diff --git a/UI/data/locale/en-US.ini b/UI/data/locale/en-US.ini
index fd074879f..b2892163f 100644
--- a/UI/data/locale/en-US.ini
+++ b/UI/data/locale/en-US.ini
@@ -1056,6 +1056,7 @@ Basic.Settings.Advanced.Video.ColorRange="Color Range"
Basic.Settings.Advanced.Video.ColorRange.Partial="Limited"
Basic.Settings.Advanced.Video.ColorRange.Full="Full"
Basic.Settings.Advanced.Video.SdrWhiteLevel="SDR White Level (nits)"
+Basic.Settings.Advanced.Video.HdrNominalPeakLevel="HDR Nominal Peak Level (nits)"
Basic.Settings.Advanced.Audio.MonitoringDevice="Monitoring Device"
Basic.Settings.Advanced.Audio.MonitoringDevice.Default="Default"
Basic.Settings.Advanced.Audio.DisableAudioDucking="Disable Windows audio ducking"
diff --git a/UI/forms/OBSBasicSettings.ui b/UI/forms/OBSBasicSettings.ui
index c6bf8146f..596017e42 100644
--- a/UI/forms/OBSBasicSettings.ui
+++ b/UI/forms/OBSBasicSettings.ui
@@ -5170,6 +5170,32 @@
+ -
+
+
+
+ 0
+ 0
+
+
+
+ Basic.Settings.Advanced.Video.HdrNominalPeakLevel
+
+
+ hdrNominalPeakLevel
+
+
+
+ -
+
+
+ 400
+
+
+ 10000
+
+
+
-
diff --git a/UI/window-basic-main.cpp b/UI/window-basic-main.cpp
index ea943d742..eb8811d35 100644
--- a/UI/window-basic-main.cpp
+++ b/UI/window-basic-main.cpp
@@ -1497,6 +1497,8 @@ bool OBSBasic::InitBasicConfigDefaults()
config_set_default_string(basicConfig, "Video", "ColorRange",
"Partial");
config_set_default_uint(basicConfig, "Video", "SdrWhiteLevel", 300);
+ config_set_default_uint(basicConfig, "Video", "HdrNominalPeakLevel",
+ 1000);
config_set_default_string(basicConfig, "Audio", "MonitoringDeviceId",
"default");
@@ -4414,8 +4416,11 @@ int OBSBasic::ResetVideo()
}
if (ret == OBS_VIDEO_SUCCESS) {
- obs_set_video_sdr_white_level((float)config_get_uint(
- basicConfig, "Video", "SdrWhiteLevel"));
+ const float sdr_white_level = (float)config_get_uint(
+ basicConfig, "Video", "SdrWhiteLevel");
+ const float hdr_nominal_peak_level = (float)config_get_uint(
+ basicConfig, "Video", "HdrNominalPeakLevel");
+ obs_set_video_levels(sdr_white_level, hdr_nominal_peak_level);
OBSBasicStats::InitializeValues();
OBSProjector::UpdateMultiviewProjectors();
}
diff --git a/UI/window-basic-settings.cpp b/UI/window-basic-settings.cpp
index f7940828e..509d05463 100644
--- a/UI/window-basic-settings.cpp
+++ b/UI/window-basic-settings.cpp
@@ -537,6 +537,7 @@ OBSBasicSettings::OBSBasicSettings(QWidget *parent)
HookWidget(ui->colorSpace, COMBO_CHANGED, ADV_CHANGED);
HookWidget(ui->colorRange, COMBO_CHANGED, ADV_CHANGED);
HookWidget(ui->sdrWhiteLevel, SCROLL_CHANGED, ADV_CHANGED);
+ HookWidget(ui->hdrNominalPeakLevel, SCROLL_CHANGED, ADV_CHANGED);
HookWidget(ui->disableOSXVSync, CHECK_CHANGED, ADV_CHANGED);
HookWidget(ui->resetOSXVSync, CHECK_CHANGED, ADV_CHANGED);
if (obs_audio_monitoring_available())
@@ -2596,6 +2597,8 @@ void OBSBasicSettings::LoadAdvancedSettings()
config_get_string(main->Config(), "Video", "ColorRange");
uint32_t sdrWhiteLevel = (uint32_t)config_get_uint(
main->Config(), "Video", "SdrWhiteLevel");
+ uint32_t hdrNominalPeakLevel = (uint32_t)config_get_uint(
+ main->Config(), "Video", "HdrNominalPeakLevel");
QString monDevName;
QString monDevId;
@@ -2670,6 +2673,7 @@ void OBSBasicSettings::LoadAdvancedSettings()
SetComboByValue(ui->colorSpace, videoColorSpace);
SetComboByValue(ui->colorRange, videoColorRange);
ui->sdrWhiteLevel->setValue(sdrWhiteLevel);
+ ui->hdrNominalPeakLevel->setValue(hdrNominalPeakLevel);
if (!SetComboByValue(ui->bindToIP, bindIP))
SetInvalidValue(ui->bindToIP, bindIP, bindIP);
@@ -3376,6 +3380,7 @@ void OBSBasicSettings::SaveAdvancedSettings()
SaveComboData(ui->colorSpace, "Video", "ColorSpace");
SaveComboData(ui->colorRange, "Video", "ColorRange");
SaveSpinBox(ui->sdrWhiteLevel, "Video", "SdrWhiteLevel");
+ SaveSpinBox(ui->hdrNominalPeakLevel, "Video", "HdrNominalPeakLevel");
if (obs_audio_monitoring_available()) {
SaveCombo(ui->monitoringDevice, "Audio",
"MonitoringDeviceName");
diff --git a/docs/sphinx/reference-core.rst b/docs/sphinx/reference-core.rst
index 79ba786c5..95444ef45 100644
--- a/docs/sphinx/reference-core.rst
+++ b/docs/sphinx/reference-core.rst
@@ -160,9 +160,17 @@ Initialization, Shutdown, and Information
---------------------
-.. function:: void obs_set_video_sdr_white_level(float sdr_white_level)
+.. function:: float obs_get_video_hdr_nominal_peak_level(void)
- Sets the current SDR white level.
+ Gets the current HDR nominal peak level.
+
+ :return: HDR nominal peak level, 1000.f if no video
+
+---------------------
+
+.. function:: void obs_set_video_sdr_white_level(float sdr_white_level, float hdr_nominal_peak_level)
+
+ Sets the current video levels.
---------------------
diff --git a/libobs/data/color.effect b/libobs/data/color.effect
index f606e4900..6ac04c2a1 100644
--- a/libobs/data/color.effect
+++ b/libobs/data/color.effect
@@ -71,15 +71,61 @@ float linear_to_hlg_channel(float u)
return (u <= (1.0 /12.0)) ? sqrt(3.0 * u) : ((log2((12.0 * u) - 0.28466892) * m) + 0.55991073);
}
-float3 linear_to_hlg(float3 rgb)
+float eetf_0_1000(float Lw, float maxRGB1_pq)
+{
+ float Lw_pq = linear_to_st2084_channel(Lw / 10000.);
+ float E1 = maxRGB1_pq / Lw_pq;
+ float maxLum = linear_to_st2084_channel(.1) / Lw_pq;
+ float KS = (1.5 * maxLum) - 0.5;
+ float E2 = E1;
+ if (E1 > KS)
+ {
+ float T = (E1 - KS) / (1. - KS);
+ float Tsquared = T * T;
+ float Tcubed = Tsquared * T;
+ float P = (2. * Tcubed - 3. * Tsquared + 1.) * KS + (Tcubed - 2. * Tsquared + T) * (1. - KS) + (-2. * Tcubed + 3. * Tsquared) * maxLum;
+ E2 = P;
+ }
+ float E3 = E2;
+ float E4 = E3 * Lw_pq;
+ return E4;
+}
+
+float3 maxRGB_eetf(float3 rgb, float Lw, float Lmax)
+{
+ float maxRGB_linear = max(max(rgb.r, rgb.g), rgb.b);
+ float maxRGB1_pq = linear_to_st2084_channel(maxRGB_linear);
+ float maxRGB2_pq = eetf_0_1000(Lw, maxRGB1_pq);
+ float maxRGB2_linear = st2084_to_linear_channel(maxRGB2_pq);
+ float scaling_ratio = maxRGB2_linear / maxRGB_linear;
+
+ // scaling_ratio could be NaN
+ scaling_ratio = max(0., scaling_ratio);
+
+ rgb *= scaling_ratio;
+ return rgb;
+}
+
+float3 linear_to_hlg(float3 rgb, float Lw)
{
rgb = saturate(rgb);
- float yd = (0.2627 * rgb.r) + (0.678 * rgb.g) + (0.0593 * rgb.b);
- // pow(0, exponent) can lead to NaN, use smallest positive normal number
- yd = max(6.10352e-5, yd);
+ if (Lw > 1000.)
+ {
+ rgb = maxRGB_eetf(rgb, Lw, 1000.);
+ rgb *= 10000. / Lw;
+ }
+ else
+ {
+ rgb *= 10.;
+ }
- rgb *= pow(yd, -1.0 / 6.0);
+ float Yd = dot(rgb, float3(0.2627, 0.678, 0.0593));
+
+ // pow(0., exponent) can lead to NaN, use smallest positive normal number
+ Yd = max(6.10352e-5, Yd);
+
+ rgb *= pow(Yd, -1. / 6.);
return float3(linear_to_hlg_channel(rgb.r), linear_to_hlg_channel(rgb.g), linear_to_hlg_channel(rgb.b));
}
@@ -91,10 +137,10 @@ float hlg_to_linear_channel(float u)
return (u <= 0.5) ? ((u * u) / 3.0) : ((exp2(u * m + a) + 0.28466892) / 12.0);
}
-float3 hlg_to_linear(float3 v)
+float3 hlg_to_linear(float3 v, float exponent)
{
float3 rgb = float3(hlg_to_linear_channel(v.r), hlg_to_linear_channel(v.g), hlg_to_linear_channel(v.b));
- float ys = dot(rgb, float3(0.2627, 0.678, 0.0593));
- rgb *= pow(ys, 0.2);
+ float Ys = dot(rgb, float3(0.2627, 0.678, 0.0593));
+ rgb *= pow(Ys, exponent);
return rgb;
}
diff --git a/libobs/data/format_conversion.effect b/libobs/data/format_conversion.effect
index 84dd478b5..2688e76ae 100644
--- a/libobs/data/format_conversion.effect
+++ b/libobs/data/format_conversion.effect
@@ -26,6 +26,8 @@ uniform float height_d2;
uniform float width_x2_i;
uniform float maximum_over_sdr_white_nits;
uniform float sdr_white_nits_over_maximum;
+uniform float hlg_exponent;
+uniform float hlg_lw;
uniform float4 color_vec0;
uniform float4 color_vec1;
@@ -213,7 +215,7 @@ float PS_HLG_Y_709_2020(FragPos frag_in) : TARGET
{
float3 rgb = image.Load(int3(frag_in.pos.xy, 0)).rgb * sdr_white_nits_over_maximum;
rgb = rec709_to_rec2020(rgb);
- rgb = linear_to_hlg(rgb);
+ rgb = linear_to_hlg(rgb, hlg_lw);
float y = dot(color_vec0.xyz, rgb) + color_vec0.w;
y = (65472. / 65535.) * y + (32. / 65535.); // set up truncation to 10 bits
return y;
@@ -241,7 +243,7 @@ float PS_I010_HLG_Y_709_2020(FragPos frag_in) : TARGET
{
float3 rgb = image.Load(int3(frag_in.pos.xy, 0)).rgb * sdr_white_nits_over_maximum;
rgb = rec709_to_rec2020(rgb);
- rgb = linear_to_hlg(rgb);
+ rgb = linear_to_hlg(rgb, hlg_lw);
float y = dot(color_vec0.xyz, rgb) + color_vec0.w;
return y * (1023. / 65535.);
}
@@ -288,7 +290,7 @@ float2 PS_HLG_UV_709_2020_WideWide(FragTexWideWide frag_in) : TARGET
float3 rgb_bottomright = image.Sample(def_sampler, frag_in.uuvv.yw).rgb;
float3 rgb = (rgb_topleft + rgb_topright + rgb_bottomleft + rgb_bottomright) * (0.25 * sdr_white_nits_over_maximum);
rgb = rec709_to_rec2020(rgb);
- rgb = linear_to_hlg(rgb);
+ rgb = linear_to_hlg(rgb, hlg_lw);
float u = dot(color_vec1.xyz, rgb) + color_vec1.w;
float v = dot(color_vec2.xyz, rgb) + color_vec2.w;
float2 uv = float2(u, v);
@@ -364,7 +366,7 @@ float PS_I010_HLG_U_709_2020_WideWide(FragTexWideWide frag_in) : TARGET
float3 rgb_bottomright = image.Sample(def_sampler, frag_in.uuvv.yw).rgb;
float3 rgb = (rgb_topleft + rgb_topright + rgb_bottomleft + rgb_bottomright) * (0.25 * sdr_white_nits_over_maximum);
rgb = rec709_to_rec2020(rgb);
- rgb = linear_to_hlg(rgb);
+ rgb = linear_to_hlg(rgb, hlg_lw);
float u = dot(color_vec1.xyz, rgb) + color_vec1.w;
return u * (1023. / 65535.);
}
@@ -402,7 +404,7 @@ float PS_I010_HLG_V_709_2020_WideWide(FragTexWideWide frag_in) : TARGET
float3 rgb_bottomright = image.Sample(def_sampler, frag_in.uuvv.yw).rgb;
float3 rgb = (rgb_topleft + rgb_topright + rgb_bottomleft + rgb_bottomright) * (0.25 * sdr_white_nits_over_maximum);
rgb = rec709_to_rec2020(rgb);
- rgb = linear_to_hlg(rgb);
+ rgb = linear_to_hlg(rgb, hlg_lw);
float v = dot(color_vec2.xyz, rgb) + color_vec2.w;
return v * (1023. / 65535.);
}
@@ -587,7 +589,7 @@ float4 PSI010_HLG_2020_709_Reverse(VertTexPos frag_in) : TARGET
float cr = image2.Load(xy0_chroma).x * ratio;
float3 yuv = float3(y, cb, cr);
float3 hlg = YUV_to_RGB(yuv);
- float3 hdr2020 = hlg_to_linear(hlg) * maximum_over_sdr_white_nits;
+ float3 hdr2020 = hlg_to_linear(hlg, hlg_exponent) * maximum_over_sdr_white_nits;
float3 rgb = rec2020_to_rec709(hdr2020);
return float4(rgb, 1.0);
}
@@ -619,7 +621,7 @@ float4 PSP010_HLG_2020_709_Reverse(VertTexPos frag_in) : TARGET
float2 cbcr = image1.Load(int3(frag_in.uv, 0)).xy;
float3 yuv = float3(y, cbcr);
float3 hlg = YUV_to_RGB(yuv);
- float3 hdr2020 = hlg_to_linear(hlg) * maximum_over_sdr_white_nits;
+ float3 hdr2020 = hlg_to_linear(hlg, hlg_exponent) * maximum_over_sdr_white_nits;
float3 rgb = rec2020_to_rec709(hdr2020);
return float4(rgb, 1.0);
}
diff --git a/libobs/obs-internal.h b/libobs/obs-internal.h
index a8802cf43..1ced6fe1c 100644
--- a/libobs/obs-internal.h
+++ b/libobs/obs-internal.h
@@ -305,7 +305,6 @@ struct obs_core_video {
bool conversion_needed;
float conversion_width_i;
float conversion_height_i;
- float maximum_nits;
uint32_t output_width;
uint32_t output_height;
@@ -326,7 +325,8 @@ struct obs_core_video {
gs_effect_t *deinterlace_yadif_2x_effect;
struct obs_video_info ovi;
- uint32_t sdr_white_level;
+ float sdr_white_level;
+ float hdr_nominal_peak_level;
pthread_mutex_t task_mutex;
struct circlebuf tasks;
diff --git a/libobs/obs-source.c b/libobs/obs-source.c
index 6f1c3f573..f94a04f42 100644
--- a/libobs/obs-source.c
+++ b/libobs/obs-source.c
@@ -2159,10 +2159,18 @@ static bool update_async_texrender(struct obs_source *source,
set_eparam(conv, "height_d2", (float)cy * 0.5f);
set_eparam(conv, "width_x2_i", 0.5f / (float)cx);
- const float maximum_nits =
- (frame->trc == VIDEO_TRC_HLG) ? 1000.f : 10000.f;
+ const float hdr_nominal_peak_level =
+ obs->video.hdr_nominal_peak_level;
+ const float maximum_nits = (frame->trc == VIDEO_TRC_HLG)
+ ? hdr_nominal_peak_level
+ : 10000.f;
set_eparam(conv, "maximum_over_sdr_white_nits",
maximum_nits / obs_get_video_sdr_white_level());
+ const float hlg_gamma =
+ 1.2f +
+ (0.42f * log10f(hdr_nominal_peak_level / 1000.f));
+ const float hlg_exponent = hlg_gamma - 1.f;
+ set_eparam(conv, "hlg_exponent", hlg_exponent);
struct vec4 vec0, vec1, vec2;
vec4_set(&vec0, frame->color_matrix[0], frame->color_matrix[1],
diff --git a/libobs/obs-video.c b/libobs/obs-video.c
index 2cf6d0640..a9c2527d0 100644
--- a/libobs/obs-video.c
+++ b/libobs/obs-video.c
@@ -316,6 +316,7 @@ static void render_convert_texture(struct obs_core_video *video,
gs_eparam_t *height_i = gs_effect_get_param_by_name(effect, "height_i");
gs_eparam_t *sdr_white_nits_over_maximum = gs_effect_get_param_by_name(
effect, "sdr_white_nits_over_maximum");
+ gs_eparam_t *hlg_lw = gs_effect_get_param_by_name(effect, "hlg_lw");
struct vec4 vec0, vec1, vec2;
vec4_set(&vec0, video->color_matrix[4], video->color_matrix[5],
@@ -328,11 +329,14 @@ static void render_convert_texture(struct obs_core_video *video,
gs_enable_blending(false);
if (convert_textures[0]) {
+ const float hdr_nominal_peak_level =
+ video->hdr_nominal_peak_level;
const float multiplier =
- obs_get_video_sdr_white_level() / video->maximum_nits;
+ obs_get_video_sdr_white_level() / 10000.f;
gs_effect_set_texture(image, texture);
gs_effect_set_vec4(color_vec0, &vec0);
gs_effect_set_float(sdr_white_nits_over_maximum, multiplier);
+ gs_effect_set_float(hlg_lw, hdr_nominal_peak_level);
render_convert_plane(effect, convert_textures[0],
video->conversion_techs[0]);
@@ -346,6 +350,7 @@ static void render_convert_texture(struct obs_core_video *video,
video->conversion_height_i);
gs_effect_set_float(sdr_white_nits_over_maximum,
multiplier);
+ gs_effect_set_float(hlg_lw, hdr_nominal_peak_level);
render_convert_plane(effect, convert_textures[1],
video->conversion_techs[1]);
@@ -358,6 +363,8 @@ static void render_convert_texture(struct obs_core_video *video,
video->conversion_height_i);
gs_effect_set_float(sdr_white_nits_over_maximum,
multiplier);
+ gs_effect_set_float(hlg_lw,
+ hdr_nominal_peak_level);
render_convert_plane(
effect, convert_textures[2],
video->conversion_techs[2]);
diff --git a/libobs/obs.c b/libobs/obs.c
index ff6775170..913277fe0 100644
--- a/libobs/obs.c
+++ b/libobs/obs.c
@@ -54,7 +54,6 @@ static inline void calc_gpu_conversion_sizes(const struct obs_video_info *ovi)
video->conversion_techs[2] = NULL;
video->conversion_width_i = 0.f;
video->conversion_height_i = 0.f;
- video->maximum_nits = 10000.f;
switch ((uint32_t)ovi->output_format) {
case VIDEO_FORMAT_I420:
@@ -88,7 +87,6 @@ static inline void calc_gpu_conversion_sizes(const struct obs_video_info *ovi)
video->conversion_techs[0] = "I010_HLG_Y";
video->conversion_techs[1] = "I010_HLG_U";
video->conversion_techs[2] = "I010_HLG_V";
- video->maximum_nits = 1000.f;
} else {
video->conversion_techs[0] = "I010_SRGB_Y";
video->conversion_techs[1] = "I010_SRGB_U";
@@ -105,7 +103,6 @@ static inline void calc_gpu_conversion_sizes(const struct obs_video_info *ovi)
} else if (ovi->colorspace == VIDEO_CS_2100_HLG) {
video->conversion_techs[0] = "P010_HLG_Y";
video->conversion_techs[1] = "P010_HLG_UV";
- video->maximum_nits = 1000.f;
} else {
video->conversion_techs[0] = "P010_SRGB_Y";
video->conversion_techs[1] = "P010_SRGB_UV";
@@ -1443,12 +1440,19 @@ float obs_get_video_sdr_white_level(void)
return video->graphics ? video->sdr_white_level : 300.f;
}
-void obs_set_video_sdr_white_level(float sdr_white_level)
+float obs_get_video_hdr_nominal_peak_level(void)
+{
+ struct obs_core_video *video = &obs->video;
+ return video->graphics ? video->hdr_nominal_peak_level : 1000.f;
+}
+
+void obs_set_video_levels(float sdr_white_level, float hdr_nominal_peak_level)
{
struct obs_core_video *video = &obs->video;
assert(video->graphics);
- video->sdr_white_level = (uint32_t)sdr_white_level;
+ video->sdr_white_level = sdr_white_level;
+ video->hdr_nominal_peak_level = hdr_nominal_peak_level;
}
bool obs_get_audio_info(struct obs_audio_info *oai)
diff --git a/libobs/obs.h b/libobs/obs.h
index 7cc5f1f81..312c853bc 100644
--- a/libobs/obs.h
+++ b/libobs/obs.h
@@ -417,11 +417,15 @@ EXPORT bool obs_reset_audio(const struct obs_audio_info *oai);
/** Gets the current video settings, returns false if no video */
EXPORT bool obs_get_video_info(struct obs_video_info *ovi);
-/** Gets the SDR white level, returns 300.0 if no video */
+/** Gets the SDR white level, returns 300.f if no video */
EXPORT float obs_get_video_sdr_white_level(void);
-/** Sets the SDR white level */
-EXPORT void obs_set_video_sdr_white_level(float sdr_white_level);
+/** Gets the HDR nominal peak level, returns 1000.f if no video */
+EXPORT float obs_get_video_hdr_nominal_peak_level(void);
+
+/** Sets the video levels */
+EXPORT void obs_set_video_levels(float sdr_white_level,
+ float hdr_nominal_peak_level);
/** Gets the current audio settings, returns false if no audio */
EXPORT bool obs_get_audio_info(struct obs_audio_info *oai);