| /* |
| * jdcolext-neon.c - colorspace conversion (Arm Neon) |
| * |
| * Copyright (C) 2020, Arm Limited. All Rights Reserved. |
| * Copyright (C) 2020, D. R. Commander. All Rights Reserved. |
| * |
| * 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-neon.c. */ |
| |
| |
| /* YCbCr -> RGB conversion is defined by the following equations: |
| * R = Y + 1.40200 * (Cr - 128) |
| * G = Y - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) |
| * B = Y + 1.77200 * (Cb - 128) |
| * |
| * Scaled integer constants are used to avoid floating-point arithmetic: |
| * 0.3441467 = 11277 * 2^-15 |
| * 0.7141418 = 23401 * 2^-15 |
| * 1.4020386 = 22971 * 2^-14 |
| * 1.7720337 = 29033 * 2^-14 |
| * These constants are defined in jdcolor-neon.c. |
| * |
| * To ensure correct results, rounding is used when descaling. |
| */ |
| |
| /* Notes on safe memory access for YCbCr -> RGB conversion routines: |
| * |
| * Input memory buffers can be safely overread up to the next multiple of |
| * ALIGN_SIZE bytes, since they are always allocated by alloc_sarray() in |
| * jmemmgr.c. |
| * |
| * The output buffer cannot safely be written beyond output_width, since |
| * output_buf points to a possibly unpadded row in the decompressed image |
| * buffer allocated by the calling program. |
| */ |
| |
| void jsimd_ycc_rgb_convert_neon(JDIMENSION output_width, JSAMPIMAGE input_buf, |
| JDIMENSION input_row, JSAMPARRAY output_buf, |
| int num_rows) |
| { |
| JSAMPROW outptr; |
| /* Pointers to Y, Cb, and Cr data */ |
| JSAMPROW inptr0, inptr1, inptr2; |
| |
| const int16x4_t consts = vld1_s16(jsimd_ycc_rgb_convert_neon_consts); |
| const int16x8_t neg_128 = vdupq_n_s16(-128); |
| |
| while (--num_rows >= 0) { |
| inptr0 = input_buf[0][input_row]; |
| inptr1 = input_buf[1][input_row]; |
| inptr2 = input_buf[2][input_row]; |
| input_row++; |
| outptr = *output_buf++; |
| int cols_remaining = output_width; |
| for (; cols_remaining >= 16; cols_remaining -= 16) { |
| uint8x16_t y = vld1q_u8(inptr0); |
| uint8x16_t cb = vld1q_u8(inptr1); |
| uint8x16_t cr = vld1q_u8(inptr2); |
| /* Subtract 128 from Cb and Cr. */ |
| int16x8_t cr_128_l = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), |
| vget_low_u8(cr))); |
| int16x8_t cr_128_h = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), |
| vget_high_u8(cr))); |
| int16x8_t cb_128_l = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), |
| vget_low_u8(cb))); |
| int16x8_t cb_128_h = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), |
| vget_high_u8(cb))); |
| /* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */ |
| int32x4_t g_sub_y_ll = vmull_lane_s16(vget_low_s16(cb_128_l), consts, 0); |
| int32x4_t g_sub_y_lh = vmull_lane_s16(vget_high_s16(cb_128_l), |
| consts, 0); |
| int32x4_t g_sub_y_hl = vmull_lane_s16(vget_low_s16(cb_128_h), consts, 0); |
| int32x4_t g_sub_y_hh = vmull_lane_s16(vget_high_s16(cb_128_h), |
| consts, 0); |
| g_sub_y_ll = vmlsl_lane_s16(g_sub_y_ll, vget_low_s16(cr_128_l), |
| consts, 1); |
| g_sub_y_lh = vmlsl_lane_s16(g_sub_y_lh, vget_high_s16(cr_128_l), |
| consts, 1); |
| g_sub_y_hl = vmlsl_lane_s16(g_sub_y_hl, vget_low_s16(cr_128_h), |
| consts, 1); |
| g_sub_y_hh = vmlsl_lane_s16(g_sub_y_hh, vget_high_s16(cr_128_h), |
| consts, 1); |
| /* Descale G components: shift right 15, round, and narrow to 16-bit. */ |
| int16x8_t g_sub_y_l = vcombine_s16(vrshrn_n_s32(g_sub_y_ll, 15), |
| vrshrn_n_s32(g_sub_y_lh, 15)); |
| int16x8_t g_sub_y_h = vcombine_s16(vrshrn_n_s32(g_sub_y_hl, 15), |
| vrshrn_n_s32(g_sub_y_hh, 15)); |
| /* Compute R-Y: 1.40200 * (Cr - 128) */ |
| int16x8_t r_sub_y_l = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128_l, 1), |
| consts, 2); |
| int16x8_t r_sub_y_h = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128_h, 1), |
| consts, 2); |
| /* Compute B-Y: 1.77200 * (Cb - 128) */ |
| int16x8_t b_sub_y_l = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128_l, 1), |
| consts, 3); |
| int16x8_t b_sub_y_h = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128_h, 1), |
| consts, 3); |
| /* Add Y. */ |
| int16x8_t r_l = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y_l), |
| vget_low_u8(y))); |
| int16x8_t r_h = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y_h), |
| vget_high_u8(y))); |
| int16x8_t b_l = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y_l), |
| vget_low_u8(y))); |
| int16x8_t b_h = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y_h), |
| vget_high_u8(y))); |
| int16x8_t g_l = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y_l), |
| vget_low_u8(y))); |
| int16x8_t g_h = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y_h), |
| vget_high_u8(y))); |
| |
| #if RGB_PIXELSIZE == 4 |
| uint8x16x4_t rgba; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgba.val[RGB_RED] = vcombine_u8(vqmovun_s16(r_l), vqmovun_s16(r_h)); |
| rgba.val[RGB_GREEN] = vcombine_u8(vqmovun_s16(g_l), vqmovun_s16(g_h)); |
| rgba.val[RGB_BLUE] = vcombine_u8(vqmovun_s16(b_l), vqmovun_s16(b_h)); |
| /* Set alpha channel to opaque (0xFF). */ |
| rgba.val[RGB_ALPHA] = vdupq_n_u8(0xFF); |
| /* Store RGBA pixel data to memory. */ |
| vst4q_u8(outptr, rgba); |
| #elif RGB_PIXELSIZE == 3 |
| uint8x16x3_t rgb; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgb.val[RGB_RED] = vcombine_u8(vqmovun_s16(r_l), vqmovun_s16(r_h)); |
| rgb.val[RGB_GREEN] = vcombine_u8(vqmovun_s16(g_l), vqmovun_s16(g_h)); |
| rgb.val[RGB_BLUE] = vcombine_u8(vqmovun_s16(b_l), vqmovun_s16(b_h)); |
| /* Store RGB pixel data to memory. */ |
| vst3q_u8(outptr, rgb); |
| #else |
| /* Pack R, G, and B values in ratio 5:6:5. */ |
| uint16x8_t rgb565_l = vqshluq_n_s16(r_l, 8); |
| rgb565_l = vsriq_n_u16(rgb565_l, vqshluq_n_s16(g_l, 8), 5); |
| rgb565_l = vsriq_n_u16(rgb565_l, vqshluq_n_s16(b_l, 8), 11); |
| uint16x8_t rgb565_h = vqshluq_n_s16(r_h, 8); |
| rgb565_h = vsriq_n_u16(rgb565_h, vqshluq_n_s16(g_h, 8), 5); |
| rgb565_h = vsriq_n_u16(rgb565_h, vqshluq_n_s16(b_h, 8), 11); |
| /* Store RGB pixel data to memory. */ |
| vst1q_u16((uint16_t *)outptr, rgb565_l); |
| vst1q_u16(((uint16_t *)outptr) + 8, rgb565_h); |
| #endif |
| |
| /* Increment pointers. */ |
| inptr0 += 16; |
| inptr1 += 16; |
| inptr2 += 16; |
| outptr += (RGB_PIXELSIZE * 16); |
| } |
| |
| if (cols_remaining >= 8) { |
| uint8x8_t y = vld1_u8(inptr0); |
| uint8x8_t cb = vld1_u8(inptr1); |
| uint8x8_t cr = vld1_u8(inptr2); |
| /* Subtract 128 from Cb and Cr. */ |
| int16x8_t cr_128 = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cr)); |
| int16x8_t cb_128 = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cb)); |
| /* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */ |
| int32x4_t g_sub_y_l = vmull_lane_s16(vget_low_s16(cb_128), consts, 0); |
| int32x4_t g_sub_y_h = vmull_lane_s16(vget_high_s16(cb_128), consts, 0); |
| g_sub_y_l = vmlsl_lane_s16(g_sub_y_l, vget_low_s16(cr_128), consts, 1); |
| g_sub_y_h = vmlsl_lane_s16(g_sub_y_h, vget_high_s16(cr_128), consts, 1); |
| /* Descale G components: shift right 15, round, and narrow to 16-bit. */ |
| int16x8_t g_sub_y = vcombine_s16(vrshrn_n_s32(g_sub_y_l, 15), |
| vrshrn_n_s32(g_sub_y_h, 15)); |
| /* Compute R-Y: 1.40200 * (Cr - 128) */ |
| int16x8_t r_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128, 1), |
| consts, 2); |
| /* Compute B-Y: 1.77200 * (Cb - 128) */ |
| int16x8_t b_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128, 1), |
| consts, 3); |
| /* Add Y. */ |
| int16x8_t r = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y), y)); |
| int16x8_t b = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y), y)); |
| int16x8_t g = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y), y)); |
| |
| #if RGB_PIXELSIZE == 4 |
| uint8x8x4_t rgba; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgba.val[RGB_RED] = vqmovun_s16(r); |
| rgba.val[RGB_GREEN] = vqmovun_s16(g); |
| rgba.val[RGB_BLUE] = vqmovun_s16(b); |
| /* Set alpha channel to opaque (0xFF). */ |
| rgba.val[RGB_ALPHA] = vdup_n_u8(0xFF); |
| /* Store RGBA pixel data to memory. */ |
| vst4_u8(outptr, rgba); |
| #elif RGB_PIXELSIZE == 3 |
| uint8x8x3_t rgb; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgb.val[RGB_RED] = vqmovun_s16(r); |
| rgb.val[RGB_GREEN] = vqmovun_s16(g); |
| rgb.val[RGB_BLUE] = vqmovun_s16(b); |
| /* Store RGB pixel data to memory. */ |
| vst3_u8(outptr, rgb); |
| #else |
| /* Pack R, G, and B values in ratio 5:6:5. */ |
| uint16x8_t rgb565 = vqshluq_n_s16(r, 8); |
| rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(g, 8), 5); |
| rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(b, 8), 11); |
| /* Store RGB pixel data to memory. */ |
| vst1q_u16((uint16_t *)outptr, rgb565); |
| #endif |
| |
| /* Increment pointers. */ |
| inptr0 += 8; |
| inptr1 += 8; |
| inptr2 += 8; |
| outptr += (RGB_PIXELSIZE * 8); |
| cols_remaining -= 8; |
| } |
| |
| /* Handle the tail elements. */ |
| if (cols_remaining > 0) { |
| uint8x8_t y = vld1_u8(inptr0); |
| uint8x8_t cb = vld1_u8(inptr1); |
| uint8x8_t cr = vld1_u8(inptr2); |
| /* Subtract 128 from Cb and Cr. */ |
| int16x8_t cr_128 = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cr)); |
| int16x8_t cb_128 = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cb)); |
| /* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */ |
| int32x4_t g_sub_y_l = vmull_lane_s16(vget_low_s16(cb_128), consts, 0); |
| int32x4_t g_sub_y_h = vmull_lane_s16(vget_high_s16(cb_128), consts, 0); |
| g_sub_y_l = vmlsl_lane_s16(g_sub_y_l, vget_low_s16(cr_128), consts, 1); |
| g_sub_y_h = vmlsl_lane_s16(g_sub_y_h, vget_high_s16(cr_128), consts, 1); |
| /* Descale G components: shift right 15, round, and narrow to 16-bit. */ |
| int16x8_t g_sub_y = vcombine_s16(vrshrn_n_s32(g_sub_y_l, 15), |
| vrshrn_n_s32(g_sub_y_h, 15)); |
| /* Compute R-Y: 1.40200 * (Cr - 128) */ |
| int16x8_t r_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128, 1), |
| consts, 2); |
| /* Compute B-Y: 1.77200 * (Cb - 128) */ |
| int16x8_t b_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128, 1), |
| consts, 3); |
| /* Add Y. */ |
| int16x8_t r = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y), y)); |
| int16x8_t b = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y), y)); |
| int16x8_t g = |
| vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y), y)); |
| |
| #if RGB_PIXELSIZE == 4 |
| uint8x8x4_t rgba; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgba.val[RGB_RED] = vqmovun_s16(r); |
| rgba.val[RGB_GREEN] = vqmovun_s16(g); |
| rgba.val[RGB_BLUE] = vqmovun_s16(b); |
| /* Set alpha channel to opaque (0xFF). */ |
| rgba.val[RGB_ALPHA] = vdup_n_u8(0xFF); |
| /* Store RGBA pixel data to memory. */ |
| switch (cols_remaining) { |
| case 7: |
| vst4_lane_u8(outptr + 6 * RGB_PIXELSIZE, rgba, 6); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 6: |
| vst4_lane_u8(outptr + 5 * RGB_PIXELSIZE, rgba, 5); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 5: |
| vst4_lane_u8(outptr + 4 * RGB_PIXELSIZE, rgba, 4); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 4: |
| vst4_lane_u8(outptr + 3 * RGB_PIXELSIZE, rgba, 3); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 3: |
| vst4_lane_u8(outptr + 2 * RGB_PIXELSIZE, rgba, 2); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 2: |
| vst4_lane_u8(outptr + RGB_PIXELSIZE, rgba, 1); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 1: |
| vst4_lane_u8(outptr, rgba, 0); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| default: |
| break; |
| } |
| #elif RGB_PIXELSIZE == 3 |
| uint8x8x3_t rgb; |
| /* Convert each component to unsigned and narrow, clamping to [0-255]. */ |
| rgb.val[RGB_RED] = vqmovun_s16(r); |
| rgb.val[RGB_GREEN] = vqmovun_s16(g); |
| rgb.val[RGB_BLUE] = vqmovun_s16(b); |
| /* Store RGB pixel data to memory. */ |
| switch (cols_remaining) { |
| case 7: |
| vst3_lane_u8(outptr + 6 * RGB_PIXELSIZE, rgb, 6); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 6: |
| vst3_lane_u8(outptr + 5 * RGB_PIXELSIZE, rgb, 5); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 5: |
| vst3_lane_u8(outptr + 4 * RGB_PIXELSIZE, rgb, 4); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 4: |
| vst3_lane_u8(outptr + 3 * RGB_PIXELSIZE, rgb, 3); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 3: |
| vst3_lane_u8(outptr + 2 * RGB_PIXELSIZE, rgb, 2); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 2: |
| vst3_lane_u8(outptr + RGB_PIXELSIZE, rgb, 1); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 1: |
| vst3_lane_u8(outptr, rgb, 0); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| default: |
| break; |
| } |
| #else |
| /* Pack R, G, and B values in ratio 5:6:5. */ |
| uint16x8_t rgb565 = vqshluq_n_s16(r, 8); |
| rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(g, 8), 5); |
| rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(b, 8), 11); |
| /* Store RGB565 pixel data to memory. */ |
| switch (cols_remaining) { |
| case 7: |
| vst1q_lane_u16((uint16_t *)(outptr + 6 * RGB_PIXELSIZE), rgb565, 6); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 6: |
| vst1q_lane_u16((uint16_t *)(outptr + 5 * RGB_PIXELSIZE), rgb565, 5); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 5: |
| vst1q_lane_u16((uint16_t *)(outptr + 4 * RGB_PIXELSIZE), rgb565, 4); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 4: |
| vst1q_lane_u16((uint16_t *)(outptr + 3 * RGB_PIXELSIZE), rgb565, 3); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 3: |
| vst1q_lane_u16((uint16_t *)(outptr + 2 * RGB_PIXELSIZE), rgb565, 2); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 2: |
| vst1q_lane_u16((uint16_t *)(outptr + RGB_PIXELSIZE), rgb565, 1); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| case 1: |
| vst1q_lane_u16((uint16_t *)outptr, rgb565, 0); |
| FALLTHROUGH /*FALLTHROUGH*/ |
| default: |
| break; |
| } |
| #endif |
| } |
| } |
| } |
