initial commit, 4.5 stable

thirdparty/astcenc/astcenc_decompress_symbolic.cpp

@@ -0,0 +1,622 @@
+// SPDX-License-Identifier: Apache-2.0
+// ----------------------------------------------------------------------------
+// Copyright 2011-2024 Arm Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy
+// of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+// ----------------------------------------------------------------------------
+
+/**
+ * @brief Functions to decompress a symbolic block.
+ */
+
+#include "astcenc_internal.h"
+
+#include <stdio.h>
+#include <assert.h>
+
+/**
+ * @brief Compute the integer linear interpolation of two color endpoints.
+ *
+ * @param u8_mask       The mask for lanes using decode_unorm8 rather than decode_f16.
+ * @param color0        The endpoint0 color.
+ * @param color1        The endpoint1 color.
+ * @param weights       The interpolation weight (between 0 and 64).
+ *
+ * @return The interpolated color.
+ */
+static vint4 lerp_color_int(
+	vmask4 u8_mask,
+	vint4 color0,
+	vint4 color1,
+	vint4 weights
+) {
+	vint4 weight1 = weights;
+	vint4 weight0 = vint4(64) - weight1;
+
+	vint4 color = (color0 * weight0) + (color1 * weight1) + vint4(32);
+	color = asr<6>(color);
+
+	// For decode_unorm8 values force the codec to bit replicate. This allows the
+	// rest of the codec to assume the full 0xFFFF range for everything and ignore
+	// the decode_mode setting
+	vint4 color_u8 = asr<8>(color) * vint4(257);
+	color = select(color, color_u8, u8_mask);
+
+	return color;
+}
+
+/**
+ * @brief Convert integer color value into a float value for the decoder.
+ *
+ * @param data       The integer color value post-interpolation.
+ * @param lns_mask   If set treat lane as HDR (LNS) else LDR (unorm16).
+ *
+ * @return The float color value.
+ */
+static inline vfloat4 decode_texel(
+	vint4 data,
+	vmask4 lns_mask
+) {
+	vint4 color_lns = vint4::zero();
+	vint4 color_unorm = vint4::zero();
+
+	if (any(lns_mask))
+	{
+		color_lns = lns_to_sf16(data);
+	}
+
+	if (!all(lns_mask))
+	{
+		color_unorm = unorm16_to_sf16(data);
+	}
+
+	// Pick components and then convert to FP16
+	vint4 datai = select(color_unorm, color_lns, lns_mask);
+	return float16_to_float(datai);
+}
+
+/* See header for documentation. */
+void unpack_weights(
+	const block_size_descriptor& bsd,
+	const symbolic_compressed_block& scb,
+	const decimation_info& di,
+	bool is_dual_plane,
+	int weights_plane1[BLOCK_MAX_TEXELS],
+	int weights_plane2[BLOCK_MAX_TEXELS]
+) {
+	// Safe to overshoot as all arrays are allocated to full size
+	if (!is_dual_plane)
+	{
+		// Build full 64-entry weight lookup table
+		vtable_64x8 table;
+		vtable_prepare(table, scb.weights);
+
+		for (unsigned int i = 0; i < bsd.texel_count; i += ASTCENC_SIMD_WIDTH)
+		{
+			vint summed_value(8);
+			vint weight_count(di.texel_weight_count + i);
+			int max_weight_count = hmax_s(weight_count);
+
+			promise(max_weight_count > 0);
+			for (int j = 0; j < max_weight_count; j++)
+			{
+				vint texel_weights(di.texel_weights_tr[j] + i);
+				vint texel_weights_int(di.texel_weight_contribs_int_tr[j] + i);
+
+				summed_value += vtable_lookup_32bit(table, texel_weights) * texel_weights_int;
+			}
+
+			store(lsr<4>(summed_value), weights_plane1 + i);
+		}
+	}
+	else
+	{
+		// Build a 32-entry weight lookup table per plane
+		// Plane 1
+		vtable_32x8 tab_plane1;
+		vtable_prepare(tab_plane1, scb.weights);
+
+		// Plane 2
+		vtable_32x8 tab_plane2;
+		vtable_prepare(tab_plane2, scb.weights + 32);
+
+		for (unsigned int i = 0; i < bsd.texel_count; i += ASTCENC_SIMD_WIDTH)
+		{
+			vint sum_plane1(8);
+			vint sum_plane2(8);
+
+			vint weight_count(di.texel_weight_count + i);
+			int max_weight_count = hmax_s(weight_count);
+
+			promise(max_weight_count > 0);
+			for (int j = 0; j < max_weight_count; j++)
+			{
+				vint texel_weights(di.texel_weights_tr[j] + i);
+				vint texel_weights_int(di.texel_weight_contribs_int_tr[j] + i);
+
+				sum_plane1 += vtable_lookup_32bit(tab_plane1, texel_weights) * texel_weights_int;
+				sum_plane2 += vtable_lookup_32bit(tab_plane2, texel_weights) * texel_weights_int;
+			}
+
+			store(lsr<4>(sum_plane1), weights_plane1 + i);
+			store(lsr<4>(sum_plane2), weights_plane2 + i);
+		}
+	}
+}
+
+/**
+ * @brief Return an FP32 NaN value for use in error colors.
+ *
+ * This NaN encoding will turn into 0xFFFF when converted to an FP16 NaN.
+ *
+ * @return The float color value.
+ */
+static float error_color_nan()
+{
+	if32 v;
+	v.u = 0xFFFFE000U;
+	return v.f;
+}
+
+/* See header for documentation. */
+void decompress_symbolic_block(
+	astcenc_profile decode_mode,
+	const block_size_descriptor& bsd,
+	int xpos,
+	int ypos,
+	int zpos,
+	const symbolic_compressed_block& scb,
+	image_block& blk
+) {
+	blk.xpos = xpos;
+	blk.ypos = ypos;
+	blk.zpos = zpos;
+
+	blk.data_min = vfloat4::zero();
+	blk.data_mean = vfloat4::zero();
+	blk.data_max = vfloat4::zero();
+	blk.grayscale = false;
+
+	// If we detected an error-block, blow up immediately.
+	if (scb.block_type == SYM_BTYPE_ERROR)
+	{
+		for (unsigned int i = 0; i < bsd.texel_count; i++)
+		{
+			blk.data_r[i] = error_color_nan();
+			blk.data_g[i] = error_color_nan();
+			blk.data_b[i] = error_color_nan();
+			blk.data_a[i] = error_color_nan();
+			blk.rgb_lns[i] = 0;
+			blk.alpha_lns[i] = 0;
+		}
+
+		return;
+	}
+
+	if ((scb.block_type == SYM_BTYPE_CONST_F16) ||
+	    (scb.block_type == SYM_BTYPE_CONST_U16))
+	{
+		vfloat4 color;
+		uint8_t use_lns = 0;
+
+		// UNORM16 constant color block
+		if (scb.block_type == SYM_BTYPE_CONST_U16)
+		{
+			vint4 colori(scb.constant_color);
+
+			// Determine the UNORM8 rounding on the decode
+			vmask4 u8_mask = get_u8_component_mask(decode_mode, blk);
+
+			// The real decoder would just use the top 8 bits, but we rescale
+			// in to a 16-bit value that rounds correctly.
+			vint4 colori_u8 = asr<8>(colori) * 257;
+			colori = select(colori, colori_u8, u8_mask);
+
+			vint4 colorf16 = unorm16_to_sf16(colori);
+			color = float16_to_float(colorf16);
+		}
+		// FLOAT16 constant color block
+		else
+		{
+			switch (decode_mode)
+			{
+			case ASTCENC_PRF_LDR_SRGB:
+			case ASTCENC_PRF_LDR:
+				color = vfloat4(error_color_nan());
+				break;
+			case ASTCENC_PRF_HDR_RGB_LDR_A:
+			case ASTCENC_PRF_HDR:
+				// Constant-color block; unpack from FP16 to FP32.
+				color = float16_to_float(vint4(scb.constant_color));
+				use_lns = 1;
+				break;
+			}
+		}
+
+		for (unsigned int i = 0; i < bsd.texel_count; i++)
+		{
+			blk.data_r[i] = color.lane<0>();
+			blk.data_g[i] = color.lane<1>();
+			blk.data_b[i] = color.lane<2>();
+			blk.data_a[i] = color.lane<3>();
+			blk.rgb_lns[i] = use_lns;
+			blk.alpha_lns[i] = use_lns;
+		}
+
+		return;
+	}
+
+	// Get the appropriate partition-table entry
+	int partition_count = scb.partition_count;
+	const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
+
+	// Get the appropriate block descriptors
+	const auto& bm = bsd.get_block_mode(scb.block_mode);
+	const auto& di = bsd.get_decimation_info(bm.decimation_mode);
+
+	bool is_dual_plane = static_cast<bool>(bm.is_dual_plane);
+
+	// Unquantize and undecimate the weights
+	int plane1_weights[BLOCK_MAX_TEXELS];
+	int plane2_weights[BLOCK_MAX_TEXELS];
+	unpack_weights(bsd, scb, di, is_dual_plane, plane1_weights, plane2_weights);
+
+	// Now that we have endpoint colors and weights, we can unpack texel colors
+	int plane2_component = scb.plane2_component;
+	vmask4 plane2_mask = vint4::lane_id() == vint4(plane2_component);
+
+	vmask4 u8_mask = get_u8_component_mask(decode_mode, blk);
+
+	for (int i = 0; i < partition_count; i++)
+	{
+		// Decode the color endpoints for this partition
+		vint4 ep0;
+		vint4 ep1;
+		bool rgb_lns;
+		bool a_lns;
+
+		unpack_color_endpoints(decode_mode,
+		                       scb.color_formats[i],
+		                       scb.color_values[i],
+		                       rgb_lns, a_lns,
+		                       ep0, ep1);
+
+		vmask4 lns_mask(rgb_lns, rgb_lns, rgb_lns, a_lns);
+
+		int texel_count = pi.partition_texel_count[i];
+		for (int j = 0; j < texel_count; j++)
+		{
+			int tix = pi.texels_of_partition[i][j];
+			vint4 weight = select(vint4(plane1_weights[tix]), vint4(plane2_weights[tix]), plane2_mask);
+			vint4 color = lerp_color_int(u8_mask, ep0, ep1, weight);
+			vfloat4 colorf = decode_texel(color, lns_mask);
+
+			blk.data_r[tix] = colorf.lane<0>();
+			blk.data_g[tix] = colorf.lane<1>();
+			blk.data_b[tix] = colorf.lane<2>();
+			blk.data_a[tix] = colorf.lane<3>();
+		}
+	}
+}
+
+#if !defined(ASTCENC_DECOMPRESS_ONLY)
+
+/* See header for documentation. */
+float compute_symbolic_block_difference_2plane(
+	const astcenc_config& config,
+	const block_size_descriptor& bsd,
+	const symbolic_compressed_block& scb,
+	const image_block& blk
+) {
+	// If we detected an error-block, blow up immediately.
+	if (scb.block_type == SYM_BTYPE_ERROR)
+	{
+		return ERROR_CALC_DEFAULT;
+	}
+
+	assert(scb.block_mode >= 0);
+	assert(scb.partition_count == 1);
+	assert(bsd.get_block_mode(scb.block_mode).is_dual_plane == 1);
+
+	// Get the appropriate block descriptor
+	const block_mode& bm = bsd.get_block_mode(scb.block_mode);
+	const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
+
+	// Unquantize and undecimate the weights
+	int plane1_weights[BLOCK_MAX_TEXELS];
+	int plane2_weights[BLOCK_MAX_TEXELS];
+	unpack_weights(bsd, scb, di, true, plane1_weights, plane2_weights);
+
+	vmask4 plane2_mask = vint4::lane_id() == vint4(scb.plane2_component);
+
+	vfloat4 summa = vfloat4::zero();
+
+	// Decode the color endpoints for this partition
+	vint4 ep0;
+	vint4 ep1;
+	bool rgb_lns;
+	bool a_lns;
+
+	unpack_color_endpoints(config.profile,
+	                       scb.color_formats[0],
+	                       scb.color_values[0],
+	                       rgb_lns, a_lns,
+	                       ep0, ep1);
+
+	vmask4 u8_mask = get_u8_component_mask(config.profile, blk);
+
+	// Unpack and compute error for each texel in the partition
+	unsigned int texel_count = bsd.texel_count;
+	for (unsigned int i = 0; i < texel_count; i++)
+	{
+		vint4 weight = select(vint4(plane1_weights[i]), vint4(plane2_weights[i]), plane2_mask);
+		vint4 colori = lerp_color_int(u8_mask, ep0, ep1, weight);
+
+		vfloat4 color = int_to_float(colori);
+		vfloat4 oldColor = blk.texel(i);
+
+		// Compare error using a perceptual decode metric for RGBM textures
+		if (config.flags & ASTCENC_FLG_MAP_RGBM)
+		{
+			// Fail encodings that result in zero weight M pixels. Note that this can cause
+			// "interesting" artifacts if we reject all useful encodings - we typically get max
+			// brightness encodings instead which look just as bad. We recommend users apply a
+			// bias to their stored M value, limiting the lower value to 16 or 32 to avoid
+			// getting small M values post-quantization, but we can't prove it would never
+			// happen, especially at low bit rates ...
+			if (color.lane<3>() == 0.0f)
+			{
+				return -ERROR_CALC_DEFAULT;
+			}
+
+			// Compute error based on decoded RGBM color
+			color = vfloat4(
+				color.lane<0>() * color.lane<3>() * config.rgbm_m_scale,
+				color.lane<1>() * color.lane<3>() * config.rgbm_m_scale,
+				color.lane<2>() * color.lane<3>() * config.rgbm_m_scale,
+				1.0f
+			);
+
+			oldColor = vfloat4(
+				oldColor.lane<0>() * oldColor.lane<3>() * config.rgbm_m_scale,
+				oldColor.lane<1>() * oldColor.lane<3>() * config.rgbm_m_scale,
+				oldColor.lane<2>() * oldColor.lane<3>() * config.rgbm_m_scale,
+				1.0f
+			);
+		}
+
+		vfloat4 error = oldColor - color;
+		error = min(abs(error), 1e15f);
+		error = error * error;
+
+		summa += min(dot(error, blk.channel_weight), ERROR_CALC_DEFAULT);
+	}
+
+	return summa.lane<0>();
+}
+
+/* See header for documentation. */
+float compute_symbolic_block_difference_1plane(
+	const astcenc_config& config,
+	const block_size_descriptor& bsd,
+	const symbolic_compressed_block& scb,
+	const image_block& blk
+) {
+	assert(bsd.get_block_mode(scb.block_mode).is_dual_plane == 0);
+
+	// If we detected an error-block, blow up immediately.
+	if (scb.block_type == SYM_BTYPE_ERROR)
+	{
+		return ERROR_CALC_DEFAULT;
+	}
+
+	assert(scb.block_mode >= 0);
+
+	// Get the appropriate partition-table entry
+	unsigned int partition_count = scb.partition_count;
+	const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
+
+	// Get the appropriate block descriptor
+	const block_mode& bm = bsd.get_block_mode(scb.block_mode);
+	const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
+
+	// Unquantize and undecimate the weights
+	int plane1_weights[BLOCK_MAX_TEXELS];
+	unpack_weights(bsd, scb, di, false, plane1_weights, nullptr);
+
+	vmask4 u8_mask = get_u8_component_mask(config.profile, blk);
+
+	vfloat4 summa = vfloat4::zero();
+	for (unsigned int i = 0; i < partition_count; i++)
+	{
+		// Decode the color endpoints for this partition
+		vint4 ep0;
+		vint4 ep1;
+		bool rgb_lns;
+		bool a_lns;
+
+		unpack_color_endpoints(config.profile,
+		                       scb.color_formats[i],
+		                       scb.color_values[i],
+		                       rgb_lns, a_lns,
+		                       ep0, ep1);
+
+		// Unpack and compute error for each texel in the partition
+		unsigned int texel_count = pi.partition_texel_count[i];
+		for (unsigned int j = 0; j < texel_count; j++)
+		{
+			unsigned int tix = pi.texels_of_partition[i][j];
+			vint4 colori = lerp_color_int(u8_mask, ep0, ep1,
+			                              vint4(plane1_weights[tix]));
+
+			vfloat4 color = int_to_float(colori);
+			vfloat4 oldColor = blk.texel(tix);
+
+			// Compare error using a perceptual decode metric for RGBM textures
+			if (config.flags & ASTCENC_FLG_MAP_RGBM)
+			{
+				// Fail encodings that result in zero weight M pixels. Note that this can cause
+				// "interesting" artifacts if we reject all useful encodings - we typically get max
+				// brightness encodings instead which look just as bad. We recommend users apply a
+				// bias to their stored M value, limiting the lower value to 16 or 32 to avoid
+				// getting small M values post-quantization, but we can't prove it would never
+				// happen, especially at low bit rates ...
+				if (color.lane<3>() == 0.0f)
+				{
+					return -ERROR_CALC_DEFAULT;
+				}
+
+				// Compute error based on decoded RGBM color
+				color = vfloat4(
+					color.lane<0>() * color.lane<3>() * config.rgbm_m_scale,
+					color.lane<1>() * color.lane<3>() * config.rgbm_m_scale,
+					color.lane<2>() * color.lane<3>() * config.rgbm_m_scale,
+					1.0f
+				);
+
+				oldColor = vfloat4(
+					oldColor.lane<0>() * oldColor.lane<3>() * config.rgbm_m_scale,
+					oldColor.lane<1>() * oldColor.lane<3>() * config.rgbm_m_scale,
+					oldColor.lane<2>() * oldColor.lane<3>() * config.rgbm_m_scale,
+					1.0f
+				);
+			}
+
+			vfloat4 error = oldColor - color;
+			error = min(abs(error), 1e15f);
+			error = error * error;
+
+			summa += min(dot(error, blk.channel_weight), ERROR_CALC_DEFAULT);
+		}
+	}
+
+	return summa.lane<0>();
+}
+
+/* See header for documentation. */
+float compute_symbolic_block_difference_1plane_1partition(
+	const astcenc_config& config,
+	const block_size_descriptor& bsd,
+	const symbolic_compressed_block& scb,
+	const image_block& blk
+) {
+	// If we detected an error-block, blow up immediately.
+	if (scb.block_type == SYM_BTYPE_ERROR)
+	{
+		return ERROR_CALC_DEFAULT;
+	}
+
+	assert(scb.block_mode >= 0);
+	assert(bsd.get_partition_info(scb.partition_count, scb.partition_index).partition_count == 1);
+
+	// Get the appropriate block descriptor
+	const block_mode& bm = bsd.get_block_mode(scb.block_mode);
+	const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
+
+	// Unquantize and undecimate the weights
+	ASTCENC_ALIGNAS int plane1_weights[BLOCK_MAX_TEXELS];
+	unpack_weights(bsd, scb, di, false, plane1_weights, nullptr);
+
+	// Decode the color endpoints for this partition
+	vint4 ep0;
+	vint4 ep1;
+	bool rgb_lns;
+	bool a_lns;
+
+	unpack_color_endpoints(config.profile,
+	                       scb.color_formats[0],
+	                       scb.color_values[0],
+	                       rgb_lns, a_lns,
+	                       ep0, ep1);
+
+	vmask4 u8_mask = get_u8_component_mask(config.profile, blk);
+
+	// Unpack and compute error for each texel in the partition
+	vfloatacc summav = vfloatacc::zero();
+
+	vint lane_id = vint::lane_id();
+
+	unsigned int texel_count = bsd.texel_count;
+	for (unsigned int i = 0; i < texel_count; i += ASTCENC_SIMD_WIDTH)
+	{
+		// Compute EP1 contribution
+		vint weight1 = vint::loada(plane1_weights + i);
+		vint ep1_r = vint(ep1.lane<0>()) * weight1;
+		vint ep1_g = vint(ep1.lane<1>()) * weight1;
+		vint ep1_b = vint(ep1.lane<2>()) * weight1;
+		vint ep1_a = vint(ep1.lane<3>()) * weight1;
+
+		// Compute EP0 contribution
+		vint weight0 = vint(64) - weight1;
+		vint ep0_r = vint(ep0.lane<0>()) * weight0;
+		vint ep0_g = vint(ep0.lane<1>()) * weight0;
+		vint ep0_b = vint(ep0.lane<2>()) * weight0;
+		vint ep0_a = vint(ep0.lane<3>()) * weight0;
+
+		// Combine contributions
+		vint colori_r = asr<6>(ep0_r + ep1_r + vint(32));
+		vint colori_g = asr<6>(ep0_g + ep1_g + vint(32));
+		vint colori_b = asr<6>(ep0_b + ep1_b + vint(32));
+		vint colori_a = asr<6>(ep0_a + ep1_a + vint(32));
+
+		// If using a U8 decode mode bit replicate top 8 bits
+		// so rest of codec can assume 0xFFFF max range everywhere
+		vint colori_r8 = asr<8>(colori_r) * vint(257);
+		colori_r = select(colori_r, colori_r8, vmask(u8_mask.lane<0>()));
+
+		vint colori_g8 = asr<8>(colori_g) * vint(257);
+		colori_g = select(colori_g, colori_g8, vmask(u8_mask.lane<1>()));
+
+		vint colori_b8 = asr<8>(colori_b) * vint(257);
+		colori_b = select(colori_b, colori_b8, vmask(u8_mask.lane<2>()));
+
+		vint colori_a8 = asr<8>(colori_a) * vint(257);
+		colori_a = select(colori_a, colori_a8, vmask(u8_mask.lane<3>()));
+
+		// Compute color diff
+		vfloat color_r = int_to_float(colori_r);
+		vfloat color_g = int_to_float(colori_g);
+		vfloat color_b = int_to_float(colori_b);
+		vfloat color_a = int_to_float(colori_a);
+
+		vfloat color_orig_r = loada(blk.data_r + i);
+		vfloat color_orig_g = loada(blk.data_g + i);
+		vfloat color_orig_b = loada(blk.data_b + i);
+		vfloat color_orig_a = loada(blk.data_a + i);
+
+		vfloat color_error_r = min(abs(color_orig_r - color_r), vfloat(1e15f));
+		vfloat color_error_g = min(abs(color_orig_g - color_g), vfloat(1e15f));
+		vfloat color_error_b = min(abs(color_orig_b - color_b), vfloat(1e15f));
+		vfloat color_error_a = min(abs(color_orig_a - color_a), vfloat(1e15f));
+
+		// Compute squared error metric
+		color_error_r = color_error_r * color_error_r;
+		color_error_g = color_error_g * color_error_g;
+		color_error_b = color_error_b * color_error_b;
+		color_error_a = color_error_a * color_error_a;
+
+		vfloat metric = color_error_r * blk.channel_weight.lane<0>()
+		              + color_error_g * blk.channel_weight.lane<1>()
+		              + color_error_b * blk.channel_weight.lane<2>()
+		              + color_error_a * blk.channel_weight.lane<3>();
+
+		// Mask off bad lanes
+		vmask mask = lane_id < vint(texel_count);
+		lane_id += vint(ASTCENC_SIMD_WIDTH);
+		haccumulate(summav, metric, mask);
+	}
+
+	return hadd_s(summav);
+}
+
+#endif