--- /dev/null
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "nir_vulkan.h"
+#include <math.h>
+
+static nir_ssa_def *
+y_range(nir_builder *b,
+ nir_ssa_def *y_channel,
+ int bpc,
+ VkSamplerYcbcrRange range)
+{
+ switch (range) {
+ case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
+ return y_channel;
+ case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
+ return nir_fmul(b,
+ nir_fadd(b,
+ nir_fmul(b, y_channel,
+ nir_imm_float(b, pow(2, bpc) - 1)),
+ nir_imm_float(b, -16.0f * pow(2, bpc - 8))),
+ nir_frcp(b, nir_imm_float(b, 219.0f * pow(2, bpc - 8))));
+ default:
+ unreachable("missing Ycbcr range");
+ return NULL;
+ }
+}
+
+static nir_ssa_def *
+chroma_range(nir_builder *b,
+ nir_ssa_def *chroma_channel,
+ int bpc,
+ VkSamplerYcbcrRange range)
+{
+ switch (range) {
+ case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
+ return nir_fadd(b, chroma_channel,
+ nir_imm_float(b, -pow(2, bpc - 1) / (pow(2, bpc) - 1.0f)));
+ case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
+ return nir_fmul(b,
+ nir_fadd(b,
+ nir_fmul(b, chroma_channel,
+ nir_imm_float(b, pow(2, bpc) - 1)),
+ nir_imm_float(b, -128.0f * pow(2, bpc - 8))),
+ nir_frcp(b, nir_imm_float(b, 224.0f * pow(2, bpc - 8))));
+ default:
+ unreachable("missing Ycbcr range");
+ return NULL;
+ }
+}
+
+typedef struct nir_const_value_3_4 {
+ nir_const_value v[3][4];
+} nir_const_value_3_4;
+
+static const nir_const_value_3_4 *
+ycbcr_model_to_rgb_matrix(VkSamplerYcbcrModelConversion model)
+{
+ switch (model) {
+ case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601: {
+ static const nir_const_value_3_4 bt601 = { {
+ { { .f32 = 1.402f }, { .f32 = 1.0f }, { .f32 = 0.0f }, { .f32 = 0.0f } },
+ { { .f32 = -0.714136286201022f }, { .f32 = 1.0f }, { .f32 = -0.344136286201022f }, { .f32 = 0.0f } },
+ { { .f32 = 0.0f }, { .f32 = 1.0f }, { .f32 = 1.772f }, { .f32 = 0.0f } },
+ } };
+
+ return &bt601;
+ }
+ case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709: {
+ static const nir_const_value_3_4 bt709 = { {
+ { { .f32 = 1.5748031496063f }, { .f32 = 1.0f }, { .f32 = 0.0f }, { .f32 = 0.0f } },
+ { { .f32 = -0.468125209181067f }, { .f32 = 1.0f }, { .f32 = -0.187327487470334f }, { .f32 = 0.0f } },
+ { { .f32 = 0.0f }, { .f32 = 1.0f }, { .f32 = 1.85563184264242f }, { .f32 = 0.0f } },
+ } };
+
+ return &bt709;
+ }
+ case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020: {
+ static const nir_const_value_3_4 bt2020 = { {
+ { { .f32 = 1.4746f }, { .f32 = 1.0f }, { .f32 = 0.0f }, { .f32 = 0.0f } },
+ { { .f32 = -0.571353126843658f }, { .f32 = 1.0f }, { .f32 = -0.164553126843658f }, { .f32 = 0.0f } },
+ { { .f32 = 0.0f }, { .f32 = 1.0f }, { .f32 = 1.8814f }, { .f32 = 0.0f } },
+ } };
+
+ return &bt2020;
+ }
+ default:
+ unreachable("missing Ycbcr model");
+ return NULL;
+ }
+}
+
+nir_ssa_def *
+nir_convert_ycbcr_to_rgb(nir_builder *b,
+ VkSamplerYcbcrModelConversion model,
+ VkSamplerYcbcrRange range,
+ nir_ssa_def *raw_channels,
+ uint32_t *bpcs)
+{
+ nir_ssa_def *expanded_channels =
+ nir_vec4(b,
+ chroma_range(b, nir_channel(b, raw_channels, 0), bpcs[0], range),
+ y_range(b, nir_channel(b, raw_channels, 1), bpcs[1], range),
+ chroma_range(b, nir_channel(b, raw_channels, 2), bpcs[2], range),
+ nir_imm_float(b, 1.0f));
+
+ if (model == VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY)
+ return expanded_channels;
+
+ const nir_const_value_3_4 *conversion_matrix =
+ ycbcr_model_to_rgb_matrix(model);
+
+ nir_ssa_def *converted_channels[] = {
+ nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[0])),
+ nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[1])),
+ nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[2]))
+ };
+
+ return nir_vec4(b,
+ converted_channels[0], converted_channels[1],
+ converted_channels[2], nir_imm_float(b, 1.0f));
+}