DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (5b81998bb7ab)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 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 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
diff -up8 png.h png.h
--- png.h	2012-06-14 07:28:00 -0400
+++ png.h	2012-07-07 10:21:31 -0400
@@ -423,24 +423,18 @@
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
 #define PNG_LIBPNG_VER 10511 /* 1.5.11 */
 
-/* Library configuration: these options cannot be changed after
- * the library has been built.
- */
-#ifndef PNGLCONF_H
-    /* If pnglibconf.h is missing, you can
-     * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
-     */
-#   include "pnglibconf.h"
+#ifndef MOZPNGCONF_H
+#   include "mozpngconf.h"
 #endif
 
 #ifndef PNG_VERSION_INFO_ONLY
 #  ifndef PNG_BUILDING_SYMBOL_TABLE
   /*
    *   Standard header files (not needed for the version info or while
    *   building symbol table -- see scripts/pnglibconf.dfa)
    */
@@ -540,16 +534,27 @@ extern "C" {
  * Otherwise the calls are mapped to png_error.
  */
 
 /* Section 2: type definitions, including structures and compile time
  * constants.
  * See pngconf.h for base types that vary by machine/system
  */
 
+#ifdef PNG_APNG_SUPPORTED
+/* dispose_op flags from inside fcTL */
+#define PNG_DISPOSE_OP_NONE        0x00
+#define PNG_DISPOSE_OP_BACKGROUND  0x01
+#define PNG_DISPOSE_OP_PREVIOUS    0x02
+
+/* blend_op flags from inside fcTL */
+#define PNG_BLEND_OP_SOURCE        0x00
+#define PNG_BLEND_OP_OVER          0x01
+#endif /* PNG_APNG_SUPPORTED */
+
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
 typedef char* png_libpng_version_1_5_11;
 
 /* Three color definitions.  The order of the red, green, and blue, (and the
  * exact size) is not important, although the size of the fields need to
  * be png_byte or png_uint_16 (as defined below).
@@ -823,16 +828,20 @@ typedef png_info FAR * FAR * png_infopp;
 #define PNG_INFO_oFFs 0x0100
 #define PNG_INFO_tIME 0x0200
 #define PNG_INFO_pCAL 0x0400
 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
 #define PNG_INFO_IDAT 0x8000   /* ESR, 1.0.6 */
+#ifdef PNG_APNG_SUPPORTED
+#define PNG_INFO_acTL 0x10000
+#define PNG_INFO_fcTL 0x20000
+#endif
 
 /* This is used for the transformation routines, as some of them
  * change these values for the row.  It also should enable using
  * the routines for other purposes.
  */
 typedef struct png_row_info_struct
 {
    png_uint_32 width;    /* width of row */
@@ -868,16 +877,20 @@ typedef PNG_CALLBACK(void, *png_flush_pt
 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
     int));
 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
     int));
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
+#ifdef PNG_APNG_SUPPORTED
+typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
+    png_uint_32));
+#endif
 
 /* The following callback receives png_uint_32 row_number, int pass for the
  * png_bytep data of the row.  When transforming an interlaced image the
  * row number is the row number within the sub-image of the interlace pass, so
  * the value will increase to the height of the sub-image (not the full image)
  * then reset to 0 for the next pass.
  *
  * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
@@ -2644,26 +2657,99 @@ PNG_EXPORT(207, void, png_save_uint_16, 
 #endif
 
 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
 PNG_EXPORT(234, void, png_set_check_for_invalid_index, (png_structp png_ptr,
     int allowed));
 #endif
 
+#ifdef PNG_APNG_SUPPORTED
+PNG_EXPORT(235, png_uint_32, png_get_acTL, (png_structp png_ptr,
+   png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
+
+PNG_EXPORT(236, png_uint_32, png_set_acTL, (png_structp png_ptr,
+   png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
+
+PNG_EXPORT(237, png_uint_32, png_get_num_frames, (png_structp png_ptr,
+   png_infop info_ptr));
+
+PNG_EXPORT(238, png_uint_32, png_get_num_plays, (png_structp png_ptr,
+   png_infop info_ptr));
+
+PNG_EXPORT(239, png_uint_32, png_get_next_frame_fcTL,
+   (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
+   png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
+   png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
+   png_byte *blend_op));
+
+PNG_EXPORT(240, png_uint_32, png_set_next_frame_fcTL,
+   (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
+   png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
+   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
+   png_byte blend_op));
+
+PNG_EXPORT(241, png_uint_32, png_get_next_frame_width,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(242, png_uint_32, png_get_next_frame_height,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(243, png_uint_32, png_get_next_frame_x_offset,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(244, png_uint_32, png_get_next_frame_y_offset,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(245, png_uint_16, png_get_next_frame_delay_num,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(246, png_uint_16, png_get_next_frame_delay_den,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(247, png_byte, png_get_next_frame_dispose_op,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(248, png_byte, png_get_next_frame_blend_op,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(249, png_byte, png_get_first_frame_is_hidden,
+   (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(250, png_uint_32, png_set_first_frame_is_hidden,
+   (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
+
+#ifdef PNG_READ_APNG_SUPPORTED
+PNG_EXPORT(251, void, png_read_frame_head, (png_structp png_ptr,
+   png_infop info_ptr));
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXPORT(252, void, png_set_progressive_frame_fn, (png_structp png_ptr,
+   png_progressive_frame_ptr frame_info_fn,
+   png_progressive_frame_ptr frame_end_fn));
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PNG_READ_APNG_SUPPORTED */
+
+#ifdef PNG_WRITE_APNG_SUPPORTED
+PNG_EXPORT(253, void, png_write_frame_head, (png_structp png_ptr,
+   png_infop info_ptr, png_bytepp row_pointers,
+   png_uint_32 width, png_uint_32 height,
+   png_uint_32 x_offset, png_uint_32 y_offset,
+   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
+   png_byte blend_op));
+
+PNG_EXPORT(254, void, png_write_frame_tail, (png_structp png_ptr,
+   png_infop info_ptr));
+#endif /* PNG_WRITE_APNG_SUPPORTED */
+#endif /* PNG_APNG_SUPPORTED */
+
 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
  * defs
  */
 
 /* The last ordinal number (this is the *last* one already used; the next
  * one to use is one more than this.)  Maintainer, remember to add an entry to
  * scripts/symbols.def as well.
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
+#ifdef PNG_APNG_SUPPORTED
+  PNG_EXPORT_LAST_ORDINAL(254);
+#else
   PNG_EXPORT_LAST_ORDINAL(234);
+#endif /* PNG_APNG_SUPPORTED */
 #endif
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* PNG_VERSION_INFO_ONLY */
 /* Do not put anything past this line */
diff -up8 pngget.c pngget.c
--- pngget.c	2012-06-14 07:28:00 -0400
+++ pngget.c	2012-04-24 20:51:09 -0400
@@ -1116,9 +1116,171 @@ png_get_io_chunk_type (png_const_structp
 png_const_bytep PNGAPI
 png_get_io_chunk_name (png_structp png_ptr)
 {
    PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
    return png_ptr->io_chunk_string;
 }
 #endif /* ?PNG_IO_STATE_SUPPORTED */
 
+#ifdef PNG_APNG_SUPPORTED
+png_uint_32 PNGAPI
+png_get_acTL(png_structp png_ptr, png_infop info_ptr,
+             png_uint_32 *num_frames, png_uint_32 *num_plays)
+{
+    png_debug1(1, "in %s retrieval function", "acTL");
+
+    if (png_ptr != NULL && info_ptr != NULL &&
+        (info_ptr->valid & PNG_INFO_acTL) &&
+        num_frames != NULL && num_plays != NULL)
+    {
+        *num_frames = info_ptr->num_frames;
+        *num_plays = info_ptr->num_plays;
+        return (1);
+    }
+
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_num_frames(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_num_frames()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->num_frames);
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_num_plays(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_num_plays()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->num_plays);
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
+             png_uint_32 *width, png_uint_32 *height,
+             png_uint_32 *x_offset, png_uint_32 *y_offset,
+             png_uint_16 *delay_num, png_uint_16 *delay_den,
+             png_byte *dispose_op, png_byte *blend_op)
+{
+    png_debug1(1, "in %s retrieval function", "fcTL");
+
+    if (png_ptr != NULL && info_ptr != NULL &&
+        (info_ptr->valid & PNG_INFO_fcTL) &&
+        width != NULL && height != NULL &&
+        x_offset != NULL && y_offset != NULL &&
+        delay_num != NULL && delay_den != NULL &&
+        dispose_op != NULL && blend_op != NULL)
+    {
+        *width = info_ptr->next_frame_width;
+        *height = info_ptr->next_frame_height;
+        *x_offset = info_ptr->next_frame_x_offset;
+        *y_offset = info_ptr->next_frame_y_offset;
+        *delay_num = info_ptr->next_frame_delay_num;
+        *delay_den = info_ptr->next_frame_delay_den;
+        *dispose_op = info_ptr->next_frame_dispose_op;
+        *blend_op = info_ptr->next_frame_blend_op;
+        return (1);
+    }
+
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_next_frame_width(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_width()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_width);
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_next_frame_height(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_height()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_height);
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_next_frame_x_offset(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_x_offset()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_x_offset);
+    return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_next_frame_y_offset(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_y_offset()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_y_offset);
+    return (0);
+}
+
+png_uint_16 PNGAPI
+png_get_next_frame_delay_num(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_delay_num()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_delay_num);
+    return (0);
+}
+
+png_uint_16 PNGAPI
+png_get_next_frame_delay_den(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_delay_den()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_delay_den);
+    return (0);
+}
+
+png_byte PNGAPI
+png_get_next_frame_dispose_op(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_dispose_op()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_dispose_op);
+    return (0);
+}
+
+png_byte PNGAPI
+png_get_next_frame_blend_op(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_get_next_frame_blend_op()");
+
+    if (png_ptr != NULL && info_ptr != NULL)
+        return (info_ptr->next_frame_blend_op);
+    return (0);
+}
+
+png_byte PNGAPI
+png_get_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_first_frame_is_hidden()");
+
+    if (png_ptr != NULL)
+       return (png_byte)(png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN);
+
+    PNG_UNUSED(info_ptr)
+
+    return 0;
+}
+#endif /* PNG_APNG_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff -up8 pnginfo.h pnginfo.h
--- pnginfo.h	2012-06-14 07:28:00 -0400
+++ pnginfo.h	2012-03-03 22:17:56 -0500
@@ -260,10 +260,23 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 
 #ifdef PNG_INFO_IMAGE_SUPPORTED
    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
       non-zero */
    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
    png_bytepp row_pointers;        /* the image bits */
 #endif
 
+#ifdef PNG_APNG_SUPPORTED
+   png_uint_32 num_frames; /* including default image */
+   png_uint_32 num_plays;
+   png_uint_32 next_frame_width;
+   png_uint_32 next_frame_height;
+   png_uint_32 next_frame_x_offset;
+   png_uint_32 next_frame_y_offset;
+   png_uint_16 next_frame_delay_num;
+   png_uint_16 next_frame_delay_den;
+   png_byte next_frame_dispose_op;
+   png_byte next_frame_blend_op;
+#endif
+
 };
 #endif /* PNGINFO_H */
diff -up8 pngpread.c pngpread.c
--- pngpread.c	2012-06-14 07:28:00 -0400
+++ pngpread.c	2012-07-16 20:05:38 -0400
@@ -210,16 +210,119 @@ png_push_read_chunk(png_structp png_ptr,
       png_crc_read(png_ptr, chunk_tag, 4);
       png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
       png_check_chunk_name(png_ptr, png_ptr->chunk_name);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
    chunk_name = png_ptr->chunk_name;
 
+#ifdef PNG_READ_APNG_SUPPORTED
+   if (png_ptr->num_frames_read > 0 &&
+       png_ptr->num_frames_read < info_ptr->num_frames)
+   {
+      if (chunk_name == png_IDAT)
+      {
+         /* Discard trailing IDATs for the first frame */
+         if (png_ptr->mode & PNG_HAVE_fcTL || png_ptr->num_frames_read > 1)
+            png_error(png_ptr, "out of place IDAT");
+
+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+         {
+            png_push_save_buffer(png_ptr);
+            return;
+         }
+
+         png_push_crc_skip(png_ptr, png_ptr->push_length);
+         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+         return;
+      }
+      else if (chunk_name == png_fdAT)
+      {
+         if (png_ptr->buffer_size < 4)
+         {
+            png_push_save_buffer(png_ptr);
+            return;
+         }
+
+         png_ensure_sequence_number(png_ptr, 4);
+
+         if (!(png_ptr->mode & PNG_HAVE_fcTL))
+         {
+            /* Discard trailing fdATs for frames other than the first */
+            if (png_ptr->num_frames_read < 2)
+               png_error(png_ptr, "out of place fdAT");
+
+            if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+            {
+               png_push_save_buffer(png_ptr);
+               return;
+            }
+
+            png_push_crc_skip(png_ptr, png_ptr->push_length);
+            png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+            return;
+         }
+
+         else
+         {
+            /* frame data follows */
+            png_ptr->idat_size = png_ptr->push_length - 4;
+            png_ptr->mode |= PNG_HAVE_IDAT;
+            png_ptr->process_mode = PNG_READ_IDAT_MODE;
+
+            return;
+         }
+      }
+
+      else if (chunk_name == png_fcTL)
+      {
+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+         {
+            png_push_save_buffer(png_ptr);
+            return;
+         }
+
+         png_read_reset(png_ptr);
+         png_ptr->mode &= ~PNG_HAVE_fcTL;
+
+         png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
+
+         if (!(png_ptr->mode & PNG_HAVE_fcTL))
+            png_error(png_ptr, "missing required fcTL chunk");
+
+         png_read_reinit(png_ptr, info_ptr);
+         png_progressive_read_reset(png_ptr);
+
+         if (png_ptr->frame_info_fn != NULL)
+            (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read);
+
+         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+
+         return;
+      }
+
+      else
+      {
+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+         {
+            png_push_save_buffer(png_ptr);
+            return;
+         }
+         png_warning(png_ptr, "Skipped (ignored) a chunk "
+                              "between APNG chunks");
+         png_push_crc_skip(png_ptr, png_ptr->push_length);
+         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+         return;
+      }
+
+      return;
+   }
+#endif /* PNG_READ_APNG_SUPPORTED */
+
    if (chunk_name == png_IDAT)
    {
       /* This is here above the if/else case statement below because if the
        * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
        * completely skipped.
        *
        * TODO: there must be a better way of doing this.
        */
@@ -313,16 +416,20 @@ png_push_read_chunk(png_structp png_ptr,
          if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
             if (png_ptr->push_length == 0)
                return;
 
          if (png_ptr->mode & PNG_AFTER_IDAT)
             png_benign_error(png_ptr, "Too many IDATs found");
       }
 
+#ifdef PNG_READ_APNG_SUPPORTED
+      png_have_info(png_ptr, info_ptr);
+#endif
+
       png_ptr->idat_size = png_ptr->push_length;
       png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
       png_push_have_info(png_ptr, info_ptr);
       png_ptr->zstream.avail_out =
           (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
           png_ptr->iwidth) + 1;
       png_ptr->zstream.next_out = png_ptr->row_buf;
@@ -546,16 +653,38 @@ png_push_read_chunk(png_structp png_ptr,
          return;
       }
 
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
 #endif
 
+#ifdef PNG_READ_APNG_SUPPORTED
+   else if (chunk_name == png_acTL)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+   else if (chunk_name == png_fcTL)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif /* PNG_READ_APNG_SUPPORTED */
+
    else
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
          png_push_save_buffer(png_ptr);
          return;
       }
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
@@ -753,40 +882,91 @@ void /* PRIVATE */
 png_push_read_IDAT(png_structp png_ptr)
 {
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
       png_byte chunk_tag[4];
 
       /* TODO: this code can be commoned up with the same code in push_read */
+#ifdef PNG_READ_APNG_SUPPORTED
+      if (png_ptr->buffer_size < 12)
+#else
       if (png_ptr->buffer_size < 8)
+#endif
       {
          png_push_save_buffer(png_ptr);
          return;
       }
 
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, chunk_tag, 4);
       png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
 
+#ifdef PNG_READ_APNG_SUPPORTED
+      if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0)
+      {
+          if (png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)
+          {
+              png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+              if (png_ptr->frame_end_fn != NULL)
+                 (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
+              png_ptr->num_frames_read++;
+              return;
+          }
+          else
+          {
+              if (png_ptr->chunk_name == png_IEND)
+                  png_error(png_ptr, "Not enough image data");
+              if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+              {
+                 png_push_save_buffer(png_ptr);
+                 return;
+              }
+              png_warning(png_ptr, "Skipping (ignoring) a chunk between "
+                                   "APNG chunks");
+              png_crc_finish(png_ptr, png_ptr->push_length);
+              png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+              return;
+          }
+      }
+      else
+#endif
+#ifdef PNG_READ_APNG_SUPPORTED
+      if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0)
+#else
       if (png_ptr->chunk_name != png_IDAT)
+#endif
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
 
          if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
             png_error(png_ptr, "Not enough compressed data");
 
+#ifdef PNG_READ_APNG_SUPPORTED
+         if (png_ptr->frame_end_fn != NULL)
+            (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
+         png_ptr->num_frames_read++;
+#endif
+
          return;
       }
 
       png_ptr->idat_size = png_ptr->push_length;
+
+#ifdef PNG_READ_APNG_SUPPORTED
+      if (png_ptr->num_frames_read > 0)
+      {
+         png_ensure_sequence_number(png_ptr, 4);
+         png_ptr->idat_size -= 4;
+      }
+#endif
    }
 
    if (png_ptr->idat_size && png_ptr->save_buffer_size)
    {
       png_size_t save_size = png_ptr->save_buffer_size;
       png_uint_32 idat_size = png_ptr->idat_size;
 
       /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
@@ -854,16 +1034,25 @@ png_push_read_IDAT(png_structp png_ptr)
 void /* PRIVATE */
 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
    png_size_t buffer_length)
 {
    /* The caller checks for a non-zero buffer length. */
    if (!(buffer_length > 0) || buffer == NULL)
       png_error(png_ptr, "No IDAT data (internal error)");
 
+#ifdef PNG_READ_APNG_SUPPORTED
+   /* If the app is not APNG-aware, decode only the first frame */
+   if (!(png_ptr->apng_flags & PNG_APNG_APP) && png_ptr->num_frames_read > 0)
+   {
+     png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+     return;
+   }
+#endif
+
    /* This routine must process all the data it has been given
     * before returning, calling the row callback as required to
     * handle the uncompressed results.
     */
    png_ptr->zstream.next_in = buffer;
    png_ptr->zstream.avail_in = (uInt)buffer_length;
 
    /* Keep going until the decompressed data is all processed
@@ -1299,16 +1488,28 @@ png_set_progressive_read_fn(png_structp 
 
    png_ptr->info_fn = info_fn;
    png_ptr->row_fn = row_fn;
    png_ptr->end_fn = end_fn;
 
    png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
 }
 
+#ifdef PNG_READ_APNG_SUPPORTED
+void PNGAPI
+png_set_progressive_frame_fn(png_structp png_ptr,
+   png_progressive_frame_ptr frame_info_fn,
+   png_progressive_frame_ptr frame_end_fn)
+{
+   png_ptr->frame_info_fn = frame_info_fn;
+   png_ptr->frame_end_fn = frame_end_fn;
+   png_ptr->apng_flags |= PNG_APNG_APP;
+}
+#endif
+
 png_voidp PNGAPI
 png_get_progressive_ptr(png_const_structp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);
 
    return png_ptr->io_ptr;
 }
diff -up8 pngpriv.h pngpriv.h
--- pngpriv.h	2012-06-14 07:28:00 -0400
+++ pngpriv.h	2012-07-16 20:05:38 -0400
@@ -462,16 +462,20 @@ typedef PNG_CONST png_uint_16p FAR * png
 #define PNG_HAVE_sRGB               0x80
 #define PNG_HAVE_CHUNK_HEADER      0x100
 #define PNG_WROTE_tIME             0x200
 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
 #define PNG_BACKGROUND_IS_GRAY     0x800
 #define PNG_HAVE_PNG_SIGNATURE    0x1000
 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
 #define PNG_HAVE_iCCP             0x4000
+#ifdef PNG_APNG_SUPPORTED
+#define PNG_HAVE_acTL             0x8000
+#define PNG_HAVE_fcTL            0x10000
+#endif
 
 /* Flags for the transformations the PNG library does on the image data */
 #define PNG_BGR                 0x0001
 #define PNG_INTERLACE           0x0002
 #define PNG_PACK                0x0004
 #define PNG_SHIFT               0x0008
 #define PNG_SWAP_BYTES          0x0010
 #define PNG_INVERT_MONO         0x0020
@@ -657,16 +661,26 @@ PNG_EXTERN png_fixed_point png_fixed PNG
 #define png_sPLT PNG_CHUNK(115,  80,  76,  84)
 #define png_sRGB PNG_CHUNK(115,  82,  71,  66)
 #define png_sTER PNG_CHUNK(115,  84,  69,  82)
 #define png_tEXt PNG_CHUNK(116,  69,  88, 116)
 #define png_tIME PNG_CHUNK(116,  73,  77,  69)
 #define png_tRNS PNG_CHUNK(116,  82,  78,  83)
 #define png_zTXt PNG_CHUNK(122,  84,  88, 116)
 
+#ifdef PNG_APNG_SUPPORTED
+#define png_acTL PNG_CHUNK( 97,  99,  84,  76)
+#define png_fcTL PNG_CHUNK(102,  99,  84,  76)
+#define png_fdAT PNG_CHUNK(102, 100,  65,  84)
+
+/* For png_struct.apng_flags: */
+#define PNG_FIRST_FRAME_HIDDEN       0x0001
+#define PNG_APNG_APP                 0x0002
+#endif
+
 /* The following will work on (signed char*) strings, whereas the get_uint_32
  * macro will fail on top-bit-set values because of the sign extension.
  */
 #define PNG_CHUNK_FROM_STRING(s)\
    PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
 
 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
  * signed and the argument is a (char[])  This macro will fail miserably on
@@ -1338,16 +1352,55 @@ PNG_EXTERN void png_push_read_iTXt PNGAR
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
     png_bytep row));
 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
 
+#ifdef PNG_APNG_SUPPORTED
+PNG_EXTERN void png_ensure_fcTL_is_valid PNGARG((png_structp png_ptr,
+   png_uint_32 width, png_uint_32 height,
+   png_uint_32 x_offset, png_uint_32 y_offset,
+   png_uint_16 delay_num, png_uint_16 delay_den,
+   png_byte dispose_op, png_byte blend_op));
+
+#ifdef PNG_READ_APNG_SUPPORTED
+PNG_EXTERN void png_handle_acTL PNGARG((png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 length));
+PNG_EXTERN void png_handle_fcTL PNGARG((png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 length));
+PNG_EXTERN void png_handle_fdAT PNGARG((png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 length));
+PNG_EXTERN void png_have_info PNGARG((png_structp png_ptr, png_infop info_ptr));
+PNG_EXTERN void png_ensure_sequence_number PNGARG((png_structp png_ptr,
+   png_uint_32 length));
+PNG_EXTERN void png_read_reset PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_read_reinit PNGARG((png_structp png_ptr,
+   png_infop info_ptr));
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void png_progressive_read_reset PNGARG((png_structp png_ptr));
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PNG_READ_APNG_SUPPORTED */
+
+#ifdef PNG_WRITE_APNG_SUPPORTED
+PNG_EXTERN void png_write_acTL PNGARG((png_structp png_ptr,
+   png_uint_32 num_frames, png_uint_32 num_plays));
+PNG_EXTERN void png_write_fcTL PNGARG((png_structp png_ptr,
+   png_uint_32 width, png_uint_32 height,
+   png_uint_32 x_offset, png_uint_32 y_offset,
+   png_uint_16 delay_num, png_uint_16 delay_den,
+   png_byte dispose_op, png_byte blend_op));
+PNG_EXTERN void png_write_reset PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_write_reinit PNGARG((png_structp png_ptr,
+   png_infop info_ptr, png_uint_32 width, png_uint_32 height));
+#endif /* PNG_WRITE_APNG_SUPPORTED */
+#endif /* PNG_APNG_SUPPORTED */
+
 /* Added at libpng version 1.4.0 */
 #ifdef PNG_CHECK_cHRM_SUPPORTED
 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
     png_fixed_point int_white_x, png_fixed_point int_white_y,
     png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
     int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
     png_fixed_point int_blue_y));
 #endif
diff -up8 pngread.c pngread.c
--- pngread.c	2012-06-14 07:28:00 -0400
+++ pngread.c	2012-07-16 20:05:38 -0400
@@ -235,16 +235,19 @@ png_read_info(png_structp png_ptr, png_i
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
 
          else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
              !(png_ptr->mode & PNG_HAVE_PLTE))
             png_error(png_ptr, "Missing PLTE before IDAT");
 
+#ifdef PNG_READ_APNG_SUPPORTED
+         png_have_info(png_ptr, info_ptr);
+#endif
          png_ptr->idat_size = length;
          png_ptr->mode |= PNG_HAVE_IDAT;
          break;
       }
 
 #ifdef PNG_READ_bKGD_SUPPORTED
       else if (chunk_name == png_bKGD)
          png_handle_bKGD(png_ptr, info_ptr, length);
@@ -325,22 +328,100 @@ png_read_info(png_structp png_ptr, png_i
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iTXt_SUPPORTED
       else if (chunk_name == png_iTXt)
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
 
+#ifdef PNG_READ_APNG_SUPPORTED
+      else if (chunk_name == png_acTL)
+         png_handle_acTL(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_fcTL)
+         png_handle_fcTL(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_fdAT)
+         png_handle_fdAT(png_ptr, info_ptr, length);
+#endif
+
       else
          png_handle_unknown(png_ptr, info_ptr, length);
    }
 }
 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 
+#ifdef PNG_READ_APNG_SUPPORTED
+void PNGAPI
+png_read_frame_head(png_structp png_ptr, png_infop info_ptr)
+{
+    png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */
+
+    png_debug(0, "Reading frame head");
+
+    if (!(png_ptr->mode & PNG_HAVE_acTL))
+        png_error(png_ptr, "attempt to png_read_frame_head() but "
+                           "no acTL present");
+
+    /* do nothing for the main IDAT */
+    if (png_ptr->num_frames_read == 0)
+        return;
+
+    png_crc_finish(png_ptr, 0); /* CRC from last IDAT or fdAT chunk */
+
+    png_read_reset(png_ptr);
+    png_ptr->mode &= ~PNG_HAVE_fcTL;
+
+    have_chunk_after_DAT = 0;
+    for (;;)
+    {
+        png_uint_32 length = png_read_chunk_header(png_ptr);
+
+        if (png_ptr->chunk_name == png_IDAT)
+        {
+            /* discard trailing IDATs for the first frame */
+            if (have_chunk_after_DAT || png_ptr->num_frames_read > 1)
+                png_error(png_ptr, "png_read_frame_head(): out of place IDAT");
+            png_crc_finish(png_ptr, length);
+        }
+
+        else if (png_ptr->chunk_name == png_fcTL)
+        {
+            png_handle_fcTL(png_ptr, info_ptr, length);
+            have_chunk_after_DAT = 1;
+        }
+
+        else if (png_ptr->chunk_name == png_fdAT)
+        {
+            png_ensure_sequence_number(png_ptr, length);
+
+            /* discard trailing fdATs for frames other than the first */
+            if (!have_chunk_after_DAT && png_ptr->num_frames_read > 1)
+                png_crc_finish(png_ptr, length - 4);
+            else if(png_ptr->mode & PNG_HAVE_fcTL)
+            {
+                png_ptr->idat_size = length - 4;
+                png_ptr->mode |= PNG_HAVE_IDAT;
+
+                break;
+            }
+            else
+                png_error(png_ptr, "png_read_frame_head(): out of place fdAT");
+        }
+        else
+        {
+            png_warning(png_ptr, "Skipped (ignored) a chunk "
+                                 "between APNG chunks");
+            png_crc_finish(png_ptr, length);
+        }
+    }
+}
+#endif /* PNG_READ_APNG_SUPPORTED */
+
 /* Optional call to update the users info_ptr structure */
 void PNGAPI
 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 {
    png_debug(1, "in png_read_update_info");
 
    if (png_ptr == NULL)
       return;
@@ -532,24 +613,57 @@ png_read_row(png_structp png_ptr, png_by
    png_ptr->zstream.avail_out =
        (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
        png_ptr->iwidth) + 1);
 
    do
    {
       if (!(png_ptr->zstream.avail_in))
       {
+#ifdef PNG_READ_APNG_SUPPORTED
+         png_uint_32 bytes_to_skip = 0;
+
+         while (!png_ptr->idat_size || bytes_to_skip != 0)
+         {
+            png_crc_finish(png_ptr, bytes_to_skip);
+            bytes_to_skip = 0;
+
+            png_ptr->idat_size = png_read_chunk_header(png_ptr);
+            if (png_ptr->num_frames_read == 0)
+            {
+               if (png_ptr->chunk_name != png_IDAT)
+                  png_error(png_ptr, "Not enough image data");
+            }
+            else
+            {
+               if (png_ptr->chunk_name == png_IEND)
+                  png_error(png_ptr, "Not enough image data");
+               if (png_ptr->chunk_name != png_fdAT)
+               {
+                  png_warning(png_ptr, "Skipped (ignored) a chunk "
+                                       "between APNG chunks");
+                  bytes_to_skip = png_ptr->idat_size;
+                  continue;
+               }
+
+               png_ensure_sequence_number(png_ptr, png_ptr->idat_size);
+
+               png_ptr->idat_size -= 4;
+            }
+         }
+#else
          while (!png_ptr->idat_size)
          {
             png_crc_finish(png_ptr, 0);
 
             png_ptr->idat_size = png_read_chunk_header(png_ptr);
             if (png_ptr->chunk_name != png_IDAT)
                png_error(png_ptr, "Not enough image data");
          }
+#endif
          png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
          png_ptr->zstream.next_in = png_ptr->zbuf;
          if (png_ptr->zbuf_size > png_ptr->idat_size)
             png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
          png_crc_read(png_ptr, png_ptr->zbuf,
              (png_size_t)png_ptr->zstream.avail_in);
          png_ptr->idat_size -= png_ptr->zstream.avail_in;
       }
@@ -558,16 +672,19 @@ png_read_row(png_structp png_ptr, png_by
 
       if (ret == Z_STREAM_END)
       {
          if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
             png_ptr->idat_size)
             png_benign_error(png_ptr, "Extra compressed data");
          png_ptr->mode |= PNG_AFTER_IDAT;
          png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+#ifdef PNG_READ_APNG_SUPPORTED
+         png_ptr->num_frames_read++;
+#endif
          break;
       }
 
       if (ret != Z_OK)
          png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
              "Decompression error");
 
    } while (png_ptr->zstream.avail_out);
diff -up8 pngrutil.c pngrutil.c
--- pngrutil.c	2012-06-14 07:28:00 -0400
+++ pngrutil.c	2012-04-24 20:51:09 -0400
@@ -542,16 +542,21 @@ png_handle_IHDR(png_structp png_ptr, png
    width = png_get_uint_31(png_ptr, buf);
    height = png_get_uint_31(png_ptr, buf + 4);
    bit_depth = buf[8];
    color_type = buf[9];
    compression_type = buf[10];
    filter_type = buf[11];
    interlace_type = buf[12];
 
+#ifdef PNG_READ_APNG_SUPPORTED
+   png_ptr->first_frame_width = width;
+   png_ptr->first_frame_height = height;
+#endif
+
    /* Set internal variables */
    png_ptr->width = width;
    png_ptr->height = height;
    png_ptr->bit_depth = (png_byte)bit_depth;
    png_ptr->interlaced = (png_byte)interlace_type;
    png_ptr->color_type = (png_byte)color_type;
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    png_ptr->filter_type = (png_byte)filter_type;
@@ -2609,16 +2614,189 @@ png_handle_iTXt(png_structp png_ptr, png
    png_free(png_ptr, png_ptr->chunkdata);
    png_ptr->chunkdata = NULL;
 
    if (ret)
       png_error(png_ptr, "Insufficient memory to store iTXt chunk");
 }
 #endif
 
+#ifdef PNG_READ_APNG_SUPPORTED
+void /* PRIVATE */
+png_handle_acTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+    png_byte data[8];
+    png_uint_32 num_frames;
+    png_uint_32 num_plays;
+    png_uint_32 didSet;
+
+    png_debug(1, "in png_handle_acTL");
+
+    if (!(png_ptr->mode & PNG_HAVE_IHDR))
+    {
+        png_error(png_ptr, "Missing IHDR before acTL");
+    }
+    else if (png_ptr->mode & PNG_HAVE_IDAT)
+    {
+        png_warning(png_ptr, "Invalid acTL after IDAT skipped");
+        png_crc_finish(png_ptr, length);
+        return;
+    }
+    else if (png_ptr->mode & PNG_HAVE_acTL)
+    {
+        png_warning(png_ptr, "Duplicate acTL skipped");
+        png_crc_finish(png_ptr, length);
+        return;
+    }
+    else if (length != 8)
+    {
+        png_warning(png_ptr, "acTL with invalid length skipped");
+        png_crc_finish(png_ptr, length);
+        return;
+    }
+
+    png_crc_read(png_ptr, data, 8);
+    png_crc_finish(png_ptr, 0);
+
+    num_frames = png_get_uint_31(png_ptr, data);
+    num_plays = png_get_uint_31(png_ptr, data + 4);
+
+    /* the set function will do error checking on num_frames */
+    didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays);
+    if(didSet)
+        png_ptr->mode |= PNG_HAVE_acTL;
+}
+
+void /* PRIVATE */
+png_handle_fcTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+    png_byte data[22];
+    png_uint_32 width;
+    png_uint_32 height;
+    png_uint_32 x_offset;
+    png_uint_32 y_offset;
+    png_uint_16 delay_num;
+    png_uint_16 delay_den;
+    png_byte dispose_op;
+    png_byte blend_op;
+
+    png_debug(1, "in png_handle_fcTL");
+
+    png_ensure_sequence_number(png_ptr, length);
+
+    if (!(png_ptr->mode & PNG_HAVE_IHDR))
+    {
+        png_error(png_ptr, "Missing IHDR before fcTL");
+    }
+    else if (png_ptr->mode & PNG_HAVE_IDAT)
+    {
+        /* for any frames other then the first this message may be misleading,
+        * but correct. PNG_HAVE_IDAT is unset before the frame head is read
+        * i can't think of a better message */
+        png_warning(png_ptr, "Invalid fcTL after IDAT skipped");
+        png_crc_finish(png_ptr, length-4);
+        return;
+    }
+    else if (png_ptr->mode & PNG_HAVE_fcTL)
+    {
+        png_warning(png_ptr, "Duplicate fcTL within one frame skipped");
+        png_crc_finish(png_ptr, length-4);
+        return;
+    }
+    else if (length != 26)
+    {
+        png_warning(png_ptr, "fcTL with invalid length skipped");
+        png_crc_finish(png_ptr, length-4);
+        return;
+    }
+
+    png_crc_read(png_ptr, data, 22);
+    png_crc_finish(png_ptr, 0);
+
+    width = png_get_uint_31(png_ptr, data);
+    height = png_get_uint_31(png_ptr, data + 4);
+    x_offset = png_get_uint_31(png_ptr, data + 8);
+    y_offset = png_get_uint_31(png_ptr, data + 12);
+    delay_num = png_get_uint_16(data + 16);
+    delay_den = png_get_uint_16(data + 18);
+    dispose_op = data[20];
+    blend_op = data[21];
+
+    if (png_ptr->num_frames_read == 0 && (x_offset != 0 || y_offset != 0))
+    {
+        png_warning(png_ptr, "fcTL for the first frame must have zero offset");
+        return;
+    }
+
+    if (info_ptr != NULL)
+    {
+        if (png_ptr->num_frames_read == 0 &&
+            (width != info_ptr->width || height != info_ptr->height))
+        {
+            png_warning(png_ptr, "size in first frame's fcTL must match "
+                               "the size in IHDR");
+            return;
+        }
+
+        /* The set function will do more error checking */
+        png_set_next_frame_fcTL(png_ptr, info_ptr, width, height,
+                                x_offset, y_offset, delay_num, delay_den,
+                                dispose_op, blend_op);
+
+        png_read_reinit(png_ptr, info_ptr);
+
+        png_ptr->mode |= PNG_HAVE_fcTL;
+    }
+}
+
+void /* PRIVATE */
+png_have_info(png_structp png_ptr, png_infop info_ptr)
+{
+    if((info_ptr->valid & PNG_INFO_acTL) && !(info_ptr->valid & PNG_INFO_fcTL))
+    {
+        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
+        info_ptr->num_frames++;
+    }
+}
+
+void /* PRIVATE */
+png_handle_fdAT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+    png_ensure_sequence_number(png_ptr, length);
+
+    /* This function is only called from png_read_end(), png_read_info(),
+    * and png_push_read_chunk() which means that:
+    * - the user doesn't want to read this frame
+    * - or this is an out-of-place fdAT
+    * in either case it is safe to ignore the chunk with a warning */
+    png_warning(png_ptr, "ignoring fdAT chunk");
+    png_crc_finish(png_ptr, length - 4);
+    PNG_UNUSED(info_ptr)
+}
+
+void /* PRIVATE */
+png_ensure_sequence_number(png_structp png_ptr, png_uint_32 length)
+{
+    png_byte data[4];
+    png_uint_32 sequence_number;
+
+    if (length < 4)
+        png_error(png_ptr, "invalid fcTL or fdAT chunk found");
+
+    png_crc_read(png_ptr, data, 4);
+    sequence_number = png_get_uint_31(png_ptr, data);
+
+    if (sequence_number != png_ptr->next_seq_num)
+        png_error(png_ptr, "fcTL or fdAT chunk with out-of-order sequence "
+                           "number found");
+
+    png_ptr->next_seq_num++;
+}
+#endif /* PNG_READ_APNG_SUPPORTED */
+
 /* This function is called when we haven't found a handler for a
  * chunk.  If there isn't a problem with the chunk itself (ie bad
  * chunk name, CRC, or a critical chunk), the chunk is silently ignored
  * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
  * case it will be saved away to be written out later.
  */
 void /* PRIVATE */
 png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
@@ -4151,9 +4329,86 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED
    png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
    png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
    png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
    png_debug1(3, "irowbytes = %lu",
        (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
 
    png_ptr->flags |= PNG_FLAG_ROW_INIT;
 }
+
+#ifdef PNG_READ_APNG_SUPPORTED
+/* This function is to be called after the main IDAT set has been read and
+ * before a new IDAT is read. It resets some parts of png_ptr
+ * to make them usable by the read functions again */
+void /* PRIVATE */
+png_read_reset(png_structp png_ptr)
+{
+    png_ptr->mode &= ~PNG_HAVE_IDAT;
+    png_ptr->mode &= ~PNG_AFTER_IDAT;
+    png_ptr->row_number = 0;
+    png_ptr->pass = 0;
+    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+void /* PRIVATE */
+png_read_reinit(png_structp png_ptr, png_infop info_ptr)
+{
+    png_ptr->width = info_ptr->next_frame_width;
+    png_ptr->height = info_ptr->next_frame_height;
+    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
+    png_ptr->info_rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,
+        png_ptr->width);
+    if (png_ptr->prev_row)
+        png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+}
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* same as png_read_reset() but for the progressive reader */
+void /* PRIVATE */
+png_progressive_read_reset(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+    const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+    /* Offset to next interlace block */
+    const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+    /* Start of interlace block in the y direction */
+    const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+    /* Offset to next interlace block in the y direction */
+    const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+    if (png_ptr->interlaced)
+    {
+        if (!(png_ptr->transformations & PNG_INTERLACE))
+            png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+                                png_pass_ystart[0]) / png_pass_yinc[0];
+        else
+            png_ptr->num_rows = png_ptr->height;
+
+        png_ptr->iwidth = (png_ptr->width +
+                           png_pass_inc[png_ptr->pass] - 1 -
+                           png_pass_start[png_ptr->pass]) /
+                           png_pass_inc[png_ptr->pass];
+    }
+    else
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+    {
+        png_ptr->num_rows = png_ptr->height;
+        png_ptr->iwidth = png_ptr->width;
+    }
+    png_ptr->flags &= ~PNG_FLAG_ZLIB_FINISHED;
+    if (inflateReset(&(png_ptr->zstream)) != Z_OK)
+        png_error(png_ptr, "inflateReset failed");
+    png_ptr->zstream.avail_in = 0;
+    png_ptr->zstream.next_in = 0;
+    png_ptr->zstream.next_out = png_ptr->row_buf;
+    png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth,
+        png_ptr->iwidth) + 1;
+}
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PNG_READ_APNG_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED */
diff -up8 pngset.c pngset.c
--- pngset.c	2012-06-14 07:28:00 -0400
+++ pngset.c	2012-07-07 10:21:31 -0400
@@ -257,16 +257,21 @@ png_set_IHDR(png_structp png_ptr, png_in
        (PNG_UINT_32_MAX >> 3)      /* 8-byte RRGGBBAA pixels */
        - 48       /* bigrowbuf hack */
        - 1        /* filter byte */
        - 7*8      /* rounding of width to multiple of 8 pixels */
        - 8)       /* extra max_pixel_depth pad */
       info_ptr->rowbytes = 0;
    else
       info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+
+#ifdef PNG_APNG_SUPPORTED
+   /* for non-animated png. this may be overwritten from an acTL chunk later */
+   info_ptr->num_frames = 1;
+#endif
 }
 
 #ifdef PNG_oFFs_SUPPORTED
 void PNGAPI
 png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
     png_int_32 offset_x, png_int_32 offset_y, int unit_type)
 {
    png_debug1(1, "in %s storage function", "oFFs");
@@ -1017,16 +1022,157 @@ png_set_sPLT(png_structp png_ptr,
 
    info_ptr->splt_palettes = np;
    info_ptr->splt_palettes_num += nentries;
    info_ptr->valid |= PNG_INFO_sPLT;
    info_ptr->free_me |= PNG_FREE_SPLT;
 }
 #endif /* PNG_sPLT_SUPPORTED */
 
+#ifdef PNG_APNG_SUPPORTED
+png_uint_32 PNGAPI
+png_set_acTL(png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 num_frames, png_uint_32 num_plays)
+{
+    png_debug1(1, "in %s storage function", "acTL");
+
+    if (png_ptr == NULL || info_ptr == NULL)
+    {
+        png_warning(png_ptr,
+                    "Call to png_set_acTL() with NULL png_ptr "
+                    "or info_ptr ignored");
+        return (0);
+    }
+    if (num_frames == 0)
+    {
+        png_warning(png_ptr,
+                    "Ignoring attempt to set acTL with num_frames zero");
+        return (0);
+    }
+    if (num_frames > PNG_UINT_31_MAX)
+    {
+        png_warning(png_ptr,
+                    "Ignoring attempt to set acTL with num_frames > 2^31-1");
+        return (0);
+    }
+    if (num_plays > PNG_UINT_31_MAX)
+    {
+        png_warning(png_ptr,
+                    "Ignoring attempt to set acTL with num_plays "
+                    "> 2^31-1");
+        return (0);
+    }
+
+    info_ptr->num_frames = num_frames;
+    info_ptr->num_plays = num_plays;
+
+    info_ptr->valid |= PNG_INFO_acTL;
+
+    return (1);
+}
+
+/* delay_num and delay_den can hold any 16-bit values including zero */
+png_uint_32 PNGAPI
+png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 width, png_uint_32 height,
+    png_uint_32 x_offset, png_uint_32 y_offset,
+    png_uint_16 delay_num, png_uint_16 delay_den,
+    png_byte dispose_op, png_byte blend_op)
+{
+    png_debug1(1, "in %s storage function", "fcTL");
+
+    if (png_ptr == NULL || info_ptr == NULL)
+    {
+        png_warning(png_ptr,
+                    "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
+                    "ignored");
+        return (0);
+    }
+
+    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
+                             delay_num, delay_den, dispose_op, blend_op);
+
+    if (blend_op == PNG_BLEND_OP_OVER)
+    {
+        if (!(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) &&
+            !(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
+        {
+          png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
+                               "and wasteful for opaque images, ignored");
+          blend_op = PNG_BLEND_OP_SOURCE;
+        }
+    }
+
+    info_ptr->next_frame_width = width;
+    info_ptr->next_frame_height = height;
+    info_ptr->next_frame_x_offset = x_offset;
+    info_ptr->next_frame_y_offset = y_offset;
+    info_ptr->next_frame_delay_num = delay_num;
+    info_ptr->next_frame_delay_den = delay_den;
+    info_ptr->next_frame_dispose_op = dispose_op;
+    info_ptr->next_frame_blend_op = blend_op;
+
+    info_ptr->valid |= PNG_INFO_fcTL;
+
+    return (1);
+}
+
+void /* PRIVATE */
+png_ensure_fcTL_is_valid(png_structp png_ptr,
+    png_uint_32 width, png_uint_32 height,
+    png_uint_32 x_offset, png_uint_32 y_offset,
+    png_uint_16 delay_num, png_uint_16 delay_den,
+    png_byte dispose_op, png_byte blend_op)
+{
+    if (width + x_offset > png_ptr->first_frame_width ||
+        height + y_offset > png_ptr->first_frame_height)
+        png_error(png_ptr, "dimensions of a frame are greater than"
+                           "the ones in IHDR");
+    if (width > PNG_UINT_31_MAX)
+        png_error(png_ptr, "invalid width in fcTL (> 2^31-1)");
+    if (height > PNG_UINT_31_MAX)
+        png_error(png_ptr, "invalid height in fcTL (> 2^31-1)");
+    if (x_offset > PNG_UINT_31_MAX)
+        png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
+    if (y_offset > PNG_UINT_31_MAX)
+        png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
+
+    if (dispose_op != PNG_DISPOSE_OP_NONE &&
+        dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
+        dispose_op != PNG_DISPOSE_OP_PREVIOUS)
+        png_error(png_ptr, "invalid dispose_op in fcTL");
+
+    if (blend_op != PNG_BLEND_OP_SOURCE &&
+        blend_op != PNG_BLEND_OP_OVER)
+        png_error(png_ptr, "invalid blend_op in fcTL");
+
+    PNG_UNUSED(delay_num)
+    PNG_UNUSED(delay_den)
+}
+
+png_uint_32 PNGAPI
+png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
+                              png_byte is_hidden)
+{
+    png_debug(1, "in png_first_frame_is_hidden()");
+
+    if (png_ptr == NULL)
+        return 0;
+
+    if (is_hidden)
+        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
+    else
+        png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;
+
+    PNG_UNUSED(info_ptr)
+
+    return 1;
+}
+#endif /* PNG_APNG_SUPPORTED */
+
 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
 void PNGAPI
 png_set_unknown_chunks(png_structp png_ptr,
    png_infop info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
 {
    png_unknown_chunkp np;
    int i;
 
diff -up8 pngstruct.h pngstruct.h
--- pngstruct.h	2012-06-14 07:28:00 -0400
+++ pngstruct.h	2012-07-07 10:21:31 -0400
@@ -288,16 +288,37 @@ struct png_struct_def
    png_uint_32 mng_features_permitted;
 #endif
 
 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    png_byte filter_type;
 #endif
 
+#ifdef PNG_APNG_SUPPORTED
+   png_uint_32 apng_flags;
+   png_uint_32 next_seq_num;         /* next fcTL/fdAT chunk sequence number */
+   png_uint_32 first_frame_width;
+   png_uint_32 first_frame_height;
+
+#ifdef PNG_READ_APNG_SUPPORTED
+   png_uint_32 num_frames_read;      /* incremented after all image data of */
+                                     /* a frame is read */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
+   png_progressive_frame_ptr frame_end_fn;  /* frame data read callback */
+#endif
+#endif
+
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   png_uint_32 num_frames_to_write;
+   png_uint_32 num_frames_written;
+#endif
+#endif /* PNG_APNG_SUPPORTED */
+
 /* New members added in libpng-1.2.0 */
 
 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
 #ifdef PNG_USER_MEM_SUPPORTED
    png_voidp mem_ptr;             /* user supplied struct for mem functions */
    png_malloc_ptr malloc_fn;      /* function for allocating memory */
    png_free_ptr free_fn;          /* function for freeing memory */
 #endif
diff -up8 pngwrite.c pngwrite.c
--- pngwrite.c	2012-06-14 07:28:00 -0400
+++ pngwrite.c	2012-07-07 10:21:31 -0400
@@ -53,16 +53,20 @@ png_write_info_before_PLTE(png_structp p
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
        info_ptr->interlace_type);
 #else
        0);
 #endif
    /* The rest of these check to see if the valid field has the appropriate
     * flag set, and if it does, writes the chunk.
     */
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_acTL)
+      png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays);
+#endif
 #ifdef PNG_WRITE_gAMA_SUPPORTED
    if (info_ptr->valid & PNG_INFO_gAMA)
       png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
 #endif
 #ifdef PNG_WRITE_sRGB_SUPPORTED
    if (info_ptr->valid & PNG_INFO_sRGB)
       png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
 #endif
@@ -305,16 +309,22 @@ png_write_end(png_structp png_ptr, png_i
    if (!(png_ptr->mode & PNG_HAVE_IDAT))
       png_error(png_ptr, "No IDATs written into file");
 
 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
    if (png_ptr->num_palette_max > png_ptr->num_palette)
       png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
 #endif
 
+    /* See if user wants us to write information chunks */
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   if (png_ptr->num_frames_written != png_ptr->num_frames_to_write)
+      png_error(png_ptr, "Not enough frames written");
+#endif
+
    /* See if user wants us to write information chunks */
    if (info_ptr != NULL)
    {
 #ifdef PNG_WRITE_TEXT_SUPPORTED
       int i; /* local index variable */
 #endif
 #ifdef PNG_WRITE_tIME_SUPPORTED
       /* Check to see if user has supplied a time chunk */
@@ -1660,9 +1670,47 @@ png_write_png(png_structp png_ptr, png_i
 
    /* It is REQUIRED to call this to finish writing the rest of the file */
    png_write_end(png_ptr, info_ptr);
 
    PNG_UNUSED(transforms)   /* Quiet compiler warnings */
    PNG_UNUSED(params)
 }
 #endif
+
+#ifdef PNG_WRITE_APNG_SUPPORTED
+void PNGAPI
+png_write_frame_head(png_structp png_ptr, png_infop info_ptr,
+    png_bytepp row_pointers, png_uint_32 width, png_uint_32 height,
+    png_uint_32 x_offset, png_uint_32 y_offset,
+    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
+    png_byte blend_op)
+{
+    png_debug(1, "in png_write_frame_head");
+
+    /* there is a chance this has been set after png_write_info was called,
+    * so it would be set but not written. is there a way to be sure? */
+    if (!(info_ptr->valid & PNG_INFO_acTL))
+        png_error(png_ptr, "png_write_frame_head(): acTL not set");
+
+    png_write_reset(png_ptr);
+
+    png_write_reinit(png_ptr, info_ptr, width, height);
+
+    if ( !(png_ptr->num_frames_written == 0 &&
+           (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) ) )
+        png_write_fcTL(png_ptr, width, height, x_offset, y_offset,
+                       delay_num, delay_den, dispose_op, blend_op);
+
+    PNG_UNUSED(row_pointers)
+}
+
+void PNGAPI
+png_write_frame_tail(png_structp png_ptr, png_infop info_ptr)
+{
+    png_debug(1, "in png_write_frame_tail");
+
+    png_ptr->num_frames_written++;
+
+    PNG_UNUSED(info_ptr)
+}
+#endif /* PNG_WRITE_APNG_SUPPORTED */
 #endif /* PNG_WRITE_SUPPORTED */
diff -up8 pngwutil.c pngwutil.c
--- pngwutil.c	2012-06-14 07:28:00 -0400
+++ pngwutil.c	2012-04-24 20:51:09 -0400
@@ -816,16 +816,21 @@ png_write_IHDR(png_structp png_ptr, png_
    buf[9] = (png_byte)color_type;
    buf[10] = (png_byte)compression_type;
    buf[11] = (png_byte)filter_type;
    buf[12] = (png_byte)interlace_type;
 
    /* Write the chunk */
    png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
 
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   png_ptr->first_frame_width = width;
+   png_ptr->first_frame_height = height;
+#endif
+
    /* Initialize zlib with PNG info */
    png_ptr->zstream.zalloc = png_zalloc;
    png_ptr->zstream.zfree = png_zfree;
    png_ptr->zstream.opaque = (voidpf)png_ptr;
 
    if (!(png_ptr->do_filter))
    {
       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
@@ -1030,17 +1035,38 @@ png_write_IDAT(png_structp png_ptr, png_
       }
 
       else
          png_error(png_ptr,
              "Invalid zlib compression method or flags in IDAT");
    }
 #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
 
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   if (png_ptr->num_frames_written == 0)
+#endif
    png_write_complete_chunk(png_ptr, png_IDAT, data, length);
+#ifdef PNG_WRITE_APNG_SUPPORTED
+   else
+   {
+      png_byte buf[4];
+
+      png_write_chunk_header(png_ptr, png_fdAT, 4 + length);
+
+      png_save_uint_32(buf, png_ptr->next_seq_num);
+      png_write_chunk_data(png_ptr, buf, 4);
+
+      png_write_chunk_data(png_ptr, data, length);
+
+      png_write_chunk_end(png_ptr);
+
+      png_ptr->next_seq_num++;
+   }
+#endif /* PNG_WRITE_APNG_SUPPORTED */
+
    png_ptr->mode |= PNG_HAVE_IDAT;
 
    /* Prior to 1.5.4 this code was replicated in every caller (except at the
     * end, where it isn't technically necessary).  Since this function has
     * flushed the data we can safely reset the zlib output buffer here.
     */
    png_ptr->zstream.next_out = png_ptr->zbuf;
    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
@@ -1992,16 +2018,74 @@ png_write_tIME(png_structp png_ptr, png_
    buf[4] = mod_time->hour;
    buf[5] = mod_time->minute;
    buf[6] = mod_time->second;
 
    png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
 }
 #endif
 
+#ifdef PNG_WRITE_APNG_SUPPORTED
+void /* PRIVATE */
+png_write_acTL(png_structp png_ptr,
+    png_uint_32 num_frames, png_uint_32 num_plays)
+{
+    png_byte buf[8];
+
+    png_debug(1, "in png_write_acTL");
+
+    png_ptr->num_frames_to_write = num_frames;
+
+    if (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN)
+        num_frames--;
+
+    png_save_uint_32(buf, num_frames);
+    png_save_uint_32(buf + 4, num_plays);
+
+    png_write_complete_chunk(png_ptr, png_acTL, buf, (png_size_t)8);
+}
+
+void /* PRIVATE */
+png_write_fcTL(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
+    png_uint_32 x_offset, png_uint_32 y_offset,
+    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
+    png_byte blend_op)
+{
+    png_byte buf[26];
+
+    png_debug(1, "in png_write_fcTL");
+
+    if (png_ptr->num_frames_written == 0 && (x_offset != 0 || y_offset != 0))
+        png_error(png_ptr, "x and/or y offset for the first frame aren't 0");
+    if (png_ptr->num_frames_written == 0 &&
+        (width != png_ptr->first_frame_width ||
+         height != png_ptr->first_frame_height))
+        png_error(png_ptr, "width and/or height in the first frame's fcTL "
+                           "don't match the ones in IHDR");
+
+    /* more error checking */
+    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
+                             delay_num, delay_den, dispose_op, blend_op);
+
+    png_save_uint_32(buf, png_ptr->next_seq_num);
+    png_save_uint_32(buf + 4, width);
+    png_save_uint_32(buf + 8, height);
+    png_save_uint_32(buf + 12, x_offset);
+    png_save_uint_32(buf + 16, y_offset);
+    png_save_uint_16(buf + 20, delay_num);
+    png_save_uint_16(buf + 22, delay_den);
+    buf[24] = dispose_op;
+    buf[25] = blend_op;
+
+    png_write_complete_chunk(png_ptr, png_fcTL, buf, (png_size_t)26);
+
+    png_ptr->next_seq_num++;
+}
+#endif /* PNG_WRITE_APNG_SUPPORTED */
+
 /* Initializes the row writing capability of libpng */
 void /* PRIVATE */
 png_write_start_row(png_structp png_ptr)
 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -3171,9 +3255,44 @@ png_write_filtered_row(png_structp png_p
 
    if (png_ptr->flush_dist > 0 &&
        png_ptr->flush_rows >= png_ptr->flush_dist)
    {
       png_write_flush(png_ptr);
    }
 #endif
 }
+
+#ifdef PNG_WRITE_APNG_SUPPORTED
+void /* PRIVATE */
+png_write_reset(png_structp png_ptr)
+{
+    png_ptr->row_number = 0;
+    png_ptr->pass = 0;
+    png_ptr->mode &= ~PNG_HAVE_IDAT;
+}
+
+void /* PRIVATE */
+png_write_reinit(png_structp png_ptr, png_infop info_ptr,
+                 png_uint_32 width, png_uint_32 height)
+{
+    if (png_ptr->num_frames_written == 0 &&
+        (width != png_ptr->first_frame_width ||
+         height != png_ptr->first_frame_height))
+        png_error(png_ptr, "width and/or height in the first frame's fcTL "
+                           "don't match the ones in IHDR");
+    if (width > png_ptr->first_frame_width ||
+        height > png_ptr->first_frame_height)
+        png_error(png_ptr, "width and/or height for a frame greater than"
+                           "the ones in IHDR");
+
+    png_set_IHDR(png_ptr, info_ptr, width, height,
+                 info_ptr->bit_depth, info_ptr->color_type,
+                 info_ptr->interlace_type, info_ptr->compression_type,
+                 info_ptr->filter_type);
+
+    png_ptr->width = width;
+    png_ptr->height = height;
+    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+    png_ptr->usr_width = png_ptr->width;
+}
+#endif /* PNG_WRITE_APNG_SUPPORTED */
 #endif /* PNG_WRITE_SUPPORTED */