diff options
Diffstat (limited to 'media/libjpeg/simd/arm/aarch32/jccolext-neon.c')
| -rw-r--r-- | media/libjpeg/simd/arm/aarch32/jccolext-neon.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/media/libjpeg/simd/arm/aarch32/jccolext-neon.c b/media/libjpeg/simd/arm/aarch32/jccolext-neon.c new file mode 100644 index 0000000000..362102d2b2 --- /dev/null +++ b/media/libjpeg/simd/arm/aarch32/jccolext-neon.c @@ -0,0 +1,148 @@ +/* + * jccolext-neon.c - colorspace conversion (32-bit 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 jccolor-neon.c */ + + +/* RGB -> YCbCr conversion is defined by the following equations: + * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B + * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + 128 + * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + 128 + * + * Avoid floating point arithmetic by using shifted integer constants: + * 0.29899597 = 19595 * 2^-16 + * 0.58700561 = 38470 * 2^-16 + * 0.11399841 = 7471 * 2^-16 + * 0.16874695 = 11059 * 2^-16 + * 0.33125305 = 21709 * 2^-16 + * 0.50000000 = 32768 * 2^-16 + * 0.41868592 = 27439 * 2^-16 + * 0.08131409 = 5329 * 2^-16 + * These constants are defined in jccolor-neon.c + * + * We add the fixed-point equivalent of 0.5 to Cb and Cr, which effectively + * rounds up or down the result via integer truncation. + */ + +void jsimd_rgb_ycc_convert_neon(JDIMENSION image_width, JSAMPARRAY input_buf, + JSAMPIMAGE output_buf, JDIMENSION output_row, + int num_rows) +{ + /* Pointer to RGB(X/A) input data */ + JSAMPROW inptr; + /* Pointers to Y, Cb, and Cr output data */ + JSAMPROW outptr0, outptr1, outptr2; + /* Allocate temporary buffer for final (image_width % 8) pixels in row. */ + ALIGN(16) uint8_t tmp_buf[8 * RGB_PIXELSIZE]; + + /* Set up conversion constants. */ +#ifdef HAVE_VLD1_U16_X2 + const uint16x4x2_t consts = vld1_u16_x2(jsimd_rgb_ycc_neon_consts); +#else + /* GCC does not currently support the intrinsic vld1_<type>_x2(). */ + const uint16x4_t consts1 = vld1_u16(jsimd_rgb_ycc_neon_consts); + const uint16x4_t consts2 = vld1_u16(jsimd_rgb_ycc_neon_consts + 4); + const uint16x4x2_t consts = { { consts1, consts2 } }; +#endif + const uint32x4_t scaled_128_5 = vdupq_n_u32((128 << 16) + 32767); + + while (--num_rows >= 0) { + inptr = *input_buf++; + outptr0 = output_buf[0][output_row]; + outptr1 = output_buf[1][output_row]; + outptr2 = output_buf[2][output_row]; + output_row++; + + int cols_remaining = image_width; + for (; cols_remaining > 0; cols_remaining -= 8) { + + /* To prevent buffer overread by the vector load instructions, the last + * (image_width % 8) columns of data are first memcopied to a temporary + * buffer large enough to accommodate the vector load. + */ + if (cols_remaining < 8) { + memcpy(tmp_buf, inptr, cols_remaining * RGB_PIXELSIZE); + inptr = tmp_buf; + } + +#if RGB_PIXELSIZE == 4 + uint8x8x4_t input_pixels = vld4_u8(inptr); +#else + uint8x8x3_t input_pixels = vld3_u8(inptr); +#endif + uint16x8_t r = vmovl_u8(input_pixels.val[RGB_RED]); + uint16x8_t g = vmovl_u8(input_pixels.val[RGB_GREEN]); + uint16x8_t b = vmovl_u8(input_pixels.val[RGB_BLUE]); + + /* Compute Y = 0.29900 * R + 0.58700 * G + 0.11400 * B */ + uint32x4_t y_low = vmull_lane_u16(vget_low_u16(r), consts.val[0], 0); + y_low = vmlal_lane_u16(y_low, vget_low_u16(g), consts.val[0], 1); + y_low = vmlal_lane_u16(y_low, vget_low_u16(b), consts.val[0], 2); + uint32x4_t y_high = vmull_lane_u16(vget_high_u16(r), consts.val[0], 0); + y_high = vmlal_lane_u16(y_high, vget_high_u16(g), consts.val[0], 1); + y_high = vmlal_lane_u16(y_high, vget_high_u16(b), consts.val[0], 2); + + /* Compute Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + 128 */ + uint32x4_t cb_low = scaled_128_5; + cb_low = vmlsl_lane_u16(cb_low, vget_low_u16(r), consts.val[0], 3); + cb_low = vmlsl_lane_u16(cb_low, vget_low_u16(g), consts.val[1], 0); + cb_low = vmlal_lane_u16(cb_low, vget_low_u16(b), consts.val[1], 1); + uint32x4_t cb_high = scaled_128_5; + cb_high = vmlsl_lane_u16(cb_high, vget_high_u16(r), consts.val[0], 3); + cb_high = vmlsl_lane_u16(cb_high, vget_high_u16(g), consts.val[1], 0); + cb_high = vmlal_lane_u16(cb_high, vget_high_u16(b), consts.val[1], 1); + + /* Compute Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + 128 */ + uint32x4_t cr_low = scaled_128_5; + cr_low = vmlal_lane_u16(cr_low, vget_low_u16(r), consts.val[1], 1); + cr_low = vmlsl_lane_u16(cr_low, vget_low_u16(g), consts.val[1], 2); + cr_low = vmlsl_lane_u16(cr_low, vget_low_u16(b), consts.val[1], 3); + uint32x4_t cr_high = scaled_128_5; + cr_high = vmlal_lane_u16(cr_high, vget_high_u16(r), consts.val[1], 1); + cr_high = vmlsl_lane_u16(cr_high, vget_high_u16(g), consts.val[1], 2); + cr_high = vmlsl_lane_u16(cr_high, vget_high_u16(b), consts.val[1], 3); + + /* Descale Y values (rounding right shift) and narrow to 16-bit. */ + uint16x8_t y_u16 = vcombine_u16(vrshrn_n_u32(y_low, 16), + vrshrn_n_u32(y_high, 16)); + /* Descale Cb values (right shift) and narrow to 16-bit. */ + uint16x8_t cb_u16 = vcombine_u16(vshrn_n_u32(cb_low, 16), + vshrn_n_u32(cb_high, 16)); + /* Descale Cr values (right shift) and narrow to 16-bit. */ + uint16x8_t cr_u16 = vcombine_u16(vshrn_n_u32(cr_low, 16), + vshrn_n_u32(cr_high, 16)); + /* Narrow Y, Cb, and Cr values to 8-bit and store to memory. Buffer + * overwrite is permitted up to the next multiple of ALIGN_SIZE bytes. + */ + vst1_u8(outptr0, vmovn_u16(y_u16)); + vst1_u8(outptr1, vmovn_u16(cb_u16)); + vst1_u8(outptr2, vmovn_u16(cr_u16)); + + /* Increment pointers. */ + inptr += (8 * RGB_PIXELSIZE); + outptr0 += 8; + outptr1 += 8; + outptr2 += 8; + } + } +} |