src/gallium/auxiliary/vl/vl_csc.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 Younes Manton.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "util/u_math.h"
  29 #include "util/u_debug.h"
  30
  31 #include "vl_csc.h"
  32
  33 /*
  34  * Color space conversion formulas
  35  *
  36  * To convert YCbCr to RGB,
  37  *    vec4  ycbcr, rgb
  38  *    mat44 csc
  39  *    rgb = csc * ycbcr
  40  *
  41  * To calculate the color space conversion matrix csc with ProcAmp adjustments,
  42  *    mat44 csc, cstd, procamp, bias
  43  *    csc = cstd * (procamp * bias)
  44  *
  45  * Where cstd is a matrix corresponding to one of the color standards (BT.601, BT.709, etc)
  46  * adjusted for the kind of YCbCr -> RGB mapping wanted (1:1, full),
  47  * bias is a matrix corresponding to the kind of YCbCr -> RGB mapping wanted (1:1, full)
  48  *
  49  * To calculate procamp,
  50  *    mat44 procamp, hue, saturation, brightness, contrast
  51  *    procamp = brightness * (saturation * (contrast * hue))
  52  * Alternatively,
  53  *    procamp = saturation * (brightness * (contrast * hue))
  54  *
  55  * contrast
  56  * [ c, 0, 0, 0]
  57  * [ 0, c, 0, 0]
  58  * [ 0, 0, c, 0]
  59  * [ 0, 0, 0, 1]
  60  *
  61  * brightness
  62  * [ 1, 0, 0, b/c]
  63  * [ 0, 1, 0,   0]
  64  * [ 0, 0, 1,   0]
  65  * [ 0, 0, 0,   1]
  66  *
  67  * saturation
  68  * [ 1, 0, 0, 0]
  69  * [ 0, s, 0, 0]
  70  * [ 0, 0, s, 0]
  71  * [ 0, 0, 0, 1]
  72  *
  73  * hue
  74  * [ 1,       0,      0, 0]
  75  * [ 0,  cos(h), sin(h), 0]
  76  * [ 0, -sin(h), cos(h), 0]
  77  * [ 0,       0,      0, 1]
  78  *
  79  * procamp
  80  * [ c,           0,          0, b]
  81  * [ 0,  c*s*cos(h), c*s*sin(h), 0]
  82  * [ 0, -c*s*sin(h), c*s*cos(h), 0]
  83  * [ 0,           0,          0, 1]
  84  *
  85  * bias
  86  * [ 1, 0, 0,  ybias]
  87  * [ 0, 1, 0, cbbias]
  88  * [ 0, 0, 1, crbias]
  89  * [ 0, 0, 0,      1]
  90  *
  91  * csc
  92  * [ c*cstd[ 0], c*cstd[ 1]*s*cos(h) - c*cstd[ 2]*s*sin(h), c*cstd[ 2]*s*cos(h) + c*cstd[ 1]*s*sin(h), cstd[ 3] + cstd[ 0]*(b + c*ybias) + cstd[ 1]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 2]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))]
  93  * [ c*cstd[ 4], c*cstd[ 5]*s*cos(h) - c*cstd[ 6]*s*sin(h), c*cstd[ 6]*s*cos(h) + c*cstd[ 5]*s*sin(h), cstd[ 7] + cstd[ 4]*(b + c*ybias) + cstd[ 5]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 6]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))]
  94  * [ c*cstd[ 8], c*cstd[ 9]*s*cos(h) - c*cstd[10]*s*sin(h), c*cstd[10]*s*cos(h) + c*cstd[ 9]*s*sin(h), cstd[11] + cstd[ 8]*(b + c*ybias) + cstd[ 9]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[10]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))]
  95  * [ c*cstd[12], c*cstd[13]*s*cos(h) - c*cstd[14]*s*sin(h), c*cstd[14]*s*cos(h) + c*cstd[13]*s*sin(h), cstd[15] + cstd[12]*(b + c*ybias) + cstd[13]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[14]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))]
  96  */
  97
  98 /*
  99  * Converts ITU-R BT.601 YCbCr pixels to RGB pixels where:
 100  * Y is in [16,235], Cb and Cr are in [16,240]
 101  * R, G, and B are in [16,235]
 102  */
 103 static const vl_csc_matrix bt_601 =
 104 {
 105    { 1.0f,  0.0f,    1.371f, 0.0f, },
 106    { 1.0f, -0.336f, -0.698f, 0.0f, },
 107    { 1.0f,  1.732f,  0.0f,   0.0f, }
 108 };
 109
 110 /*
 111  * Converts ITU-R BT.709 YCbCr pixels to RGB pixels where:
 112  * Y is in [16,235], Cb and Cr are in [16,240]
 113  * R, G, and B are in [16,235]
 114  */
 115 static const vl_csc_matrix bt_709 =
 116 {
 117    { 1.0f,  0.0f,    1.540f, 0.0f, },
 118    { 1.0f, -0.183f, -0.459f, 0.0f, },
 119    { 1.0f,  1.816f,  0.0f,   0.0f, }
 120 };
 121
 122 /*
 123  * Converts SMPTE 240M YCbCr pixels to RGB pixels where:
 124  * Y is in [16,235], Cb and Cr are in [16,240]
 125  * R, G, and B are in [16,235]
 126  */
 127 static const vl_csc_matrix smpte240m =
 128 {
 129    { 1.0f,  0.0f,    1.541f, 0.0f, },
 130    { 1.0f, -0.221f, -0.466f, 0.0f, },
 131    { 1.0f,  1.785f,  0.0f,   0.0f, }
 132 };
 133
 134 static const vl_csc_matrix bt_709_rev  = {
 135    { 0.183f,  0.614f,  0.062f, 0.0625f},
 136    {-0.101f, -0.338f,  0.439f, 0.5f   },
 137    { 0.439f, -0.399f, -0.040f, 0.5f   }
 138 };
 139
 140 static const vl_csc_matrix identity =
 141 {
 142    { 1.0f, 0.0f, 0.0f, 0.0f, },
 143    { 0.0f, 1.0f, 0.0f, 0.0f, },
 144    { 0.0f, 0.0f, 1.0f, 0.0f, }
 145 };
 146
 147 const struct vl_procamp vl_default_procamp = {
 148    0.0f,  /* brightness */
 149    1.0f,  /* contrast   */
 150    1.0f,  /* saturation */
 151    0.0f   /* hue        */
 152 };
 153
 154 void vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs,
 155                        struct vl_procamp *procamp,
 156                        bool full_range,
 157                        vl_csc_matrix *matrix)
 158 {
 159    float cbbias = -128.0f/255.0f;
 160    float crbias = -128.0f/255.0f;
 161
 162    const struct vl_procamp *p = procamp ? procamp : &vl_default_procamp;
 163    float c = p->contrast;
 164    float s = p->saturation;
 165    float b = p->brightness;
 166    float h = p->hue;
 167    float x, y;
 168
 169    const vl_csc_matrix *cstd;
 170
 171    if (full_range) {
 172       c *= 1.164f;              /* Adjust for the y range */
 173       b *= 1.164f;              /* Adjust for the y range */
 174       b -= c * 16.0f  / 255.0f; /* Adjust for the y bias */
 175    }
 176
 177    /* Parameter substitutions */
 178    x = c * s * cosf(h);
 179    y = c * s * sinf(h);
 180
 181    assert(matrix);
 182
 183    switch (cs) {
 184       case VL_CSC_COLOR_STANDARD_BT_601:
 185          cstd = &bt_601;
 186          break;
 187       case VL_CSC_COLOR_STANDARD_BT_709:
 188          cstd = &bt_709;
 189          break;
 190       case VL_CSC_COLOR_STANDARD_SMPTE_240M:
 191          cstd = &smpte240m;
 192          break;
 193       case VL_CSC_COLOR_STANDARD_BT_709_REV:
 194          memcpy(matrix, bt_709_rev, sizeof(vl_csc_matrix));
 195          return;
 196       case VL_CSC_COLOR_STANDARD_IDENTITY:
 197       default:
 198          assert(cs == VL_CSC_COLOR_STANDARD_IDENTITY);
 199          memcpy(matrix, identity, sizeof(vl_csc_matrix));
 200          return;
 201    }
 202
 203    (*matrix)[0][0] = c * (*cstd)[0][0];
 204    (*matrix)[0][1] = (*cstd)[0][1] * x - (*cstd)[0][2] * y;
 205    (*matrix)[0][2] = (*cstd)[0][2] * x + (*cstd)[0][1] * y;
 206    (*matrix)[0][3] = (*cstd)[0][3] + (*cstd)[0][0] * b +
 207                      (*cstd)[0][1] * (x * cbbias + y * crbias) +
 208                      (*cstd)[0][2] * (x * crbias - y * cbbias);
 209
 210    (*matrix)[1][0] = c * (*cstd)[1][0];
 211    (*matrix)[1][1] = (*cstd)[1][1] * x - (*cstd)[1][2] * y;
 212    (*matrix)[1][2] = (*cstd)[1][2] * x + (*cstd)[1][1] * y;
 213    (*matrix)[1][3] = (*cstd)[1][3] + (*cstd)[1][0] * b +
 214                      (*cstd)[1][1] * (x * cbbias + y * crbias) +
 215                      (*cstd)[1][2] * (x * crbias - y * cbbias);
 216
 217    (*matrix)[2][0] = c * (*cstd)[2][0];
 218    (*matrix)[2][1] = (*cstd)[2][1] * x - (*cstd)[2][2] * y;
 219    (*matrix)[2][2] = (*cstd)[2][2] * x + (*cstd)[2][1] * y;
 220    (*matrix)[2][3] = (*cstd)[2][3] + (*cstd)[2][0] * b +
 221                      (*cstd)[2][1] * (x * cbbias + y * crbias) +
 222                      (*cstd)[2][2] * (x * crbias - y * cbbias);
 223 }