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