upsampling.c revision 793ee12c6df9cad3806238d32528c49a3ff9331d
1// Copyright 2011 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// YUV to RGB upsampling functions. 11// 12// Author: somnath@google.com (Somnath Banerjee) 13 14#include "./dsp.h" 15#include "./yuv.h" 16 17#if defined(__cplusplus) || defined(c_plusplus) 18extern "C" { 19#endif 20 21//------------------------------------------------------------------------------ 22// Fancy upsampler 23 24#ifdef FANCY_UPSAMPLING 25 26// Fancy upsampling functions to convert YUV to RGB 27WebPUpsampleLinePairFunc WebPUpsamplers[MODE_LAST]; 28 29// Given samples laid out in a square as: 30// [a b] 31// [c d] 32// we interpolate u/v as: 33// ([9*a + 3*b + 3*c + d 3*a + 9*b + 3*c + d] + [8 8]) / 16 34// ([3*a + b + 9*c + 3*d a + 3*b + 3*c + 9*d] [8 8]) / 16 35 36// We process u and v together stashed into 32bit (16bit each). 37#define LOAD_UV(u, v) ((u) | ((v) << 16)) 38 39#define UPSAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \ 40static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \ 41 const uint8_t* top_u, const uint8_t* top_v, \ 42 const uint8_t* cur_u, const uint8_t* cur_v, \ 43 uint8_t* top_dst, uint8_t* bottom_dst, int len) { \ 44 int x; \ 45 const int last_pixel_pair = (len - 1) >> 1; \ 46 uint32_t tl_uv = LOAD_UV(top_u[0], top_v[0]); /* top-left sample */ \ 47 uint32_t l_uv = LOAD_UV(cur_u[0], cur_v[0]); /* left-sample */ \ 48 if (top_y) { \ 49 const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \ 50 FUNC(top_y[0], uv0 & 0xff, (uv0 >> 16), top_dst); \ 51 } \ 52 if (bottom_y) { \ 53 const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \ 54 FUNC(bottom_y[0], uv0 & 0xff, (uv0 >> 16), bottom_dst); \ 55 } \ 56 for (x = 1; x <= last_pixel_pair; ++x) { \ 57 const uint32_t t_uv = LOAD_UV(top_u[x], top_v[x]); /* top sample */ \ 58 const uint32_t uv = LOAD_UV(cur_u[x], cur_v[x]); /* sample */ \ 59 /* precompute invariant values associated with first and second diagonals*/\ 60 const uint32_t avg = tl_uv + t_uv + l_uv + uv + 0x00080008u; \ 61 const uint32_t diag_12 = (avg + 2 * (t_uv + l_uv)) >> 3; \ 62 const uint32_t diag_03 = (avg + 2 * (tl_uv + uv)) >> 3; \ 63 if (top_y) { \ 64 const uint32_t uv0 = (diag_12 + tl_uv) >> 1; \ 65 const uint32_t uv1 = (diag_03 + t_uv) >> 1; \ 66 FUNC(top_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \ 67 top_dst + (2 * x - 1) * XSTEP); \ 68 FUNC(top_y[2 * x - 0], uv1 & 0xff, (uv1 >> 16), \ 69 top_dst + (2 * x - 0) * XSTEP); \ 70 } \ 71 if (bottom_y) { \ 72 const uint32_t uv0 = (diag_03 + l_uv) >> 1; \ 73 const uint32_t uv1 = (diag_12 + uv) >> 1; \ 74 FUNC(bottom_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \ 75 bottom_dst + (2 * x - 1) * XSTEP); \ 76 FUNC(bottom_y[2 * x + 0], uv1 & 0xff, (uv1 >> 16), \ 77 bottom_dst + (2 * x + 0) * XSTEP); \ 78 } \ 79 tl_uv = t_uv; \ 80 l_uv = uv; \ 81 } \ 82 if (!(len & 1)) { \ 83 if (top_y) { \ 84 const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \ 85 FUNC(top_y[len - 1], uv0 & 0xff, (uv0 >> 16), \ 86 top_dst + (len - 1) * XSTEP); \ 87 } \ 88 if (bottom_y) { \ 89 const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \ 90 FUNC(bottom_y[len - 1], uv0 & 0xff, (uv0 >> 16), \ 91 bottom_dst + (len - 1) * XSTEP); \ 92 } \ 93 } \ 94} 95 96// All variants implemented. 97UPSAMPLE_FUNC(UpsampleRgbLinePair, VP8YuvToRgb, 3) 98UPSAMPLE_FUNC(UpsampleBgrLinePair, VP8YuvToBgr, 3) 99UPSAMPLE_FUNC(UpsampleRgbaLinePair, VP8YuvToRgba, 4) 100UPSAMPLE_FUNC(UpsampleBgraLinePair, VP8YuvToBgra, 4) 101UPSAMPLE_FUNC(UpsampleArgbLinePair, VP8YuvToArgb, 4) 102UPSAMPLE_FUNC(UpsampleRgba4444LinePair, VP8YuvToRgba4444, 2) 103UPSAMPLE_FUNC(UpsampleRgb565LinePair, VP8YuvToRgb565, 2) 104 105#undef LOAD_UV 106#undef UPSAMPLE_FUNC 107 108#endif // FANCY_UPSAMPLING 109 110//------------------------------------------------------------------------------ 111// simple point-sampling 112 113#define SAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \ 114static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \ 115 const uint8_t* u, const uint8_t* v, \ 116 uint8_t* top_dst, uint8_t* bottom_dst, int len) { \ 117 int i; \ 118 for (i = 0; i < len - 1; i += 2) { \ 119 FUNC(top_y[0], u[0], v[0], top_dst); \ 120 FUNC(top_y[1], u[0], v[0], top_dst + XSTEP); \ 121 FUNC(bottom_y[0], u[0], v[0], bottom_dst); \ 122 FUNC(bottom_y[1], u[0], v[0], bottom_dst + XSTEP); \ 123 top_y += 2; \ 124 bottom_y += 2; \ 125 u++; \ 126 v++; \ 127 top_dst += 2 * XSTEP; \ 128 bottom_dst += 2 * XSTEP; \ 129 } \ 130 if (i == len - 1) { /* last one */ \ 131 FUNC(top_y[0], u[0], v[0], top_dst); \ 132 FUNC(bottom_y[0], u[0], v[0], bottom_dst); \ 133 } \ 134} 135 136// All variants implemented. 137SAMPLE_FUNC(SampleRgbLinePair, VP8YuvToRgb, 3) 138SAMPLE_FUNC(SampleBgrLinePair, VP8YuvToBgr, 3) 139SAMPLE_FUNC(SampleRgbaLinePair, VP8YuvToRgba, 4) 140SAMPLE_FUNC(SampleBgraLinePair, VP8YuvToBgra, 4) 141SAMPLE_FUNC(SampleArgbLinePair, VP8YuvToArgb, 4) 142SAMPLE_FUNC(SampleRgba4444LinePair, VP8YuvToRgba4444, 2) 143SAMPLE_FUNC(SampleRgb565LinePair, VP8YuvToRgb565, 2) 144 145#undef SAMPLE_FUNC 146 147const WebPSampleLinePairFunc WebPSamplers[MODE_LAST] = { 148 SampleRgbLinePair, // MODE_RGB 149 SampleRgbaLinePair, // MODE_RGBA 150 SampleBgrLinePair, // MODE_BGR 151 SampleBgraLinePair, // MODE_BGRA 152 SampleArgbLinePair, // MODE_ARGB 153 SampleRgba4444LinePair, // MODE_RGBA_4444 154 SampleRgb565LinePair, // MODE_RGB_565 155 SampleRgbaLinePair, // MODE_rgbA 156 SampleBgraLinePair, // MODE_bgrA 157 SampleArgbLinePair, // MODE_Argb 158 SampleRgba4444LinePair // MODE_rgbA_4444 159}; 160 161//------------------------------------------------------------------------------ 162 163#if !defined(FANCY_UPSAMPLING) 164#define DUAL_SAMPLE_FUNC(FUNC_NAME, FUNC) \ 165static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bot_y, \ 166 const uint8_t* top_u, const uint8_t* top_v, \ 167 const uint8_t* bot_u, const uint8_t* bot_v, \ 168 uint8_t* top_dst, uint8_t* bot_dst, int len) { \ 169 const int half_len = len >> 1; \ 170 int x; \ 171 if (top_dst != NULL) { \ 172 for (x = 0; x < half_len; ++x) { \ 173 FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x + 0); \ 174 FUNC(top_y[2 * x + 1], top_u[x], top_v[x], top_dst + 8 * x + 4); \ 175 } \ 176 if (len & 1) FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x); \ 177 } \ 178 if (bot_dst != NULL) { \ 179 for (x = 0; x < half_len; ++x) { \ 180 FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x + 0); \ 181 FUNC(bot_y[2 * x + 1], bot_u[x], bot_v[x], bot_dst + 8 * x + 4); \ 182 } \ 183 if (len & 1) FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x); \ 184 } \ 185} 186 187DUAL_SAMPLE_FUNC(DualLineSamplerBGRA, VP8YuvToBgra) 188DUAL_SAMPLE_FUNC(DualLineSamplerARGB, VP8YuvToArgb) 189#undef DUAL_SAMPLE_FUNC 190 191#endif // !FANCY_UPSAMPLING 192 193WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last) { 194 WebPInitUpsamplers(); 195 VP8YUVInit(); 196#ifdef FANCY_UPSAMPLING 197 return WebPUpsamplers[alpha_is_last ? MODE_BGRA : MODE_ARGB]; 198#else 199 return (alpha_is_last ? DualLineSamplerBGRA : DualLineSamplerARGB); 200#endif 201} 202 203//------------------------------------------------------------------------------ 204// YUV444 converter 205 206#define YUV444_FUNC(FUNC_NAME, FUNC, XSTEP) \ 207static void FUNC_NAME(const uint8_t* y, const uint8_t* u, const uint8_t* v, \ 208 uint8_t* dst, int len) { \ 209 int i; \ 210 for (i = 0; i < len; ++i) FUNC(y[i], u[i], v[i], &dst[i * XSTEP]); \ 211} 212 213YUV444_FUNC(Yuv444ToRgb, VP8YuvToRgb, 3) 214YUV444_FUNC(Yuv444ToBgr, VP8YuvToBgr, 3) 215YUV444_FUNC(Yuv444ToRgba, VP8YuvToRgba, 4) 216YUV444_FUNC(Yuv444ToBgra, VP8YuvToBgra, 4) 217YUV444_FUNC(Yuv444ToArgb, VP8YuvToArgb, 4) 218YUV444_FUNC(Yuv444ToRgba4444, VP8YuvToRgba4444, 2) 219YUV444_FUNC(Yuv444ToRgb565, VP8YuvToRgb565, 2) 220 221#undef YUV444_FUNC 222 223const WebPYUV444Converter WebPYUV444Converters[MODE_LAST] = { 224 Yuv444ToRgb, // MODE_RGB 225 Yuv444ToRgba, // MODE_RGBA 226 Yuv444ToBgr, // MODE_BGR 227 Yuv444ToBgra, // MODE_BGRA 228 Yuv444ToArgb, // MODE_ARGB 229 Yuv444ToRgba4444, // MODE_RGBA_4444 230 Yuv444ToRgb565, // MODE_RGB_565 231 Yuv444ToRgba, // MODE_rgbA 232 Yuv444ToBgra, // MODE_bgrA 233 Yuv444ToArgb, // MODE_Argb 234 Yuv444ToRgba4444 // MODE_rgbA_4444 235}; 236 237//------------------------------------------------------------------------------ 238// Premultiplied modes 239 240// non dithered-modes 241 242// (x * a * 32897) >> 23 is bit-wise equivalent to (int)(x * a / 255.) 243// for all 8bit x or a. For bit-wise equivalence to (int)(x * a / 255. + .5), 244// one can use instead: (x * a * 65793 + (1 << 23)) >> 24 245#if 1 // (int)(x * a / 255.) 246#define MULTIPLIER(a) ((a) * 32897UL) 247#define PREMULTIPLY(x, m) (((x) * (m)) >> 23) 248#else // (int)(x * a / 255. + .5) 249#define MULTIPLIER(a) ((a) * 65793UL) 250#define PREMULTIPLY(x, m) (((x) * (m) + (1UL << 23)) >> 24) 251#endif 252 253static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first, 254 int w, int h, int stride) { 255 while (h-- > 0) { 256 uint8_t* const rgb = rgba + (alpha_first ? 1 : 0); 257 const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3); 258 int i; 259 for (i = 0; i < w; ++i) { 260 const uint32_t a = alpha[4 * i]; 261 if (a != 0xff) { 262 const uint32_t mult = MULTIPLIER(a); 263 rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult); 264 rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult); 265 rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult); 266 } 267 } 268 rgba += stride; 269 } 270} 271#undef MULTIPLIER 272#undef PREMULTIPLY 273 274// rgbA4444 275 276#define MULTIPLIER(a) ((a) * 0x1111) // 0x1111 ~= (1 << 16) / 15 277 278static WEBP_INLINE uint8_t dither_hi(uint8_t x) { 279 return (x & 0xf0) | (x >> 4); 280} 281 282static WEBP_INLINE uint8_t dither_lo(uint8_t x) { 283 return (x & 0x0f) | (x << 4); 284} 285 286static WEBP_INLINE uint8_t multiply(uint8_t x, uint32_t m) { 287 return (x * m) >> 16; 288} 289 290static void ApplyAlphaMultiply4444(uint8_t* rgba4444, 291 int w, int h, int stride) { 292 while (h-- > 0) { 293 int i; 294 for (i = 0; i < w; ++i) { 295 const uint8_t a = (rgba4444[2 * i + 1] & 0x0f); 296 const uint32_t mult = MULTIPLIER(a); 297 const uint8_t r = multiply(dither_hi(rgba4444[2 * i + 0]), mult); 298 const uint8_t g = multiply(dither_lo(rgba4444[2 * i + 0]), mult); 299 const uint8_t b = multiply(dither_hi(rgba4444[2 * i + 1]), mult); 300 rgba4444[2 * i + 0] = (r & 0xf0) | ((g >> 4) & 0x0f); 301 rgba4444[2 * i + 1] = (b & 0xf0) | a; 302 } 303 rgba4444 += stride; 304 } 305} 306#undef MULTIPLIER 307 308void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int) 309 = ApplyAlphaMultiply; 310void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int) 311 = ApplyAlphaMultiply4444; 312 313//------------------------------------------------------------------------------ 314// Main call 315 316void WebPInitUpsamplers(void) { 317#ifdef FANCY_UPSAMPLING 318 WebPUpsamplers[MODE_RGB] = UpsampleRgbLinePair; 319 WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair; 320 WebPUpsamplers[MODE_BGR] = UpsampleBgrLinePair; 321 WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair; 322 WebPUpsamplers[MODE_ARGB] = UpsampleArgbLinePair; 323 WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair; 324 WebPUpsamplers[MODE_RGB_565] = UpsampleRgb565LinePair; 325 326 // If defined, use CPUInfo() to overwrite some pointers with faster versions. 327 if (VP8GetCPUInfo != NULL) { 328#if defined(WEBP_USE_SSE2) 329 if (VP8GetCPUInfo(kSSE2)) { 330 WebPInitUpsamplersSSE2(); 331 } 332#endif 333#if defined(WEBP_USE_NEON) 334 if (VP8GetCPUInfo(kNEON)) { 335 WebPInitUpsamplersNEON(); 336 } 337#endif 338 } 339#endif // FANCY_UPSAMPLING 340} 341 342void WebPInitPremultiply(void) { 343 WebPApplyAlphaMultiply = ApplyAlphaMultiply; 344 WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply4444; 345 346#ifdef FANCY_UPSAMPLING 347 WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair; 348 WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair; 349 WebPUpsamplers[MODE_Argb] = UpsampleArgbLinePair; 350 WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair; 351 352 if (VP8GetCPUInfo != NULL) { 353#if defined(WEBP_USE_SSE2) 354 if (VP8GetCPUInfo(kSSE2)) { 355 WebPInitPremultiplySSE2(); 356 } 357#endif 358#if defined(WEBP_USE_NEON) 359 if (VP8GetCPUInfo(kNEON)) { 360 WebPInitPremultiplyNEON(); 361 } 362#endif 363 } 364#endif // FANCY_UPSAMPLING 365} 366 367#if defined(__cplusplus) || defined(c_plusplus) 368} // extern "C" 369#endif 370