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libavutil/csp.c
715 строк
24 KB
James Almer
avutil/csp: don't dereference NULL pointer in av_csp_primaries_desc_from_id()
01 ноя 2025, 18:41
01 ноя 2025, 18:41
633d424
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/* * 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]; }