libavcodec/pngdec.c

   1 /*
   2  * PNG image format
   3  * Copyright (c) 2003 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include "avcodec.h"
  22 #include "bytestream.h"
  23 #include "png.h"
  24 #include "dsputil.h"
  25
  26 /* TODO:
  27  * - add 2, 4 and 16 bit depth support
  28  */
  29
  30 #include <zlib.h>
  31
  32 //#define DEBUG
  33
  34 typedef struct PNGDecContext {
  35     DSPContext dsp;
  36
  37     const uint8_t *bytestream;
  38     const uint8_t *bytestream_start;
  39     const uint8_t *bytestream_end;
  40     AVFrame picture;
  41
  42     int state;
  43     int width, height;
  44     int bit_depth;
  45     int color_type;
  46     int compression_type;
  47     int interlace_type;
  48     int filter_type;
  49     int channels;
  50     int bits_per_pixel;
  51     int bpp;
  52
  53     uint8_t *image_buf;
  54     int image_linesize;
  55     uint32_t palette[256];
  56     uint8_t *crow_buf;
  57     uint8_t *last_row;
  58     uint8_t *tmp_row;
  59     int pass;
  60     int crow_size; /* compressed row size (include filter type) */
  61     int row_size; /* decompressed row size */
  62     int pass_row_size; /* decompress row size of the current pass */
  63     int y;
  64     z_stream zstream;
  65 } PNGDecContext;
  66
  67 /* Mask to determine which y pixels can be written in a pass */
  68 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
  69     0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
  70 };
  71
  72 /* Mask to determine which pixels to overwrite while displaying */
  73 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
  74     0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
  75 };
  76
  77 /* NOTE: we try to construct a good looking image at each pass. width
  78    is the original image width. We also do pixel format conversion at
  79    this stage */
  80 static void png_put_interlaced_row(uint8_t *dst, int width,
  81                                    int bits_per_pixel, int pass,
  82                                    int color_type, const uint8_t *src)
  83 {
  84     int x, mask, dsp_mask, j, src_x, b, bpp;
  85     uint8_t *d;
  86     const uint8_t *s;
  87
  88     mask = ff_png_pass_mask[pass];
  89     dsp_mask = png_pass_dsp_mask[pass];
  90     switch(bits_per_pixel) {
  91     case 1:
  92         /* we must initialize the line to zero before writing to it */
  93         if (pass == 0)
  94             memset(dst, 0, (width + 7) >> 3);
  95         src_x = 0;
  96         for(x = 0; x < width; x++) {
  97             j = (x & 7);
  98             if ((dsp_mask << j) & 0x80) {
  99                 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
 100                 dst[x >> 3] |= b << (7 - j);
 101             }
 102             if ((mask << j) & 0x80)
 103                 src_x++;
 104         }
 105         break;
 106     default:
 107         bpp = bits_per_pixel >> 3;
 108         d = dst;
 109         s = src;
 110         if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 111             for(x = 0; x < width; x++) {
 112                 j = x & 7;
 113                 if ((dsp_mask << j) & 0x80) {
 114                     *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
 115                 }
 116                 d += bpp;
 117                 if ((mask << j) & 0x80)
 118                     s += bpp;
 119             }
 120         } else {
 121             for(x = 0; x < width; x++) {
 122                 j = x & 7;
 123                 if ((dsp_mask << j) & 0x80) {
 124                     memcpy(d, s, bpp);
 125                 }
 126                 d += bpp;
 127                 if ((mask << j) & 0x80)
 128                     s += bpp;
 129             }
 130         }
 131         break;
 132     }
 133 }
 134
 135 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
 136 {
 137     int i;
 138     for(i = 0; i < w; i++) {
 139         int a, b, c, p, pa, pb, pc;
 140
 141         a = dst[i - bpp];
 142         b = top[i];
 143         c = top[i - bpp];
 144
 145         p = b - c;
 146         pc = a - c;
 147
 148         pa = abs(p);
 149         pb = abs(pc);
 150         pc = abs(p + pc);
 151
 152         if (pa <= pb && pa <= pc)
 153             p = a;
 154         else if (pb <= pc)
 155             p = b;
 156         else
 157             p = c;
 158         dst[i] = p + src[i];
 159     }
 160 }
 161
 162 #define UNROLL1(bpp, op) {\
 163                  r = dst[0];\
 164     if(bpp >= 2) g = dst[1];\
 165     if(bpp >= 3) b = dst[2];\
 166     if(bpp >= 4) a = dst[3];\
 167     for(; i < size; i+=bpp) {\
 168         dst[i+0] = r = op(r, src[i+0], last[i+0]);\
 169         if(bpp == 1) continue;\
 170         dst[i+1] = g = op(g, src[i+1], last[i+1]);\
 171         if(bpp == 2) continue;\
 172         dst[i+2] = b = op(b, src[i+2], last[i+2]);\
 173         if(bpp == 3) continue;\
 174         dst[i+3] = a = op(a, src[i+3], last[i+3]);\
 175     }\
 176 }
 177
 178 #define UNROLL_FILTER(op)\
 179          if(bpp == 1) UNROLL1(1, op)\
 180     else if(bpp == 2) UNROLL1(2, op)\
 181     else if(bpp == 3) UNROLL1(3, op)\
 182     else if(bpp == 4) UNROLL1(4, op)\
 183
 184 /* NOTE: 'dst' can be equal to 'last' */
 185 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
 186                            uint8_t *src, uint8_t *last, int size, int bpp)
 187 {
 188     int i, p, r, g, b, a;
 189
 190     switch(filter_type) {
 191     case PNG_FILTER_VALUE_NONE:
 192         memcpy(dst, src, size);
 193         break;
 194     case PNG_FILTER_VALUE_SUB:
 195         for(i = 0; i < bpp; i++) {
 196             dst[i] = src[i];
 197         }
 198         if(bpp == 4) {
 199             p = *(int*)dst;
 200             for(; i < size; i+=bpp) {
 201                 int s = *(int*)(src+i);
 202                 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
 203                 *(int*)(dst+i) = p;
 204             }
 205         } else {
 206 #define OP_SUB(x,s,l) x+s
 207             UNROLL_FILTER(OP_SUB);
 208         }
 209         break;
 210     case PNG_FILTER_VALUE_UP:
 211         dsp->add_bytes_l2(dst, src, last, size);
 212         break;
 213     case PNG_FILTER_VALUE_AVG:
 214         for(i = 0; i < bpp; i++) {
 215             p = (last[i] >> 1);
 216             dst[i] = p + src[i];
 217         }
 218 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
 219         UNROLL_FILTER(OP_AVG);
 220         break;
 221     case PNG_FILTER_VALUE_PAETH:
 222         for(i = 0; i < bpp; i++) {
 223             p = last[i];
 224             dst[i] = p + src[i];
 225         }
 226         if(bpp > 1 && size > 4) {
 227             // would write off the end of the array if we let it process the last pixel with bpp=3
 228             int w = bpp==4 ? size : size-3;
 229             dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
 230             i = w;
 231         }
 232         ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
 233         break;
 234     }
 235 }
 236
 237 static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco)
 238 {
 239     int j;
 240     unsigned int r, g, b, a;
 241
 242     for(j = 0;j < width; j++) {
 243         r = src[0];
 244         g = src[1];
 245         b = src[2];
 246         a = src[3];
 247         if(loco) {
 248             r = (r+g)&0xff;
 249             b = (b+g)&0xff;
 250         }
 251         *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
 252         dst += 4;
 253         src += 4;
 254     }
 255 }
 256
 257 static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco)
 258 {
 259     if(loco)
 260         convert_to_rgb32_loco(dst, src, width, 1);
 261     else
 262         convert_to_rgb32_loco(dst, src, width, 0);
 263 }
 264
 265 static void deloco_rgb24(uint8_t *dst, int size)
 266 {
 267     int i;
 268     for(i=0; i<size; i+=3) {
 269         int g = dst[i+1];
 270         dst[i+0] += g;
 271         dst[i+2] += g;
 272     }
 273 }
 274
 275 /* process exactly one decompressed row */
 276 static void png_handle_row(PNGDecContext *s)
 277 {
 278     uint8_t *ptr, *last_row;
 279     int got_line;
 280
 281     if (!s->interlace_type) {
 282         ptr = s->image_buf + s->image_linesize * s->y;
 283         /* need to swap bytes correctly for RGB_ALPHA */
 284         if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 285             png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
 286                            s->last_row, s->row_size, s->bpp);
 287             convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO);
 288             FFSWAP(uint8_t*, s->last_row, s->tmp_row);
 289         } else {
 290             /* in normal case, we avoid one copy */
 291             if (s->y == 0)
 292                 last_row = s->last_row;
 293             else
 294                 last_row = ptr - s->image_linesize;
 295
 296             png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
 297                            last_row, s->row_size, s->bpp);
 298         }
 299         /* loco lags by 1 row so that it doesn't interfere with top prediction */
 300         if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
 301             s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0)
 302             deloco_rgb24(ptr - s->image_linesize, s->row_size);
 303         s->y++;
 304         if (s->y == s->height) {
 305             s->state |= PNG_ALLIMAGE;
 306             if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
 307                 s->color_type == PNG_COLOR_TYPE_RGB)
 308                 deloco_rgb24(ptr, s->row_size);
 309         }
 310     } else {
 311         got_line = 0;
 312         for(;;) {
 313             ptr = s->image_buf + s->image_linesize * s->y;
 314             if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
 315                 /* if we already read one row, it is time to stop to
 316                    wait for the next one */
 317                 if (got_line)
 318                     break;
 319                 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
 320                                s->last_row, s->pass_row_size, s->bpp);
 321                 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
 322                 got_line = 1;
 323             }
 324             if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
 325                 /* NOTE: RGB32 is handled directly in png_put_interlaced_row */
 326                 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
 327                                        s->color_type, s->last_row);
 328             }
 329             s->y++;
 330             if (s->y == s->height) {
 331                 for(;;) {
 332                     if (s->pass == NB_PASSES - 1) {
 333                         s->state |= PNG_ALLIMAGE;
 334                         goto the_end;
 335                     } else {
 336                         s->pass++;
 337                         s->y = 0;
 338                         s->pass_row_size = ff_png_pass_row_size(s->pass,
 339                                                              s->bits_per_pixel,
 340                                                              s->width);
 341                         s->crow_size = s->pass_row_size + 1;
 342                         if (s->pass_row_size != 0)
 343                             break;
 344                         /* skip pass if empty row */
 345                     }
 346                 }
 347             }
 348         }
 349     the_end: ;
 350     }
 351 }
 352
 353 static int png_decode_idat(PNGDecContext *s, int length)
 354 {
 355     int ret;
 356     s->zstream.avail_in = length;
 357     s->zstream.next_in = s->bytestream;
 358     s->bytestream += length;
 359
 360     if(s->bytestream > s->bytestream_end)
 361         return -1;
 362
 363     /* decode one line if possible */
 364     while (s->zstream.avail_in > 0) {
 365         ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
 366         if (ret != Z_OK && ret != Z_STREAM_END) {
 367             return -1;
 368         }
 369         if (s->zstream.avail_out == 0) {
 370             if (!(s->state & PNG_ALLIMAGE)) {
 371                 png_handle_row(s);
 372             }
 373             s->zstream.avail_out = s->crow_size;
 374             s->zstream.next_out = s->crow_buf;
 375         }
 376     }
 377     return 0;
 378 }
 379
 380 static int decode_frame(AVCodecContext *avctx,
 381                         void *data, int *data_size,
 382                         const uint8_t *buf, int buf_size)
 383 {
 384     PNGDecContext * const s = avctx->priv_data;
 385     AVFrame *picture = data;
 386     AVFrame * const p= &s->picture;
 387     uint32_t tag, length;
 388     int ret, crc;
 389
 390     s->bytestream_start=
 391     s->bytestream= buf;
 392     s->bytestream_end= buf + buf_size;
 393
 394     /* check signature */
 395     if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
 396         memcmp(s->bytestream, ff_mngsig, 8) != 0)
 397         return -1;
 398     s->bytestream+= 8;
 399     s->y=
 400     s->state=0;
 401 //    memset(s, 0, sizeof(PNGDecContext));
 402     /* init the zlib */
 403     s->zstream.zalloc = ff_png_zalloc;
 404     s->zstream.zfree = ff_png_zfree;
 405     s->zstream.opaque = NULL;
 406     ret = inflateInit(&s->zstream);
 407     if (ret != Z_OK)
 408         return -1;
 409     for(;;) {
 410         int tag32;
 411         if (s->bytestream >= s->bytestream_end)
 412             goto fail;
 413         length = bytestream_get_be32(&s->bytestream);
 414         if (length > 0x7fffffff)
 415             goto fail;
 416         tag32 = bytestream_get_be32(&s->bytestream);
 417         tag = bswap_32(tag32);
 418 #ifdef DEBUG
 419         av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
 420                (tag & 0xff),
 421                ((tag >> 8) & 0xff),
 422                ((tag >> 16) & 0xff),
 423                ((tag >> 24) & 0xff), length);
 424 #endif
 425         switch(tag) {
 426         case MKTAG('I', 'H', 'D', 'R'):
 427             if (length != 13)
 428                 goto fail;
 429             s->width = bytestream_get_be32(&s->bytestream);
 430             s->height = bytestream_get_be32(&s->bytestream);
 431             if(avcodec_check_dimensions(avctx, s->width, s->height)){
 432                 s->width= s->height= 0;
 433                 goto fail;
 434             }
 435             s->bit_depth = *s->bytestream++;
 436             s->color_type = *s->bytestream++;
 437             s->compression_type = *s->bytestream++;
 438             s->filter_type = *s->bytestream++;
 439             s->interlace_type = *s->bytestream++;
 440             crc = bytestream_get_be32(&s->bytestream);
 441             s->state |= PNG_IHDR;
 442 #ifdef DEBUG
 443             av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
 444                    s->width, s->height, s->bit_depth, s->color_type,
 445                    s->compression_type, s->filter_type, s->interlace_type);
 446 #endif
 447             break;
 448         case MKTAG('I', 'D', 'A', 'T'):
 449             if (!(s->state & PNG_IHDR))
 450                 goto fail;
 451             if (!(s->state & PNG_IDAT)) {
 452                 /* init image info */
 453                 avctx->width = s->width;
 454                 avctx->height = s->height;
 455
 456                 s->channels = ff_png_get_nb_channels(s->color_type);
 457                 s->bits_per_pixel = s->bit_depth * s->channels;
 458                 s->bpp = (s->bits_per_pixel + 7) >> 3;
 459                 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
 460
 461                 if (s->bit_depth == 8 &&
 462                     s->color_type == PNG_COLOR_TYPE_RGB) {
 463                     avctx->pix_fmt = PIX_FMT_RGB24;
 464                 } else if (s->bit_depth == 8 &&
 465                            s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 466                     avctx->pix_fmt = PIX_FMT_RGB32;
 467                 } else if (s->bit_depth == 8 &&
 468                            s->color_type == PNG_COLOR_TYPE_GRAY) {
 469                     avctx->pix_fmt = PIX_FMT_GRAY8;
 470                 } else if (s->bit_depth == 16 &&
 471                            s->color_type == PNG_COLOR_TYPE_GRAY) {
 472                     avctx->pix_fmt = PIX_FMT_GRAY16BE;
 473                 } else if (s->bit_depth == 1 &&
 474                            s->color_type == PNG_COLOR_TYPE_GRAY) {
 475                     avctx->pix_fmt = PIX_FMT_MONOBLACK;
 476                 } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
 477                     avctx->pix_fmt = PIX_FMT_PAL8;
 478                 } else {
 479                     goto fail;
 480                 }
 481                 if(p->data[0])
 482                     avctx->release_buffer(avctx, p);
 483
 484                 p->reference= 0;
 485                 if(avctx->get_buffer(avctx, p) < 0){
 486                     av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 487                     goto fail;
 488                 }
 489                 p->pict_type= FF_I_TYPE;
 490                 p->key_frame= 1;
 491                 p->interlaced_frame = !!s->interlace_type;
 492
 493                 /* compute the compressed row size */
 494                 if (!s->interlace_type) {
 495                     s->crow_size = s->row_size + 1;
 496                 } else {
 497                     s->pass = 0;
 498                     s->pass_row_size = ff_png_pass_row_size(s->pass,
 499                                                          s->bits_per_pixel,
 500                                                          s->width);
 501                     s->crow_size = s->pass_row_size + 1;
 502                 }
 503 #ifdef DEBUG
 504                 av_log(avctx, AV_LOG_DEBUG, "row_size=%d crow_size =%d\n",
 505                        s->row_size, s->crow_size);
 506 #endif
 507                 s->image_buf = p->data[0];
 508                 s->image_linesize = p->linesize[0];
 509                 /* copy the palette if needed */
 510                 if (s->color_type == PNG_COLOR_TYPE_PALETTE)
 511                     memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
 512                 /* empty row is used if differencing to the first row */
 513                 s->last_row = av_mallocz(s->row_size);
 514                 if (!s->last_row)
 515                     goto fail;
 516                 if (s->interlace_type ||
 517                     s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 518                     s->tmp_row = av_malloc(s->row_size);
 519                     if (!s->tmp_row)
 520                         goto fail;
 521                 }
 522                 /* compressed row */
 523                 s->crow_buf = av_malloc(s->row_size + 1);
 524                 if (!s->crow_buf)
 525                     goto fail;
 526                 s->zstream.avail_out = s->crow_size;
 527                 s->zstream.next_out = s->crow_buf;
 528             }
 529             s->state |= PNG_IDAT;
 530             if (png_decode_idat(s, length) < 0)
 531                 goto fail;
 532             /* skip crc */
 533             crc = bytestream_get_be32(&s->bytestream);
 534             break;
 535         case MKTAG('P', 'L', 'T', 'E'):
 536             {
 537                 int n, i, r, g, b;
 538
 539                 if ((length % 3) != 0 || length > 256 * 3)
 540                     goto skip_tag;
 541                 /* read the palette */
 542                 n = length / 3;
 543                 for(i=0;i<n;i++) {
 544                     r = *s->bytestream++;
 545                     g = *s->bytestream++;
 546                     b = *s->bytestream++;
 547                     s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
 548                 }
 549                 for(;i<256;i++) {
 550                     s->palette[i] = (0xff << 24);
 551                 }
 552                 s->state |= PNG_PLTE;
 553                 crc = bytestream_get_be32(&s->bytestream);
 554             }
 555             break;
 556         case MKTAG('t', 'R', 'N', 'S'):
 557             {
 558                 int v, i;
 559
 560                 /* read the transparency. XXX: Only palette mode supported */
 561                 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
 562                     length > 256 ||
 563                     !(s->state & PNG_PLTE))
 564                     goto skip_tag;
 565                 for(i=0;i<length;i++) {
 566                     v = *s->bytestream++;
 567                     s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
 568                 }
 569                 crc = bytestream_get_be32(&s->bytestream);
 570             }
 571             break;
 572         case MKTAG('I', 'E', 'N', 'D'):
 573             if (!(s->state & PNG_ALLIMAGE))
 574                 goto fail;
 575             crc = bytestream_get_be32(&s->bytestream);
 576             goto exit_loop;
 577         default:
 578             /* skip tag */
 579         skip_tag:
 580             s->bytestream += length + 4;
 581             break;
 582         }
 583     }
 584  exit_loop:
 585     *picture= s->picture;
 586     *data_size = sizeof(AVFrame);
 587
 588     ret = s->bytestream - s->bytestream_start;
 589  the_end:
 590     inflateEnd(&s->zstream);
 591     av_freep(&s->crow_buf);
 592     av_freep(&s->last_row);
 593     av_freep(&s->tmp_row);
 594     return ret;
 595  fail:
 596     ret = -1;
 597     goto the_end;
 598 }
 599
 600 static av_cold int png_dec_init(AVCodecContext *avctx){
 601     PNGDecContext *s = avctx->priv_data;
 602
 603     avcodec_get_frame_defaults(&s->picture);
 604     avctx->coded_frame= &s->picture;
 605     dsputil_init(&s->dsp, avctx);
 606
 607     return 0;
 608 }
 609
 610 AVCodec png_decoder = {
 611     "png",
 612     CODEC_TYPE_VIDEO,
 613     CODEC_ID_PNG,
 614     sizeof(PNGDecContext),
 615     png_dec_init,
 616     NULL,
 617     NULL, //decode_end,
 618     decode_frame,
 619     0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
 620     NULL,
 621     .long_name = NULL_IF_CONFIG_SMALL("PNG image"),
 622 };