y4minput.c 39.5 KB
Newer Older
1
/*
2
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3
 *
4
 *  Use of this source code is governed by a BSD-style license
5 6
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
7
 *  in the file PATENTS.  All contributing project authors may
8
 *  be found in the AUTHORS file in the root of the source tree.
9 10 11 12
 *
 *  Based on code from the OggTheora software codec source code,
 *  Copyright (C) 2002-2010 The Xiph.Org Foundation and contributors.
 */
13
#include <errno.h>
14 15
#include <stdlib.h>
#include <string.h>
16 17

#include "vpx/vpx_integer.h"
18 19
#include "y4minput.h"

20 21 22 23 24
// Reads 'size' bytes from 'file' into 'buf' with some fault tolerance.
// Returns true on success.
static int file_read(void *buf, size_t size, FILE *file) {
  const int kMaxRetries = 5;
  int retry_count = 0;
25
  int file_error;
26 27
  size_t len = 0;
  do {
28
    const size_t n = fread((uint8_t *)buf + len, 1, size - len, file);
29
    len += n;
30 31
    file_error = ferror(file);
    if (file_error) {
32 33 34 35 36 37 38 39 40
      if (errno == EINTR || errno == EAGAIN) {
        clearerr(file);
        continue;
      } else {
        fprintf(stderr, "Error reading file: %u of %u bytes read, %d: %s\n",
                (uint32_t)len, (uint32_t)size, errno, strerror(errno));
        return 0;
      }
    }
41 42 43
  } while (!feof(file) && len < size && ++retry_count < kMaxRetries);

  if (!feof(file) && len != size) {
44 45 46 47 48
    fprintf(stderr,
            "Error reading file: %u of %u bytes read,"
            " error: %d, retries: %d, %d: %s\n",
            (uint32_t)len, (uint32_t)size, file_error, retry_count, errno,
            strerror(errno));
49
  }
50 51 52
  return len == size;
}

John Koleszar's avatar
John Koleszar committed
53
static int y4m_parse_tags(y4m_input *_y4m, char *_tags) {
54 55 56 57 58 59
  int got_w;
  int got_h;
  int got_fps;
  int got_interlace;
  int got_par;
  int got_chroma;
60 61
  char *p;
  char *q;
John Koleszar's avatar
John Koleszar committed
62 63
  got_w = got_h = got_fps = got_interlace = got_par = got_chroma = 0;
  for (p = _tags;; p = q) {
64
    /*Skip any leading spaces.*/
65
    while (*p == ' ') p++;
66
    /*If that's all we have, stop.*/
67
    if (p[0] == '\0') break;
68
    /*Find the end of this tag.*/
69 70
    for (q = p + 1; *q != '\0' && *q != ' '; q++) {
    }
71
    /*Process the tag.*/
John Koleszar's avatar
John Koleszar committed
72 73
    switch (p[0]) {
      case 'W': {
74
        if (sscanf(p + 1, "%d", &_y4m->pic_w) != 1) return -1;
John Koleszar's avatar
John Koleszar committed
75
        got_w = 1;
76 77
        break;
      }
John Koleszar's avatar
John Koleszar committed
78
      case 'H': {
79
        if (sscanf(p + 1, "%d", &_y4m->pic_h) != 1) return -1;
John Koleszar's avatar
John Koleszar committed
80
        got_h = 1;
81 82
        break;
      }
John Koleszar's avatar
John Koleszar committed
83 84
      case 'F': {
        if (sscanf(p + 1, "%d:%d", &_y4m->fps_n, &_y4m->fps_d) != 2) {
85 86
          return -1;
        }
John Koleszar's avatar
John Koleszar committed
87
        got_fps = 1;
88 89
        break;
      }
John Koleszar's avatar
John Koleszar committed
90 91 92
      case 'I': {
        _y4m->interlace = p[1];
        got_interlace = 1;
93 94
        break;
      }
John Koleszar's avatar
John Koleszar committed
95 96
      case 'A': {
        if (sscanf(p + 1, "%d:%d", &_y4m->par_n, &_y4m->par_d) != 2) {
97 98
          return -1;
        }
John Koleszar's avatar
John Koleszar committed
99
        got_par = 1;
100 101
        break;
      }
John Koleszar's avatar
John Koleszar committed
102
      case 'C': {
103
        if (q - p > 16) return -1;
John Koleszar's avatar
John Koleszar committed
104 105 106
        memcpy(_y4m->chroma_type, p + 1, q - p - 1);
        _y4m->chroma_type[q - p - 1] = '\0';
        got_chroma = 1;
107 108
        break;
      }
109
        /*Ignore unknown tags.*/
110 111
    }
  }
112 113 114
  if (!got_w || !got_h || !got_fps) return -1;
  if (!got_interlace) _y4m->interlace = '?';
  if (!got_par) _y4m->par_n = _y4m->par_d = 0;
115 116
  /*Chroma-type is not specified in older files, e.g., those generated by
     mplayer.*/
117
  if (!got_chroma) strcpy(_y4m->chroma_type, "420");
118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142
  return 0;
}

/*All anti-aliasing filters in the following conversion functions are based on
   one of two window functions:
  The 6-tap Lanczos window (for down-sampling and shifts):
   sinc(\pi*t)*sinc(\pi*t/3), |t|<3  (sinc(t)==sin(t)/t)
   0,                         |t|>=3
  The 4-tap Mitchell window (for up-sampling):
   7|t|^3-12|t|^2+16/3,             |t|<1
   -(7/3)|x|^3+12|x|^2-20|x|+32/3,  |t|<2
   0,                               |t|>=2
  The number of taps is intentionally kept small to reduce computational
   overhead and limit ringing.

  The taps from these filters are scaled so that their sum is 1, and the result
   is scaled by 128 and rounded to integers to create a filter whose
   intermediate values fit inside 16 bits.
  Coefficients are rounded in such a way as to ensure their sum is still 128,
   which is usually equivalent to normal rounding.

  Conversions which require both horizontal and vertical filtering could
   have these steps pipelined, for less memory consumption and better cache
   performance, but we do them separately for simplicity.*/

143 144 145
#define OC_MINI(_a, _b) ((_a) > (_b) ? (_b) : (_a))
#define OC_MAXI(_a, _b) ((_a) < (_b) ? (_b) : (_a))
#define OC_CLAMPI(_a, _b, _c) (OC_MAXI(_a, OC_MINI(_b, _c)))
146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188

/*420jpeg chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  420mpeg2 chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  BR      |       BR      |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  BR      |       BR      |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  We use a resampling filter to shift the site locations one quarter pixel (at
   the chroma plane's resolution) to the right.
  The 4:2:2 modes look exactly the same, except there are twice as many chroma
   lines, and they are vertically co-sited with the luma samples in both the
   mpeg2 and jpeg cases (thus requiring no vertical resampling).*/
static void y4m_42xmpeg2_42xjpeg_helper(unsigned char *_dst,
189 190
                                        const unsigned char *_src, int _c_w,
                                        int _c_h) {
191 192
  int y;
  int x;
John Koleszar's avatar
John Koleszar committed
193
  for (y = 0; y < _c_h; y++) {
194 195
    /*Filter: [4 -17 114 35 -9 1]/128, derived from a 6-tap Lanczos
       window.*/
John Koleszar's avatar
John Koleszar committed
196
    for (x = 0; x < OC_MINI(_c_w, 2); x++) {
197
      _dst[x] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
198 199 200 201 202 203
          0,
          (4 * _src[0] - 17 * _src[OC_MAXI(x - 1, 0)] + 114 * _src[x] +
           35 * _src[OC_MINI(x + 1, _c_w - 1)] -
           9 * _src[OC_MINI(x + 2, _c_w - 1)] + _src[OC_MINI(x + 3, _c_w - 1)] +
           64) >>
              7,
204
          255);
205
    }
John Koleszar's avatar
John Koleszar committed
206
    for (; x < _c_w - 3; x++) {
207
      _dst[x] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
208 209 210 211
          0,
          (4 * _src[x - 2] - 17 * _src[x - 1] + 114 * _src[x] +
           35 * _src[x + 1] - 9 * _src[x + 2] + _src[x + 3] + 64) >>
              7,
212
          255);
213
    }
John Koleszar's avatar
John Koleszar committed
214
    for (; x < _c_w; x++) {
215
      _dst[x] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
216 217 218 219 220
          0,
          (4 * _src[x - 2] - 17 * _src[x - 1] + 114 * _src[x] +
           35 * _src[OC_MINI(x + 1, _c_w - 1)] -
           9 * _src[OC_MINI(x + 2, _c_w - 1)] + _src[_c_w - 1] + 64) >>
              7,
221
          255);
222
    }
John Koleszar's avatar
John Koleszar committed
223 224
    _dst += _c_w;
    _src += _c_w;
225 226 227 228
  }
}

/*Handles both 422 and 420mpeg2 to 422jpeg and 420jpeg, respectively.*/
John Koleszar's avatar
John Koleszar committed
229 230
static void y4m_convert_42xmpeg2_42xjpeg(y4m_input *_y4m, unsigned char *_dst,
                                         unsigned char *_aux) {
231 232 233 234 235
  int c_w;
  int c_h;
  int c_sz;
  int pli;
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
236
  _dst += _y4m->pic_w * _y4m->pic_h;
237
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
238 239 240 241 242 243 244
  c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
  c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
  for (pli = 1; pli < 3; pli++) {
    y4m_42xmpeg2_42xjpeg_helper(_dst, _aux, c_w, c_h);
    _dst += c_sz;
    _aux += c_sz;
245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
  }
}

/*This format is only used for interlaced content, but is included for
   completeness.

  420jpeg chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  420paldv chroma samples are sited like:
  YR------Y-------YR------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YB------Y-------YB------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YR------Y-------YR------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YB------Y-------YB------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  We use a resampling filter to shift the site locations one quarter pixel (at
   the chroma plane's resolution) to the right.
  Then we use another filter to move the C_r location down one quarter pixel,
   and the C_b location up one quarter pixel.*/
John Koleszar's avatar
John Koleszar committed
291 292
static void y4m_convert_42xpaldv_42xjpeg(y4m_input *_y4m, unsigned char *_dst,
                                         unsigned char *_aux) {
293
  unsigned char *tmp;
294 295 296 297 298 299
  int c_w;
  int c_h;
  int c_sz;
  int pli;
  int y;
  int x;
300
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
301
  _dst += _y4m->pic_w * _y4m->pic_h;
302
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
303 304 305 306 307
  c_w = (_y4m->pic_w + 1) / 2;
  c_h = (_y4m->pic_h + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
  c_sz = c_w * c_h;
  tmp = _aux + 2 * c_sz;
  for (pli = 1; pli < 3; pli++) {
308 309 310
    /*First do the horizontal re-sampling.
      This is the same as the mpeg2 case, except that after the horizontal
       case, we need to apply a second vertical filter.*/
John Koleszar's avatar
John Koleszar committed
311 312 313 314
    y4m_42xmpeg2_42xjpeg_helper(tmp, _aux, c_w, c_h);
    _aux += c_sz;
    switch (pli) {
      case 1: {
315 316
        /*Slide C_b up a quarter-pel.
          This is the same filter used above, but in the other order.*/
John Koleszar's avatar
John Koleszar committed
317 318
        for (x = 0; x < c_w; x++) {
          for (y = 0; y < OC_MINI(c_h, 3); y++) {
319
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
320 321 322 323 324 325
                0,
                (tmp[0] - 9 * tmp[OC_MAXI(y - 2, 0) * c_w] +
                 35 * tmp[OC_MAXI(y - 1, 0) * c_w] + 114 * tmp[y * c_w] -
                 17 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] +
                 4 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] + 64) >>
                    7,
326
                255);
327
          }
John Koleszar's avatar
John Koleszar committed
328
          for (; y < c_h - 2; y++) {
329
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
330 331 332 333 334
                0,
                (tmp[(y - 3) * c_w] - 9 * tmp[(y - 2) * c_w] +
                 35 * tmp[(y - 1) * c_w] + 114 * tmp[y * c_w] -
                 17 * tmp[(y + 1) * c_w] + 4 * tmp[(y + 2) * c_w] + 64) >>
                    7,
335
                255);
336
          }
John Koleszar's avatar
John Koleszar committed
337
          for (; y < c_h; y++) {
338
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
339 340 341 342 343 344
                0,
                (tmp[(y - 3) * c_w] - 9 * tmp[(y - 2) * c_w] +
                 35 * tmp[(y - 1) * c_w] + 114 * tmp[y * c_w] -
                 17 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] +
                 4 * tmp[(c_h - 1) * c_w] + 64) >>
                    7,
345
                255);
346 347 348 349
          }
          _dst++;
          tmp++;
        }
John Koleszar's avatar
John Koleszar committed
350 351
        _dst += c_sz - c_w;
        tmp -= c_w;
352 353
        break;
      }
John Koleszar's avatar
John Koleszar committed
354
      case 2: {
355 356
        /*Slide C_r down a quarter-pel.
          This is the same as the horizontal filter.*/
John Koleszar's avatar
John Koleszar committed
357 358
        for (x = 0; x < c_w; x++) {
          for (y = 0; y < OC_MINI(c_h, 2); y++) {
359 360 361 362 363 364 365 366
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
                0,
                (4 * tmp[0] - 17 * tmp[OC_MAXI(y - 1, 0) * c_w] +
                 114 * tmp[y * c_w] + 35 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] -
                 9 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] +
                 tmp[OC_MINI(y + 3, c_h - 1) * c_w] + 64) >>
                    7,
                255);
367
          }
John Koleszar's avatar
John Koleszar committed
368
          for (; y < c_h - 3; y++) {
369
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
370 371 372 373 374
                0,
                (4 * tmp[(y - 2) * c_w] - 17 * tmp[(y - 1) * c_w] +
                 114 * tmp[y * c_w] + 35 * tmp[(y + 1) * c_w] -
                 9 * tmp[(y + 2) * c_w] + tmp[(y + 3) * c_w] + 64) >>
                    7,
375
                255);
376
          }
John Koleszar's avatar
John Koleszar committed
377
          for (; y < c_h; y++) {
378 379 380 381 382 383 384 385
            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
                0,
                (4 * tmp[(y - 2) * c_w] - 17 * tmp[(y - 1) * c_w] +
                 114 * tmp[y * c_w] + 35 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] -
                 9 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] + tmp[(c_h - 1) * c_w] +
                 64) >>
                    7,
                255);
386 387 388 389
          }
          _dst++;
          tmp++;
        }
390 391
        break;
      }
392 393 394 395 396 397 398 399 400 401 402 403 404 405
    }
    /*For actual interlaced material, this would have to be done separately on
       each field, and the shift amounts would be different.
      C_r moves down 1/8, C_b up 3/8 in the top field, and C_r moves down 3/8,
       C_b up 1/8 in the bottom field.
      The corresponding filters would be:
       Down 1/8 (reverse order for up): [3 -11 125 15 -4 0]/128
       Down 3/8 (reverse order for up): [4 -19 98 56 -13 2]/128*/
  }
}

/*Perform vertical filtering to reduce a single plane from 4:2:2 to 4:2:0.
  This is used as a helper by several converation routines.*/
static void y4m_422jpeg_420jpeg_helper(unsigned char *_dst,
406 407
                                       const unsigned char *_src, int _c_w,
                                       int _c_h) {
408 409 410
  int y;
  int x;
  /*Filter: [3 -17 78 78 -17 3]/128, derived from a 6-tap Lanczos window.*/
John Koleszar's avatar
John Koleszar committed
411 412
  for (x = 0; x < _c_w; x++) {
    for (y = 0; y < OC_MINI(_c_h, 2); y += 2) {
413
      _dst[(y >> 1) * _c_w] =
clang-format's avatar
clang-format committed
414 415 416 417 418
          OC_CLAMPI(0,
                    (64 * _src[0] + 78 * _src[OC_MINI(1, _c_h - 1) * _c_w] -
                     17 * _src[OC_MINI(2, _c_h - 1) * _c_w] +
                     3 * _src[OC_MINI(3, _c_h - 1) * _c_w] + 64) >>
                        7,
419
                    255);
420
    }
John Koleszar's avatar
John Koleszar committed
421
    for (; y < _c_h - 3; y += 2) {
422
      _dst[(y >> 1) * _c_w] =
clang-format's avatar
clang-format committed
423 424 425 426 427
          OC_CLAMPI(0,
                    (3 * (_src[(y - 2) * _c_w] + _src[(y + 3) * _c_w]) -
                     17 * (_src[(y - 1) * _c_w] + _src[(y + 2) * _c_w]) +
                     78 * (_src[y * _c_w] + _src[(y + 1) * _c_w]) + 64) >>
                        7,
428
                    255);
429
    }
John Koleszar's avatar
John Koleszar committed
430
    for (; y < _c_h; y += 2) {
431 432 433 434 435 436 437 438
      _dst[(y >> 1) * _c_w] = OC_CLAMPI(
          0,
          (3 * (_src[(y - 2) * _c_w] + _src[(_c_h - 1) * _c_w]) -
           17 * (_src[(y - 1) * _c_w] + _src[OC_MINI(y + 2, _c_h - 1) * _c_w]) +
           78 * (_src[y * _c_w] + _src[OC_MINI(y + 1, _c_h - 1) * _c_w]) +
           64) >>
              7,
          255);
439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
    }
    _src++;
    _dst++;
  }
}

/*420jpeg chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  422jpeg chroma samples are sited like:
  Y---BR--Y-------Y---BR--Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y---BR--Y-------Y---BR--Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y---BR--Y-------Y---BR--Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y---BR--Y-------Y---BR--Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  We use a resampling filter to decimate the chroma planes by two in the
   vertical direction.*/
John Koleszar's avatar
John Koleszar committed
483 484
static void y4m_convert_422jpeg_420jpeg(y4m_input *_y4m, unsigned char *_dst,
                                        unsigned char *_aux) {
485 486 487 488 489 490 491 492
  int c_w;
  int c_h;
  int c_sz;
  int dst_c_w;
  int dst_c_h;
  int dst_c_sz;
  int pli;
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
493
  _dst += _y4m->pic_w * _y4m->pic_h;
494
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
495 496 497 498 499 500 501 502 503 504
  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
  c_h = _y4m->pic_h;
  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
  dst_c_sz = dst_c_w * dst_c_h;
  for (pli = 1; pli < 3; pli++) {
    y4m_422jpeg_420jpeg_helper(_dst, _aux, c_w, c_h);
    _aux += c_sz;
    _dst += dst_c_sz;
505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547
  }
}

/*420jpeg chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  422 chroma samples are sited like:
  YBR-----Y-------YBR-----Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------YBR-----Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------YBR-----Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------YBR-----Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  We use a resampling filter to shift the original site locations one quarter
   pixel (at the original chroma resolution) to the right.
  Then we use a second resampling filter to decimate the chroma planes by two
   in the vertical direction.*/
John Koleszar's avatar
John Koleszar committed
548 549
static void y4m_convert_422_420jpeg(y4m_input *_y4m, unsigned char *_dst,
                                    unsigned char *_aux) {
550
  unsigned char *tmp;
551 552 553 554 555 556
  int c_w;
  int c_h;
  int c_sz;
  int dst_c_h;
  int dst_c_sz;
  int pli;
557
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
558
  _dst += _y4m->pic_w * _y4m->pic_h;
559
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
560 561 562 563 564 565 566
  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
  c_h = _y4m->pic_h;
  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
  dst_c_sz = c_w * dst_c_h;
  tmp = _aux + 2 * c_sz;
  for (pli = 1; pli < 3; pli++) {
567 568 569 570
    /*In reality, the horizontal and vertical steps could be pipelined, for
       less memory consumption and better cache performance, but we do them
       separately for simplicity.*/
    /*First do horizontal filtering (convert to 422jpeg)*/
John Koleszar's avatar
John Koleszar committed
571
    y4m_42xmpeg2_42xjpeg_helper(tmp, _aux, c_w, c_h);
572
    /*Now do the vertical filtering.*/
John Koleszar's avatar
John Koleszar committed
573 574 575
    y4m_422jpeg_420jpeg_helper(_dst, tmp, c_w, c_h);
    _aux += c_sz;
    _dst += dst_c_sz;
576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619
  }
}

/*420jpeg chroma samples are sited like:
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |   BR  |       |   BR  |
  |       |       |       |
  Y-------Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  411 chroma samples are sited like:
  YBR-----Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |
  YBR-----Y-------Y-------Y-------
  |       |       |       |
  |       |       |       |
  |       |       |       |

  We use a filter to resample at site locations one eighth pixel (at the source
   chroma plane's horizontal resolution) and five eighths of a pixel to the
   right.
  Then we use another filter to decimate the planes by 2 in the vertical
   direction.*/
John Koleszar's avatar
John Koleszar committed
620 621
static void y4m_convert_411_420jpeg(y4m_input *_y4m, unsigned char *_dst,
                                    unsigned char *_aux) {
622
  unsigned char *tmp;
623 624 625 626 627 628 629 630 631 632
  int c_w;
  int c_h;
  int c_sz;
  int dst_c_w;
  int dst_c_h;
  int dst_c_sz;
  int tmp_sz;
  int pli;
  int y;
  int x;
633
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
634
  _dst += _y4m->pic_w * _y4m->pic_h;
635
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
636 637 638 639 640 641 642 643 644
  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
  c_h = _y4m->pic_h;
  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
  dst_c_sz = dst_c_w * dst_c_h;
  tmp_sz = dst_c_w * c_h;
  tmp = _aux + 2 * c_sz;
  for (pli = 1; pli < 3; pli++) {
645 646 647 648
    /*In reality, the horizontal and vertical steps could be pipelined, for
       less memory consumption and better cache performance, but we do them
       separately for simplicity.*/
    /*First do horizontal filtering (convert to 422jpeg)*/
John Koleszar's avatar
John Koleszar committed
649
    for (y = 0; y < c_h; y++) {
650 651
      /*Filters: [1 110 18 -1]/128 and [-3 50 86 -5]/128, both derived from a
         4-tap Mitchell window.*/
John Koleszar's avatar
John Koleszar committed
652
      for (x = 0; x < OC_MINI(c_w, 1); x++) {
653
        tmp[x << 1] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
654 655 656 657
            0,
            (111 * _aux[0] + 18 * _aux[OC_MINI(1, c_w - 1)] -
             _aux[OC_MINI(2, c_w - 1)] + 64) >>
                7,
658 659
            255);
        tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
660 661 662 663
            0,
            (47 * _aux[0] + 86 * _aux[OC_MINI(1, c_w - 1)] -
             5 * _aux[OC_MINI(2, c_w - 1)] + 64) >>
                7,
664
            255);
665
      }
John Koleszar's avatar
John Koleszar committed
666
      for (; x < c_w - 2; x++) {
667
        tmp[x << 1] =
clang-format's avatar
clang-format committed
668 669 670 671
            (unsigned char)OC_CLAMPI(0,
                                     (_aux[x - 1] + 110 * _aux[x] +
                                      18 * _aux[x + 1] - _aux[x + 2] + 64) >>
                                         7,
672 673
                                     255);
        tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
674 675 676 677
            0,
            (-3 * _aux[x - 1] + 50 * _aux[x] + 86 * _aux[x + 1] -
             5 * _aux[x + 2] + 64) >>
                7,
678
            255);
679
      }
John Koleszar's avatar
John Koleszar committed
680
      for (; x < c_w; x++) {
681
        tmp[x << 1] = (unsigned char)OC_CLAMPI(
clang-format's avatar
clang-format committed
682 683 684 685
            0,
            (_aux[x - 1] + 110 * _aux[x] + 18 * _aux[OC_MINI(x + 1, c_w - 1)] -
             _aux[c_w - 1] + 64) >>
                7,
686
            255);
John Koleszar's avatar
John Koleszar committed
687
        if ((x << 1 | 1) < dst_c_w) {
688 689 690 691 692 693
          tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
              0,
              (-3 * _aux[x - 1] + 50 * _aux[x] +
               86 * _aux[OC_MINI(x + 1, c_w - 1)] - 5 * _aux[c_w - 1] + 64) >>
                  7,
              255);
694 695
        }
      }
John Koleszar's avatar
John Koleszar committed
696 697
      tmp += dst_c_w;
      _aux += c_w;
698
    }
John Koleszar's avatar
John Koleszar committed
699
    tmp -= tmp_sz;
700
    /*Now do the vertical filtering.*/
John Koleszar's avatar
John Koleszar committed
701 702
    y4m_422jpeg_420jpeg_helper(_dst, tmp, dst_c_w, c_h);
    _dst += dst_c_sz;
703 704 705 706
  }
}

/*Convert 444 to 420jpeg.*/
John Koleszar's avatar
John Koleszar committed
707 708
static void y4m_convert_444_420jpeg(y4m_input *_y4m, unsigned char *_dst,
                                    unsigned char *_aux) {
709
  unsigned char *tmp;
710 711 712 713 714 715 716 717 718 719
  int c_w;
  int c_h;
  int c_sz;
  int dst_c_w;
  int dst_c_h;
  int dst_c_sz;
  int tmp_sz;
  int pli;
  int y;
  int x;
720
  /*Skip past the luma data.*/
John Koleszar's avatar
John Koleszar committed
721
  _dst += _y4m->pic_w * _y4m->pic_h;
722
  /*Compute the size of each chroma plane.*/
John Koleszar's avatar
John Koleszar committed
723 724 725 726 727 728 729 730 731
  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
  c_h = _y4m->pic_h;
  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
  dst_c_sz = dst_c_w * dst_c_h;
  tmp_sz = dst_c_w * c_h;
  tmp = _aux + 2 * c_sz;
  for (pli = 1; pli < 3; pli++) {
732
    /*Filter: [3 -17 78 78 -17 3]/128, derived from a 6-tap Lanczos window.*/
John Koleszar's avatar
John Koleszar committed
733 734
    for (y = 0; y < c_h; y++) {
      for (x = 0; x < OC_MINI(c_w, 2); x += 2) {
clang-format's avatar
clang-format committed
735 736 737 738 739 740
        tmp[x >> 1] = OC_CLAMPI(0,
                                (64 * _aux[0] + 78 * _aux[OC_MINI(1, c_w - 1)] -
                                 17 * _aux[OC_MINI(2, c_w - 1)] +
                                 3 * _aux[OC_MINI(3, c_w - 1)] + 64) >>
                                    7,
                                255);
741
      }
John Koleszar's avatar
John Koleszar committed
742
      for (; x < c_w - 3; x += 2) {
clang-format's avatar
clang-format committed
743 744 745 746 747
        tmp[x >> 1] = OC_CLAMPI(0,
                                (3 * (_aux[x - 2] + _aux[x + 3]) -
                                 17 * (_aux[x - 1] + _aux[x + 2]) +
                                 78 * (_aux[x] + _aux[x + 1]) + 64) >>
                                    7,
748
                                255);
749
      }
John Koleszar's avatar
John Koleszar committed
750
      for (; x < c_w; x += 2) {
clang-format's avatar
clang-format committed
751 752 753 754 755 756 757
        tmp[x >> 1] =
            OC_CLAMPI(0,
                      (3 * (_aux[x - 2] + _aux[c_w - 1]) -
                       17 * (_aux[x - 1] + _aux[OC_MINI(x + 2, c_w - 1)]) +
                       78 * (_aux[x] + _aux[OC_MINI(x + 1, c_w - 1)]) + 64) >>
                          7,
                      255);
758
      }
John Koleszar's avatar
John Koleszar committed
759 760
      tmp += dst_c_w;
      _aux += c_w;
761
    }
John Koleszar's avatar
John Koleszar committed
762
    tmp -= tmp_sz;
763
    /*Now do the vertical filtering.*/
John Koleszar's avatar
John Koleszar committed
764 765
    y4m_422jpeg_420jpeg_helper(_dst, tmp, dst_c_w, c_h);
    _dst += dst_c_sz;
766 767 768 769
  }
}

/*The image is padded with empty chroma components at 4:2:0.*/
John Koleszar's avatar
John Koleszar committed
770 771
static void y4m_convert_mono_420jpeg(y4m_input *_y4m, unsigned char *_dst,
                                     unsigned char *_aux) {
772
  int c_sz;
Yaowu Xu's avatar
Yaowu Xu committed
773
  (void)_aux;
John Koleszar's avatar
John Koleszar committed
774 775 776 777
  _dst += _y4m->pic_w * _y4m->pic_h;
  c_sz = ((_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h) *
         ((_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v);
  memset(_dst, 128, c_sz * 2);
778 779 780
}

/*No conversion function needed.*/
John Koleszar's avatar
John Koleszar committed
781 782
static void y4m_convert_null(y4m_input *_y4m, unsigned char *_dst,
                             unsigned char *_aux) {
Yaowu Xu's avatar
Yaowu Xu committed
783 784 785
  (void)_y4m;
  (void)_dst;
  (void)_aux;
786 787
}

788 789
int y4m_input_open(y4m_input *_y4m, FILE *_fin, char *_skip, int _nskip,
                   int only_420) {
790 791 792
  char buffer[80] = { 0 };
  int ret;
  int i;
793
  /*Read until newline, or 80 cols, whichever happens first.*/
John Koleszar's avatar
John Koleszar committed
794 795 796
  for (i = 0; i < 79; i++) {
    if (_nskip > 0) {
      buffer[i] = *_skip++;
797
      _nskip--;
John Koleszar's avatar
John Koleszar committed
798
    } else {
799
      if (!file_read(buffer + i, 1, _fin)) return -1;
800
    }
801
    if (buffer[i] == '\n') break;
802 803
  }
  /*We skipped too much header data.*/
804
  if (_nskip > 0) return -1;
John Koleszar's avatar
John Koleszar committed
805 806
  if (i == 79) {
    fprintf(stderr, "Error parsing header; not a YUV2MPEG2 file?\n");
807 808
    return -1;
  }
John Koleszar's avatar
John Koleszar committed
809 810 811
  buffer[i] = '\0';
  if (memcmp(buffer, "YUV4MPEG", 8)) {
    fprintf(stderr, "Incomplete magic for YUV4MPEG file.\n");
812 813
    return -1;
  }
John Koleszar's avatar
John Koleszar committed
814 815
  if (buffer[8] != '2') {
    fprintf(stderr, "Incorrect YUV input file version; YUV4MPEG2 required.\n");
816
  }
John Koleszar's avatar
John Koleszar committed
817 818 819
  ret = y4m_parse_tags(_y4m, buffer + 5);
  if (ret < 0) {
    fprintf(stderr, "Error parsing YUV4MPEG2 header.\n");
820 821
    return ret;
  }
John Koleszar's avatar
John Koleszar committed
822
  if (_y4m->interlace == '?') {
823 824
    fprintf(stderr,
            "Warning: Input video interlacing format unknown; "
John Koleszar's avatar
John Koleszar committed
825 826
            "assuming progressive scan.\n");
  } else if (_y4m->interlace != 'p') {
827 828
    fprintf(stderr,
            "Input video is interlaced; "
John Koleszar's avatar
John Koleszar committed
829
            "Only progressive scan handled.\n");
830 831
    return -1;
  }
832
  _y4m->vpx_fmt = VPX_IMG_FMT_I420;
833 834
  _y4m->bps = 12;
  _y4m->bit_depth = 8;
John Koleszar's avatar
John Koleszar committed
835 836
  if (strcmp(_y4m->chroma_type, "420") == 0 ||
      strcmp(_y4m->chroma_type, "420jpeg") == 0) {
837 838 839 840 841
    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
        _y4m->dst_c_dec_v = 2;
    _y4m->dst_buf_read_sz =
        _y4m->pic_w * _y4m->pic_h +
        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
842
    /* Natively supported: no conversion required. */
John Koleszar's avatar
John Koleszar committed
843 844
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
845 846 847 848 849
  } else if (strcmp(_y4m->chroma_type, "420p10") == 0) {
    _y4m->src_c_dec_h = 2;
    _y4m->dst_c_dec_h = 2;
    _y4m->src_c_dec_v = 2;
    _y4m->dst_c_dec_v = 2;
850 851 852
    _y4m->dst_buf_read_sz =
        2 * (_y4m->pic_w * _y4m->pic_h +
             2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2));
853 854 855 856 857 858 859 860 861 862 863 864 865 866 867
    /* Natively supported: no conversion required. */
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    _y4m->bit_depth = 10;
    _y4m->bps = 15;
    _y4m->vpx_fmt = VPX_IMG_FMT_I42016;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 420p10 to 420jpeg\n");
      return -1;
    }
  } else if (strcmp(_y4m->chroma_type, "420p12") == 0) {
    _y4m->src_c_dec_h = 2;
    _y4m->dst_c_dec_h = 2;
    _y4m->src_c_dec_v = 2;
    _y4m->dst_c_dec_v = 2;
868 869 870
    _y4m->dst_buf_read_sz =
        2 * (_y4m->pic_w * _y4m->pic_h +
             2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2));
871 872 873 874 875 876 877 878 879 880
    /* Natively supported: no conversion required. */
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    _y4m->bit_depth = 12;
    _y4m->bps = 18;
    _y4m->vpx_fmt = VPX_IMG_FMT_I42016;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 420p12 to 420jpeg\n");
      return -1;
    }
John Koleszar's avatar
John Koleszar committed
881
  } else if (strcmp(_y4m->chroma_type, "420mpeg2") == 0) {
882 883
    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
        _y4m->dst_c_dec_v = 2;
John Koleszar's avatar
John Koleszar committed
884
    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
885
    /*Chroma filter required: read into the aux buf first.*/
John Koleszar's avatar
John Koleszar committed
886
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz =
887
        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
John Koleszar's avatar
John Koleszar committed
888 889
    _y4m->convert = y4m_convert_42xmpeg2_42xjpeg;
  } else if (strcmp(_y4m->chroma_type, "420paldv") == 0) {
890 891
    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
        _y4m->dst_c_dec_v = 2;
John Koleszar's avatar
John Koleszar committed
892
    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
893 894 895
    /*Chroma filter required: read into the aux buf first.
      We need to make two filter passes, so we need some extra space in the
       aux buffer.*/
John Koleszar's avatar
John Koleszar committed
896
    _y4m->aux_buf_sz = 3 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
897 898
    _y4m->aux_buf_read_sz =
        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
John Koleszar's avatar
John Koleszar committed
899 900 901 902 903 904
    _y4m->convert = y4m_convert_42xpaldv_42xjpeg;
  } else if (strcmp(_y4m->chroma_type, "422jpeg") == 0) {
    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = 2;
    _y4m->src_c_dec_v = 1;
    _y4m->dst_c_dec_v = 2;
    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
905
    /*Chroma filter required: read into the aux buf first.*/
906 907
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz =
        2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
John Koleszar's avatar
John Koleszar committed
908 909
    _y4m->convert = y4m_convert_422jpeg_420jpeg;
  } else if (strcmp(_y4m->chroma_type, "422") == 0) {
910
    _y4m->src_c_dec_h = 2;
John Koleszar's avatar
John Koleszar committed
911
    _y4m->src_c_dec_v = 1;
912 913 914 915 916 917 918 919
    if (only_420) {
      _y4m->dst_c_dec_h = 2;
      _y4m->dst_c_dec_v = 2;
      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
      /*Chroma filter required: read into the aux buf first.
        We need to make two filter passes, so we need some extra space in the
         aux buffer.*/
      _y4m->aux_buf_read_sz = 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
920 921
      _y4m->aux_buf_sz =
          _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
922 923 924
      _y4m->convert = y4m_convert_422_420jpeg;
    } else {
      _y4m->vpx_fmt = VPX_IMG_FMT_I422;
925
      _y4m->bps = 16;
926 927
      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
928 929
      _y4m->dst_buf_read_sz =
          _y4m->pic_w * _y4m->pic_h + 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
930 931 932
      /*Natively supported: no conversion required.*/
      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
      _y4m->convert = y4m_convert_null;
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
    }
  } else if (strcmp(_y4m->chroma_type, "422p10") == 0) {
    _y4m->src_c_dec_h = 2;
    _y4m->src_c_dec_v = 1;
    _y4m->vpx_fmt = VPX_IMG_FMT_I42216;
    _y4m->bps = 20;
    _y4m->bit_depth = 10;
    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
    _y4m->dst_buf_read_sz = 2 * (_y4m->pic_w * _y4m->pic_h +
                                 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h);
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 422p10 to 420jpeg\n");
      return -1;
    }
  } else if (strcmp(_y4m->chroma_type, "422p12") == 0) {
    _y4m->src_c_dec_h = 2;
    _y4m->src_c_dec_v = 1;
    _y4m->vpx_fmt = VPX_IMG_FMT_I42216;
    _y4m->bps = 24;
    _y4m->bit_depth = 12;
    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
    _y4m->dst_buf_read_sz = 2 * (_y4m->pic_w * _y4m->pic_h +
                                 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h);
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 422p12 to 420jpeg\n");
      return -1;
    }
John Koleszar's avatar
John Koleszar committed
966 967 968 969 970 971
  } else if (strcmp(_y4m->chroma_type, "411") == 0) {
    _y4m->src_c_dec_h = 4;
    _y4m->dst_c_dec_h = 2;
    _y4m->src_c_dec_v = 1;
    _y4m->dst_c_dec_v = 2;
    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
972 973 974
    /*Chroma filter required: read into the aux buf first.
      We need to make two filter passes, so we need some extra space in the
       aux buffer.*/
John Koleszar's avatar
John Koleszar committed
975
    _y4m->aux_buf_read_sz = 2 * ((_y4m->pic_w + 3) / 4) * _y4m->pic_h;
976 977
    _y4m->aux_buf_sz =
        _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
John Koleszar's avatar
John Koleszar committed
978 979 980 981
    _y4m->convert = y4m_convert_411_420jpeg;
  } else if (strcmp(_y4m->chroma_type, "444") == 0) {
    _y4m->src_c_dec_h = 1;
    _y4m->src_c_dec_v = 1;
982 983 984 985 986 987 988 989
    if (only_420) {
      _y4m->dst_c_dec_h = 2;
      _y4m->dst_c_dec_v = 2;
      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
      /*Chroma filter required: read into the aux buf first.
        We need to make two filter passes, so we need some extra space in the
         aux buffer.*/
      _y4m->aux_buf_read_sz = 2 * _y4m->pic_w * _y4m->pic_h;
990 991
      _y4m->aux_buf_sz =
          _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
992 993 994
      _y4m->convert = y4m_convert_444_420jpeg;
    } else {
      _y4m->vpx_fmt = VPX_IMG_FMT_I444;
995
      _y4m->bps = 24;
996 997 998 999 1000 1001 1002
      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
      _y4m->dst_buf_read_sz = 3 * _y4m->pic_w * _y4m->pic_h;
      /*Natively supported: no conversion required.*/
      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
      _y4m->convert = y4m_convert_null;
    }
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032
  } else if (strcmp(_y4m->chroma_type, "444p10") == 0) {
    _y4m->src_c_dec_h = 1;
    _y4m->src_c_dec_v = 1;
    _y4m->vpx_fmt = VPX_IMG_FMT_I44416;
    _y4m->bps = 30;
    _y4m->bit_depth = 10;
    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
    _y4m->dst_buf_read_sz = 2 * 3 * _y4m->pic_w * _y4m->pic_h;
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 444p10 to 420jpeg\n");
      return -1;
    }
  } else if (strcmp(_y4m->chroma_type, "444p12") == 0) {
    _y4m->src_c_dec_h = 1;
    _y4m->src_c_dec_v = 1;
    _y4m->vpx_fmt = VPX_IMG_FMT_I44416;
    _y4m->bps = 36;
    _y4m->bit_depth = 12;
    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
    _y4m->dst_buf_read_sz = 2 * 3 * _y4m->pic_w * _y4m->pic_h;
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_null;
    if (only_420) {
      fprintf(stderr, "Unsupported conversion from 444p12 to 420jpeg\n");
      return -1;
    }
John Koleszar's avatar
John Koleszar committed
1033 1034 1035
  } else if (strcmp(_y4m->chroma_type, "444alpha") == 0) {
    _y4m->src_c_dec_h = 1;
    _y4m->src_c_dec_v = 1;
1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
    if (only_420) {
      _y4m->dst_c_dec_h = 2;
      _y4m->dst_c_dec_v = 2;
      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
      /*Chroma filter required: read into the aux buf first.
        We need to make two filter passes, so we need some extra space in the
         aux buffer.
        The extra plane also gets read into the aux buf.
        It will be discarded.*/
      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 3 * _y4m->pic_w * _y4m->pic_h;
      _y4m->convert = y4m_convert_444_420jpeg;
    } else {
      _y4m->vpx_fmt = VPX_IMG_FMT_444A;
1049
      _y4m->bps = 32;
1050 1051 1052 1053 1054 1055 1056
      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
      _y4m->dst_buf_read_sz = 4 * _y4m->pic_w * _y4m->pic_h;
      /*Natively supported: no conversion required.*/
      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
      _y4m->convert = y4m_convert_null;
    }
John Koleszar's avatar
John Koleszar committed
1057 1058 1059 1060
  } else if (strcmp(_y4m->chroma_type, "mono") == 0) {
    _y4m->src_c_dec_h = _y4m->src_c_dec_v = 0;
    _y4m->dst_c_dec_h = _y4m->dst_c_dec_v = 2;
    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
1061
    /*No extra space required, but we need to clear the chroma planes.*/
John Koleszar's avatar
John Koleszar committed
1062 1063 1064 1065
    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
    _y4m->convert = y4m_convert_mono_420jpeg;
  } else {
    fprintf(stderr, "Unknown chroma sampling type: %s\n", _y4m->chroma_type);
1066 1067 1068 1069
    return -1;
  }
  /*The size of the final frame buffers is always computed from the
     destination chroma decimation type.*/
1070 1071 1072 1073
  _y4m->dst_buf_sz =
      _y4m->pic_w * _y4m->pic_h +
      2 * ((_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h) *
          ((_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v);
1074
  if (_y4m->bit_depth == 8)
1075
    _y4m->dst_buf = (unsigned char *)malloc(_y4m->dst_buf_sz);
1076
  else
1077
    _y4m->dst_buf = (unsigned char *)malloc(2 * _y4m->dst_buf_sz);
1078 1079 1080

  if (_y4m->aux_buf_sz > 0)
    _y4m->aux_buf = (unsigned char *)malloc(_y4m->aux_buf_sz);
1081 1082 1083
  return 0;
}

John Koleszar's avatar
John Koleszar committed
1084
void y4m_input_close(y4m_input *_y4m) {
1085 1086 1087 1088
  free(_y4m->dst_buf);
  free(_y4m->aux_buf);
}

John Koleszar's avatar
John Koleszar committed
1089
int y4m_input_fetch_frame(y4m_input *_y4m, FILE *_fin, vpx_image_t *_img) {
1090
  char frame[6];
1091 1092 1093 1094 1095
  int pic_sz;
  int c_w;
  int c_h;
  int c_sz;
  int bytes_per_sample = _y4m->bit_depth > 8 ? 2 : 1;
1096
  /*Read and skip the frame header.*/
1097
  if (!file_read(frame, 6, _fin)) return 0;
John Koleszar's avatar
John Koleszar committed
1098 1099
  if (memcmp(frame, "FRAME", 5)) {
    fprintf(stderr, "Loss of framing in Y4M input data\n");
1100 1101
    return -1;
  }
John Koleszar's avatar
John Koleszar committed
1102
  if (frame[5] != '\n') {
1103
    char c;
1104 1105 1106
    int j;
    for (j = 0; j < 79 && file_read(&c, 1, _fin) && c != '\n'; j++) {
    }
John Koleszar's avatar
John Koleszar committed
1107 1108
    if (j == 79) {
      fprintf(stderr, "Error parsing Y4M frame header\n");
1109 1110 1111 1112
      return -1;
    }
  }
  /*Read the frame data that needs no conversion.*/
1113
  if (!file_read(_y4m->dst_buf, _y4m->dst_buf_read_sz, _fin)) {
John Koleszar's avatar
John Koleszar committed
1114
    fprintf(stderr, "Error reading Y4M frame data.\n");
1115 1116 1117
    return -1;
  }
  /*Read the frame data that does need conversion.*/
1118
  if (!file_read(_y4m->aux_buf, _y4m->aux_buf_read_sz, _fin)) {
John Koleszar's avatar
John Koleszar committed
1119
    fprintf(stderr, "Error reading Y4M frame data.\n");
1120 1121 1122
    return -1;
  }
  /*Now convert the just read frame.*/
John Koleszar's avatar
John Koleszar committed
1123
  (*_y4m->convert)(_y4m, _y4m->dst_buf, _y4m->aux_buf);
1124 1125 1126
  /*Fill in the frame buffer pointers.
    We don't use vpx_img_wrap() because it forces padding for odd picture
     sizes, which would require a separate fread call for every row.*/
John Koleszar's avatar
John Koleszar committed
1127
  memset(_img, 0, sizeof(*_img));
1128
  /*Y4M has the planes in Y'CbCr order, which libvpx calls Y, U, and V.*/
1129
  _img->fmt = _y4m->vpx_fmt;
John Koleszar's avatar
John Koleszar committed
1130 1131
  _img->w = _img->d_w = _y4m->pic_w;
  _img->h = _img->d_h = _y4m->pic_h;
1132 1133
  _img->x_chroma_shift = _y4m->dst_c_dec_h >> 1;
  _img->y_chroma_shift = _y4m->dst_c_dec_v >> 1;
1134
  _img->bps = _y4m->bps;
1135

1136
  /*Set up the buffer pointers.*/
1137
  pic_sz = _y4m->pic_w * _y4m->pic_h * bytes_per_sample;
John Koleszar's avatar
John Koleszar committed
1138
  c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
1139
  c_w *= bytes_per_sample;
John Koleszar's avatar
John Koleszar committed
1140 1141
  c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
  c_sz = c_w * c_h;
1142
  _img->stride[VPX_PLANE_Y] = _img->stride[VPX_PLANE_ALPHA] =
1143
      _y4m->pic_w * bytes_per_sample;
1144 1145 1146 1147 1148
  _img->stride[VPX_PLANE_U] = _img->stride[VPX_PLANE_V] = c_w;
  _img->planes[VPX_PLANE_Y] = _y4m->dst_buf;
  _img->planes[VPX_PLANE_U] = _y4m->dst_buf + pic_sz;
  _img->planes[VPX_PLANE_V] = _y4m->dst_buf + pic_sz + c_sz;
  _img->planes[VPX_PLANE_ALPHA] = _y4m->dst_buf + pic_sz + 2 * c_sz;
1149
  return 1;
1150
}