1 // Copyright 2014 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 decoder 11 // 12 // Author: Skal (pascal.massimino (at) gmail.com) 13 14 #include "./dsp.h" 15 16 #if defined(WEBP_USE_NEON) 17 18 #include <arm_neon.h> 19 20 #include "./lossless.h" 21 #include "./neon.h" 22 23 //------------------------------------------------------------------------------ 24 // Colorspace conversion functions 25 26 #if !defined(WORK_AROUND_GCC) 27 // gcc 4.6.0 had some trouble (NDK-r9) with this code. We only use it for 28 // gcc-4.8.x at least. 29 static void ConvertBGRAToRGBA(const uint32_t* src, 30 int num_pixels, uint8_t* dst) { 31 const uint32_t* const end = src + (num_pixels & ~15); 32 for (; src < end; src += 16) { 33 uint8x16x4_t pixel = vld4q_u8((uint8_t*)src); 34 // swap B and R. (VSWP d0,d2 has no intrinsics equivalent!) 35 const uint8x16_t tmp = pixel.val[0]; 36 pixel.val[0] = pixel.val[2]; 37 pixel.val[2] = tmp; 38 vst4q_u8(dst, pixel); 39 dst += 64; 40 } 41 VP8LConvertBGRAToRGBA_C(src, num_pixels & 15, dst); // left-overs 42 } 43 44 static void ConvertBGRAToBGR(const uint32_t* src, 45 int num_pixels, uint8_t* dst) { 46 const uint32_t* const end = src + (num_pixels & ~15); 47 for (; src < end; src += 16) { 48 const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src); 49 const uint8x16x3_t tmp = { { pixel.val[0], pixel.val[1], pixel.val[2] } }; 50 vst3q_u8(dst, tmp); 51 dst += 48; 52 } 53 VP8LConvertBGRAToBGR_C(src, num_pixels & 15, dst); // left-overs 54 } 55 56 static void ConvertBGRAToRGB(const uint32_t* src, 57 int num_pixels, uint8_t* dst) { 58 const uint32_t* const end = src + (num_pixels & ~15); 59 for (; src < end; src += 16) { 60 const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src); 61 const uint8x16x3_t tmp = { { pixel.val[2], pixel.val[1], pixel.val[0] } }; 62 vst3q_u8(dst, tmp); 63 dst += 48; 64 } 65 VP8LConvertBGRAToRGB_C(src, num_pixels & 15, dst); // left-overs 66 } 67 68 #else // WORK_AROUND_GCC 69 70 // gcc-4.6.0 fallback 71 72 static const uint8_t kRGBAShuffle[8] = { 2, 1, 0, 3, 6, 5, 4, 7 }; 73 74 static void ConvertBGRAToRGBA(const uint32_t* src, 75 int num_pixels, uint8_t* dst) { 76 const uint32_t* const end = src + (num_pixels & ~1); 77 const uint8x8_t shuffle = vld1_u8(kRGBAShuffle); 78 for (; src < end; src += 2) { 79 const uint8x8_t pixels = vld1_u8((uint8_t*)src); 80 vst1_u8(dst, vtbl1_u8(pixels, shuffle)); 81 dst += 8; 82 } 83 VP8LConvertBGRAToRGBA_C(src, num_pixels & 1, dst); // left-overs 84 } 85 86 static const uint8_t kBGRShuffle[3][8] = { 87 { 0, 1, 2, 4, 5, 6, 8, 9 }, 88 { 10, 12, 13, 14, 16, 17, 18, 20 }, 89 { 21, 22, 24, 25, 26, 28, 29, 30 } 90 }; 91 92 static void ConvertBGRAToBGR(const uint32_t* src, 93 int num_pixels, uint8_t* dst) { 94 const uint32_t* const end = src + (num_pixels & ~7); 95 const uint8x8_t shuffle0 = vld1_u8(kBGRShuffle[0]); 96 const uint8x8_t shuffle1 = vld1_u8(kBGRShuffle[1]); 97 const uint8x8_t shuffle2 = vld1_u8(kBGRShuffle[2]); 98 for (; src < end; src += 8) { 99 uint8x8x4_t pixels; 100 INIT_VECTOR4(pixels, 101 vld1_u8((const uint8_t*)(src + 0)), 102 vld1_u8((const uint8_t*)(src + 2)), 103 vld1_u8((const uint8_t*)(src + 4)), 104 vld1_u8((const uint8_t*)(src + 6))); 105 vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0)); 106 vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1)); 107 vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2)); 108 dst += 8 * 3; 109 } 110 VP8LConvertBGRAToBGR_C(src, num_pixels & 7, dst); // left-overs 111 } 112 113 static const uint8_t kRGBShuffle[3][8] = { 114 { 2, 1, 0, 6, 5, 4, 10, 9 }, 115 { 8, 14, 13, 12, 18, 17, 16, 22 }, 116 { 21, 20, 26, 25, 24, 30, 29, 28 } 117 }; 118 119 static void ConvertBGRAToRGB(const uint32_t* src, 120 int num_pixels, uint8_t* dst) { 121 const uint32_t* const end = src + (num_pixels & ~7); 122 const uint8x8_t shuffle0 = vld1_u8(kRGBShuffle[0]); 123 const uint8x8_t shuffle1 = vld1_u8(kRGBShuffle[1]); 124 const uint8x8_t shuffle2 = vld1_u8(kRGBShuffle[2]); 125 for (; src < end; src += 8) { 126 uint8x8x4_t pixels; 127 INIT_VECTOR4(pixels, 128 vld1_u8((const uint8_t*)(src + 0)), 129 vld1_u8((const uint8_t*)(src + 2)), 130 vld1_u8((const uint8_t*)(src + 4)), 131 vld1_u8((const uint8_t*)(src + 6))); 132 vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0)); 133 vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1)); 134 vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2)); 135 dst += 8 * 3; 136 } 137 VP8LConvertBGRAToRGB_C(src, num_pixels & 7, dst); // left-overs 138 } 139 140 #endif // !WORK_AROUND_GCC 141 142 //------------------------------------------------------------------------------ 143 144 #ifdef USE_INTRINSICS 145 146 static WEBP_INLINE uint32_t Average2(const uint32_t* const a, 147 const uint32_t* const b) { 148 const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a)); 149 const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b)); 150 const uint8x8_t avg = vhadd_u8(a0, b0); 151 return vget_lane_u32(vreinterpret_u32_u8(avg), 0); 152 } 153 154 static WEBP_INLINE uint32_t Average3(const uint32_t* const a, 155 const uint32_t* const b, 156 const uint32_t* const c) { 157 const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a)); 158 const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b)); 159 const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c)); 160 const uint8x8_t avg1 = vhadd_u8(a0, c0); 161 const uint8x8_t avg2 = vhadd_u8(avg1, b0); 162 return vget_lane_u32(vreinterpret_u32_u8(avg2), 0); 163 } 164 165 static WEBP_INLINE uint32_t Average4(const uint32_t* const a, 166 const uint32_t* const b, 167 const uint32_t* const c, 168 const uint32_t* const d) { 169 const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a)); 170 const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b)); 171 const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c)); 172 const uint8x8_t d0 = vreinterpret_u8_u64(vcreate_u64(*d)); 173 const uint8x8_t avg1 = vhadd_u8(a0, b0); 174 const uint8x8_t avg2 = vhadd_u8(c0, d0); 175 const uint8x8_t avg3 = vhadd_u8(avg1, avg2); 176 return vget_lane_u32(vreinterpret_u32_u8(avg3), 0); 177 } 178 179 static uint32_t Predictor5(uint32_t left, const uint32_t* const top) { 180 return Average3(&left, top + 0, top + 1); 181 } 182 183 static uint32_t Predictor6(uint32_t left, const uint32_t* const top) { 184 return Average2(&left, top - 1); 185 } 186 187 static uint32_t Predictor7(uint32_t left, const uint32_t* const top) { 188 return Average2(&left, top + 0); 189 } 190 191 static uint32_t Predictor8(uint32_t left, const uint32_t* const top) { 192 (void)left; 193 return Average2(top - 1, top + 0); 194 } 195 196 static uint32_t Predictor9(uint32_t left, const uint32_t* const top) { 197 (void)left; 198 return Average2(top + 0, top + 1); 199 } 200 201 static uint32_t Predictor10(uint32_t left, const uint32_t* const top) { 202 return Average4(&left, top - 1, top + 0, top + 1); 203 } 204 205 //------------------------------------------------------------------------------ 206 207 static WEBP_INLINE uint32_t Select(const uint32_t* const c0, 208 const uint32_t* const c1, 209 const uint32_t* const c2) { 210 const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0)); 211 const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1)); 212 const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2)); 213 const uint8x8_t bc = vabd_u8(p1, p2); // |b-c| 214 const uint8x8_t ac = vabd_u8(p0, p2); // |a-c| 215 const int16x4_t sum_bc = vreinterpret_s16_u16(vpaddl_u8(bc)); 216 const int16x4_t sum_ac = vreinterpret_s16_u16(vpaddl_u8(ac)); 217 const int32x2_t diff = vpaddl_s16(vsub_s16(sum_bc, sum_ac)); 218 const int32_t pa_minus_pb = vget_lane_s32(diff, 0); 219 return (pa_minus_pb <= 0) ? *c0 : *c1; 220 } 221 222 static uint32_t Predictor11(uint32_t left, const uint32_t* const top) { 223 return Select(top + 0, &left, top - 1); 224 } 225 226 static WEBP_INLINE uint32_t ClampedAddSubtractFull(const uint32_t* const c0, 227 const uint32_t* const c1, 228 const uint32_t* const c2) { 229 const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0)); 230 const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1)); 231 const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2)); 232 const uint16x8_t sum0 = vaddl_u8(p0, p1); // add and widen 233 const uint16x8_t sum1 = vqsubq_u16(sum0, vmovl_u8(p2)); // widen and subtract 234 const uint8x8_t out = vqmovn_u16(sum1); // narrow and clamp 235 return vget_lane_u32(vreinterpret_u32_u8(out), 0); 236 } 237 238 static uint32_t Predictor12(uint32_t left, const uint32_t* const top) { 239 return ClampedAddSubtractFull(&left, top + 0, top - 1); 240 } 241 242 static WEBP_INLINE uint32_t ClampedAddSubtractHalf(const uint32_t* const c0, 243 const uint32_t* const c1, 244 const uint32_t* const c2) { 245 const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0)); 246 const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1)); 247 const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2)); 248 const uint8x8_t avg = vhadd_u8(p0, p1); // Average(c0,c1) 249 const uint8x8_t ab = vshr_n_u8(vqsub_u8(avg, p2), 1); // (a-b)>>1 saturated 250 const uint8x8_t ba = vshr_n_u8(vqsub_u8(p2, avg), 1); // (b-a)>>1 saturated 251 const uint8x8_t out = vqsub_u8(vqadd_u8(avg, ab), ba); 252 return vget_lane_u32(vreinterpret_u32_u8(out), 0); 253 } 254 255 static uint32_t Predictor13(uint32_t left, const uint32_t* const top) { 256 return ClampedAddSubtractHalf(&left, top + 0, top - 1); 257 } 258 259 //------------------------------------------------------------------------------ 260 // Subtract-Green Transform 261 262 // vtbl? are unavailable in iOS/arm64 builds. 263 #if !defined(__aarch64__) 264 265 // 255 = byte will be zero'd 266 static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255 }; 267 268 static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) { 269 const uint32_t* const end = argb_data + (num_pixels & ~3); 270 const uint8x8_t shuffle = vld1_u8(kGreenShuffle); 271 for (; argb_data < end; argb_data += 4) { 272 const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data); 273 const uint8x16_t greens = 274 vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle), 275 vtbl1_u8(vget_high_u8(argb), shuffle)); 276 vst1q_u8((uint8_t*)argb_data, vsubq_u8(argb, greens)); 277 } 278 // fallthrough and finish off with plain-C 279 VP8LSubtractGreenFromBlueAndRed_C(argb_data, num_pixels & 3); 280 } 281 282 static void AddGreenToBlueAndRed(uint32_t* argb_data, int num_pixels) { 283 const uint32_t* const end = argb_data + (num_pixels & ~3); 284 const uint8x8_t shuffle = vld1_u8(kGreenShuffle); 285 for (; argb_data < end; argb_data += 4) { 286 const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data); 287 const uint8x16_t greens = 288 vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle), 289 vtbl1_u8(vget_high_u8(argb), shuffle)); 290 vst1q_u8((uint8_t*)argb_data, vaddq_u8(argb, greens)); 291 } 292 // fallthrough and finish off with plain-C 293 VP8LAddGreenToBlueAndRed_C(argb_data, num_pixels & 3); 294 } 295 296 #endif // !__aarch64__ 297 298 #endif // USE_INTRINSICS 299 300 #endif // WEBP_USE_NEON 301 302 //------------------------------------------------------------------------------ 303 304 extern void VP8LDspInitNEON(void); 305 306 void VP8LDspInitNEON(void) { 307 #if defined(WEBP_USE_NEON) 308 VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA; 309 VP8LConvertBGRAToBGR = ConvertBGRAToBGR; 310 VP8LConvertBGRAToRGB = ConvertBGRAToRGB; 311 312 #ifdef USE_INTRINSICS 313 VP8LPredictors[5] = Predictor5; 314 VP8LPredictors[6] = Predictor6; 315 VP8LPredictors[7] = Predictor7; 316 VP8LPredictors[8] = Predictor8; 317 VP8LPredictors[9] = Predictor9; 318 VP8LPredictors[10] = Predictor10; 319 VP8LPredictors[11] = Predictor11; 320 VP8LPredictors[12] = Predictor12; 321 VP8LPredictors[13] = Predictor13; 322 323 #if !defined(__aarch64__) 324 VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed; 325 VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed; 326 #endif 327 #endif 328 329 #endif // WEBP_USE_NEON 330 } 331 332 //------------------------------------------------------------------------------ 333
