FFmpeg
colorspace.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com>
3  * This file is part of FFmpeg.
4  *
5  * FFmpeg is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * FFmpeg is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with FFmpeg; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #include "libavutil/frame.h"
22 #include "libavutil/pixdesc.h"
23 
24 #include "colorspace.h"
25 
26 
27 void ff_matrix_invert_3x3(const double in[3][3], double out[3][3])
28 {
29  double m00 = in[0][0], m01 = in[0][1], m02 = in[0][2],
30  m10 = in[1][0], m11 = in[1][1], m12 = in[1][2],
31  m20 = in[2][0], m21 = in[2][1], m22 = in[2][2];
32  int i, j;
33  double det;
34 
35  out[0][0] = (m11 * m22 - m21 * m12);
36  out[0][1] = -(m01 * m22 - m21 * m02);
37  out[0][2] = (m01 * m12 - m11 * m02);
38  out[1][0] = -(m10 * m22 - m20 * m12);
39  out[1][1] = (m00 * m22 - m20 * m02);
40  out[1][2] = -(m00 * m12 - m10 * m02);
41  out[2][0] = (m10 * m21 - m20 * m11);
42  out[2][1] = -(m00 * m21 - m20 * m01);
43  out[2][2] = (m00 * m11 - m10 * m01);
44 
45  det = m00 * out[0][0] + m10 * out[0][1] + m20 * out[0][2];
46  det = 1.0 / det;
47 
48  for (i = 0; i < 3; i++) {
49  for (j = 0; j < 3; j++)
50  out[i][j] *= det;
51  }
52 }
53 
54 void ff_matrix_mul_3x3(double dst[3][3],
55  const double src1[3][3], const double src2[3][3])
56 {
57  int m, n;
58 
59  for (m = 0; m < 3; m++)
60  for (n = 0; n < 3; n++)
61  dst[m][n] = src2[m][0] * src1[0][n] +
62  src2[m][1] * src1[1][n] +
63  src2[m][2] * src1[2][n];
64 }
65 /*
66  * see e.g. http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
67  */
68 void ff_fill_rgb2xyz_table(const struct PrimaryCoefficients *coeffs,
69  const struct WhitepointCoefficients *wp,
70  double rgb2xyz[3][3])
71 {
72  double i[3][3], sr, sg, sb, zw;
73 
74  rgb2xyz[0][0] = coeffs->xr / coeffs->yr;
75  rgb2xyz[0][1] = coeffs->xg / coeffs->yg;
76  rgb2xyz[0][2] = coeffs->xb / coeffs->yb;
77  rgb2xyz[1][0] = rgb2xyz[1][1] = rgb2xyz[1][2] = 1.0;
78  rgb2xyz[2][0] = (1.0 - coeffs->xr - coeffs->yr) / coeffs->yr;
79  rgb2xyz[2][1] = (1.0 - coeffs->xg - coeffs->yg) / coeffs->yg;
80  rgb2xyz[2][2] = (1.0 - coeffs->xb - coeffs->yb) / coeffs->yb;
81  ff_matrix_invert_3x3(rgb2xyz, i);
82  zw = 1.0 - wp->xw - wp->yw;
83  sr = i[0][0] * wp->xw + i[0][1] * wp->yw + i[0][2] * zw;
84  sg = i[1][0] * wp->xw + i[1][1] * wp->yw + i[1][2] * zw;
85  sb = i[2][0] * wp->xw + i[2][1] * wp->yw + i[2][2] * zw;
86  rgb2xyz[0][0] *= sr;
87  rgb2xyz[0][1] *= sg;
88  rgb2xyz[0][2] *= sb;
89  rgb2xyz[1][0] *= sr;
90  rgb2xyz[1][1] *= sg;
91  rgb2xyz[1][2] *= sb;
92  rgb2xyz[2][0] *= sr;
93  rgb2xyz[2][1] *= sg;
94  rgb2xyz[2][2] *= sb;
95 }
96 static const double ycgco_matrix[3][3] =
97 {
98  { 0.25, 0.5, 0.25 },
99  { -0.25, 0.5, -0.25 },
100  { 0.5, 0, -0.5 },
101 };
102 
103 static const double gbr_matrix[3][3] =
104 {
105  { 0, 1, 0 },
106  { 0, -0.5, 0.5 },
107  { 0.5, -0.5, 0 },
108 };
109 
110 /*
111  * All constants explained in e.g. https://linuxtv.org/downloads/v4l-dvb-apis/ch02s06.html
112  * The older ones (bt470bg/m) are also explained in their respective ITU docs
113  * (e.g. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.470-5-199802-S!!PDF-E.pdf)
114  * whereas the newer ones can typically be copied directly from wikipedia :)
115  */
117  [AVCOL_SPC_FCC] = { 0.30, 0.59, 0.11 },
118  [AVCOL_SPC_BT470BG] = { 0.299, 0.587, 0.114 },
119  [AVCOL_SPC_SMPTE170M] = { 0.299, 0.587, 0.114 },
120  [AVCOL_SPC_BT709] = { 0.2126, 0.7152, 0.0722 },
121  [AVCOL_SPC_SMPTE240M] = { 0.212, 0.701, 0.087 },
122  [AVCOL_SPC_YCOCG] = { 0.25, 0.5, 0.25 },
123  [AVCOL_SPC_RGB] = { 1, 1, 1 },
124  [AVCOL_SPC_BT2020_NCL] = { 0.2627, 0.6780, 0.0593 },
125  [AVCOL_SPC_BT2020_CL] = { 0.2627, 0.6780, 0.0593 },
126 };
127 
129 {
130  const struct LumaCoefficients *coeffs;
131 
132  if (csp >= AVCOL_SPC_NB)
133  return NULL;
134  coeffs = &luma_coefficients[csp];
135  if (!coeffs->cr)
136  return NULL;
137 
138  return coeffs;
139 }
140 
141 void ff_fill_rgb2yuv_table(const struct LumaCoefficients *coeffs,
142  double rgb2yuv[3][3])
143 {
144  double bscale, rscale;
145 
146  // special ycgco matrix
147  if (coeffs->cr == 0.25 && coeffs->cg == 0.5 && coeffs->cb == 0.25) {
148  memcpy(rgb2yuv, ycgco_matrix, sizeof(double) * 9);
149  return;
150  } else if (coeffs->cr == 1 && coeffs->cg == 1 && coeffs->cb == 1) {
151  memcpy(rgb2yuv, gbr_matrix, sizeof(double) * 9);
152  return;
153  }
154 
155  rgb2yuv[0][0] = coeffs->cr;
156  rgb2yuv[0][1] = coeffs->cg;
157  rgb2yuv[0][2] = coeffs->cb;
158  bscale = 0.5 / (coeffs->cb - 1.0);
159  rscale = 0.5 / (coeffs->cr - 1.0);
160  rgb2yuv[1][0] = bscale * coeffs->cr;
161  rgb2yuv[1][1] = bscale * coeffs->cg;
162  rgb2yuv[1][2] = 0.5;
163  rgb2yuv[2][0] = 0.5;
164  rgb2yuv[2][1] = rscale * coeffs->cg;
165  rgb2yuv[2][2] = rscale * coeffs->cb;
166 }
167 
169 {
171  double peak = 0;
172 
173  if (sd) {
175  peak = clm->MaxCLL / REFERENCE_WHITE;
176  }
177 
179  if (!peak && sd) {
181  if (metadata->has_luminance)
182  peak = av_q2d(metadata->max_luminance) / REFERENCE_WHITE;
183  }
184 
185  // For untagged source, use peak of 10000 if SMPTE ST.2084
186  // otherwise assume HLG with reference display peak 1000.
187  if (!peak)
188  peak = in->color_trc == AVCOL_TRC_SMPTE2084 ? 100.0f : 10.0f;
189 
190  return peak;
191 }
192 
193 void ff_update_hdr_metadata(AVFrame *in, double peak)
194 {
196 
197  if (sd) {
199  clm->MaxCLL = (unsigned)(peak * REFERENCE_WHITE);
200  }
201 
203  if (sd) {
205  if (metadata->has_luminance)
206  metadata->max_luminance = av_d2q(peak * REFERENCE_WHITE, 10000);
207  }
208 }
AVFrame::color_trc
enum AVColorTransferCharacteristic color_trc
Definition: frame.h:534
AVMasteringDisplayMetadata::max_luminance
AVRational max_luminance
Max luminance of mastering display (cd/m^2).
Definition: mastering_display_metadata.h:57
gbr_matrix
static const double gbr_matrix[3][3]
Definition: colorspace.c:103
luma_coefficients
static const struct LumaCoefficients luma_coefficients[AVCOL_SPC_NB]
Definition: colorspace.c:116
out
FILE * out
Definition: movenc.c:54
av_frame_get_side_data
AVFrameSideData * av_frame_get_side_data(const AVFrame *frame, enum AVFrameSideDataType type)
Definition: frame.c:617
ff_matrix_invert_3x3
void ff_matrix_invert_3x3(const double in[3][3], double out[3][3])
Definition: colorspace.c:27
AVMasteringDisplayMetadata::has_luminance
int has_luminance
Flag indicating whether the luminance (min_ and max_) have been set.
Definition: mastering_display_metadata.h:67
ycgco_matrix
static const double ycgco_matrix[3][3]
Definition: colorspace.c:96
AVContentLightMetadata::MaxCLL
unsigned MaxCLL
Max content light level (cd/m^2).
Definition: mastering_display_metadata.h:102
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
pixdesc.h
AVCOL_SPC_YCOCG
@ AVCOL_SPC_YCOCG
Definition: pixfmt.h:512
LumaCoefficients::cb
double cb
Definition: colorspace.h:29
AVCOL_SPC_NB
@ AVCOL_SPC_NB
Not part of ABI.
Definition: pixfmt.h:519
LumaCoefficients
Definition: colorspace.h:28
ff_determine_signal_peak
double ff_determine_signal_peak(AVFrame *in)
Definition: colorspace.c:168
AVCOL_SPC_RGB
@ AVCOL_SPC_RGB
order of coefficients is actually GBR, also IEC 61966-2-1 (sRGB), YZX and ST 428-1
Definition: pixfmt.h:503
WhitepointCoefficients::xw
double xw
Definition: colorspace.h:37
AVCOL_SPC_BT2020_CL
@ AVCOL_SPC_BT2020_CL
ITU-R BT2020 constant luminance system.
Definition: pixfmt.h:514
AVContentLightMetadata
Content light level needed by to transmit HDR over HDMI (CTA-861.3).
Definition: mastering_display_metadata.h:98
AVCOL_SPC_BT470BG
@ AVCOL_SPC_BT470BG
also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
Definition: pixfmt.h:508
LumaCoefficients::cg
double cg
Definition: colorspace.h:29
colorspace.h
PrimaryCoefficients
Definition: colorspace.h:32
PrimaryCoefficients::yg
double yg
Definition: colorspace.h:33
ff_get_luma_coefficients
const struct LumaCoefficients * ff_get_luma_coefficients(enum AVColorSpace csp)
Definition: colorspace.c:128
PrimaryCoefficients::xb
double xb
Definition: colorspace.h:33
AVCOL_SPC_SMPTE170M
@ AVCOL_SPC_SMPTE170M
also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
Definition: pixfmt.h:509
ff_fill_rgb2yuv_table
void ff_fill_rgb2yuv_table(const struct LumaCoefficients *coeffs, double rgb2yuv[3][3])
Definition: colorspace.c:141
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
PrimaryCoefficients::xr
double xr
Definition: colorspace.h:33
if
if(ret)
Definition: filter_design.txt:179
rgb2yuv
RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT RGB2YUV_SHIFT uint8_t const uint8_t const uint8_t const uint8_t int uint32_t * rgb2yuv
Definition: input.c:400
ff_matrix_mul_3x3
void ff_matrix_mul_3x3(double dst[3][3], const double src1[3][3], const double src2[3][3])
Definition: colorspace.c:54
NULL
#define NULL
Definition: coverity.c:32
ff_fill_rgb2xyz_table
void ff_fill_rgb2xyz_table(const struct PrimaryCoefficients *coeffs, const struct WhitepointCoefficients *wp, double rgb2xyz[3][3])
Definition: colorspace.c:68
AV_FRAME_DATA_MASTERING_DISPLAY_METADATA
@ AV_FRAME_DATA_MASTERING_DISPLAY_METADATA
Mastering display metadata associated with a video frame.
Definition: frame.h:119
AVCOL_TRC_SMPTE2084
@ AVCOL_TRC_SMPTE2084
SMPTE ST 2084 for 10-, 12-, 14- and 16-bit systems.
Definition: pixfmt.h:490
PrimaryCoefficients::yb
double yb
Definition: colorspace.h:33
PrimaryCoefficients::xg
double xg
Definition: colorspace.h:33
ff_update_hdr_metadata
void ff_update_hdr_metadata(AVFrame *in, double peak)
Definition: colorspace.c:193
AVFrameSideData::data
uint8_t * data
Definition: frame.h:211
frame.h
REFERENCE_WHITE
#define REFERENCE_WHITE
Definition: colorspace.h:26
WhitepointCoefficients
Definition: colorspace.h:36
AVCOL_SPC_SMPTE240M
@ AVCOL_SPC_SMPTE240M
derived from 170M primaries and D65 white point, 170M is derived from BT470 System M's primaries
Definition: pixfmt.h:510
src1
#define src1
Definition: h264pred.c:140
AV_FRAME_DATA_CONTENT_LIGHT_LEVEL
@ AV_FRAME_DATA_CONTENT_LIGHT_LEVEL
Content light level (based on CTA-861.3).
Definition: frame.h:136
i
int i
Definition: input.c:406
WhitepointCoefficients::yw
double yw
Definition: colorspace.h:37
AVCOL_SPC_BT2020_NCL
@ AVCOL_SPC_BT2020_NCL
ITU-R BT2020 non-constant luminance system.
Definition: pixfmt.h:513
AVColorSpace
AVColorSpace
YUV colorspace type.
Definition: pixfmt.h:502
av_d2q
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
AVMasteringDisplayMetadata
Mastering display metadata capable of representing the color volume of the display used to master the...
Definition: mastering_display_metadata.h:38
PrimaryCoefficients::yr
double yr
Definition: colorspace.h:33
LumaCoefficients::cr
double cr
Definition: colorspace.h:29
AVCOL_SPC_FCC
@ AVCOL_SPC_FCC
FCC Title 47 Code of Federal Regulations 73.682 (a)(20)
Definition: pixfmt.h:507
mastering_display_metadata.h
AVFrameSideData
Structure to hold side data for an AVFrame.
Definition: frame.h:209
AVCOL_SPC_BT709
@ AVCOL_SPC_BT709
also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / derived in SMPTE RP 177 Annex B
Definition: pixfmt.h:504