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 34typedef 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 picture1, picture2; 41 AVFrame *current_picture, *last_picture; 42 43 int state; 44 int width, height; 45 int bit_depth; 46 int color_type; 47 int compression_type; 48 int interlace_type; 49 int filter_type; 50 int channels; 51 int bits_per_pixel; 52 int bpp; 53 54 uint8_t *image_buf; 55 int image_linesize; 56 uint32_t palette[256]; 57 uint8_t *crow_buf; 58 uint8_t *last_row; 59 uint8_t *tmp_row; 60 int pass; 61 int crow_size; /* compressed row size (include filter type) */ 62 int row_size; /* decompressed row size */ 63 int pass_row_size; /* decompress row size of the current pass */ 64 int y; 65 z_stream zstream; 66} PNGDecContext; 67 68/* Mask to determine which y pixels can be written in a pass */ 69static const uint8_t png_pass_dsp_ymask[NB_PASSES] = { 70 0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55, 71}; 72 73/* Mask to determine which pixels to overwrite while displaying */ 74static const uint8_t png_pass_dsp_mask[NB_PASSES] = { 75 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff 76}; 77 78/* NOTE: we try to construct a good looking image at each pass. width 79 is the original image width. We also do pixel format conversion at 80 this stage */ 81static void png_put_interlaced_row(uint8_t *dst, int width, 82 int bits_per_pixel, int pass, 83 int color_type, const uint8_t *src) 84{ 85 int x, mask, dsp_mask, j, src_x, b, bpp; 86 uint8_t *d; 87 const uint8_t *s; 88 89 mask = ff_png_pass_mask[pass]; 90 dsp_mask = png_pass_dsp_mask[pass]; 91 switch(bits_per_pixel) { 92 case 1: 93 /* we must initialize the line to zero before writing to it */ 94 if (pass == 0) 95 memset(dst, 0, (width + 7) >> 3); 96 src_x = 0; 97 for(x = 0; x < width; x++) { 98 j = (x & 7); 99 if ((dsp_mask << j) & 0x80) { 100 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1; 101 dst[x >> 3] |= b << (7 - j); 102 } 103 if ((mask << j) & 0x80) 104 src_x++; 105 } 106 break; 107 default: 108 bpp = bits_per_pixel >> 3; 109 d = dst; 110 s = src; 111 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 112 for(x = 0; x < width; x++) { 113 j = x & 7; 114 if ((dsp_mask << j) & 0x80) { 115 *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2]; 116 } 117 d += bpp; 118 if ((mask << j) & 0x80) 119 s += bpp; 120 } 121 } else { 122 for(x = 0; x < width; x++) { 123 j = x & 7; 124 if ((dsp_mask << j) & 0x80) { 125 memcpy(d, s, bpp); 126 } 127 d += bpp; 128 if ((mask << j) & 0x80) 129 s += bpp; 130 } 131 } 132 break; 133 } 134} 135 136void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp) 137{ 138 int i; 139 for(i = 0; i < w; i++) { 140 int a, b, c, p, pa, pb, pc; 141 142 a = dst[i - bpp]; 143 b = top[i]; 144 c = top[i - bpp]; 145 146 p = b - c; 147 pc = a - c; 148 149 pa = abs(p); 150 pb = abs(pc); 151 pc = abs(p + pc); 152 153 if (pa <= pb && pa <= pc) 154 p = a; 155 else if (pb <= pc) 156 p = b; 157 else 158 p = c; 159 dst[i] = p + src[i]; 160 } 161} 162 163#define UNROLL1(bpp, op) {\ 164 r = dst[0];\ 165 if(bpp >= 2) g = dst[1];\ 166 if(bpp >= 3) b = dst[2];\ 167 if(bpp >= 4) a = dst[3];\ 168 for(; i < size; i+=bpp) {\ 169 dst[i+0] = r = op(r, src[i+0], last[i+0]);\ 170 if(bpp == 1) continue;\ 171 dst[i+1] = g = op(g, src[i+1], last[i+1]);\ 172 if(bpp == 2) continue;\ 173 dst[i+2] = b = op(b, src[i+2], last[i+2]);\ 174 if(bpp == 3) continue;\ 175 dst[i+3] = a = op(a, src[i+3], last[i+3]);\ 176 }\ 177} 178 179#define UNROLL_FILTER(op)\ 180 if(bpp == 1) UNROLL1(1, op)\ 181 else if(bpp == 2) UNROLL1(2, op)\ 182 else if(bpp == 3) UNROLL1(3, op)\ 183 else if(bpp == 4) UNROLL1(4, op)\ 184 else {\ 185 for (; i < size; i += bpp) {\ 186 int j;\ 187 for (j = 0; j < bpp; j++)\ 188 dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\ 189 }\ 190 } 191 192/* NOTE: 'dst' can be equal to 'last' */ 193static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type, 194 uint8_t *src, uint8_t *last, int size, int bpp) 195{ 196 int i, p, r, g, b, a; 197 198 switch(filter_type) { 199 case PNG_FILTER_VALUE_NONE: 200 memcpy(dst, src, size); 201 break; 202 case PNG_FILTER_VALUE_SUB: 203 for(i = 0; i < bpp; i++) { 204 dst[i] = src[i]; 205 } 206 if(bpp == 4) { 207 p = *(int*)dst; 208 for(; i < size; i+=bpp) { 209 int s = *(int*)(src+i); 210 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080); 211 *(int*)(dst+i) = p; 212 } 213 } else { 214#define OP_SUB(x,s,l) x+s 215 UNROLL_FILTER(OP_SUB); 216 } 217 break; 218 case PNG_FILTER_VALUE_UP: 219 dsp->add_bytes_l2(dst, src, last, size); 220 break; 221 case PNG_FILTER_VALUE_AVG: 222 for(i = 0; i < bpp; i++) { 223 p = (last[i] >> 1); 224 dst[i] = p + src[i]; 225 } 226#define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff 227 UNROLL_FILTER(OP_AVG); 228 break; 229 case PNG_FILTER_VALUE_PAETH: 230 for(i = 0; i < bpp; i++) { 231 p = last[i]; 232 dst[i] = p + src[i]; 233 } 234 if(bpp > 1 && size > 4) { 235 // would write off the end of the array if we let it process the last pixel with bpp=3 236 int w = bpp==4 ? size : size-3; 237 dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp); 238 i = w; 239 } 240 ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp); 241 break; 242 } 243} 244 245static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco) 246{ 247 int j; 248 unsigned int r, g, b, a; 249 250 for(j = 0;j < width; j++) { 251 r = src[0]; 252 g = src[1]; 253 b = src[2]; 254 a = src[3]; 255 if(loco) { 256 r = (r+g)&0xff; 257 b = (b+g)&0xff; 258 } 259 *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b; 260 dst += 4; 261 src += 4; 262 } 263} 264 265static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco) 266{ 267 if(loco) 268 convert_to_rgb32_loco(dst, src, width, 1); 269 else 270 convert_to_rgb32_loco(dst, src, width, 0); 271} 272 273static void deloco_rgb24(uint8_t *dst, int size) 274{ 275 int i; 276 for(i=0; i<size; i+=3) { 277 int g = dst[i+1]; 278 dst[i+0] += g; 279 dst[i+2] += g; 280 } 281} 282 283/* process exactly one decompressed row */ 284static void png_handle_row(PNGDecContext *s) 285{ 286 uint8_t *ptr, *last_row; 287 int got_line; 288 289 if (!s->interlace_type) { 290 ptr = s->image_buf + s->image_linesize * s->y; 291 /* need to swap bytes correctly for RGB_ALPHA */ 292 if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 293 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, 294 s->last_row, s->row_size, s->bpp); 295 convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO); 296 FFSWAP(uint8_t*, s->last_row, s->tmp_row); 297 } else { 298 /* in normal case, we avoid one copy */ 299 if (s->y == 0) 300 last_row = s->last_row; 301 else 302 last_row = ptr - s->image_linesize; 303 304 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1, 305 last_row, s->row_size, s->bpp); 306 } 307 /* loco lags by 1 row so that it doesn't interfere with top prediction */ 308 if (s->filter_type == PNG_FILTER_TYPE_LOCO && 309 s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0) 310 deloco_rgb24(ptr - s->image_linesize, s->row_size); 311 s->y++; 312 if (s->y == s->height) { 313 s->state |= PNG_ALLIMAGE; 314 if (s->filter_type == PNG_FILTER_TYPE_LOCO && 315 s->color_type == PNG_COLOR_TYPE_RGB) 316 deloco_rgb24(ptr, s->row_size); 317 } 318 } else { 319 got_line = 0; 320 for(;;) { 321 ptr = s->image_buf + s->image_linesize * s->y; 322 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) { 323 /* if we already read one row, it is time to stop to 324 wait for the next one */ 325 if (got_line) 326 break; 327 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, 328 s->last_row, s->pass_row_size, s->bpp); 329 FFSWAP(uint8_t*, s->last_row, s->tmp_row); 330 got_line = 1; 331 } 332 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) { 333 /* NOTE: RGB32 is handled directly in png_put_interlaced_row */ 334 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass, 335 s->color_type, s->last_row); 336 } 337 s->y++; 338 if (s->y == s->height) { 339 for(;;) { 340 if (s->pass == NB_PASSES - 1) { 341 s->state |= PNG_ALLIMAGE; 342 goto the_end; 343 } else { 344 s->pass++; 345 s->y = 0; 346 s->pass_row_size = ff_png_pass_row_size(s->pass, 347 s->bits_per_pixel, 348 s->width); 349 s->crow_size = s->pass_row_size + 1; 350 if (s->pass_row_size != 0) 351 break; 352 /* skip pass if empty row */ 353 } 354 } 355 } 356 } 357 the_end: ; 358 } 359} 360 361static int png_decode_idat(PNGDecContext *s, int length) 362{ 363 int ret; 364 s->zstream.avail_in = length; 365 s->zstream.next_in = s->bytestream; 366 s->bytestream += length; 367 368 if(s->bytestream > s->bytestream_end) 369 return -1; 370 371 /* decode one line if possible */ 372 while (s->zstream.avail_in > 0) { 373 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH); 374 if (ret != Z_OK && ret != Z_STREAM_END) { 375 return -1; 376 } 377 if (s->zstream.avail_out == 0) { 378 if (!(s->state & PNG_ALLIMAGE)) { 379 png_handle_row(s); 380 } 381 s->zstream.avail_out = s->crow_size; 382 s->zstream.next_out = s->crow_buf; 383 } 384 } 385 return 0; 386} 387 388static int decode_frame(AVCodecContext *avctx, 389 void *data, int *data_size, 390 AVPacket *avpkt) 391{ 392 const uint8_t *buf = avpkt->data; 393 int buf_size = avpkt->size; 394 PNGDecContext * const s = avctx->priv_data; 395 AVFrame *picture = data; 396 AVFrame *p; 397 uint8_t *crow_buf_base = NULL; 398 uint32_t tag, length; 399 int ret, crc; 400 401 FFSWAP(AVFrame *, s->current_picture, s->last_picture); 402 avctx->coded_frame= s->current_picture; 403 p = s->current_picture; 404 405 s->bytestream_start= 406 s->bytestream= buf; 407 s->bytestream_end= buf + buf_size; 408 409 /* check signature */ 410 if (memcmp(s->bytestream, ff_pngsig, 8) != 0 && 411 memcmp(s->bytestream, ff_mngsig, 8) != 0) 412 return -1; 413 s->bytestream+= 8; 414 s->y= 415 s->state=0; 416// memset(s, 0, sizeof(PNGDecContext)); 417 /* init the zlib */ 418 s->zstream.zalloc = ff_png_zalloc; 419 s->zstream.zfree = ff_png_zfree; 420 s->zstream.opaque = NULL; 421 ret = inflateInit(&s->zstream); 422 if (ret != Z_OK) 423 return -1; 424 for(;;) { 425 int tag32; 426 if (s->bytestream >= s->bytestream_end) 427 goto fail; 428 length = bytestream_get_be32(&s->bytestream); 429 if (length > 0x7fffffff) 430 goto fail; 431 tag32 = bytestream_get_be32(&s->bytestream); 432 tag = bswap_32(tag32); 433 dprintf(avctx, "png: tag=%c%c%c%c length=%u\n", 434 (tag & 0xff), 435 ((tag >> 8) & 0xff), 436 ((tag >> 16) & 0xff), 437 ((tag >> 24) & 0xff), length); 438 switch(tag) { 439 case MKTAG('I', 'H', 'D', 'R'): 440 if (length != 13) 441 goto fail; 442 s->width = bytestream_get_be32(&s->bytestream); 443 s->height = bytestream_get_be32(&s->bytestream); 444 if(avcodec_check_dimensions(avctx, s->width, s->height)){ 445 s->width= s->height= 0; 446 goto fail; 447 } 448 s->bit_depth = *s->bytestream++; 449 s->color_type = *s->bytestream++; 450 s->compression_type = *s->bytestream++; 451 s->filter_type = *s->bytestream++; 452 s->interlace_type = *s->bytestream++; 453 crc = bytestream_get_be32(&s->bytestream); 454 s->state |= PNG_IHDR; 455 dprintf(avctx, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n", 456 s->width, s->height, s->bit_depth, s->color_type, 457 s->compression_type, s->filter_type, s->interlace_type); 458 break; 459 case MKTAG('I', 'D', 'A', 'T'): 460 if (!(s->state & PNG_IHDR)) 461 goto fail; 462 if (!(s->state & PNG_IDAT)) { 463 /* init image info */ 464 avctx->width = s->width; 465 avctx->height = s->height; 466 467 s->channels = ff_png_get_nb_channels(s->color_type); 468 s->bits_per_pixel = s->bit_depth * s->channels; 469 s->bpp = (s->bits_per_pixel + 7) >> 3; 470 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3; 471 472 if (s->bit_depth == 8 && 473 s->color_type == PNG_COLOR_TYPE_RGB) { 474 avctx->pix_fmt = PIX_FMT_RGB24; 475 } else if (s->bit_depth == 8 && 476 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 477 avctx->pix_fmt = PIX_FMT_RGB32; 478 } else if (s->bit_depth == 8 && 479 s->color_type == PNG_COLOR_TYPE_GRAY) { 480 avctx->pix_fmt = PIX_FMT_GRAY8; 481 } else if (s->bit_depth == 16 && 482 s->color_type == PNG_COLOR_TYPE_GRAY) { 483 avctx->pix_fmt = PIX_FMT_GRAY16BE; 484 } else if (s->bit_depth == 16 && 485 s->color_type == PNG_COLOR_TYPE_RGB) { 486 avctx->pix_fmt = PIX_FMT_RGB48BE; 487 } else if (s->bit_depth == 1 && 488 s->color_type == PNG_COLOR_TYPE_GRAY) { 489 avctx->pix_fmt = PIX_FMT_MONOBLACK; 490 } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) { 491 avctx->pix_fmt = PIX_FMT_PAL8; 492 } else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { 493 avctx->pix_fmt = PIX_FMT_Y400A; 494 } else { 495 goto fail; 496 } 497 if(p->data[0]) 498 avctx->release_buffer(avctx, p); 499 500 p->reference= 0; 501 if(avctx->get_buffer(avctx, p) < 0){ 502 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 503 goto fail; 504 } 505 p->pict_type= FF_I_TYPE; 506 p->key_frame= 1; 507 p->interlaced_frame = !!s->interlace_type; 508 509 /* compute the compressed row size */ 510 if (!s->interlace_type) { 511 s->crow_size = s->row_size + 1; 512 } else { 513 s->pass = 0; 514 s->pass_row_size = ff_png_pass_row_size(s->pass, 515 s->bits_per_pixel, 516 s->width); 517 s->crow_size = s->pass_row_size + 1; 518 } 519 dprintf(avctx, "row_size=%d crow_size =%d\n", 520 s->row_size, s->crow_size); 521 s->image_buf = p->data[0]; 522 s->image_linesize = p->linesize[0]; 523 /* copy the palette if needed */ 524 if (s->color_type == PNG_COLOR_TYPE_PALETTE) 525 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t)); 526 /* empty row is used if differencing to the first row */ 527 s->last_row = av_mallocz(s->row_size); 528 if (!s->last_row) 529 goto fail; 530 if (s->interlace_type || 531 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 532 s->tmp_row = av_malloc(s->row_size); 533 if (!s->tmp_row) 534 goto fail; 535 } 536 /* compressed row */ 537 crow_buf_base = av_malloc(s->row_size + 16); 538 if (!crow_buf_base) 539 goto fail; 540 541 /* we want crow_buf+1 to be 16-byte aligned */ 542 s->crow_buf = crow_buf_base + 15; 543 s->zstream.avail_out = s->crow_size; 544 s->zstream.next_out = s->crow_buf; 545 } 546 s->state |= PNG_IDAT; 547 if (png_decode_idat(s, length) < 0) 548 goto fail; 549 /* skip crc */ 550 crc = bytestream_get_be32(&s->bytestream); 551 break; 552 case MKTAG('P', 'L', 'T', 'E'): 553 { 554 int n, i, r, g, b; 555 556 if ((length % 3) != 0 || length > 256 * 3) 557 goto skip_tag; 558 /* read the palette */ 559 n = length / 3; 560 for(i=0;i<n;i++) { 561 r = *s->bytestream++; 562 g = *s->bytestream++; 563 b = *s->bytestream++; 564 s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b; 565 } 566 for(;i<256;i++) { 567 s->palette[i] = (0xff << 24); 568 } 569 s->state |= PNG_PLTE; 570 crc = bytestream_get_be32(&s->bytestream); 571 } 572 break; 573 case MKTAG('t', 'R', 'N', 'S'): 574 { 575 int v, i; 576 577 /* read the transparency. XXX: Only palette mode supported */ 578 if (s->color_type != PNG_COLOR_TYPE_PALETTE || 579 length > 256 || 580 !(s->state & PNG_PLTE)) 581 goto skip_tag; 582 for(i=0;i<length;i++) { 583 v = *s->bytestream++; 584 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24); 585 } 586 crc = bytestream_get_be32(&s->bytestream); 587 } 588 break; 589 case MKTAG('I', 'E', 'N', 'D'): 590 if (!(s->state & PNG_ALLIMAGE)) 591 goto fail; 592 crc = bytestream_get_be32(&s->bytestream); 593 goto exit_loop; 594 default: 595 /* skip tag */ 596 skip_tag: 597 s->bytestream += length + 4; 598 break; 599 } 600 } 601 exit_loop: 602 /* handle p-frames only if a predecessor frame is available */ 603 if(s->last_picture->data[0] != NULL) { 604 if(!(avpkt->flags & AV_PKT_FLAG_KEY)) { 605 int i, j; 606 uint8_t *pd = s->current_picture->data[0]; 607 uint8_t *pd_last = s->last_picture->data[0]; 608 609 for(j=0; j < s->height; j++) { 610 for(i=0; i < s->width * s->bpp; i++) { 611 pd[i] += pd_last[i]; 612 } 613 pd += s->image_linesize; 614 pd_last += s->image_linesize; 615 } 616 } 617 } 618 619 *picture= *s->current_picture; 620 *data_size = sizeof(AVFrame); 621 622 ret = s->bytestream - s->bytestream_start; 623 the_end: 624 inflateEnd(&s->zstream); 625 av_free(crow_buf_base); 626 s->crow_buf = NULL; 627 av_freep(&s->last_row); 628 av_freep(&s->tmp_row); 629 return ret; 630 fail: 631 ret = -1; 632 goto the_end; 633} 634 635static av_cold int png_dec_init(AVCodecContext *avctx){ 636 PNGDecContext *s = avctx->priv_data; 637 638 s->current_picture = &s->picture1; 639 s->last_picture = &s->picture2; 640 avcodec_get_frame_defaults(&s->picture1); 641 avcodec_get_frame_defaults(&s->picture2); 642 dsputil_init(&s->dsp, avctx); 643 644 return 0; 645} 646 647static av_cold int png_dec_end(AVCodecContext *avctx) 648{ 649 PNGDecContext *s = avctx->priv_data; 650 651 if (s->picture1.data[0]) 652 avctx->release_buffer(avctx, &s->picture1); 653 if (s->picture2.data[0]) 654 avctx->release_buffer(avctx, &s->picture2); 655 656 return 0; 657} 658 659AVCodec png_decoder = { 660 "png", 661 AVMEDIA_TYPE_VIDEO, 662 CODEC_ID_PNG, 663 sizeof(PNGDecContext), 664 png_dec_init, 665 NULL, 666 png_dec_end, 667 decode_frame, 668 CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/, 669 NULL, 670 .long_name = NULL_IF_CONFIG_SMALL("PNG image"), 671}; 672