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

   1 /*
   2  * qscale: Quick, high-quality JPEG-to-JPEG scaler.
   3  * Copyright (C) 2008 Steinar H. Gunderson <sgunderson@bigfoot.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 2 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  17  */
  18
  19 #include <stdio.h>
  20 #include <malloc.h>
  21 #include <math.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include "jpeglib.h"
  25 #include "libqscale.h"
  26
  27 /* The number of pixels to process at a time when scaling vertically. */
  28 #define CACHE_LINE_FACTOR 16
  29
  30 /* Whether to use SSE for horizontal scaling or not (requires SSE3). */
  31 #define USE_HORIZONTAL_SSE 0
  32
  33 /* Whether to use SSE for vertical scaling or not (requires only SSE1). */
  34 #define USE_VERTICAL_SSE 0
  35
  36 #if USE_VERTICAL_SSE
  37 #undef CACHE_LINE_FACTOR
  38 #define CACHE_LINE_FACTOR 16
  39 #endif
  40
  41 #ifndef M_PI
  42 #define M_PI 3.14159265358979323846264
  43 #endif
  44
  45 double sinc(double x)
  46 {
  47         static const double cutoff = 1.220703668e-4;  /* sqrt(sqrt(eps)) */
  48
  49         if (abs(x) < cutoff) {
  50                 /* For small |x|, use Taylor series instead */
  51                 const double x2 = x * x;
  52                 const double x4 = x2 * x2;
  53
  54                 return 1.0 - x2 / 6.0 + x4 / 120.0;
  55         } else {
  56                 return sin(x) / x;
  57         }
  58 }
  59
  60 double lanczos_tap(double x)
  61 {
  62         if (x < -3.0 || x > 3.0)
  63                 return 0.0;
  64         if (x < 0.0)
  65                 return sinc(-x*M_PI) * sinc(-x*M_PI / 3.0);
  66         else
  67                 return sinc(x*M_PI) * sinc(x*M_PI / 3.0);
  68 }
  69
  70
  71 struct pix_desc {
  72         unsigned start, end;
  73         unsigned startcoeff;
  74 };
  75
  76 void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw, unsigned sstride, unsigned dstride)
  77 {
  78         struct pix_desc *pd = (struct pix_desc *)malloc(nw * sizeof(struct pix_desc));
  79         int size_coeffs = 8;
  80         float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
  81         int num_coeffs = 0;
  82         int x, y;
  83         double sf = (double)w / (double)nw;
  84         double support = (w > nw) ? (3.0 * sf) : (3.0 / sf);
  85
  86         /* calculate the filter */
  87         for (x = 0; x < nw; ++x) {
  88                 int start = ceil(x * sf - support);
  89                 int end = floor(x * sf + support);
  90                 int sx;
  91                 double sum = 0.0;
  92
  93                 if (start < 0) {
  94                         start = 0;
  95                 }
  96                 if (end > w - 1) {
  97                         end = w - 1;
  98                 }
  99
 100 #if USE_HORIZONTAL_SSE
 101                 /* round up so we get a multiple of four for the SSE code */
 102                 int num = (end - start + 1);
 103                 if (num % 4 != 0) {
 104                         /* prefer aligning it if possible */
 105                         if (start % 4 != 0 && start % 4 <= num % 4) {
 106                                 num += start % 4;
 107                                 start -= start % 4;
 108                         }
 109                         if (num % 4 != 0) {
 110                                 end += 4 - (num % 4);
 111                         }
 112                 }
 113 #endif
 114
 115                 pd[x].start = start;
 116                 pd[x].end = end;
 117                 pd[x].startcoeff = num_coeffs;
 118
 119                 for (sx = start; sx <= end; ++sx) {
 120                         double nd = (w > nw) ? (sx/sf - x) : (sx - x*sf);
 121                         double f = lanczos_tap(nd);
 122                         if (num_coeffs == size_coeffs) {
 123                                 size_coeffs <<= 1;
 124                                 coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
 125                         }
 126
 127                         coeffs[num_coeffs++] = f;
 128                         sum += f;
 129                 }
 130
 131                 for (sx = start; sx <= end; ++sx) {
 132                         coeffs[pd[x].startcoeff + sx - start] /= sum;
 133                 }
 134         }
 135
 136         for (y = 0; y < h; ++y) {
 137                 float *sptr = pix + y*sstride;
 138                 unsigned char *dptr = npix + y*dstride;
 139                 unsigned char ch;
 140                 for (x = 0; x < nw; ++x) {
 141 #if USE_HORIZONTAL_SSE
 142                         int result;
 143                         float acc;
 144                         long tmp;
 145                         static const float low = 0.0, high = 255.0;
 146                         __asm__ (
 147                                 "pxor %1, %1               \n"
 148                                 "xor %2, %2                \n"
 149                                 "0:                        \n"
 150                                 "movups (%4,%2),%%xmm1     \n"
 151                                 "movups (%3,%2),%%xmm2     \n"
 152                                 "mulps %%xmm2,%%xmm1       \n"
 153                                 "addps %%xmm1,%1           \n"
 154                                 "add $16,%2                \n"
 155                                 "dec %5                    \n"
 156                                 "jnz 0b                    \n"
 157                                 "haddps %1,%1              \n"
 158                                 "haddps %1,%1              \n"
 159                                 "maxss %6,%1               \n"
 160                                 "minss %7,%1               \n"
 161                                 "cvtss2si %1,%0            \n"
 162                                 : "=r" (result),
 163                                   "=&x" (acc),
 164                                   "=&r" (tmp)
 165                                 : "r" (&coeffs[pd[x].startcoeff]),
 166                                   "r" (&sptr[pd[x].start]),
 167                                   "r" ((pd[x].end - pd[x].start + 1)/4),
 168                                   "m" (low),
 169                                   "m" (high)
 170                                 : "memory", "xmm1", "xmm2"
 171                         );
 172
 173                         *dptr++ = (unsigned char)result;
 174 #else
 175                         float acc = 0.0;
 176                         float *cf = &coeffs[pd[x].startcoeff];
 177                         unsigned sx;
 178
 179                         for (sx = pd[x].start; sx <= pd[x].end; ++sx) {
 180                                 acc += sptr[sx] * *cf++;
 181                         }
 182
 183                         if (acc < 0.0)
 184                                 ch = 0;
 185                         else if (acc > 255.0)
 186                                 ch = 255;
 187                         else
 188                                 ch = (unsigned char)acc;
 189                         *dptr++ = ch;
 190 #endif
 191                 }
 192                 ch = dptr[-1];
 193                 for ( ; x < dstride; ++x) {
 194                         *dptr++ = ch;
 195                 }
 196         }
 197 }
 198
 199 void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh, unsigned dstride)
 200 {
 201         struct pix_desc *pd = (struct pix_desc *)malloc(nh * sizeof(struct pix_desc));
 202         int size_coeffs = 8;
 203         float *coeffs = (float *)malloc(size_coeffs * sizeof(float));
 204         int num_coeffs = 0;
 205         int x, y, sy;
 206         double sf = (double)h / (double)nh;
 207         double support = (h > nh) ? (3.0 * sf) : (3.0 / sf);
 208
 209         /* calculate the filter */
 210         for (y = 0; y < nh; ++y) {
 211                 int start = ceil(y * sf - support);
 212                 int end = floor(y * sf + support);
 213                 double sum = 0.0;
 214
 215                 if (start < 0) {
 216                         start = 0;
 217                 }
 218                 if (end > h - 1) {
 219                         end = h - 1;
 220                 }
 221
 222                 pd[y].start = start;
 223                 pd[y].end = end;
 224                 pd[y].startcoeff = num_coeffs;
 225
 226                 for (sy = start; sy <= end; ++sy) {
 227                         double nd = (h > nh) ? (sy/sf - y) : (sy - y*sf);
 228                         double f = lanczos_tap(nd);
 229                         if (num_coeffs == size_coeffs) {
 230                                 size_coeffs <<= 1;
 231                                 coeffs = (float *)realloc(coeffs, size_coeffs * sizeof(float));
 232                         }
 233
 234                         coeffs[num_coeffs++] = f;
 235                         sum += f;
 236                 }
 237
 238                 for (sy = start; sy <= end; ++sy) {
 239                         coeffs[pd[y].startcoeff + sy - start] /= sum;
 240                 }
 241         }
 242
 243 #if CACHE_LINE_FACTOR > 1
 244         for (x = 0; x < (w/CACHE_LINE_FACTOR) * CACHE_LINE_FACTOR; x += CACHE_LINE_FACTOR) {
 245                 unsigned char *sptr = pix + x;
 246                 float *dptr = npix + x;
 247                 for (y = 0; y < nh; ++y) {
 248 #if USE_VERTICAL_SSE
 249                         /*
 250                          * xmm0 - xmm3: acc[0..15]
 251                          * xmm4: current filter coefficient
 252                          * xmm5, xmm6, xmm7: scratchpad
 253                          */
 254                         __asm__ (
 255                                 /* clear */
 256                                 "pxor %%xmm0, %%xmm0          \n"
 257                                 "pxor %%xmm1, %%xmm1          \n"
 258                                 "pxor %%xmm2, %%xmm2          \n"
 259                                 "pxor %%xmm3, %%xmm3          \n"
 260
 261                                 /* main loop */
 262                                 "0:                           \n"
 263
 264                                 /* a zero is useful during unpacking */
 265                                 "pxor %%xmm4, %%xmm4          \n"
 266
 267                                 /* fetch all 16 source bytes */
 268                                 "movups (%0), %%xmm5          \n"
 269                                 "prefetcht0 (%0,%3,4)         \n"
 270
 271                                 /* unpack into words (xmm5, xmm7) */
 272                                 "movaps %%xmm5, %%xmm7        \n"
 273                                 "punpcklbw %%xmm4, %%xmm5     \n"
 274                                 "punpckhbw %%xmm4, %%xmm7     \n"
 275
 276                                 /* unpack xmm5 into dwords (xmm5, xmm6) */
 277                                 "movaps %%xmm5, %%xmm6        \n"
 278                                 "punpcklwd %%xmm4, %%xmm5     \n"
 279                                 "punpckhwd %%xmm4, %%xmm6     \n"
 280
 281                                 /* convert xmm5, xmm6 to floats */
 282                                 "cvtdq2ps %%xmm5, %%xmm5      \n"
 283                                 "cvtdq2ps %%xmm6, %%xmm6      \n"
 284
 285                                 /* fetch the coefficient */
 286                                 "movss (%2), %%xmm4           \n"
 287                                 "shufps $0x0, %%xmm4, %%xmm4  \n"
 288
 289                                 /* do the muls for xmm5 and xmm6 */
 290                                 "mulps %%xmm4, %%xmm5         \n"
 291                                 "mulps %%xmm4, %%xmm6         \n"
 292                                 "addps %%xmm5, %%xmm0         \n"
 293                                 "addps %%xmm6, %%xmm1         \n"
 294
 295                                 /* get the zero back again */
 296                                 "pxor %%xmm4, %%xmm4          \n"
 297
 298                                 /* unpack xmm7 into dwords (xmm7, xmm6) */
 299                                 "movaps %%xmm7, %%xmm6        \n"
 300                                 "punpcklwd %%xmm4, %%xmm7     \n"
 301                                 "punpckhwd %%xmm4, %%xmm6     \n"
 302
 303                                 /* convert xmm7, xmm6 to floats */
 304                                 "cvtdq2ps %%xmm7, %%xmm7      \n"
 305                                 "cvtdq2ps %%xmm6, %%xmm6      \n"
 306
 307                                 /* fetch the coefficient */
 308                                 "movss (%2), %%xmm4           \n"
 309                                 "shufps $0x0, %%xmm4, %%xmm4  \n"
 310
 311                                 /* do the second set of muls */
 312                                 "mulps %%xmm4, %%xmm7         \n"
 313                                 "mulps %%xmm4, %%xmm6         \n"
 314                                 "addps %%xmm7, %%xmm2         \n"
 315                                 "addps %%xmm6, %%xmm3         \n"
 316
 317                                 /* move along, and loop */
 318                                 "add $4, %2                   \n"
 319                                 "add %3, %0                   \n"
 320                                 "dec %1                       \n"
 321                                 "jnz 0b                       \n"
 322
 323                                 /* store the values */
 324                                 "movaps %%xmm0, (%4)          \n"
 325                                 "movaps %%xmm1, 16(%4)        \n"
 326                                 "movaps %%xmm2, 32(%4)        \n"
 327                                 "movaps %%xmm3, 48(%4)        \n"
 328                                 : :
 329                                 "r" (&sptr[pd[y].start * w]),        /* 0: srcptr base */
 330                                 "r" (pd[y].end - pd[y].start + 1),   /* 1: filter len */
 331                                 "r" (&coeffs[pd[y].startcoeff]),     /* 2: coeffs base */
 332                                 "r" ((long)w),                       /* 3: stride */
 333                                 "r" (dptr)                           /* 4: dstptr base */
 334                                 : "memory", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7"
 335                         );
 336 #else
 337                         int i;
 338                         float acc[CACHE_LINE_FACTOR];
 339                         for (i = 0; i < CACHE_LINE_FACTOR; ++i)
 340                                 acc[i] = 0.0;
 341                         float *cf = &coeffs[pd[y].startcoeff];
 342                         unsigned sy;
 343
 344                         for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
 345                                 for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
 346                                         acc[i] += sptr[sy * w + i] * *cf;
 347                                 }
 348                                 ++cf;
 349                         }
 350
 351                         for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
 352                                 dptr[i] = acc[i];
 353                         }
 354 #endif
 355                         dptr += dstride;
 356                 }
 357         }
 358         for (x = (x/CACHE_LINE_FACTOR)*CACHE_LINE_FACTOR; x < w; ++x) {
 359 #else
 360         for (x = 0; x < w; ++x) {
 361 #endif
 362                 unsigned char *sptr = pix + x;
 363                 float *dptr = npix + x;
 364                 for (y = 0; y < nh; ++y) {
 365                         float acc = 0.0;
 366                         float *cf = &coeffs[pd[y].startcoeff];
 367                         unsigned sy;
 368
 369                         for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
 370                                 acc += sptr[sy * w] * *cf++;
 371                         }
 372
 373                         *dptr = acc;
 374                         dptr += dstride;
 375                 }
 376         }
 377 }
 378
 379 int main(int argc, char **argv)
 380 {
 381         /* user-settable parameters */
 382         unsigned nominal_w = atoi(argv[1]);
 383         unsigned nominal_h = atoi(argv[2]);
 384         unsigned samp_h0 = 2, samp_v0 = 2;
 385         unsigned samp_h1 = 1, samp_v1 = 1;
 386         unsigned samp_h2 = 1, samp_v2 = 1;
 387         unsigned jpeg_quality = 85;
 388         /* end */
 389
 390         unsigned max_samp_h, max_samp_v;
 391         max_samp_h = samp_h0;
 392         if (samp_h1 > max_samp_h)
 393                 max_samp_h = samp_h1;
 394         if (samp_h2 > max_samp_h)
 395                 max_samp_h = samp_h2;
 396
 397         max_samp_v = samp_v0;
 398         if (samp_v1 > max_samp_v)
 399                 max_samp_v = samp_v1;
 400         if (samp_v2 > max_samp_v)
 401                 max_samp_v = samp_v2;
 402
 403         unsigned nw0 = nominal_w * samp_h0 / max_samp_h, nh0 = nominal_h * samp_v0 / max_samp_v;
 404         unsigned nw1 = nominal_w * samp_h1 / max_samp_h, nh1 = nominal_h * samp_v1 / max_samp_v;
 405         unsigned nw2 = nominal_w * samp_h2 / max_samp_h, nh2 = nominal_h * samp_v2 / max_samp_v;
 406
 407         unsigned dstride0 = (nw0 + DCTSIZE-1) & ~(DCTSIZE-1);
 408         unsigned dstride1 = (nw1 + DCTSIZE-1) & ~(DCTSIZE-1);
 409         unsigned dstride2 = (nw2 + DCTSIZE-1) & ~(DCTSIZE-1);
 410
 411         qscale_img *img = qscale_load_jpeg_from_stdio(stdin);
 412         unsigned sstride0 = (img->w0 + DCTSIZE-1) & ~(DCTSIZE-1);
 413         unsigned sstride1 = (img->w1 + DCTSIZE-1) & ~(DCTSIZE-1);
 414         unsigned sstride2 = (img->w2 + DCTSIZE-1) & ~(DCTSIZE-1);
 415
 416         JSAMPLE *data_ny, *data_ncb, *data_ncr;
 417
 418         {
 419                 float *npix = (float*)memalign(16, sstride0 * nh0 * sizeof(float));
 420                 vscale(img->data_y, npix, sstride0, img->h0, nh0, sstride0);
 421                 data_ny = (unsigned char *)malloc(nh0 * dstride0);
 422                 hscale(npix, data_ny, img->w0, nh0, nw0, sstride0, dstride0);
 423                 free(npix);
 424         }
 425         {
 426                 float *npix = (float*)memalign(16, sstride1 * nh1 * sizeof(float));
 427                 vscale(img->data_cr, npix, sstride1, img->h1, nh1, sstride1);
 428                 data_ncr = (unsigned char *)malloc(nh1 * dstride1);
 429                 hscale(npix, data_ncr, img->w1, nh1, nw1, sstride1, dstride1);
 430                 free(npix);
 431         }
 432         {
 433                 float *npix = (float*)memalign(16, sstride2 * nh2 * sizeof(float));
 434                 vscale(img->data_cb, npix, sstride2, img->h2, nh2, sstride2);
 435                 data_ncb = (unsigned char *)malloc(nh2 * dstride2);
 436                 hscale(npix, data_ncb, img->w2, nh2, nw2, sstride2, dstride2);
 437                 free(npix);
 438         }
 439
 440         struct jpeg_compress_struct cinfo;
 441         struct jpeg_error_mgr jerr;
 442         cinfo.err = jpeg_std_error(&jerr);
 443         jpeg_create_compress(&cinfo);
 444         jpeg_stdio_dest(&cinfo, stdout);
 445         cinfo.input_components = 3;
 446         jpeg_set_defaults(&cinfo);
 447         jpeg_set_quality(&cinfo, jpeg_quality, FALSE);
 448         cinfo.image_width = nominal_w;
 449         cinfo.image_height = nominal_h;
 450         cinfo.raw_data_in = TRUE;
 451         jpeg_set_colorspace(&cinfo, JCS_YCbCr);
 452         cinfo.comp_info[0].h_samp_factor = samp_h0;
 453         cinfo.comp_info[0].v_samp_factor = samp_v0;
 454         cinfo.comp_info[1].h_samp_factor = samp_h1;
 455         cinfo.comp_info[1].v_samp_factor = samp_v1;
 456         cinfo.comp_info[2].h_samp_factor = samp_h2;
 457         cinfo.comp_info[2].v_samp_factor = samp_v2;
 458         jpeg_start_compress(&cinfo, TRUE);
 459
 460         int total_lines = 0;
 461         int blocks = 0;
 462         while (total_lines < cinfo.comp_info[0].height_in_blocks * DCTSIZE) {
 463                 unsigned max_lines = cinfo.max_v_samp_factor * DCTSIZE;
 464
 465                 JSAMPROW y_row_ptrs[max_lines];
 466                 JSAMPROW cb_row_ptrs[max_lines];
 467                 JSAMPROW cr_row_ptrs[max_lines];
 468                 JSAMPROW* ptrs[] = { y_row_ptrs, cb_row_ptrs, cr_row_ptrs };
 469                 int i;
 470
 471                 for (i = 0; i < max_lines; ++i) {
 472                         /* simple edge extension */
 473                         int yline = i + blocks*DCTSIZE*cinfo.comp_info[0].v_samp_factor;
 474                         if (yline > nh0 - 1)
 475                                 yline = nh0 - 1;
 476
 477                         int cbline = i + blocks*DCTSIZE*cinfo.comp_info[1].v_samp_factor;
 478                         if (cbline > nh1 - 1)
 479                                 cbline = nh1 - 1;
 480
 481                         int crline = i + blocks*DCTSIZE*cinfo.comp_info[2].v_samp_factor;
 482                         if (crline > nh2 - 1)
 483                                 crline = nh2 - 1;
 484
 485                         y_row_ptrs[i]  = data_ny  + yline * dstride0;
 486                         cb_row_ptrs[i] = data_ncb + cbline * dstride1;
 487                         cr_row_ptrs[i] = data_ncr + crline * dstride2;
 488                 }
 489
 490                 total_lines += max_lines;
 491                 ++blocks;
 492
 493                 jpeg_write_raw_data(&cinfo, ptrs, max_lines);
 494         }
 495         jpeg_finish_compress(&cinfo);
 496         jpeg_destroy_compress(&cinfo);
 497
 498         qscale_destroy(img);
 499
 500         return 0;
 501 }
 502