| /* |
| * Copyright (c) 2015 Kevin Wheatley <kevin.j.wheatley@gmail.com> |
| * Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com> |
| * Copyright (c) 2023 Leo Izen <leo.izen@gmail.com> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file Colorspace functions for libavutil |
| * @author Ronald S. Bultje <rsbultje@gmail.com> |
| * @author Leo Izen <leo.izen@gmail.com> |
| * @author Kevin Wheatley <kevin.j.wheatley@gmail.com> |
| */ |
| |
| #include <stdlib.h> |
| #include <math.h> |
| |
| #include "attributes.h" |
| #include "csp.h" |
| #include "pixfmt.h" |
| #include "rational.h" |
| |
| #define AVR(d) { (int)(d * 100000 + 0.5), 100000 } |
| |
| /* |
| * All constants explained in e.g. https://linuxtv.org/downloads/v4l-dvb-apis/ch02s06.html |
| * The older ones (bt470bg/m) are also explained in their respective ITU docs |
| * (e.g. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.470-5-199802-S!!PDF-E.pdf) |
| * whereas the newer ones can typically be copied directly from wikipedia :) |
| */ |
| static const struct AVLumaCoefficients luma_coefficients[AVCOL_SPC_NB] = { |
| [AVCOL_SPC_FCC] = { AVR(0.30), AVR(0.59), AVR(0.11) }, |
| [AVCOL_SPC_BT470BG] = { AVR(0.299), AVR(0.587), AVR(0.114) }, |
| [AVCOL_SPC_SMPTE170M] = { AVR(0.299), AVR(0.587), AVR(0.114) }, |
| [AVCOL_SPC_BT709] = { AVR(0.2126), AVR(0.7152), AVR(0.0722) }, |
| [AVCOL_SPC_SMPTE240M] = { AVR(0.212), AVR(0.701), AVR(0.087) }, |
| [AVCOL_SPC_YCOCG] = { AVR(0.25), AVR(0.5), AVR(0.25) }, |
| [AVCOL_SPC_RGB] = { AVR(1), AVR(1), AVR(1) }, |
| [AVCOL_SPC_BT2020_NCL] = { AVR(0.2627), AVR(0.6780), AVR(0.0593) }, |
| [AVCOL_SPC_BT2020_CL] = { AVR(0.2627), AVR(0.6780), AVR(0.0593) }, |
| }; |
| |
| const struct AVLumaCoefficients *av_csp_luma_coeffs_from_avcsp(enum AVColorSpace csp) |
| { |
| const AVLumaCoefficients *coeffs; |
| |
| if ((unsigned)csp >= AVCOL_SPC_NB) |
| return NULL; |
| coeffs = &luma_coefficients[csp]; |
| if (!coeffs->cr.num) |
| return NULL; |
| |
| return coeffs; |
| } |
| |
| #define WP_D65 { AVR(0.3127), AVR(0.3290) } |
| #define WP_C { AVR(0.3100), AVR(0.3160) } |
| #define WP_DCI { AVR(0.3140), AVR(0.3510) } |
| #define WP_E { {1, 3}, {1, 3} } |
| |
| static const AVColorPrimariesDesc color_primaries[AVCOL_PRI_NB] = { |
| [AVCOL_PRI_BT709] = { WP_D65, { { AVR(0.640), AVR(0.330) }, { AVR(0.300), AVR(0.600) }, { AVR(0.150), AVR(0.060) } } }, |
| [AVCOL_PRI_BT470M] = { WP_C, { { AVR(0.670), AVR(0.330) }, { AVR(0.210), AVR(0.710) }, { AVR(0.140), AVR(0.080) } } }, |
| [AVCOL_PRI_BT470BG] = { WP_D65, { { AVR(0.640), AVR(0.330) }, { AVR(0.290), AVR(0.600) }, { AVR(0.150), AVR(0.060) } } }, |
| [AVCOL_PRI_SMPTE170M] = { WP_D65, { { AVR(0.630), AVR(0.340) }, { AVR(0.310), AVR(0.595) }, { AVR(0.155), AVR(0.070) } } }, |
| [AVCOL_PRI_SMPTE240M] = { WP_D65, { { AVR(0.630), AVR(0.340) }, { AVR(0.310), AVR(0.595) }, { AVR(0.155), AVR(0.070) } } }, |
| [AVCOL_PRI_SMPTE428] = { WP_E, { { AVR(0.735), AVR(0.265) }, { AVR(0.274), AVR(0.718) }, { AVR(0.167), AVR(0.009) } } }, |
| [AVCOL_PRI_SMPTE431] = { WP_DCI, { { AVR(0.680), AVR(0.320) }, { AVR(0.265), AVR(0.690) }, { AVR(0.150), AVR(0.060) } } }, |
| [AVCOL_PRI_SMPTE432] = { WP_D65, { { AVR(0.680), AVR(0.320) }, { AVR(0.265), AVR(0.690) }, { AVR(0.150), AVR(0.060) } } }, |
| [AVCOL_PRI_FILM] = { WP_C, { { AVR(0.681), AVR(0.319) }, { AVR(0.243), AVR(0.692) }, { AVR(0.145), AVR(0.049) } } }, |
| [AVCOL_PRI_BT2020] = { WP_D65, { { AVR(0.708), AVR(0.292) }, { AVR(0.170), AVR(0.797) }, { AVR(0.131), AVR(0.046) } } }, |
| [AVCOL_PRI_JEDEC_P22] = { WP_D65, { { AVR(0.630), AVR(0.340) }, { AVR(0.295), AVR(0.605) }, { AVR(0.155), AVR(0.077) } } }, |
| }; |
| |
| static const AVColorPrimariesDesc color_primaries_ext[AVCOL_PRI_EXT_NB - |
| AVCOL_PRI_EXT_BASE] = { |
| [AVCOL_PRI_V_GAMUT - AVCOL_PRI_EXT_BASE] = { WP_D65, { { AVR(0.730), AVR(0.280) }, { AVR(0.165), AVR(0.840) }, { AVR(0.100), AVR(-0.030) } } }, |
| }; |
| |
| const AVColorPrimariesDesc *av_csp_primaries_desc_from_id(enum AVColorPrimaries prm) |
| { |
| const AVColorPrimariesDesc *p = NULL; |
| if ((unsigned)prm < AVCOL_PRI_NB) |
| p = &color_primaries[prm]; |
| else if (((unsigned)prm >= AVCOL_PRI_EXT_BASE) && |
| ((unsigned)prm < AVCOL_PRI_EXT_NB)) |
| p = &color_primaries_ext[prm - AVCOL_PRI_EXT_BASE]; |
| if (!p || !p->prim.r.x.num) |
| return NULL; |
| return p; |
| } |
| |
| static av_always_inline AVRational abs_sub_q(AVRational r1, AVRational r2) |
| { |
| AVRational diff = av_sub_q(r1, r2); |
| /* denominator assumed to be positive */ |
| return av_make_q(abs(diff.num), diff.den); |
| } |
| |
| enum AVColorPrimaries av_csp_primaries_id_from_desc(const AVColorPrimariesDesc *prm) |
| { |
| AVRational delta; |
| |
| for (enum AVColorPrimaries p = 0; p < AVCOL_PRI_NB; p++) { |
| const AVColorPrimariesDesc *ref = &color_primaries[p]; |
| if (!ref->prim.r.x.num) |
| continue; |
| |
| delta = abs_sub_q(prm->prim.r.x, ref->prim.r.x); |
| delta = av_add_q(delta, abs_sub_q(prm->prim.r.y, ref->prim.r.y)); |
| delta = av_add_q(delta, abs_sub_q(prm->prim.g.x, ref->prim.g.x)); |
| delta = av_add_q(delta, abs_sub_q(prm->prim.g.y, ref->prim.g.y)); |
| delta = av_add_q(delta, abs_sub_q(prm->prim.b.x, ref->prim.b.x)); |
| delta = av_add_q(delta, abs_sub_q(prm->prim.b.y, ref->prim.b.y)); |
| delta = av_add_q(delta, abs_sub_q(prm->wp.x, ref->wp.x)); |
| delta = av_add_q(delta, abs_sub_q(prm->wp.y, ref->wp.y)); |
| |
| if (av_cmp_q(delta, av_make_q(1, 1000)) < 0) |
| return p; |
| } |
| |
| return AVCOL_PRI_UNSPECIFIED; |
| } |
| |
| static const double approximate_gamma[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = 1.961, |
| [AVCOL_TRC_SMPTE170M] = 1.961, |
| [AVCOL_TRC_SMPTE240M] = 1.961, |
| [AVCOL_TRC_BT1361_ECG] = 1.961, |
| [AVCOL_TRC_BT2020_10] = 1.961, |
| [AVCOL_TRC_BT2020_12] = 1.961, |
| [AVCOL_TRC_GAMMA22] = 2.2, |
| [AVCOL_TRC_IEC61966_2_1] = 2.2, |
| [AVCOL_TRC_GAMMA28] = 2.8, |
| [AVCOL_TRC_LINEAR] = 1.0, |
| [AVCOL_TRC_SMPTE428] = 2.6, |
| }; |
| |
| static const double approximate_gamma_ext[AVCOL_TRC_EXT_NB - |
| AVCOL_TRC_EXT_BASE] = { |
| [AVCOL_TRC_V_LOG - AVCOL_TRC_EXT_BASE] = 2.2, |
| }; |
| |
| double av_csp_approximate_trc_gamma(enum AVColorTransferCharacteristic trc) |
| { |
| if (trc < AVCOL_TRC_NB) |
| return approximate_gamma[trc]; |
| else if ((trc >= AVCOL_TRC_EXT_BASE) && (trc < AVCOL_TRC_EXT_NB)) |
| return approximate_gamma_ext[trc - AVCOL_TRC_EXT_BASE]; |
| return 0.0; |
| } |
| |
| static const double approximate_eotf_gamma[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = 2.2, |
| [AVCOL_TRC_SMPTE170M] = 2.2, |
| [AVCOL_TRC_SMPTE240M] = 2.2, |
| [AVCOL_TRC_BT1361_ECG] = 2.2, |
| [AVCOL_TRC_BT2020_10] = 2.2, |
| [AVCOL_TRC_BT2020_12] = 2.2, |
| [AVCOL_TRC_GAMMA22] = 2.2, |
| [AVCOL_TRC_IEC61966_2_1] = 2.2, |
| [AVCOL_TRC_GAMMA28] = 2.8, |
| [AVCOL_TRC_LINEAR] = 1.0, |
| [AVCOL_TRC_SMPTE428] = 2.6, |
| }; |
| |
| static const double approximate_eotf_gamma_ext[AVCOL_TRC_EXT_NB - |
| AVCOL_TRC_EXT_BASE] = { |
| [AVCOL_TRC_V_LOG - AVCOL_TRC_EXT_BASE] = 2.2, |
| }; |
| |
| double av_csp_approximate_eotf_gamma(enum AVColorTransferCharacteristic trc) |
| { |
| if ((unsigned)trc < AVCOL_TRC_NB) |
| return approximate_eotf_gamma[trc]; |
| else if (((unsigned)trc >= AVCOL_TRC_EXT_BASE) && |
| ((unsigned)trc < AVCOL_TRC_EXT_NB)) |
| return approximate_eotf_gamma_ext[trc - AVCOL_TRC_EXT_BASE]; |
| return 0.0; |
| } |
| |
| #define BT709_alpha 1.099296826809442 |
| #define BT709_beta 0.018053968510807 |
| |
| static double trc_bt709(double Lc) |
| { |
| const double a = BT709_alpha; |
| const double b = BT709_beta; |
| |
| return (0.0 > Lc) ? 0.0 |
| : ( b > Lc) ? 4.500 * Lc |
| : a * pow(Lc, 0.45) - (a - 1.0); |
| } |
| |
| static double trc_bt709_inv(double E) |
| { |
| const double a = BT709_alpha; |
| const double b = 4.500 * BT709_beta; |
| |
| return (0.0 > E) ? 0.0 |
| : ( b > E) ? E / 4.500 |
| : pow((E + (a - 1.0)) / a, 1.0 / 0.45); |
| } |
| |
| static double trc_gamma22(double Lc) |
| { |
| return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.2); |
| } |
| |
| static double trc_gamma22_inv(double E) |
| { |
| return (0.0 > E) ? 0.0 : pow(E, 2.2); |
| } |
| |
| static double trc_gamma28(double Lc) |
| { |
| return (0.0 > Lc) ? 0.0 : pow(Lc, 1.0/ 2.8); |
| } |
| |
| static double trc_gamma28_inv(double E) |
| { |
| return (0.0 > E) ? 0.0 : pow(E, 2.8); |
| } |
| |
| static double trc_smpte240M(double Lc) |
| { |
| const double a = 1.1115; |
| const double b = 0.0228; |
| |
| return (0.0 > Lc) ? 0.0 |
| : ( b > Lc) ? 4.000 * Lc |
| : a * pow(Lc, 0.45) - (a - 1.0); |
| } |
| |
| static double trc_smpte240M_inv(double E) |
| { |
| const double a = 1.1115; |
| const double b = 4.000 * 0.0228; |
| |
| return (0.0 > E) ? 0.0 |
| : ( b > E) ? E / 4.000 |
| : pow((E + (a - 1.0)) / a, 1.0 / 0.45); |
| } |
| |
| static double trc_linear(double Lc) |
| { |
| return Lc; |
| } |
| |
| static double trc_log(double Lc) |
| { |
| return (0.01 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.0; |
| } |
| |
| static double trc_log_inv(double E) |
| { |
| return (0.0 > E) ? 0.01 : pow(10.0, 2.0 * (E - 1.0)); |
| } |
| |
| static double trc_log_sqrt(double Lc) |
| { |
| // sqrt(10) / 1000 |
| return (0.00316227766 > Lc) ? 0.0 : 1.0 + log10(Lc) / 2.5; |
| } |
| |
| static double trc_log_sqrt_inv(double E) |
| { |
| return (0.0 > E) ? 0.00316227766 : pow(10.0, 2.5 * (E - 1.0)); |
| } |
| |
| static double trc_iec61966_2_4(double Lc) |
| { |
| const double a = BT709_alpha; |
| const double b = BT709_beta; |
| |
| return (-b >= Lc) ? -a * pow(-Lc, 0.45) + (a - 1.0) |
| : ( b > Lc) ? 4.500 * Lc |
| : a * pow( Lc, 0.45) - (a - 1.0); |
| } |
| |
| static double trc_iec61966_2_4_inv(double E) |
| { |
| const double a = BT709_alpha; |
| const double b = 4.500 * BT709_beta; |
| |
| return (-b >= E) ? -pow((-E + (a - 1.0)) / a, 1.0 / 0.45) |
| : ( b > E) ? E / 4.500 |
| : pow(( E + (a - 1.0)) / a, 1.0 / 0.45); |
| } |
| |
| static double trc_bt1361(double Lc) |
| { |
| const double a = BT709_alpha; |
| const double b = BT709_beta; |
| |
| return (-0.0045 >= Lc) ? -(a * pow(-4.0 * Lc, 0.45) + (a - 1.0)) / 4.0 |
| : ( b > Lc) ? 4.500 * Lc |
| : a * pow( Lc, 0.45) - (a - 1.0); |
| } |
| |
| static double trc_bt1361_inv(double E) |
| { |
| const double a = BT709_alpha; |
| const double b = 4.500 * BT709_beta; |
| |
| return (-0.02025 >= E) ? -pow((-4.0 * E - (a - 1.0)) / a, 1.0 / 0.45) / 4.0 |
| : ( b > E) ? E / 4.500 |
| : pow(( E + (a - 1.0)) / a, 1.0 / 0.45); |
| } |
| |
| static double trc_iec61966_2_1(double Lc) |
| { |
| const double a = 1.055; |
| const double b = 0.0031308; |
| |
| return (0.0 > Lc) ? 0.0 |
| : ( b > Lc) ? 12.92 * Lc |
| : a * pow(Lc, 1.0 / 2.4) - (a - 1.0); |
| } |
| |
| static double trc_iec61966_2_1_inv(double E) |
| { |
| const double a = 1.055; |
| const double b = 12.92 * 0.0031308; |
| |
| return (0.0 > E) ? 0.0 |
| : ( b > E) ? E / 12.92 |
| : pow((E + (a - 1.0)) / a, 2.4); |
| return E; |
| } |
| |
| #define PQ_c1 ( 3424.0 / 4096.0) /* c3-c2 + 1 */ |
| #define PQ_c2 ( 32.0 * 2413.0 / 4096.0) |
| #define PQ_c3 ( 32.0 * 2392.0 / 4096.0) |
| #define PQ_m (128.0 * 2523.0 / 4096.0) |
| #define PQ_n ( 0.25 * 2610.0 / 4096.0) |
| |
| static double trc_smpte_st2084(double Lc) |
| { |
| const double c1 = PQ_c1; |
| const double c2 = PQ_c2; |
| const double c3 = PQ_c3; |
| const double m = PQ_m; |
| const double n = PQ_n; |
| const double L = Lc / 10000.0; |
| const double Ln = pow(L, n); |
| |
| return (0.0 > Lc) ? 0.0 |
| : pow((c1 + c2 * Ln) / (1.0 + c3 * Ln), m); |
| |
| } |
| |
| static double trc_smpte_st2084_inv(double E) |
| { |
| const double c1 = PQ_c1; |
| const double c2 = PQ_c2; |
| const double c3 = PQ_c3; |
| const double m = PQ_m; |
| const double n = PQ_n; |
| const double Em = pow(E, 1.0 / m); |
| |
| return (c1 > Em) ? 0.0 |
| : 10000.0 * pow((Em - c1) / (c2 - c3 * Em), 1.0 / n); |
| } |
| |
| #define DCI_L 48.00 |
| #define DCI_P 52.37 |
| |
| static double trc_smpte_st428_1(double Lc) |
| { |
| return (0.0 > Lc) ? 0.0 : pow(DCI_L / DCI_P * Lc, 1.0 / 2.6); |
| } |
| |
| static double trc_smpte_st428_1_inv(double E) |
| { |
| return (0.0 > E) ? 0.0 : DCI_P / DCI_L * pow(E, 2.6); |
| } |
| |
| #define HLG_a 0.17883277 |
| #define HLG_b 0.28466892 |
| #define HLG_c 0.55991073 |
| |
| static double trc_arib_std_b67(double Lc) { |
| // The function uses the definition from HEVC, which assumes that the peak |
| // white is input level = 1. (this is equivalent to scaling E = Lc * 12 and |
| // using the definition from the ARIB STD-B67 spec) |
| const double a = HLG_a; |
| const double b = HLG_b; |
| const double c = HLG_c; |
| return (0.0 > Lc) ? 0.0 : |
| (Lc <= 1.0 / 12.0 ? sqrt(3.0 * Lc) : a * log(12.0 * Lc - b) + c); |
| } |
| |
| static double trc_arib_std_b67_inv(double E) |
| { |
| const double a = HLG_a; |
| const double b = HLG_b; |
| const double c = HLG_c; |
| return (0.0 > E) ? 0.0 : |
| (E <= 0.5 ? E * E / 3.0 : (exp((E - c) / a) + b) / 12.0); |
| } |
| |
| #define VLOG_c1 0.01 |
| #define VLOG_c2 0.181 |
| #define VLOG_b 0.00873 |
| #define VLOG_c 0.241514 |
| #define VLOG_d 0.598206 |
| |
| static double trc_v_log(double E) |
| { |
| const double c1 = VLOG_c1; |
| const double b = VLOG_b; |
| const double c = VLOG_c; |
| const double d = VLOG_d; |
| return (E < c1) ? (5.6 * E + 0.125) : |
| (c * log10(E + b) + d); |
| } |
| |
| static double trc_v_log_inv(double E) |
| { |
| const double c2 = VLOG_c2; |
| const double b = VLOG_b; |
| const double c = VLOG_c; |
| const double d = VLOG_d; |
| return (E < c2) ? (E - 0.125) / 5.6 : |
| (pow(10.0, ((E - d) / c)) - b); |
| } |
| |
| static const av_csp_trc_function trc_funcs[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = trc_bt709, |
| [AVCOL_TRC_GAMMA22] = trc_gamma22, |
| [AVCOL_TRC_GAMMA28] = trc_gamma28, |
| [AVCOL_TRC_SMPTE170M] = trc_bt709, |
| [AVCOL_TRC_SMPTE240M] = trc_smpte240M, |
| [AVCOL_TRC_LINEAR] = trc_linear, |
| [AVCOL_TRC_LOG] = trc_log, |
| [AVCOL_TRC_LOG_SQRT] = trc_log_sqrt, |
| [AVCOL_TRC_IEC61966_2_4] = trc_iec61966_2_4, |
| [AVCOL_TRC_BT1361_ECG] = trc_bt1361, |
| [AVCOL_TRC_IEC61966_2_1] = trc_iec61966_2_1, |
| [AVCOL_TRC_BT2020_10] = trc_bt709, |
| [AVCOL_TRC_BT2020_12] = trc_bt709, |
| [AVCOL_TRC_SMPTE2084] = trc_smpte_st2084, |
| [AVCOL_TRC_SMPTE428] = trc_smpte_st428_1, |
| [AVCOL_TRC_ARIB_STD_B67] = trc_arib_std_b67, |
| }; |
| |
| static const av_csp_trc_function trc_funcs_ext[AVCOL_TRC_EXT_NB - |
| AVCOL_TRC_EXT_BASE] = { |
| [AVCOL_TRC_V_LOG - AVCOL_TRC_EXT_BASE] = trc_v_log, |
| }; |
| |
| av_csp_trc_function av_csp_trc_func_from_id(enum AVColorTransferCharacteristic trc) |
| { |
| if ((unsigned)trc < AVCOL_TRC_NB) |
| return trc_funcs[trc]; |
| else if (((unsigned)trc >= AVCOL_TRC_EXT_BASE) && |
| ((unsigned)trc < AVCOL_TRC_EXT_NB)) |
| return trc_funcs_ext[trc - AVCOL_TRC_EXT_BASE]; |
| return NULL; |
| } |
| |
| static const av_csp_trc_function trc_inv_funcs[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = trc_bt709_inv, |
| [AVCOL_TRC_GAMMA22] = trc_gamma22_inv, |
| [AVCOL_TRC_GAMMA28] = trc_gamma28_inv, |
| [AVCOL_TRC_SMPTE170M] = trc_bt709_inv, |
| [AVCOL_TRC_SMPTE240M] = trc_smpte240M_inv, |
| [AVCOL_TRC_LINEAR] = trc_linear, |
| [AVCOL_TRC_LOG] = trc_log_inv, |
| [AVCOL_TRC_LOG_SQRT] = trc_log_sqrt_inv, |
| [AVCOL_TRC_IEC61966_2_4] = trc_iec61966_2_4_inv, |
| [AVCOL_TRC_BT1361_ECG] = trc_bt1361_inv, |
| [AVCOL_TRC_IEC61966_2_1] = trc_iec61966_2_1_inv, |
| [AVCOL_TRC_BT2020_10] = trc_bt709_inv, |
| [AVCOL_TRC_BT2020_12] = trc_bt709_inv, |
| [AVCOL_TRC_SMPTE2084] = trc_smpte_st2084_inv, |
| [AVCOL_TRC_SMPTE428] = trc_smpte_st428_1_inv, |
| [AVCOL_TRC_ARIB_STD_B67] = trc_arib_std_b67_inv, |
| }; |
| |
| static const av_csp_trc_function trc_inv_funcs_ext[AVCOL_TRC_EXT_NB - |
| AVCOL_TRC_EXT_BASE] = { |
| [AVCOL_TRC_V_LOG - AVCOL_TRC_EXT_BASE] = trc_v_log_inv, |
| }; |
| |
| av_csp_trc_function av_csp_trc_func_inv_from_id(enum AVColorTransferCharacteristic trc) |
| { |
| if ((unsigned)trc < AVCOL_TRC_NB) |
| return trc_inv_funcs[trc]; |
| else if (((unsigned)trc >= AVCOL_TRC_EXT_BASE) && |
| ((unsigned)trc < AVCOL_TRC_EXT_NB)) |
| return trc_inv_funcs_ext[trc - AVCOL_TRC_EXT_BASE]; |
| return NULL; |
| } |
| |
| static void eotf_linear(const double Lw, const double Lb, double E[3]) |
| { |
| for (int i = 0; i < 3; i++) |
| E[i] = (Lw - Lb) * E[i] + Lb; |
| } |
| |
| static void eotf_linear_inv(const double Lw, const double Lb, double L[3]) |
| { |
| for (int i = 0; i < 3; i++) |
| L[i] = (L[i] - Lb) / (Lw - Lb); |
| } |
| |
| #define WRAP_SDR_OETF(name) \ |
| static void oetf_##name(double L[3]) \ |
| { \ |
| for (int i = 0; i < 3; i++) \ |
| L[i] = trc_##name(L[i]); \ |
| } \ |
| \ |
| static void oetf_##name##_inv(double E[3]) \ |
| { \ |
| for (int i = 0; i < 3; i++) \ |
| E[i] = trc_##name##_inv(E[i]); \ |
| } |
| |
| WRAP_SDR_OETF(gamma22) |
| WRAP_SDR_OETF(gamma28) |
| WRAP_SDR_OETF(iec61966_2_1) |
| |
| #define WRAP_SDR_EOTF(name) \ |
| static void eotf_##name(double Lw, double Lb, double E[3]) \ |
| { \ |
| oetf_##name##_inv(E); \ |
| eotf_linear(Lw, Lb, E); \ |
| } \ |
| \ |
| static void eotf_##name##_inv(double Lw, double Lb, double L[3]) \ |
| { \ |
| eotf_linear_inv(Lw, Lb, L); \ |
| oetf_##name(L); \ |
| } |
| |
| WRAP_SDR_EOTF(gamma22) |
| WRAP_SDR_EOTF(gamma28) |
| WRAP_SDR_EOTF(iec61966_2_1) |
| |
| static void eotf_bt1886(const double Lw, const double Lb, double E[3]) |
| { |
| const double Lw_inv = pow(Lw, 1.0 / 2.4); |
| const double Lb_inv = pow(Lb, 1.0 / 2.4); |
| const double a = pow(Lw_inv - Lb_inv, 2.4); |
| const double b = Lb_inv / (Lw_inv - Lb_inv); |
| |
| for (int i = 0; i < 3; i++) |
| E[i] = (-b > E[i]) ? 0.0 : a * pow(E[i] + b, 2.4); |
| } |
| |
| static void eotf_bt1886_inv(const double Lw, const double Lb, double L[3]) |
| { |
| const double Lw_inv = pow(Lw, 1.0 / 2.4); |
| const double Lb_inv = pow(Lb, 1.0 / 2.4); |
| const double a = pow(Lw_inv - Lb_inv, 2.4); |
| const double b = Lb_inv / (Lw_inv - Lb_inv); |
| |
| for (int i = 0; i < 3; i++) |
| L[i] = (0.0 > L[i]) ? 0.0 : pow(L[i] / a, 1.0 / 2.4) - b; |
| } |
| |
| static void eotf_smpte_st2084(const double Lw, const double Lb, double E[3]) |
| { |
| for (int i = 0; i < 3; i++) |
| E[i] = trc_smpte_st2084_inv(E[i]); |
| } |
| |
| static void eotf_smpte_st2084_inv(const double Lw, const double Lb, double L[3]) |
| { |
| for (int i = 0; i < 3; i++) |
| L[i] = trc_smpte_st2084(L[i]); |
| } |
| |
| /* This implementation assumes an SMPTE RP 431-2 reference projector (DCI) */ |
| #define DCI_L 48.00 |
| #define DCI_P 52.37 |
| #define DCI_X (42.94 / DCI_L) |
| #define DCI_Z (45.82 / DCI_L) |
| |
| static void eotf_smpte_st428_1(const double Lw_Y, const double Lb_Y, double E[3]) |
| { |
| const double Lw[3] = { DCI_X * Lw_Y, Lw_Y, DCI_Z * Lw_Y }; |
| const double Lb[3] = { DCI_X * Lb_Y, Lb_Y, DCI_Z * Lb_Y }; |
| |
| for (int i = 0; i < 3; i++) { |
| E[i] = (0.0 > E[i]) ? 0.0 : pow(E[i], 2.6) * DCI_P / DCI_L; |
| E[i] = E[i] * (Lw[i] - Lb[i]) + Lb[i]; |
| } |
| } |
| |
| static void eotf_smpte_st428_1_inv(const double Lw_Y, const double Lb_Y, double L[3]) |
| { |
| const double Lw[3] = { DCI_X * Lw_Y, Lw_Y, DCI_Z * Lw_Y }; |
| const double Lb[3] = { DCI_X * Lb_Y, Lb_Y, DCI_Z * Lb_Y }; |
| |
| for (int i = 0; i < 3; i++) { |
| L[i] = (L[i] - Lb[i]) / (Lw[i] - Lb[i]); |
| L[i] = (0.0 > L[i]) ? 0.0 : pow(L[i] * DCI_L / DCI_P, 1.0 / 2.6); |
| } |
| } |
| |
| static void eotf_arib_std_b67(const double Lw, const double Lb, double E[3]) |
| { |
| const double gamma = fmax(1.2 + 0.42 * log10(Lw / 1000.0), 1.0); |
| |
| /** |
| * Note: This equation is technically only accurate if the contrast ratio |
| * Lw:Lb is greater than 12:1; otherwise we would need to use a different, |
| * significantly more complicated solution. Ignore this as a highly |
| * degenerate case, since any real world reference display will have a |
| * static contrast ratio multiple orders of magnitude higher. |
| */ |
| const double beta = sqrt(3 * pow(Lb / Lw, 1.0 / gamma)); |
| double luma; |
| |
| for (int i = 0; i < 3; i++) |
| E[i] = trc_arib_std_b67_inv((1 - beta) * E[i] + beta); |
| |
| luma = 0.2627 * E[0] + 0.6780 * E[1] + 0.0593 * E[2]; |
| luma = pow(fmax(luma, 0.0), gamma - 1.0); |
| for (int i = 0; i < 3; i++) |
| E[i] *= Lw * luma; |
| } |
| |
| static void eotf_arib_std_b67_inv(const double Lw, const double Lb, double L[3]) |
| { |
| const double gamma = fmax(1.2 + 0.42 * log10(Lw / 1000.0), 1.0); |
| const double beta = sqrt(3 * pow(Lb / Lw, 1 / gamma)); |
| double luma = 0.2627 * L[0] + 0.6780 * L[1] + 0.0593 * L[2]; |
| |
| if (luma > 0.0) { |
| luma = pow(luma / Lw, (1 - gamma) / gamma); |
| for (int i = 0; i < 3; i++) |
| L[i] *= luma / Lw; |
| } else { |
| L[0] = L[1] = L[2] = 0.0; |
| } |
| |
| for (int i = 0; i < 3; i++) |
| L[i] = (trc_arib_std_b67(L[i]) - beta) / (1 - beta); |
| } |
| |
| static const av_csp_eotf_function eotf_funcs[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = eotf_bt1886, |
| [AVCOL_TRC_GAMMA22] = eotf_gamma22, |
| [AVCOL_TRC_GAMMA28] = eotf_gamma28, |
| [AVCOL_TRC_SMPTE170M] = eotf_bt1886, |
| [AVCOL_TRC_SMPTE240M] = eotf_bt1886, |
| [AVCOL_TRC_LINEAR] = eotf_linear, |
| /* There is no EOTF associated with these logarithmic encodings, since they |
| * are defined purely for transmission of scene referred data. */ |
| [AVCOL_TRC_LOG] = NULL, |
| [AVCOL_TRC_LOG_SQRT] = NULL, |
| /* BT.1886 is already defined for values below 0.0, as far as physically |
| * meaningful, so we can directly use it for extended range encodings */ |
| [AVCOL_TRC_IEC61966_2_4] = eotf_bt1886, |
| [AVCOL_TRC_BT1361_ECG] = eotf_bt1886, |
| [AVCOL_TRC_IEC61966_2_1] = eotf_iec61966_2_1, |
| [AVCOL_TRC_BT2020_10] = eotf_bt1886, |
| [AVCOL_TRC_BT2020_12] = eotf_bt1886, |
| [AVCOL_TRC_SMPTE2084] = eotf_smpte_st2084, |
| [AVCOL_TRC_SMPTE428] = eotf_smpte_st428_1, |
| [AVCOL_TRC_ARIB_STD_B67] = eotf_arib_std_b67, |
| }; |
| |
| av_csp_eotf_function av_csp_itu_eotf(enum AVColorTransferCharacteristic trc) |
| { |
| if ((unsigned)trc >= AVCOL_TRC_NB) |
| return NULL; |
| return eotf_funcs[trc]; |
| } |
| |
| static const av_csp_eotf_function eotf_inv_funcs[AVCOL_TRC_NB] = { |
| [AVCOL_TRC_BT709] = eotf_bt1886_inv, |
| [AVCOL_TRC_GAMMA22] = eotf_gamma22_inv, |
| [AVCOL_TRC_GAMMA28] = eotf_gamma28_inv, |
| [AVCOL_TRC_SMPTE170M] = eotf_bt1886_inv, |
| [AVCOL_TRC_SMPTE240M] = eotf_bt1886_inv, |
| [AVCOL_TRC_LINEAR] = eotf_linear_inv, |
| [AVCOL_TRC_LOG] = NULL, |
| [AVCOL_TRC_LOG_SQRT] = NULL, |
| [AVCOL_TRC_IEC61966_2_4] = eotf_bt1886_inv, |
| [AVCOL_TRC_BT1361_ECG] = eotf_bt1886_inv, |
| [AVCOL_TRC_IEC61966_2_1] = eotf_iec61966_2_1_inv, |
| [AVCOL_TRC_BT2020_10] = eotf_bt1886_inv, |
| [AVCOL_TRC_BT2020_12] = eotf_bt1886_inv, |
| [AVCOL_TRC_SMPTE2084] = eotf_smpte_st2084_inv, |
| [AVCOL_TRC_SMPTE428] = eotf_smpte_st428_1_inv, |
| [AVCOL_TRC_ARIB_STD_B67] = eotf_arib_std_b67_inv, |
| }; |
| |
| av_csp_eotf_function av_csp_itu_eotf_inv(enum AVColorTransferCharacteristic trc) |
| { |
| if ((unsigned)trc >= AVCOL_TRC_NB) |
| return NULL; |
| return eotf_inv_funcs[trc]; |
| } |
