1// Copyright 2015 Google Inc. All Rights Reserved. 2// 3// Use of this source code is governed by a BSD-style license 4// that can be found in the COPYING file in the root of the source 5// tree. An additional intellectual property rights grant can be found 6// in the file PATENTS. All contributing project authors may 7// be found in the AUTHORS file in the root of the source tree. 8// ----------------------------------------------------------------------------- 9// 10// NEON variant of methods for lossless encoder 11// 12// Author: Skal (pascal.massimino@gmail.com) 13 14#include "src/dsp/dsp.h" 15 16#if defined(WEBP_USE_NEON) 17 18#include <arm_neon.h> 19 20#include "src/dsp/lossless.h" 21#include "src/dsp/neon.h" 22 23//------------------------------------------------------------------------------ 24// Subtract-Green Transform 25 26// vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use 27// non-standard versions there. 28#if defined(__APPLE__) && defined(__aarch64__) && \ 29 defined(__apple_build_version__) && (__apple_build_version__< 6020037) 30#define USE_VTBLQ 31#endif 32 33#ifdef USE_VTBLQ 34// 255 = byte will be zeroed 35static const uint8_t kGreenShuffle[16] = { 36 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13, 255 37}; 38 39static WEBP_INLINE uint8x16_t DoGreenShuffle_NEON(const uint8x16_t argb, 40 const uint8x16_t shuffle) { 41 return vcombine_u8(vtbl1q_u8(argb, vget_low_u8(shuffle)), 42 vtbl1q_u8(argb, vget_high_u8(shuffle))); 43} 44#else // !USE_VTBLQ 45// 255 = byte will be zeroed 46static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255 }; 47 48static WEBP_INLINE uint8x16_t DoGreenShuffle_NEON(const uint8x16_t argb, 49 const uint8x8_t shuffle) { 50 return vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle), 51 vtbl1_u8(vget_high_u8(argb), shuffle)); 52} 53#endif // USE_VTBLQ 54 55static void SubtractGreenFromBlueAndRed_NEON(uint32_t* argb_data, 56 int num_pixels) { 57 const uint32_t* const end = argb_data + (num_pixels & ~3); 58#ifdef USE_VTBLQ 59 const uint8x16_t shuffle = vld1q_u8(kGreenShuffle); 60#else 61 const uint8x8_t shuffle = vld1_u8(kGreenShuffle); 62#endif 63 for (; argb_data < end; argb_data += 4) { 64 const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data); 65 const uint8x16_t greens = DoGreenShuffle_NEON(argb, shuffle); 66 vst1q_u8((uint8_t*)argb_data, vsubq_u8(argb, greens)); 67 } 68 // fallthrough and finish off with plain-C 69 VP8LSubtractGreenFromBlueAndRed_C(argb_data, num_pixels & 3); 70} 71 72//------------------------------------------------------------------------------ 73// Color Transform 74 75static void TransformColor_NEON(const VP8LMultipliers* const m, 76 uint32_t* argb_data, int num_pixels) { 77 // sign-extended multiplying constants, pre-shifted by 6. 78#define CST(X) (((int16_t)(m->X << 8)) >> 6) 79 const int16_t rb[8] = { 80 CST(green_to_blue_), CST(green_to_red_), 81 CST(green_to_blue_), CST(green_to_red_), 82 CST(green_to_blue_), CST(green_to_red_), 83 CST(green_to_blue_), CST(green_to_red_) 84 }; 85 const int16x8_t mults_rb = vld1q_s16(rb); 86 const int16_t b2[8] = { 87 0, CST(red_to_blue_), 0, CST(red_to_blue_), 88 0, CST(red_to_blue_), 0, CST(red_to_blue_), 89 }; 90 const int16x8_t mults_b2 = vld1q_s16(b2); 91#undef CST 92#ifdef USE_VTBLQ 93 static const uint8_t kg0g0[16] = { 94 255, 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13 95 }; 96 const uint8x16_t shuffle = vld1q_u8(kg0g0); 97#else 98 static const uint8_t k0g0g[8] = { 255, 1, 255, 1, 255, 5, 255, 5 }; 99 const uint8x8_t shuffle = vld1_u8(k0g0g); 100#endif 101 const uint32x4_t mask_rb = vdupq_n_u32(0x00ff00ffu); // red-blue masks 102 int i; 103 for (i = 0; i + 4 <= num_pixels; i += 4) { 104 const uint8x16_t in = vld1q_u8((uint8_t*)(argb_data + i)); 105 // 0 g 0 g 106 const uint8x16_t greens = DoGreenShuffle_NEON(in, shuffle); 107 // x dr x db1 108 const int16x8_t A = vqdmulhq_s16(vreinterpretq_s16_u8(greens), mults_rb); 109 // r 0 b 0 110 const int16x8_t B = vshlq_n_s16(vreinterpretq_s16_u8(in), 8); 111 // x db2 0 0 112 const int16x8_t C = vqdmulhq_s16(B, mults_b2); 113 // 0 0 x db2 114 const uint32x4_t D = vshrq_n_u32(vreinterpretq_u32_s16(C), 16); 115 // x dr x db 116 const int8x16_t E = vaddq_s8(vreinterpretq_s8_u32(D), 117 vreinterpretq_s8_s16(A)); 118 // 0 dr 0 db 119 const uint32x4_t F = vandq_u32(vreinterpretq_u32_s8(E), mask_rb); 120 const int8x16_t out = vsubq_s8(vreinterpretq_s8_u8(in), 121 vreinterpretq_s8_u32(F)); 122 vst1q_s8((int8_t*)(argb_data + i), out); 123 } 124 // fallthrough and finish off with plain-C 125 VP8LTransformColor_C(m, argb_data + i, num_pixels - i); 126} 127 128#undef USE_VTBLQ 129 130//------------------------------------------------------------------------------ 131// Entry point 132 133extern void VP8LEncDspInitNEON(void); 134 135WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitNEON(void) { 136 VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed_NEON; 137 VP8LTransformColor = TransformColor_NEON; 138} 139 140#else // !WEBP_USE_NEON 141 142WEBP_DSP_INIT_STUB(VP8LEncDspInitNEON) 143 144#endif // WEBP_USE_NEON 145