libsharpyuv: add colorspace utilities

Change-Id: I620c8593dc81f39e747de5ed354332adb7278bed

Android.mk

@@ -35,6 +35,7 @@ endif
 
 sharpyuv_srcs := \
     sharpyuv/sharpyuv.c \
+    sharpyuv/sharpyuv_csp.c \
     sharpyuv/sharpyuv_dsp.c \
     sharpyuv/sharpyuv_neon.$(NEON) \
     sharpyuv/sharpyuv_sse2.c \

CMakeLists.txt

@@ -220,6 +220,7 @@ target_include_directories(sharpyuv
 set_target_properties(
   sharpyuv
   PROPERTIES PUBLIC_HEADER "${CMAKE_CURRENT_SOURCE_DIR}/sharpyuv/sharpyuv.h;\
+${CMAKE_CURRENT_SOURCE_DIR}/sharpyuv/sharpyuv_csp.h;\
 ${CMAKE_CURRENT_SOURCE_DIR}/src/webp/types.h")
 
 if(MSVC)

build.gradle

@@ -107,6 +107,7 @@ model {
           source {
             srcDir "sharpyuv"
             include "sharpyuv.c"
+            include "sharpyuv_csp.c"
             include "sharpyuv_dsp.c"
             include "sharpyuv_neon.c"
             include "sharpyuv_sse2.c"

makefile.unix

@@ -127,6 +127,7 @@ ANIM_UTIL_OBJS = \
 
 SHARPYUV_OBJS = \
     sharpyuv/sharpyuv.o \
+    sharpyuv/sharpyuv_csp.o \
     sharpyuv/sharpyuv_dsp.o \
     sharpyuv/sharpyuv_neon.o \
     sharpyuv/sharpyuv_sse2.o \

sharpyuv/Makefile.am

@@ -20,6 +20,7 @@ libsharpyuv_neon_la_CPPFLAGS = $(libsharpyuv_la_CPPFLAGS)
 libsharpyuv_neon_la_CFLAGS = $(AM_CFLAGS) $(NEON_FLAGS)
 
 libsharpyuv_la_SOURCES =
+libsharpyuv_la_SOURCES += sharpyuv_csp.c sharpyuv_csp.h
 libsharpyuv_la_SOURCES += sharpyuv_dsp.c sharpyuv_dsp.h
 libsharpyuv_la_SOURCES += sharpyuv.c sharpyuv.h
 

sharpyuv/sharpyuv.c

@@ -11,7 +11,7 @@
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
-#include "./sharpyuv.h"
+#include "sharpyuv/sharpyuv.h"
 
 #include <assert.h>
 #include <stdlib.h>
@@ -455,17 +455,6 @@ void SharpYuvInit(VP8CPUInfo cpu_info_func) {
   sharpyuv_last_cpuinfo_used = cpu_info_func;
 }
 
-// In YUV_FIX fixed point precision.
-static const SharpYuvConversionMatrix kWebpYuvMatrix = {
-  {16839,  33059,  6420,  16 << 16},
-  {-9719, -19081, 28800, 128 << 16},
-  {28800, -24116, -4684, 128 << 16},
-};
-
-const SharpYuvConversionMatrix* SharpYuvGetWebpMatrix(void) {
-  return &kWebpYuvMatrix;
-}
-
 int SharpYuvConvert(const uint8_t* r_ptr, const uint8_t* g_ptr,
                   const uint8_t* b_ptr, int step, int rgb_stride,
                   uint8_t* dst_y, int dst_stride_y, uint8_t* dst_u,

sharpyuv/sharpyuv.h

@@ -29,18 +29,15 @@ typedef struct {
   int rgb_to_v[4];
 } SharpYuvConversionMatrix;
 
-// Returns the RGB to YUV matrix used by WebP.
-const SharpYuvConversionMatrix* SharpYuvGetWebpMatrix(void);
-
 // Converts RGB to YUV420 using a downsampling algorithm that minimizes
 // artefacts caused by chroma subsampling.
 // This is slower than standard downsampling (averaging of 4 UV values).
 // Assumes that the image will be upsampled using a bilinear filter. If nearest
 // neighbor is used instead, the upsampled image might look worse than with
 // standard downsampling.
-// TODO(maryla): add 10 bits and handling of various colorspaces. Add YUV444 to
-// YUV420 conversion. Maybe also add 422 support (it's rarely used in practice,
-// especially for images).
+// TODO(maryla): add 10 bits support. Add YUV444 to YUV420 conversion.
+// Maybe also add 422 support (it's rarely used in practice, especially for
+// images).
 int SharpYuvConvert(const uint8_t* r_ptr, const uint8_t* g_ptr,
                     const uint8_t* b_ptr, int step, int rgb_stride,
                     uint8_t* dst_y, int dst_stride_y, uint8_t* dst_u,

sharpyuv/sharpyuv_csp.c

@@ -0,0 +1,111 @@
+// Copyright 2022 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Colorspace utilities.
+
+#include "sharpyuv/sharpyuv_csp.h"
+
+#include <assert.h>
+#include <math.h>
+#include <string.h>
+
+static int ToFixed16(float f) { return (int)round(f * (1 << 16)); }
+
+void SharpYuvComputeConversionMatrix(const SharpYuvColorSpace* yuv_color_space,
+                                     SharpYuvConversionMatrix* matrix) {
+  const float kr = yuv_color_space->kr;
+  const float kb = yuv_color_space->kb;
+  const float kg = 1.0f - kr - kb;
+  const float cr = 0.5f / (1.0f - kb);
+  const float cb = 0.5f / (1.0f - kr);
+
+  const int shift = yuv_color_space->bits - 8;
+
+  const float denom = (float)((1 << yuv_color_space->bits) - 1);
+  float scaleY = 1.0f;
+  float addY = 0.0f;
+  float scaleU = cr;
+  float scaleV = cb;
+  float addUV = (128 << shift);
+
+  assert(yuv_color_space->bits >= 8);
+
+  if (yuv_color_space->range == kSharpYuvRangeLimited) {
+    scaleY *= (219 << shift) / denom;
+    scaleU *= (224 << shift) / denom;
+    scaleV *= (224 << shift) / denom;
+    addY = (16 << shift);
+  }
+
+  matrix->rgb_to_y[0] = ToFixed16(kr * scaleY);
+  matrix->rgb_to_y[1] = ToFixed16(kg * scaleY);
+  matrix->rgb_to_y[2] = ToFixed16(kb * scaleY);
+  matrix->rgb_to_y[3] = ToFixed16(addY);
+
+  matrix->rgb_to_u[0] = ToFixed16(-kr * scaleU);
+  matrix->rgb_to_u[1] = ToFixed16(-kg * scaleU);
+  matrix->rgb_to_u[2] = ToFixed16((1 - kb) * scaleU);
+  matrix->rgb_to_u[3] = ToFixed16(addUV);
+
+  matrix->rgb_to_v[0] = ToFixed16((1 - kr) * scaleV);
+  matrix->rgb_to_v[1] = ToFixed16(-kg * scaleV);
+  matrix->rgb_to_v[2] = ToFixed16(-kb * scaleV);
+  matrix->rgb_to_v[3] = ToFixed16(addUV);
+}
+
+// Matrices are in YUV_FIX fixed point precision.
+// WebP's matrix, similar but not identical to kRec601LimitedMatrix.
+static const SharpYuvConversionMatrix kWebpMatrix = {
+  {16839, 33059, 6420, 16 << 16},
+  {-9719, -19081, 28800, 128 << 16},
+  {28800, -24116, -4684, 128 << 16},
+};
+// Kr=0.2990f Kb=0.1140f btits=8 range=kLimited
+static const SharpYuvConversionMatrix kRec601LimitedMatrix = {
+  {16829, 33039, 6416, 16 << 16},
+  {-9714, -19071, 28784, 128 << 16},
+  {28784, -24103, -4681, 128 << 16},
+};
+// Kr=0.2990f Kb=0.1140f btits=8 range=kFull
+static const SharpYuvConversionMatrix kRec601FullMatrix = {
+  {19595, 38470, 7471, 0},
+  {-11058, -21710, 32768, 128 << 16},
+  {32768, -27439, -5329, 128 << 16},
+};
+// Kr=0.2126f Kb=0.0722f bits=8 range=kLimited
+static const SharpYuvConversionMatrix kRec709LimitedMatrix = {
+  {11966, 40254, 4064, 16 << 16},
+  {-6596, -22189, 28784, 128 << 16},
+  {28784, -26145, -2639, 128 << 16},
+};
+// Kr=0.2126f Kb=0.0722f bits=8 range=kFull
+static const SharpYuvConversionMatrix kRec709FullMatrix = {
+  {13933, 46871, 4732, 0},
+  {-7509, -25259, 32768, 128 << 16},
+  {32768, -29763, -3005, 128 << 16},
+};
+
+const SharpYuvConversionMatrix* SharpYuvGetConversionMatrix(
+    SharpYuvMatrixType matrix_type) {
+  switch (matrix_type) {
+    case kSharpYuvMatrixWebp:
+      return &kWebpMatrix;
+    case kSharpYuvMarixRec601Limited:
+      return &kRec601LimitedMatrix;
+    case kSharpYuvMarixRec601Full:
+      return &kRec601FullMatrix;
+    case kSharpYuvMarixRec709Limited:
+      return &kRec709LimitedMatrix;
+    case kSharpYuvMarixRec709Full:
+      return &kRec709FullMatrix;
+    case kSharpYuvMarixNum:
+      return NULL;
+  }
+  return NULL;
+}

sharpyuv/sharpyuv_csp.h

@@ -0,0 +1,59 @@
+// Copyright 2022 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Colorspace utilities.
+
+#ifndef WEBP_SHARPYUV_SHARPYUV_CSP_H_
+#define WEBP_SHARPYUV_SHARPYUV_CSP_H_
+
+#include "sharpyuv/sharpyuv.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Range of YUV values.
+typedef enum {
+  kSharpYuvRangeFull,     // YUV values between [0;255] (for 8 bit)
+  kSharpYuvRangeLimited   // Y in [16;235], YUV in [16;240] (for 8 bit)
+} SharpYuvRange;
+
+// Constants that define a YUV color space.
+typedef struct {
+  // Kr and Kb are defined such that:
+  // Y = Kr * r + Kg * g + Kb * b where Kg = 1 - Kr - Kb.
+  float kr;
+  float kb;
+  int bits;  // Only 8 bit is supported by SharpYuvConvert.
+  SharpYuvRange range;
+} SharpYuvColorSpace;
+
+// Fills in 'matrix' for the given YUVColorSpace.
+void SharpYuvComputeConversionMatrix(const SharpYuvColorSpace* yuv_color_space,
+                                     SharpYuvConversionMatrix* matrix);
+
+// Enums for precomputed conversion matrices.
+typedef enum {
+  kSharpYuvMatrixWebp = 0,
+  kSharpYuvMarixRec601Limited,
+  kSharpYuvMarixRec601Full,
+  kSharpYuvMarixRec709Limited,
+  kSharpYuvMarixRec709Full,
+  kSharpYuvMarixNum
+} SharpYuvMatrixType;
+
+// Returns a pointer to a matrix for one of the predefined colorspaces.
+const SharpYuvConversionMatrix* SharpYuvGetConversionMatrix(
+    SharpYuvMatrixType matrix_type);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // WEBP_SHARPYUV_SHARPYUV_CSP_H_

sharpyuv/sharpyuv_dsp.h

@@ -9,8 +9,8 @@
 //
 // Speed-critical functions for Sharp YUV.
 
-#ifndef WEBP_SHARPYUV_DSP_H_
-#define WEBP_SHARPYUV_DSP_H_
+#ifndef WEBP_SHARPYUV_SHARPYUV_DSP_H_
+#define WEBP_SHARPYUV_SHARPYUV_DSP_H_
 
 #include <stdint.h>
 
@@ -25,4 +25,4 @@ extern void (*SharpYUVFilterRow)(const int16_t* A, const int16_t* B, int len,
 
 void SharpYuvInitDsp(VP8CPUInfo cpu_info_func);
 
-#endif  // WEBP_SHARPYUV_DSP_H_
+#endif  // WEBP_SHARPYUV_SHARPYUV_DSP_H_

src/enc/picture_csp_enc.c

@@ -16,6 +16,7 @@
 #include <math.h>
 
 #include "sharpyuv/sharpyuv.h"
+#include "sharpyuv/sharpyuv_csp.h"
 #include "src/enc/vp8i_enc.h"
 #include "src/utils/random_utils.h"
 #include "src/utils/utils.h"
@@ -202,7 +203,8 @@ static int PreprocessARGB(const uint8_t* r_ptr,
   const int ok = SharpYuvConvert(
       r_ptr, g_ptr, b_ptr, step, rgb_stride, picture->y, picture->y_stride,
       picture->u, picture->uv_stride, picture->v, picture->uv_stride,
-      picture->width, picture->height, SharpYuvGetWebpMatrix());
+      picture->width, picture->height,
+      SharpYuvGetConversionMatrix(kSharpYuvMatrixWebp));
   if (!ok) {
     return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
   }