// Copyright 2017 Google Inc. All Rights Reserved. // // Use of this source code is governed by a BSD-style license // that can be found in the COPYING file in the root of the source // tree. An additional intellectual property rights grant can be found // in the file PATENTS. All contributing project authors may // be found in the AUTHORS file in the root of the source tree. // ----------------------------------------------------------------------------- // // Utilities for processing transparent channel, NEON version. // // Author: Skal (pascal.massimino@gmail.com) #include "src/dsp/dsp.h" #if defined(WEBP_USE_NEON) #include "src/dsp/neon.h" //------------------------------------------------------------------------------ #define MULTIPLIER(a) ((a) * 0x8081) #define PREMULTIPLY(x, m) (((x) * (m)) >> 23) #define MULTIPLY_BY_ALPHA(V, ALPHA, OTHER) do { \ const uint8x8_t alpha = (V).val[(ALPHA)]; \ const uint16x8_t r1 = vmull_u8((V).val[1], alpha); \ const uint16x8_t g1 = vmull_u8((V).val[2], alpha); \ const uint16x8_t b1 = vmull_u8((V).val[(OTHER)], alpha); \ /* we use: v / 255 = (v + 1 + (v >> 8)) >> 8 */ \ const uint16x8_t r2 = vsraq_n_u16(r1, r1, 8); \ const uint16x8_t g2 = vsraq_n_u16(g1, g1, 8); \ const uint16x8_t b2 = vsraq_n_u16(b1, b1, 8); \ const uint16x8_t r3 = vaddq_u16(r2, kOne); \ const uint16x8_t g3 = vaddq_u16(g2, kOne); \ const uint16x8_t b3 = vaddq_u16(b2, kOne); \ (V).val[1] = vshrn_n_u16(r3, 8); \ (V).val[2] = vshrn_n_u16(g3, 8); \ (V).val[(OTHER)] = vshrn_n_u16(b3, 8); \ } while (0) static void ApplyAlphaMultiply_NEON(uint8_t* rgba, int alpha_first, int w, int h, int stride) { const uint16x8_t kOne = vdupq_n_u16(1u); while (h-- > 0) { uint32_t* const rgbx = (uint32_t*)rgba; int i = 0; if (alpha_first) { for (; i + 8 <= w; i += 8) { // load aaaa...|rrrr...|gggg...|bbbb... uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); MULTIPLY_BY_ALPHA(RGBX, 0, 3); vst4_u8((uint8_t*)(rgbx + i), RGBX); } } else { for (; i + 8 <= w; i += 8) { uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); MULTIPLY_BY_ALPHA(RGBX, 3, 0); vst4_u8((uint8_t*)(rgbx + i), RGBX); } } // Finish with left-overs. for (; i < w; ++i) { uint8_t* const rgb = rgba + (alpha_first ? 1 : 0); const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3); const uint32_t a = alpha[4 * i]; if (a != 0xff) { const uint32_t mult = MULTIPLIER(a); rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult); rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult); rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult); } } rgba += stride; } } #undef MULTIPLY_BY_ALPHA #undef MULTIPLIER #undef PREMULTIPLY //------------------------------------------------------------------------------ static int DispatchAlpha_NEON(const uint8_t* alpha, int alpha_stride, int width, int height, uint8_t* dst, int dst_stride) { uint32_t alpha_mask = 0xffffffffu; uint8x8_t mask8 = vdup_n_u8(0xff); uint32_t tmp[2]; int i, j; for (j = 0; j < height; ++j) { // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. // Hence the test with 'width - 1' instead of just 'width'. for (i = 0; i + 8 <= width - 1; i += 8) { uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(dst + 4 * i)); const uint8x8_t alphas = vld1_u8(alpha + i); rgbX.val[0] = alphas; vst4_u8((uint8_t*)(dst + 4 * i), rgbX); mask8 = vand_u8(mask8, alphas); } for (; i < width; ++i) { const uint32_t alpha_value = alpha[i]; dst[4 * i] = alpha_value; alpha_mask &= alpha_value; } alpha += alpha_stride; dst += dst_stride; } vst1_u8((uint8_t*)tmp, mask8); alpha_mask &= tmp[0]; alpha_mask &= tmp[1]; return (alpha_mask != 0xffffffffu); } static void DispatchAlphaToGreen_NEON(const uint8_t* alpha, int alpha_stride, int width, int height, uint32_t* dst, int dst_stride) { int i, j; uint8x8x4_t greens; // leave A/R/B channels zero'd. greens.val[0] = vdup_n_u8(0); greens.val[2] = vdup_n_u8(0); greens.val[3] = vdup_n_u8(0); for (j = 0; j < height; ++j) { for (i = 0; i + 8 <= width; i += 8) { greens.val[1] = vld1_u8(alpha + i); vst4_u8((uint8_t*)(dst + i), greens); } for (; i < width; ++i) dst[i] = alpha[i] << 8; alpha += alpha_stride; dst += dst_stride; } } static int ExtractAlpha_NEON(const uint8_t* argb, int argb_stride, int width, int height, uint8_t* alpha, int alpha_stride) { uint32_t alpha_mask = 0xffffffffu; uint8x8_t mask8 = vdup_n_u8(0xff); uint32_t tmp[2]; int i, j; for (j = 0; j < height; ++j) { // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. // Hence the test with 'width - 1' instead of just 'width'. for (i = 0; i + 8 <= width - 1; i += 8) { const uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(argb + 4 * i)); const uint8x8_t alphas = rgbX.val[0]; vst1_u8((uint8_t*)(alpha + i), alphas); mask8 = vand_u8(mask8, alphas); } for (; i < width; ++i) { alpha[i] = argb[4 * i]; alpha_mask &= alpha[i]; } argb += argb_stride; alpha += alpha_stride; } vst1_u8((uint8_t*)tmp, mask8); alpha_mask &= tmp[0]; alpha_mask &= tmp[1]; return (alpha_mask == 0xffffffffu); } static void ExtractGreen_NEON(const uint32_t* argb, uint8_t* alpha, int size) { int i; for (i = 0; i + 16 <= size; i += 16) { const uint8x16x4_t rgbX = vld4q_u8((const uint8_t*)(argb + i)); const uint8x16_t greens = rgbX.val[1]; vst1q_u8(alpha + i, greens); } for (; i < size; ++i) alpha[i] = (argb[i] >> 8) & 0xff; } //------------------------------------------------------------------------------ extern void WebPInitAlphaProcessingNEON(void); WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingNEON(void) { WebPApplyAlphaMultiply = ApplyAlphaMultiply_NEON; WebPDispatchAlpha = DispatchAlpha_NEON; WebPDispatchAlphaToGreen = DispatchAlphaToGreen_NEON; WebPExtractAlpha = ExtractAlpha_NEON; WebPExtractGreen = ExtractGreen_NEON; } #else // !WEBP_USE_NEON WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingNEON) #endif // WEBP_USE_NEON