dst_range > 1.0) {
+ if (dst_range > 1.0 && need_norm) {
GLSL("color.rgb *= 1.0 / %f; \n"
"sig_peak *= 1.0 / %f; \n",
dst_range, dst_range);
@@ -873,6 +884,41 @@ static void pl_shader_tone_map(struct pl_shader *sh, struct pl_color_space src,
GLSL("sig *= %f / sig_peak;\n", PL_DEF(param, 1.0));
break;
+ case PL_TONE_MAPPING_BT_2390:
+ // We first need to encode both sig and sig_peak into PQ space
+ GLSL("vec4 sig_pq = vec4(sig.rgb, sig_peak); \n"
+ "sig_pq *= vec4(1.0/%f); \n"
+ "sig_pq = pow(sig_pq, vec4(%f)); \n"
+ "sig_pq = (vec4(%f) + vec4(%f) * sig_pq) \n"
+ " / (vec4(1.0) + vec4(%f) * sig_pq); \n"
+ "sig_pq = pow(sig_pq, vec4(%f)); \n",
+ 10000 / PL_COLOR_SDR_WHITE, PQ_M1, PQ_C1, PQ_C2, PQ_C3, PQ_M2);
+ // Encode both the signal and the target brightness to be relative to
+ // the source peak brightness, and figure out the target peak in this space
+ GLSL("float scale = 1.0 / sig_pq.a; \n"
+ "sig_pq.rgb *= vec3(scale); \n"
+ "float maxLum = %f * scale; \n",
+ pq_delinearize(dst_range));
+ // Apply piece-wise hermite spline
+ GLSL("float ks = 1.5 * maxLum - 0.5; \n"
+ "vec3 tb = (sig_pq.rgb - vec3(ks)) / vec3(1.0 - ks); \n"
+ "vec3 tb2 = tb * tb; \n"
+ "vec3 tb3 = tb2 * tb; \n"
+ "vec3 pb = (2.0 * tb3 - 3.0 * tb2 + vec3(1.0)) * vec3(ks) + \n"
+ " (tb3 - 2.0 * tb2 + tb) * vec3(1.0 - ks) + \n"
+ " (-2.0 * tb3 + 3.0 * tb2) * vec3(maxLum); \n"
+ "sig = mix(pb, sig_pq.rgb, %s(lessThan(sig_pq.rgb, vec3(ks)))); \n",
+ sh_bvec(sh, 3));
+ // Convert back from PQ space to linear light
+ GLSL("sig *= vec3(sig_pq.a); \n"
+ "sig = pow(sig, vec3(1.0/%f)); \n"
+ "sig = max(sig - vec3(%f), 0.0) / \n"
+ " (vec3(%f) - vec3(%f) * sig); \n"
+ "sig = pow(sig, vec3(1.0/%f)); \n"
+ "sig *= vec3(%f); \n",
+ PQ_M2, PQ_C1, PQ_C2, PQ_C3, PQ_M1, 10000.0 / PL_COLOR_SDR_WHITE);
+ break;
+
default:
abort();
}
@@ -895,7 +941,7 @@ static void pl_shader_tone_map(struct pl_shader *sh, struct pl_color_space src,
}
// Undo the normalization by `dst_peak`
- if (dst_range > 1.0)
+ if (dst_range > 1.0 && need_norm)
GLSL("color.rgb *= %f; \n", dst_range);
}
diff --git a/src/tests/gpu_tests.h b/src/tests/gpu_tests.h
index 995fa063ad5e161ac9e59937bfee627ab5520dcd..22184ba5b37549aa44df5f9d39cd8642cce3a9e4 100644
--- a/src/tests/gpu_tests.h
+++ b/src/tests/gpu_tests.h
@@ -733,7 +733,7 @@ static void pl_render_tests(const struct pl_gpu *gpu)
// Test HDR stuff
image.color.sig_scale = 10.0;
target.color.sig_scale = 2.0;
- TEST_PARAMS(color_map, tone_mapping_algo, PL_TONE_MAPPING_LINEAR);
+ TEST_PARAMS(color_map, tone_mapping_algo, PL_TONE_MAPPING_BT_2390);
TEST_PARAMS(color_map, desaturation_strength, 1);
image.color.sig_scale = target.color.sig_scale = 0.0;