1 // Copyright 2012 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 // Rescaling functions 11 // 12 // Author: Skal (pascal.massimino (at) gmail.com) 13 14 #include <assert.h> 15 #include <stdlib.h> 16 #include "./rescaler.h" 17 #include "../dsp/dsp.h" 18 19 //------------------------------------------------------------------------------ 20 // Implementations of critical functions ImportRow / ExportRow 21 22 void (*WebPRescalerImportRow)(WebPRescaler* const wrk, 23 const uint8_t* const src, int channel) = NULL; 24 void (*WebPRescalerExportRow)(WebPRescaler* const wrk, int x_out) = NULL; 25 26 #define RFIX 30 27 #define MULT_FIX(x, y) (((int64_t)(x) * (y) + (1 << (RFIX - 1))) >> RFIX) 28 29 static void ImportRowC(WebPRescaler* const wrk, 30 const uint8_t* const src, int channel) { 31 const int x_stride = wrk->num_channels; 32 const int x_out_max = wrk->dst_width * wrk->num_channels; 33 int x_in = channel; 34 int x_out; 35 int accum = 0; 36 if (!wrk->x_expand) { 37 int sum = 0; 38 for (x_out = channel; x_out < x_out_max; x_out += x_stride) { 39 accum += wrk->x_add; 40 for (; accum > 0; accum -= wrk->x_sub) { 41 sum += src[x_in]; 42 x_in += x_stride; 43 } 44 { // Emit next horizontal pixel. 45 const int32_t base = src[x_in]; 46 const int32_t frac = base * (-accum); 47 x_in += x_stride; 48 wrk->frow[x_out] = (sum + base) * wrk->x_sub - frac; 49 // fresh fractional start for next pixel 50 sum = (int)MULT_FIX(frac, wrk->fx_scale); 51 } 52 } 53 } else { // simple bilinear interpolation 54 int left = src[channel], right = src[channel]; 55 for (x_out = channel; x_out < x_out_max; x_out += x_stride) { 56 if (accum < 0) { 57 left = right; 58 x_in += x_stride; 59 right = src[x_in]; 60 accum += wrk->x_add; 61 } 62 wrk->frow[x_out] = right * wrk->x_add + (left - right) * accum; 63 accum -= wrk->x_sub; 64 } 65 } 66 // Accumulate the contribution of the new row. 67 for (x_out = channel; x_out < x_out_max; x_out += x_stride) { 68 wrk->irow[x_out] += wrk->frow[x_out]; 69 } 70 } 71 72 static void ExportRowC(WebPRescaler* const wrk, int x_out) { 73 if (wrk->y_accum <= 0) { 74 uint8_t* const dst = wrk->dst; 75 int32_t* const irow = wrk->irow; 76 const int32_t* const frow = wrk->frow; 77 const int yscale = wrk->fy_scale * (-wrk->y_accum); 78 const int x_out_max = wrk->dst_width * wrk->num_channels; 79 for (; x_out < x_out_max; ++x_out) { 80 const int frac = (int)MULT_FIX(frow[x_out], yscale); 81 const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale); 82 dst[x_out] = (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255; 83 irow[x_out] = frac; // new fractional start 84 } 85 wrk->y_accum += wrk->y_add; 86 wrk->dst += wrk->dst_stride; 87 } 88 } 89 90 //------------------------------------------------------------------------------ 91 // MIPS version 92 93 #if defined(WEBP_USE_MIPS32) 94 95 static void ImportRowMIPS(WebPRescaler* const wrk, 96 const uint8_t* const src, int channel) { 97 const int x_stride = wrk->num_channels; 98 const int x_out_max = wrk->dst_width * wrk->num_channels; 99 const int fx_scale = wrk->fx_scale; 100 const int x_add = wrk->x_add; 101 const int x_sub = wrk->x_sub; 102 int* frow = wrk->frow + channel; 103 int* irow = wrk->irow + channel; 104 const uint8_t* src1 = src + channel; 105 int temp1, temp2, temp3; 106 int base, frac, sum; 107 int accum, accum1; 108 const int x_stride1 = x_stride << 2; 109 int loop_c = x_out_max - channel; 110 111 if (!wrk->x_expand) { 112 __asm__ volatile ( 113 "li %[temp1], 0x8000 \n\t" 114 "li %[temp2], 0x10000 \n\t" 115 "li %[sum], 0 \n\t" 116 "li %[accum], 0 \n\t" 117 "1: \n\t" 118 "addu %[accum], %[accum], %[x_add] \n\t" 119 "blez %[accum], 3f \n\t" 120 "2: \n\t" 121 "lbu %[temp3], 0(%[src1]) \n\t" 122 "subu %[accum], %[accum], %[x_sub] \n\t" 123 "addu %[src1], %[src1], %[x_stride] \n\t" 124 "addu %[sum], %[sum], %[temp3] \n\t" 125 "bgtz %[accum], 2b \n\t" 126 "3: \n\t" 127 "lbu %[base], 0(%[src1]) \n\t" 128 "addu %[src1], %[src1], %[x_stride] \n\t" 129 "negu %[accum1], %[accum] \n\t" 130 "mul %[frac], %[base], %[accum1] \n\t" 131 "addu %[temp3], %[sum], %[base] \n\t" 132 "mul %[temp3], %[temp3], %[x_sub] \n\t" 133 "lw %[base], 0(%[irow]) \n\t" 134 "subu %[loop_c], %[loop_c], %[x_stride] \n\t" 135 "sll %[accum1], %[frac], 2 \n\t" 136 "mult %[temp1], %[temp2] \n\t" 137 "madd %[accum1], %[fx_scale] \n\t" 138 "mfhi %[sum] \n\t" 139 "subu %[temp3], %[temp3], %[frac] \n\t" 140 "sw %[temp3], 0(%[frow]) \n\t" 141 "add %[base], %[base], %[temp3] \n\t" 142 "sw %[base], 0(%[irow]) \n\t" 143 "addu %[irow], %[irow], %[x_stride1] \n\t" 144 "addu %[frow], %[frow], %[x_stride1] \n\t" 145 "bgtz %[loop_c], 1b \n\t" 146 147 : [accum] "=&r" (accum), [src1] "+r" (src1), [temp3] "=&r" (temp3), 148 [sum] "=&r" (sum), [base] "=&r" (base), [frac] "=&r" (frac), 149 [frow] "+r" (frow), [irow] "+r" (irow), [accum1] "=&r" (accum1), 150 [temp2] "=&r" (temp2), [temp1] "=&r" (temp1) 151 : [x_stride] "r" (x_stride), [fx_scale] "r" (fx_scale), 152 [x_sub] "r" (x_sub), [x_add] "r" (x_add), 153 [loop_c] "r" (loop_c), [x_stride1] "r" (x_stride1) 154 : "memory", "hi", "lo" 155 ); 156 } else { 157 __asm__ volatile ( 158 "lbu %[temp1], 0(%[src1]) \n\t" 159 "move %[temp2], %[temp1] \n\t" 160 "li %[accum], 0 \n\t" 161 "1: \n\t" 162 "bgez %[accum], 2f \n\t" 163 "move %[temp2], %[temp1] \n\t" 164 "addu %[src1], %[x_stride] \n\t" 165 "lbu %[temp1], 0(%[src1]) \n\t" 166 "addu %[accum], %[x_add] \n\t" 167 "2: \n\t" 168 "subu %[temp3], %[temp2], %[temp1] \n\t" 169 "mul %[temp3], %[temp3], %[accum] \n\t" 170 "mul %[base], %[temp1], %[x_add] \n\t" 171 "subu %[accum], %[accum], %[x_sub] \n\t" 172 "lw %[frac], 0(%[irow]) \n\t" 173 "subu %[loop_c], %[loop_c], %[x_stride] \n\t" 174 "addu %[temp3], %[base], %[temp3] \n\t" 175 "sw %[temp3], 0(%[frow]) \n\t" 176 "addu %[frow], %[x_stride1] \n\t" 177 "addu %[frac], %[temp3] \n\t" 178 "sw %[frac], 0(%[irow]) \n\t" 179 "addu %[irow], %[x_stride1] \n\t" 180 "bgtz %[loop_c], 1b \n\t" 181 182 : [src1] "+r" (src1), [accum] "=&r" (accum), [temp1] "=&r" (temp1), 183 [temp2] "=&r" (temp2), [temp3] "=&r" (temp3), [base] "=&r" (base), 184 [frac] "=&r" (frac), [frow] "+r" (frow), [irow] "+r" (irow) 185 : [x_stride] "r" (x_stride), [x_add] "r" (x_add), [x_sub] "r" (x_sub), 186 [x_stride1] "r" (x_stride1), [loop_c] "r" (loop_c) 187 : "memory", "hi", "lo" 188 ); 189 } 190 } 191 192 static void ExportRowMIPS(WebPRescaler* const wrk, int x_out) { 193 if (wrk->y_accum <= 0) { 194 uint8_t* const dst = wrk->dst; 195 int32_t* const irow = wrk->irow; 196 const int32_t* const frow = wrk->frow; 197 const int yscale = wrk->fy_scale * (-wrk->y_accum); 198 const int x_out_max = wrk->dst_width * wrk->num_channels; 199 // if wrk->fxy_scale can fit into 32 bits use optimized code, 200 // otherwise use C code 201 if ((wrk->fxy_scale >> 32) == 0) { 202 int temp0, temp1, temp3, temp4, temp5, temp6, temp7, loop_end; 203 const int temp2 = (int)(wrk->fxy_scale); 204 const int temp8 = x_out_max << 2; 205 uint8_t* dst_t = (uint8_t*)dst; 206 int32_t* irow_t = (int32_t*)irow; 207 const int32_t* frow_t = (const int32_t*)frow; 208 209 __asm__ volatile( 210 "addiu %[temp6], $zero, -256 \n\t" 211 "addiu %[temp7], $zero, 255 \n\t" 212 "li %[temp3], 0x10000 \n\t" 213 "li %[temp4], 0x8000 \n\t" 214 "addu %[loop_end], %[frow_t], %[temp8] \n\t" 215 "1: \n\t" 216 "lw %[temp0], 0(%[frow_t]) \n\t" 217 "mult %[temp3], %[temp4] \n\t" 218 "addiu %[frow_t], %[frow_t], 4 \n\t" 219 "sll %[temp0], %[temp0], 2 \n\t" 220 "madd %[temp0], %[yscale] \n\t" 221 "mfhi %[temp1] \n\t" 222 "lw %[temp0], 0(%[irow_t]) \n\t" 223 "addiu %[dst_t], %[dst_t], 1 \n\t" 224 "addiu %[irow_t], %[irow_t], 4 \n\t" 225 "subu %[temp0], %[temp0], %[temp1] \n\t" 226 "mult %[temp3], %[temp4] \n\t" 227 "sll %[temp0], %[temp0], 2 \n\t" 228 "madd %[temp0], %[temp2] \n\t" 229 "mfhi %[temp5] \n\t" 230 "sw %[temp1], -4(%[irow_t]) \n\t" 231 "and %[temp0], %[temp5], %[temp6] \n\t" 232 "slti %[temp1], %[temp5], 0 \n\t" 233 "beqz %[temp0], 2f \n\t" 234 "xor %[temp5], %[temp5], %[temp5] \n\t" 235 "movz %[temp5], %[temp7], %[temp1] \n\t" 236 "2: \n\t" 237 "sb %[temp5], -1(%[dst_t]) \n\t" 238 "bne %[frow_t], %[loop_end], 1b \n\t" 239 240 : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3), 241 [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [temp6]"=&r"(temp6), 242 [temp7]"=&r"(temp7), [frow_t]"+r"(frow_t), [irow_t]"+r"(irow_t), 243 [dst_t]"+r"(dst_t), [loop_end]"=&r"(loop_end) 244 : [temp2]"r"(temp2), [yscale]"r"(yscale), [temp8]"r"(temp8) 245 : "memory", "hi", "lo" 246 ); 247 wrk->y_accum += wrk->y_add; 248 wrk->dst += wrk->dst_stride; 249 } else { 250 ExportRowC(wrk, x_out); 251 } 252 } 253 } 254 #endif // WEBP_USE_MIPS32 255 256 //------------------------------------------------------------------------------ 257 258 void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height, 259 uint8_t* const dst, int dst_width, int dst_height, 260 int dst_stride, int num_channels, int x_add, int x_sub, 261 int y_add, int y_sub, int32_t* const work) { 262 wrk->x_expand = (src_width < dst_width); 263 wrk->src_width = src_width; 264 wrk->src_height = src_height; 265 wrk->dst_width = dst_width; 266 wrk->dst_height = dst_height; 267 wrk->dst = dst; 268 wrk->dst_stride = dst_stride; 269 wrk->num_channels = num_channels; 270 // for 'x_expand', we use bilinear interpolation 271 wrk->x_add = wrk->x_expand ? (x_sub - 1) : x_add - x_sub; 272 wrk->x_sub = wrk->x_expand ? (x_add - 1) : x_sub; 273 wrk->y_accum = y_add; 274 wrk->y_add = y_add; 275 wrk->y_sub = y_sub; 276 wrk->fx_scale = (1 << RFIX) / x_sub; 277 wrk->fy_scale = (1 << RFIX) / y_sub; 278 wrk->fxy_scale = wrk->x_expand ? 279 ((int64_t)dst_height << RFIX) / (x_sub * src_height) : 280 ((int64_t)dst_height << RFIX) / (x_add * src_height); 281 wrk->irow = work; 282 wrk->frow = work + num_channels * dst_width; 283 284 if (WebPRescalerImportRow == NULL) { 285 WebPRescalerImportRow = ImportRowC; 286 WebPRescalerExportRow = ExportRowC; 287 if (VP8GetCPUInfo != NULL) { 288 #if defined(WEBP_USE_MIPS32) 289 if (VP8GetCPUInfo(kMIPS32)) { 290 WebPRescalerImportRow = ImportRowMIPS; 291 WebPRescalerExportRow = ExportRowMIPS; 292 } 293 #endif 294 } 295 } 296 } 297 298 #undef MULT_FIX 299 #undef RFIX 300 301 //------------------------------------------------------------------------------ 302 // all-in-one calls 303 304 int WebPRescaleNeededLines(const WebPRescaler* const wrk, int max_num_lines) { 305 const int num_lines = (wrk->y_accum + wrk->y_sub - 1) / wrk->y_sub; 306 return (num_lines > max_num_lines) ? max_num_lines : num_lines; 307 } 308 309 int WebPRescalerImport(WebPRescaler* const wrk, int num_lines, 310 const uint8_t* src, int src_stride) { 311 int total_imported = 0; 312 while (total_imported < num_lines && wrk->y_accum > 0) { 313 int channel; 314 for (channel = 0; channel < wrk->num_channels; ++channel) { 315 WebPRescalerImportRow(wrk, src, channel); 316 } 317 src += src_stride; 318 ++total_imported; 319 wrk->y_accum -= wrk->y_sub; 320 } 321 return total_imported; 322 } 323 324 int WebPRescalerExport(WebPRescaler* const rescaler) { 325 int total_exported = 0; 326 while (WebPRescalerHasPendingOutput(rescaler)) { 327 WebPRescalerExportRow(rescaler, 0); 328 ++total_exported; 329 } 330 return total_exported; 331 } 332 333 //------------------------------------------------------------------------------ 334
