[RenderEngine] Add PQ/HLG data space support. (0589adcd) · Commits · e / os / android_frameworks_native-old

services/surfaceflinger/RenderEngine/ProgramCache.cpp

+152 −78

Original line number	Diff line number	Diff line
		@@ -233,31 +233,73 @@ void ProgramCache::generateEOTF(Formatter& fs, const Key& needs) {
		}

		// Generate OOTF that modifies the relative scence light to relative display light.
		void ProgramCache::generateOOTF(Formatter& fs, const Key& needs) {
		void ProgramCache::generateOOTF(Formatter& fs, const ProgramCache::Key& needs) {
		// When HDR and non-HDR contents are mixed, or different types of HDR contents are
		// mixed, we will do a transcoding process to transcode the input content to output
		// content. Currently, the following conversions handled, they are:
		// * SDR -> HLG
		// * SDR -> PQ
		// * HLG -> PQ

		// Convert relative light to absolute light.
		switch (needs.getInputTF()) {
		case Key::INPUT_TF_ST2084:
		fs << R"__SHADER__(
		highp float CalculateY(const highp vec3 color) {
		// BT2020 standard uses the unadjusted KR = 0.2627,
		// KB = 0.0593 luminance interpretation for RGB conversion.
		return color.r * 0.262700 + color.g * 0.677998 + color.b * 0.059302;
		highp vec3 ScaleLuminance(color) {
		return color * 10000.0;
		}
		)__SHADER__";
		break;
		case Key::INPUT_TF_HLG:
		fs << R"__SHADER__(
		highp vec3 ScaleLuminance(color) {
		// The formula is:
		// alpha * pow(Y, gamma - 1.0) * color + beta;
		// where alpha is 1000.0, gamma is 1.2, beta is 0.0.
		return color * 1000.0 * pow(color.y, 0.2);
		}
		)__SHADER__";
		break;
		default:
		fs << R"__SHADER__(
		highp vec3 ScaleLuminance(color) {
		return color * displayMaxLuminance;
		}
		)__SHADER__";
		break;
		}

		// Generate OOTF that modifies the relative display light.
		// Tone map absolute light to display luminance range.
		switch (needs.getInputTF()) {
		case Key::INPUT_TF_ST2084:
		case Key::INPUT_TF_HLG:
		switch (needs.getOutputTF()) {
		case Key::OUTPUT_TF_HLG:
		// Right now when mixed PQ and HLG contents are presented,
		// HLG content will always be converted to PQ. However, for
		// completeness, we simply clamp the value to [0.0, 1000.0].
		fs << R"__SHADER__(
		highp vec3 OOTF(const highp vec3 color) {
		const float maxLumi = 10000.0;
		highp vec3 ToneMap(color) {
		return clamp(color, 0.0, 1000.0);
		}
		)__SHADER__";
		break;
		case Key::OUTPUT_TF_ST2084:
		fs << R"__SHADER__(
		highp vec3 ToneMap(color) {
		return color;
		}
		)__SHADER__";
		break;
		default:
		fs << R"__SHADER__(
		highp vec3 ToneMap(color) {
		const float maxMasteringLumi = 1000.0;
		const float maxContentLumi = 1000.0;
		const float maxInLumi = min(maxMasteringLumi, maxContentLumi);
		float maxOutLumi = displayMaxLuminance;

		// Calculate Y value in XYZ color space.
		float colorY = CalculateY(color);

		// convert to nits first
		float nits = colorY * maxLumi;
		float nits = color.y;

		// clamp to max input luminance
		nits = clamp(nits, 0.0, maxInLumi);
		@@ -275,12 +317,12 @@ void ProgramCache::generateOOTF(Formatter& fs, const Key& needs) {
		float y2 = y1 + (maxOutLumi - y1) * 0.75;

		// horizontal distances between the last three control points
		float h12 = x2 - x1;
		float h23 = maxInLumi - x2;
		const float h12 = x2 - x1;
		const float h23 = maxInLumi - x2;
		// tangents at the last three control points
		float m1 = (y2 - y1) / h12;
		float m3 = (maxOutLumi - y2) / h23;
		float m2 = (m1 + m3) / 2.0;
		const float m1 = (y2 - y1) / h12;
		const float m3 = (maxOutLumi - y2) / h23;
		const float m2 = (m1 + m3) / 2.0;

		if (nits < x0) {
		// scale [0.0, x0] to [0.0, y0] linearly
		@@ -288,7 +330,7 @@ void ProgramCache::generateOOTF(Formatter& fs, const Key& needs) {
		nits *= slope;
		} else if (nits < x1) {
		// scale [x0, x1] to [y0, y1] linearly
		float slope = (y1 - y0) / (x1 - x0);
		const float slope = (y1 - y0) / (x1 - x0);
		nits = y0 + (nits - x0) * slope;
		} else if (nits < x2) {
		// scale [x1, x2] to [y1, y2] using Hermite interp
		@@ -303,32 +345,64 @@ void ProgramCache::generateOOTF(Formatter& fs, const Key& needs) {
		}
		}

		// convert back to [0.0, 1.0]
		float targetY = nits / maxOutLumi;
		return color * (targetY / max(1e-6, colorY));
		return color * (nits / max(1e-6, color.y));
		}
		)__SHADER__";
		break;
		case Key::INPUT_TF_HLG:
		}
		break;
		default:
		// TODO(73825729) We need to revert the tone mapping in
		// hardware composer properly.
		fs << R"__SHADER__(
		highp vec3 OOTF(const highp vec3 color) {
		const float maxOutLumi = 500.0;
		const float gamma = 1.2 + 0.42 * log(maxOutLumi / 1000.0) / log(10.0);
		// The formula is:
		// alpha * pow(Y, gamma - 1.0) * color + beta;
		// where alpha is 1.0, beta is 0.0 as recommended in
		// Rec. ITU-R BT.2100-1 TABLE 5.
		return pow(CalculateY(color), gamma - 1.0) * color;
		highp vec3 ToneMap(color) {
		return color;
		}
		)__SHADER__";
		break;
		}

		// convert absolute light to relative light.
		switch (needs.getOutputTF()) {
		case Key::OUTPUT_TF_ST2084:
		fs << R"__SHADER__(
		highp vec3 NormalizeLuminance(color) {
		return color / 10000.0;
		}
		)__SHADER__";
		break;
		case Key::OUTPUT_TF_HLG:
		fs << R"__SHADER__(
		highp vec3 NormalizeLuminance(color) {
		return color / 1000.0 * pow(color.y / 1000.0, -0.2 / 1.2);
		}
		)__SHADER__";
		break;
		default:
		fs << R"__SHADER__(
		highp vec3 NormalizeLuminance(color) {
		return color / displayMaxLuminance;
		}
		)__SHADER__";
		break;
		}

		if (needs.getInputTF() == needs.getOutputTF() \|\|
		(needs.getInputTF() == Key::INPUT_TF_LINEAR &&
		needs.getOutputTF() == Key::OUTPUT_TF_SRGB) \|\|
		(needs.getInputTF() == Key::INPUT_TF_SRGB &&
		needs.getOutputTF() == Key::OUTPUT_TF_LINEAR)) {
		fs << R"__SHADER__(
		highp vec3 OOTF(const highp vec3 color) {
		return color;
		}
		)__SHADER__";
		break;
		} else {
		fs << R"__SHADER__(
		highp vec3 OOTF(const highp vec3 color) {
		return NormalizeLuminance(ToneMap(ScaleLuminance(color)));
		}
		)__SHADER__";
		}
		}