git.sesse.net Git - qscale/blob - qscale.c

   1 #include <stdio.h>
   2 #include <malloc.h>
   3 #include <math.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include "jpeglib.h"
   7
   8 #define CACHE_LINE_FACTOR 16
   9
  10 double sinc(double x)
  11 {
  12         static const double eps = 2.22045e-016;
  13         static const double cutoff = sqrt(sqrt(eps));
  14
  15         if (abs(x) < cutoff) {
  16                 // For small |x|, use Taylor series instead
  17                 const double x2 = x * x;
  18                 const double x4 = x2 * x2;
  19
  20                 return 1.0 - x2 / 6.0 + x4 / 120.0;
  21         } else {
  22                 return sin(x) / x;
  23         }
  24 }
  25
  26 double lanczos_tap(double x)
  27 {
  28         if (x < -3.0 || x > 3.0)
  29                 return 0.0;
  30         if (x < 0.0)
  31                 return sinc(-x*M_PI) * sinc(-x*M_PI / 3.0);
  32         else
  33                 return sinc(x*M_PI) * sinc(x*M_PI / 3.0);
  34 }
  35
  36
  37 struct pix_desc {
  38         unsigned start, end;
  39         unsigned startcoeff;
  40 };
  41
  42 void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw, unsigned dstride)
  43 {
  44         struct pix_desc *pd = (struct pix_desc *)malloc(nw * sizeof(struct pix_desc));
  45         int size_coeffs = 8;
  46         float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
  47         int num_coeffs = 0;
  48         int x, y;
  49         double sf = (double)w / (double)nw;
  50         double support = (w > nw) ? (3.0 * sf) : (3.0 / sf);
  51
  52         /* calculate the filter */
  53         for (x = 0; x < nw; ++x) {
  54                 int start = ceil(x * sf - support);
  55                 int end = floor(x * sf + support);
  56                 int sx;
  57                 double sum = 0.0;
  58
  59                 if (start < 0) {
  60                         start = 0;
  61                 }
  62                 if (end > w - 1) {
  63                         end = w - 1;
  64                 }
  65
  66                 // round up so we get a multiple of four for the SSE code
  67                 int num = (end - start + 1);
  68                 if (num % 4 != 0) {
  69                         // prefer aligning it if possible
  70                         if (start % 4 != 0 && start % 4 <= num % 4) {
  71                                 num += start % 4;
  72                                 start -= start % 4;
  73                         }
  74                         if (num % 4 != 0) {
  75                                 end += 4 - (num % 4);
  76                         }
  77                 }
  78
  79                 pd[x].start = start;
  80                 pd[x].end = end;
  81                 pd[x].startcoeff = num_coeffs;
  82
  83                 for (sx = start; sx <= end; ++sx) {
  84                         double nd = (w > nw) ? (sx/sf - x) : (sx - x*sf);
  85                         double f = lanczos_tap(nd);
  86                         if (num_coeffs == size_coeffs) {
  87                                 size_coeffs <<= 1;
  88                                 coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
  89                         }
  90
  91                         coeffs[num_coeffs++] = f;
  92                         sum += f;
  93                 }
  94
  95                 for (sx = start; sx <= end; ++sx) {
  96                         coeffs[pd[x].startcoeff + sx - start] /= sum;
  97                 }
  98         }
  99
 100         for (y = 0; y < h; ++y) {
 101                 float *sptr = pix + y*w;
 102                 unsigned char *dptr = npix + y*dstride;
 103                 unsigned char ch;
 104                 for (x = 0; x < nw; ++x) {
 105                         float acc;
 106                         static const float low = 0.0, high = 255.0;
 107                         asm (
 108                                 "pxor %0, %0               \n"
 109                                 "xor %%eax, %%eax          \n"
 110                                 ".lbl2:                    \n"
 111                                 "movups (%2,%%eax),%%xmm1  \n"
 112                                 "movups (%1,%%eax),%%xmm2  \n"
 113                                 "mulps %%xmm2,%%xmm1       \n"
 114                                 "addps %%xmm1,%0           \n"
 115                                 "addl $16,%%eax            \n"
 116                                 "dec %3                    \n"
 117                                 "jnz .lbl2                 \n"
 118                                 "haddps %0,%0              \n"
 119                                 "haddps %0,%0              \n"
 120                                 "maxss %4,%0               \n"
 121                                 "minss %5,%0               \n"
 122                                 : "=x" (acc)
 123                                 : "r" (&coeffs[pd[x].startcoeff]),
 124                                   "r" (&sptr[pd[x].start]),
 125                                   "r" ((pd[x].end - pd[x].start + 1)/4),
 126                                   "m" (low),
 127                                   "m" (high)
 128                                 : "eax", "xmm1", "xmm2"
 129                         );
 130
 131 #if 0
 132                         if (acc < 0.0)
 133                                 ch = 0;
 134                         else if (acc > 255.0)
 135                                 ch = 255;
 136                         else
 137                                 ch = (unsigned char)acc;
 138                         *dptr++ = ch;
 139 #endif
 140                         *dptr++ = (unsigned char)acc;
 141                 }
 142                 ch = dptr[-1];
 143                 for ( ; x < dstride; ++x) {
 144                         *dptr++ = ch;
 145                 }
 146         }
 147 }
 148
 149 void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh, unsigned dstride)
 150 {
 151         struct pix_desc *pd = (struct pix_desc *)malloc(nh * sizeof(struct pix_desc));
 152         int size_coeffs = 8;
 153         float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
 154         int num_coeffs = 0;
 155         int x, y, sy;
 156         double sf = (double)h / (double)nh;
 157         double support = (h > nh) ? (3.0 * sf) : (3.0 / sf);
 158
 159         /* calculate the filter */
 160         for (y = 0; y < nh; ++y) {
 161                 int start = ceil(y * sf - support);
 162                 int end = floor(y * sf + support);
 163                 double sum = 0.0;
 164
 165                 if (start < 0) {
 166                         start = 0;
 167                 }
 168                 if (end > h - 1) {
 169                         end = h - 1;
 170                 }
 171
 172                 pd[y].start = start;
 173                 pd[y].end = end;
 174                 pd[y].startcoeff = num_coeffs;
 175
 176                 for (sy = start; sy <= end; ++sy) {
 177                         double nd = (h > nh) ? (sy/sf - y) : (sy - y*sf);
 178                         double f = lanczos_tap(nd);
 179                         if (num_coeffs == size_coeffs) {
 180                                 size_coeffs <<= 1;
 181                                 coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
 182                         }
 183
 184                         coeffs[num_coeffs++] = f;
 185                         sum += f;
 186                 }
 187
 188                 for (sy = start; sy <= end; ++sy) {
 189                         coeffs[pd[y].startcoeff + sy - start] /= sum;
 190                 }
 191         }
 192
 193 #if CACHE_LINE_FACTOR > 1
 194         for (x = 0; x < (w/CACHE_LINE_FACTOR) * CACHE_LINE_FACTOR; x += CACHE_LINE_FACTOR) {
 195                 unsigned char *sptr = pix + x;
 196                 float *dptr = npix + x;
 197                 for (y = 0; y < nh; ++y) {
 198 #if 0
 199                         int i;
 200                         float acc[CACHE_LINE_FACTOR];
 201                         for (i = 0; i < CACHE_LINE_FACTOR; ++i)
 202                                 acc[i] = 0.0;
 203                         float *cf = &coeffs[pd[y].startcoeff];
 204                         unsigned sy;
 205
 206                         for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
 207                                 for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
 208                                         acc[i] += sptr[sy * w + i] * *cf;
 209                                 }
 210                                 ++cf;
 211                         }
 212
 213                         for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
 214                                 dptr[i] = acc[i];
 215                         }
 216 #else
 217                         /*
 218                          * xmm0 - xmm3: acc[0..15]
 219                          * xmm4: current filter coefficient
 220                          * xmm5, xmm6, xmm7: scratchpad
 221                          */
 222                         asm (
 223                                 /* clear */
 224                                 "pxor %%xmm0, %%xmm0    \n"
 225                                 "pxor %%xmm1, %%xmm1    \n"
 226                                 "pxor %%xmm2, %%xmm2    \n"
 227                                 "pxor %%xmm3, %%xmm3    \n"
 228
 229                                 /* main loop */
 230                                 ".lbl:                   \n"
 231
 232                                 /* a zero is useful during unpacking */
 233                                 "pxor %%xmm4, %%xmm4     \n"
 234
 235                                 /* fetch all 16 source bytes */
 236                                 "movups (%0), %%xmm5     \n"
 237                                 "prefetcht0 (%0,%3,4)    \n"
 238
 239                                 /* unpack into words (xmm5, xmm7) */
 240                                 "movaps %%xmm5, %%xmm7    \n"
 241                                 "punpcklbw %%xmm4, %%xmm5 \n"
 242                                 "punpckhbw %%xmm4, %%xmm7 \n"
 243
 244                                 /* unpack xmm5 into dwords (xmm5, xmm6) */
 245                                 "movaps %%xmm5, %%xmm6    \n"
 246                                 "punpcklwd %%xmm4, %%xmm5 \n"
 247                                 "punpckhwd %%xmm4, %%xmm6 \n"
 248
 249                                 /* convert xmm5, xmm6 to floats */
 250                                 "cvtdq2ps %%xmm5, %%xmm5 \n"
 251                                 "cvtdq2ps %%xmm6, %%xmm6 \n"
 252
 253                                 /* fetch the coefficient */
 254                                 "movss (%2), %%xmm4      \n"
 255                                 "shufps $0x0, %%xmm4, %%xmm4 \n"
 256
 257                                 /* do the muls for xmm5 and xmm6 */
 258                                 "mulps %%xmm4, %%xmm5    \n"
 259                                 "mulps %%xmm4, %%xmm6    \n"
 260                                 "addps %%xmm5, %%xmm0    \n"
 261                                 "addps %%xmm6, %%xmm1    \n"
 262
 263                                 /* get the zero back again */
 264                                 "pxor %%xmm4, %%xmm4     \n"
 265
 266                                 /* unpack xmm7 into dwords (xmm7, xmm6) */
 267                                 "movaps %%xmm7, %%xmm6    \n"
 268                                 "punpcklwd %%xmm4, %%xmm7 \n"
 269                                 "punpckhwd %%xmm4, %%xmm6 \n"
 270
 271                                 /* convert xmm7, xmm6 to floats */
 272                                 "cvtdq2ps %%xmm7, %%xmm7 \n"
 273                                 "cvtdq2ps %%xmm6, %%xmm6 \n"
 274
 275                                 /* fetch the coefficient */
 276                                 "movss (%2), %%xmm4      \n"
 277                                 "shufps $0x0, %%xmm4, %%xmm4 \n"
 278
 279                                 /* do the second set of muls */
 280                                 "mulps %%xmm4, %%xmm7    \n"
 281                                 "mulps %%xmm4, %%xmm6    \n"
 282                                 "addps %%xmm7, %%xmm2    \n"
 283                                 "addps %%xmm6, %%xmm3    \n"
 284
 285                                 /* move along, and loop */
 286                                 "add $4, %2              \n"
 287                                 "add %3, %0              \n"
 288                                 "dec %1                  \n"
 289                                 "jnz .lbl                \n"
 290
 291                                 /* store the values */
 292                                 "movaps %%xmm0, (%4)     \n"
 293                                 "movaps %%xmm1, 16(%4)   \n"
 294                                 "movaps %%xmm2, 32(%4)   \n"
 295                                 "movaps %%xmm3, 48(%4)   \n"
 296                                 : :
 297                                 "r" (&sptr[pd[y].start * w]),        /* 0: srcptr base */
 298                                 "r" (pd[y].end - pd[y].start + 1),   /* 1: filter len */
 299                                 "r" (&coeffs[pd[y].startcoeff]),     /* 2: coeffs base */
 300                                 "r" (w),                             /* 3: stride */
 301                                 "r" (dptr)                           /* 4: dstptr base */
 302                                 : "memory", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7"
 303                         );
 304 #endif
 305                         dptr += dstride;
 306                 }
 307         }
 308         for (x = (x/CACHE_LINE_FACTOR)*CACHE_LINE_FACTOR; x < w; ++x) {
 309 #else
 310         for (x = 0; x < w; ++x) {
 311 #endif
 312                 unsigned char *sptr = pix + x;
 313                 float *dptr = npix + x;
 314                 for (y = 0; y < nh; ++y) {
 315                         float acc = 0.0;
 316                         float *cf = &coeffs[pd[y].startcoeff];
 317                         unsigned sy;
 318
 319                         for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
 320                                 acc += sptr[sy * w] * *cf++;
 321                         }
 322
 323                         *dptr = acc;
 324                         dptr += dstride;
 325                 }
 326         }
 327 }
 328
 329 int main(int argc, char **argv)
 330 {
 331         unsigned nominal_w = atoi(argv[1]);
 332         unsigned nominal_h = atoi(argv[2]);
 333
 334         unsigned samp_h0 = 2, samp_v0 = 2;
 335         unsigned samp_h1 = 1, samp_v1 = 1;
 336         unsigned samp_h2 = 1, samp_v2 = 1;
 337         unsigned max_samp_h = 2, max_samp_v = 2;
 338
 339         unsigned nw0 = nominal_w * samp_h0 / max_samp_h, nh0 = nominal_h * samp_v0 / max_samp_v;
 340         unsigned nw1 = nominal_w * samp_h1 / max_samp_h, nh1 = nominal_h * samp_v1 / max_samp_v;
 341         unsigned nw2 = nominal_w * samp_h2 / max_samp_h, nh2 = nominal_h * samp_v2 / max_samp_v;
 342
 343         unsigned stride0 = (nw0 + DCTSIZE-1) & ~(DCTSIZE-1);
 344         unsigned stride1 = (nw1 + DCTSIZE-1) & ~(DCTSIZE-1);
 345         unsigned stride2 = (nw2 + DCTSIZE-1) & ~(DCTSIZE-1);
 346
 347         struct jpeg_decompress_struct dinfo;
 348         struct jpeg_error_mgr jerr;
 349         dinfo.err = jpeg_std_error(&jerr);
 350         jpeg_create_decompress(&dinfo);
 351         jpeg_stdio_src(&dinfo, stdin);
 352         jpeg_read_header(&dinfo, TRUE);
 353         dinfo.raw_data_out = TRUE;
 354         jpeg_start_decompress(&dinfo);
 355
 356         fprintf(stderr, "Scaling using Lanczos filter:\n");
 357         fprintf(stderr, "  Y component: %ux%u -> %ux%u\n", dinfo.comp_info[0].width_in_blocks * DCTSIZE, dinfo.comp_info[0].height_in_blocks * DCTSIZE, nw0, nh0);
 358         fprintf(stderr, "  Cb component: %ux%u -> %ux%u\n", dinfo.comp_info[1].width_in_blocks * DCTSIZE, dinfo.comp_info[1].height_in_blocks * DCTSIZE, nw1, nh1);
 359         fprintf(stderr, "  Cr component: %ux%u -> %ux%u\n", dinfo.comp_info[2].width_in_blocks * DCTSIZE, dinfo.comp_info[2].height_in_blocks * DCTSIZE, nw2, nh2);
 360
 361         JSAMPLE *data_y  = (JSAMPLE*)memalign(16, dinfo.comp_info[0].height_in_blocks * dinfo.comp_info[0].width_in_blocks * DCTSIZE * DCTSIZE);
 362         JSAMPLE *data_cb = (JSAMPLE*)memalign(16, dinfo.comp_info[1].height_in_blocks * dinfo.comp_info[1].width_in_blocks * DCTSIZE * DCTSIZE);
 363         JSAMPLE *data_cr = (JSAMPLE*)memalign(16, dinfo.comp_info[2].height_in_blocks * dinfo.comp_info[2].width_in_blocks * DCTSIZE * DCTSIZE);
 364         JSAMPLE *data_ny, *data_ncb, *data_ncr;
 365
 366         int total_lines = 0, blocks = 0;
 367         while (total_lines < dinfo.comp_info[0].height_in_blocks * DCTSIZE) {
 368                 unsigned max_lines = dinfo.max_v_samp_factor * DCTSIZE;
 369
 370                 JSAMPROW y_row_ptrs[max_lines];
 371                 JSAMPROW cb_row_ptrs[max_lines];
 372                 JSAMPROW cr_row_ptrs[max_lines];
 373                 JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
 374                 int i;
 375
 376                 for (i = 0; i < max_lines; ++i) {
 377                         y_row_ptrs[i]  = data_y  + (i+blocks*DCTSIZE*dinfo.comp_info[0].v_samp_factor) * dinfo.comp_info[0].width_in_blocks * DCTSIZE;
 378                         cb_row_ptrs[i] = data_cb + (i+blocks*DCTSIZE*dinfo.comp_info[1].v_samp_factor) * dinfo.comp_info[1].width_in_blocks * DCTSIZE;
 379                         cr_row_ptrs[i] = data_cr + (i+blocks*DCTSIZE*dinfo.comp_info[2].v_samp_factor) * dinfo.comp_info[2].width_in_blocks * DCTSIZE;
 380                 }
 381
 382                 total_lines += max_lines;
 383                 ++blocks;
 384
 385                 if (jpeg_read_raw_data(&dinfo, ptrs, max_lines) == 0)
 386                         break;
 387         }
 388
 389         {
 390                 float *npix = (float*)memalign(16, dinfo.comp_info[0].width_in_blocks * DCTSIZE * nh0 * sizeof(float));
 391                 vscale(data_y, npix, dinfo.comp_info[0].width_in_blocks * DCTSIZE, dinfo.comp_info[0].height_in_blocks * DCTSIZE, nh0, dinfo.comp_info[0].width_in_blocks * DCTSIZE);
 392                 data_ny = (unsigned char *)malloc(nw0 * stride0);
 393                 hscale(npix, data_ny, dinfo.comp_info[0].width_in_blocks * DCTSIZE, nh0, nw0, stride0);
 394                 free(npix);
 395         }
 396         {
 397                 float *npix = (float*)memalign(16, dinfo.comp_info[1].width_in_blocks * DCTSIZE * nh1 * sizeof(float));
 398                 vscale(data_cr, npix, dinfo.comp_info[1].width_in_blocks * DCTSIZE, dinfo.comp_info[1].height_in_blocks * DCTSIZE, nh1, dinfo.comp_info[1].width_in_blocks * DCTSIZE);
 399                 data_ncr = (unsigned char *)malloc(nw1 * stride1);
 400                 hscale(npix, data_ncr, dinfo.comp_info[1].width_in_blocks * DCTSIZE, nh1, nw1, stride1);
 401                 free(npix);
 402         }
 403         {
 404                 float *npix = (float*)memalign(16, dinfo.comp_info[2].width_in_blocks * DCTSIZE * nh2 * sizeof(float));
 405                 vscale(data_cb, npix, dinfo.comp_info[2].width_in_blocks * DCTSIZE, dinfo.comp_info[2].height_in_blocks * DCTSIZE, nh2, dinfo.comp_info[2].width_in_blocks * DCTSIZE);
 406                 data_ncb = (unsigned char *)malloc(nw2 * stride2);
 407                 hscale(npix, data_ncb, dinfo.comp_info[2].width_in_blocks * DCTSIZE, nh2, nw2, stride2);
 408                 free(npix);
 409         }
 410         jpeg_destroy_decompress(&dinfo);
 411
 412         struct jpeg_compress_struct cinfo;
 413         cinfo.err = jpeg_std_error(&jerr);
 414         jpeg_create_compress(&cinfo);
 415         jpeg_stdio_dest(&cinfo, stdout);
 416         cinfo.input_components = 3;
 417         jpeg_set_defaults(&cinfo);
 418         jpeg_set_quality(&cinfo, 85, FALSE);
 419         cinfo.image_width = nominal_w;
 420         cinfo.image_height = nominal_h;
 421         cinfo.raw_data_in = TRUE;
 422         jpeg_set_colorspace(&cinfo, JCS_YCbCr);
 423         cinfo.comp_info[0].h_samp_factor = samp_h0;
 424         cinfo.comp_info[0].v_samp_factor = samp_v0;
 425         cinfo.comp_info[1].h_samp_factor = samp_h1;
 426         cinfo.comp_info[1].v_samp_factor = samp_v1;
 427         cinfo.comp_info[2].h_samp_factor = samp_h2;
 428         cinfo.comp_info[2].v_samp_factor = samp_v2;
 429         jpeg_start_compress(&cinfo, TRUE);
 430
 431         total_lines = 0;
 432         blocks = 0;
 433         while (total_lines < cinfo.comp_info[0].height_in_blocks * DCTSIZE) {
 434                 unsigned max_lines = cinfo.max_v_samp_factor * DCTSIZE;
 435
 436                 JSAMPROW y_row_ptrs[max_lines];
 437                 JSAMPROW cb_row_ptrs[max_lines];
 438                 JSAMPROW cr_row_ptrs[max_lines];
 439                 JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
 440                 int i;
 441
 442                 for (i = 0; i < max_lines; ++i) {
 443                         // simple edge extension
 444                         int yline = i + blocks*DCTSIZE*cinfo.comp_info[0].v_samp_factor;
 445                         if (yline > nh0 - 1)
 446                                 yline = nh0 - 1;
 447
 448                         int cbline = i + blocks*DCTSIZE*cinfo.comp_info[1].v_samp_factor;
 449                         if (cbline > nh1 - 1)
 450                                 cbline = nh1 - 1;
 451
 452                         int crline = i + blocks*DCTSIZE*cinfo.comp_info[2].v_samp_factor;
 453                         if (crline > nh2 - 1)
 454                                 crline = nh2 - 1;
 455
 456                         y_row_ptrs[i]  = data_ny  + yline * stride0;
 457                         cb_row_ptrs[i] = data_ncb + cbline * stride1;
 458                         cr_row_ptrs[i] = data_ncr + crline * stride2;
 459                 }
 460
 461                 total_lines += max_lines;
 462                 ++blocks;
 463
 464                 jpeg_write_raw_data(&cinfo, ptrs, max_lines);
 465         }
 466         jpeg_finish_compress(&cinfo);
 467         jpeg_destroy_compress(&cinfo);
 468
 469         return 0;
 470 }
 471