/* * YCbCr-to-RGB Color Conversion (64-bit RVV 1.0) * * Copyright (C) 2022-2023, Institute of Software, Chinese Academy of Sciences. * Author: Zhiyuan Tan * Copyright (C) 2025, Samsung Electronics Co., Ltd. * Author: Filip Wasil * Copyright (C) 2025-2026, Olaf Bernstein. * Copyright (C) 2026, D. R. Commander. * * This software is provided 'as-is', without any express or implied * warranty. In no event will the authors be held liable for any damages * arising from the use of this software. * * Permission is granted to anyone to use this software for any purpose, * including commercial applications, and to alter it and redistribute it * freely, subject to the following restrictions: * * 1. The origin of this software must not be misrepresented; you must not * claim that you wrote the original software. If you use this software * in a product, an acknowledgment in the product documentation would be * appreciated but is not required. * 2. Altered source versions must be plainly marked as such, and must not be * misrepresented as being the original software. * 3. This notice may not be removed or altered from any source distribution. */ /* This file is included by jdcolor-rvv.c */ HIDDEN void jsimd_ycc_rgb_convert_rvv(JDIMENSION out_width, JSAMPIMAGE input_buf, JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows) { JSAMPROW outptr, inptr0, inptr1, inptr2; vuint8m2_t y, cb, cr; vint16m4_t y16, cb16, cb16_2, cr16, r16, g16, b16; vint32m8_t g32; vuint8m2_t r, g, b; #if RGB_PIXELSIZE == 3 vuint8m2x3_t rgb; #else vuint8m2_t a = __riscv_vmv_v_x_u8m2(0xFF, out_width); vuint8m2x4_t rgba; #endif while (--num_rows >= 0) { JDIMENSION cols_remaining = out_width; inptr0 = input_buf[0][input_row]; inptr1 = input_buf[1][input_row]; inptr2 = input_buf[2][input_row]; input_row++; outptr = *output_buf++; while (cols_remaining > 0) { /* vl = the number of 16-bit elements that can be stored in a 4-deep * RVV register group, up to a maximum of cols_remaining. For example, * this will be 64 if the register width (VLEN) is 256 and there are at * least 64 samples left in the input row. */ size_t vl = __riscv_vsetvl_e16m4(cols_remaining); /* Load Y, Cb, and Cr components into 2-deep 8-bit-element register * groups, and widen each component register group to a 4-deep signed * 16-bit-element register group. */ y = __riscv_vle8_v_u8m2(inptr0, vl); y16 = __riscv_vreinterpret_v_u16m4_i16m4(__riscv_vzext_vf2_u16m4(y, vl)); cb = __riscv_vle8_v_u8m2(inptr1, vl); cb16 = __riscv_vreinterpret_v_u16m4_i16m4(__riscv_vzext_vf2_u16m4(cb, vl)); cb16 = __riscv_vsub_vx_i16m4(cb16, CENTERJSAMPLE, vl); cr = __riscv_vle8_v_u8m2(inptr2, vl); cr16 = __riscv_vreinterpret_v_u16m4_i16m4(__riscv_vzext_vf2_u16m4(cr, vl)); cr16 = __riscv_vsub_vx_i16m4(cr16, CENTERJSAMPLE, vl); /* (128 has already been subtracted from Cb and Cr.) * * (Original) * R = Y + 1.40200 * Cr * G = Y - 0.34414 * Cb - 0.71414 * Cr * B = Y + 1.77200 * Cb * * (This implementation) * R = Y + 0.40200 * Cr + Cr * G = Y - 0.34414 * Cb + 0.28586 * Cr - Cr * B = Y - 0.22800 * Cb + Cb + Cb */ r16 = __riscv_vsll_vx_i16m4(cr16, 1, vl); /* 2 * Cr */ r16 = __riscv_vmulh_vx_i16m4(r16, F_0_402, vl); /* 2 * Cr * FIX(0.402) */ r16 = __riscv_vadd_vx_i16m4(r16, 1, vl); /* 2 * Cr * FIX(0.402) + 1 */ r16 = __riscv_vsra_vx_i16m4(r16, 1, vl); /* Cr * FIX(0.402) */ r16 = __riscv_vadd_vv_i16m4(r16, cr16, vl); /* Cr * FIX(1.402) */ r16 = __riscv_vadd_vv_i16m4(r16, y16, vl); /* Y + Cr * FIX(1.402) */ /* Range limit and narrow to 8-bit. */ r16 = __riscv_vmax_vx_i16m4(r16, 0, vl); r = __riscv_vnclipu_wx_u8m2(__riscv_vreinterpret_v_i16m4_u16m4(r16), 0, __RISCV_VXRM_RDN, vl); cb16_2 = __riscv_vsll_vx_i16m4(cb16, 1, vl); /* 2 * Cb */ b16 = __riscv_vmulh_vx_i16m4(cb16_2, -F_0_228, vl); /* 2 * Cb * -FIX(0.228) */ b16 = __riscv_vadd_vx_i16m4(b16, 1, vl); /* 2 * Cb * -FIX(0.228) + 1 */ b16 = __riscv_vsra_vx_i16m4(b16, 1, vl); /* Cb * -FIX(0.228) */ b16 = __riscv_vadd_vv_i16m4(b16, cb16_2, vl); /* Cb * FIX(1.772) */ b16 = __riscv_vadd_vv_i16m4(b16, y16, vl); /* Y + Cb * FIX(1.772) */ /* Range limit and narrow to 8-bit. */ b16 = __riscv_vmax_vx_i16m4(b16, 0, vl); b = __riscv_vnclipu_wx_u8m2(__riscv_vreinterpret_v_i16m4_u16m4(b16), 0, __RISCV_VXRM_RDN, vl); g32 = __riscv_vwmul_vx_i32m8(cb16, -F_0_344, vl); g32 = __riscv_vwmacc_vx_i32m8(g32, F_0_285, cr16, vl); g16 = __riscv_vnclip_wx_i16m4(g32, SCALEBITS, __RISCV_VXRM_RNU, vl); g16 = __riscv_vadd_vv_i16m4(g16, y16, vl); g16 = __riscv_vsub_vv_i16m4(g16, cr16, vl); /* Range limit and narrow to 8-bit. */ g16 = __riscv_vmax_vx_i16m4(g16, 0, vl); g = __riscv_vnclipu_wx_u8m2(__riscv_vreinterpret_v_i16m4_u16m4(g16), 0, __RISCV_VXRM_RDN, vl); #if RGB_PIXELSIZE == 3 /* Combine components into three 2-deep 8-bit-element register groups * (one group per component.) */ rgb = __riscv_vset_v_u8m2_u8m2x3(rgb, RGB_RED, r); rgb = __riscv_vset_v_u8m2_u8m2x3(rgb, RGB_GREEN, g); rgb = __riscv_vset_v_u8m2_u8m2x3(rgb, RGB_BLUE, b); /* Pack vl pixels into memory. */ __riscv_vsseg3e8_v_u8m2x3(outptr, rgb, vl); #else /* Combine components into four 2-deep 8-bit-element register groups (one * group per component.) */ rgba = __riscv_vset_v_u8m2_u8m2x4(rgba, RGB_RED, r); rgba = __riscv_vset_v_u8m2_u8m2x4(rgba, RGB_GREEN, g); rgba = __riscv_vset_v_u8m2_u8m2x4(rgba, RGB_BLUE, b); rgba = __riscv_vset_v_u8m2_u8m2x4(rgba, RGB_ALPHA, a); /* Pack vl pixels into memory. */ __riscv_vsseg4e8_v_u8m2x4(outptr, rgba, vl); #endif outptr += vl * RGB_PIXELSIZE; inptr0 += vl; inptr1 += vl; inptr2 += vl; cols_remaining -= vl; } } }