2 /* pngread.c - read a PNG file
4 * Last changed in libpng 1.5.2 [March 31, 2011]
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
13 * This file contains routines that an application calls directly to
14 * read a PNG file or stream.
19 #ifdef PNG_READ_SUPPORTED
21 /* Create a PNG structure for reading, and allocate any memory needed. */
22 PNG_FUNCTION(png_structp,PNGAPI
23 png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
24 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
27 #ifdef PNG_USER_MEM_SUPPORTED
28 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
29 warn_fn, NULL, NULL, NULL));
32 /* Alternate create PNG structure for reading, and allocate any memory
35 PNG_FUNCTION(png_structp,PNGAPI
36 png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
37 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
38 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
40 #endif /* PNG_USER_MEM_SUPPORTED */
42 #ifdef PNG_SETJMP_SUPPORTED
46 volatile int png_cleanup_needed = 0;
48 #ifdef PNG_SETJMP_SUPPORTED
49 #ifdef USE_FAR_KEYWORD
56 png_debug(1, "in png_create_read_struct");
58 #ifdef PNG_USER_MEM_SUPPORTED
59 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
62 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
67 /* Added at libpng-1.2.6 */
68 #ifdef PNG_USER_LIMITS_SUPPORTED
69 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
70 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
72 # ifdef PNG_USER_CHUNK_CACHE_MAX
73 /* Added at libpng-1.2.43 and 1.4.0 */
74 png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
77 # ifdef PNG_SET_USER_CHUNK_MALLOC_MAX
78 /* Added at libpng-1.2.43 and 1.4.1 */
79 png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
83 #ifdef PNG_SETJMP_SUPPORTED
84 /* Applications that neglect to set up their own setjmp() and then
85 encounter a png_error() will longjmp here. Since the jmpbuf is
86 then meaningless we abort instead of returning. */
87 #ifdef USE_FAR_KEYWORD
88 if (setjmp(png_jmpbuf))
90 if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
93 #ifdef USE_FAR_KEYWORD
94 png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
96 #endif /* PNG_SETJMP_SUPPORTED */
98 #ifdef PNG_USER_MEM_SUPPORTED
99 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
102 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
110 if (user_png_ver[i] != png_libpng_ver[i])
111 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
112 } while (png_libpng_ver[i++]);
116 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
119 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
121 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
122 * we must recompile any applications that use any older library version.
123 * For versions after libpng 1.0, we will be compatible, so we need
124 * only check the first digit.
126 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
127 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
128 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
130 #ifdef PNG_CONSOLE_IO_SUPPORTED
134 png_snprintf2(msg, 80,
135 "Application built with libpng-%.20s"
136 " but running with %.20s",
139 png_warning(png_ptr, msg);
143 "Incompatible libpng version in application and library");
145 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
149 png_cleanup_needed = 1;
153 if (!png_cleanup_needed)
155 /* Initialize zbuf - compression buffer */
156 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
157 png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, png_ptr->zbuf_size);
159 if (png_ptr->zbuf == NULL)
160 png_cleanup_needed = 1;
163 png_ptr->zstream.zalloc = png_zalloc;
164 png_ptr->zstream.zfree = png_zfree;
165 png_ptr->zstream.opaque = (voidpf)png_ptr;
167 if (!png_cleanup_needed)
169 switch (inflateInit(&png_ptr->zstream))
172 break; /* Do nothing */
175 png_warning(png_ptr, "zlib memory error");
176 png_cleanup_needed = 1;
180 png_warning(png_ptr, "zlib stream error");
181 png_cleanup_needed = 1;
184 case Z_VERSION_ERROR:
185 png_warning(png_ptr, "zlib version error");
186 png_cleanup_needed = 1;
189 default: png_warning(png_ptr, "Unknown zlib error");
190 png_cleanup_needed = 1;
194 if (png_cleanup_needed)
196 /* Clean up PNG structure and deallocate any memory. */
197 png_free(png_ptr, png_ptr->zbuf);
198 png_ptr->zbuf = NULL;
199 #ifdef PNG_USER_MEM_SUPPORTED
200 png_destroy_struct_2((png_voidp)png_ptr,
201 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
203 png_destroy_struct((png_voidp)png_ptr);
208 png_ptr->zstream.next_out = png_ptr->zbuf;
209 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
211 png_set_read_fn(png_ptr, NULL, NULL);
218 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
219 /* Read the information before the actual image data. This has been
220 * changed in v0.90 to allow reading a file that already has the magic
221 * bytes read from the stream. You can tell libpng how many bytes have
222 * been read from the beginning of the stream (up to the maximum of 8)
223 * via png_set_sig_bytes(), and we will only check the remaining bytes
224 * here. The application can then have access to the signature bytes we
225 * read if it is determined that this isn't a valid PNG file.
228 png_read_info(png_structp png_ptr, png_infop info_ptr)
230 png_debug(1, "in png_read_info");
232 if (png_ptr == NULL || info_ptr == NULL)
235 /* Read and check the PNG file signature. */
236 png_read_sig(png_ptr, info_ptr);
244 #ifdef PNG_READ_bKGD_SUPPORTED
247 #ifdef PNG_READ_cHRM_SUPPORTED
250 #ifdef PNG_READ_gAMA_SUPPORTED
253 #ifdef PNG_READ_hIST_SUPPORTED
256 #ifdef PNG_READ_iCCP_SUPPORTED
259 #ifdef PNG_READ_iTXt_SUPPORTED
262 #ifdef PNG_READ_oFFs_SUPPORTED
265 #ifdef PNG_READ_pCAL_SUPPORTED
268 #ifdef PNG_READ_pHYs_SUPPORTED
271 #ifdef PNG_READ_sBIT_SUPPORTED
274 #ifdef PNG_READ_sCAL_SUPPORTED
277 #ifdef PNG_READ_sPLT_SUPPORTED
280 #ifdef PNG_READ_sRGB_SUPPORTED
283 #ifdef PNG_READ_tEXt_SUPPORTED
286 #ifdef PNG_READ_tIME_SUPPORTED
289 #ifdef PNG_READ_tRNS_SUPPORTED
292 #ifdef PNG_READ_zTXt_SUPPORTED
295 png_uint_32 length = png_read_chunk_header(png_ptr);
296 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
298 /* This should be a binary subdivision search or a hash for
299 * matching the chunk name rather than a linear search.
301 if (!png_memcmp(chunk_name, png_IDAT, 4))
302 if (png_ptr->mode & PNG_AFTER_IDAT)
303 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
305 if (!png_memcmp(chunk_name, png_IHDR, 4))
306 png_handle_IHDR(png_ptr, info_ptr, length);
308 else if (!png_memcmp(chunk_name, png_IEND, 4))
309 png_handle_IEND(png_ptr, info_ptr, length);
311 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
312 else if (png_handle_as_unknown(png_ptr, chunk_name))
314 if (!png_memcmp(chunk_name, png_IDAT, 4))
315 png_ptr->mode |= PNG_HAVE_IDAT;
317 png_handle_unknown(png_ptr, info_ptr, length);
319 if (!png_memcmp(chunk_name, png_PLTE, 4))
320 png_ptr->mode |= PNG_HAVE_PLTE;
322 else if (!png_memcmp(chunk_name, png_IDAT, 4))
324 if (!(png_ptr->mode & PNG_HAVE_IHDR))
325 png_error(png_ptr, "Missing IHDR before IDAT");
327 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
328 !(png_ptr->mode & PNG_HAVE_PLTE))
329 png_error(png_ptr, "Missing PLTE before IDAT");
335 else if (!png_memcmp(chunk_name, png_PLTE, 4))
336 png_handle_PLTE(png_ptr, info_ptr, length);
338 else if (!png_memcmp(chunk_name, png_IDAT, 4))
340 if (!(png_ptr->mode & PNG_HAVE_IHDR))
341 png_error(png_ptr, "Missing IHDR before IDAT");
343 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
344 !(png_ptr->mode & PNG_HAVE_PLTE))
345 png_error(png_ptr, "Missing PLTE before IDAT");
347 png_ptr->idat_size = length;
348 png_ptr->mode |= PNG_HAVE_IDAT;
352 #ifdef PNG_READ_bKGD_SUPPORTED
353 else if (!png_memcmp(chunk_name, png_bKGD, 4))
354 png_handle_bKGD(png_ptr, info_ptr, length);
357 #ifdef PNG_READ_cHRM_SUPPORTED
358 else if (!png_memcmp(chunk_name, png_cHRM, 4))
359 png_handle_cHRM(png_ptr, info_ptr, length);
362 #ifdef PNG_READ_gAMA_SUPPORTED
363 else if (!png_memcmp(chunk_name, png_gAMA, 4))
364 png_handle_gAMA(png_ptr, info_ptr, length);
367 #ifdef PNG_READ_hIST_SUPPORTED
368 else if (!png_memcmp(chunk_name, png_hIST, 4))
369 png_handle_hIST(png_ptr, info_ptr, length);
372 #ifdef PNG_READ_oFFs_SUPPORTED
373 else if (!png_memcmp(chunk_name, png_oFFs, 4))
374 png_handle_oFFs(png_ptr, info_ptr, length);
377 #ifdef PNG_READ_pCAL_SUPPORTED
378 else if (!png_memcmp(chunk_name, png_pCAL, 4))
379 png_handle_pCAL(png_ptr, info_ptr, length);
382 #ifdef PNG_READ_sCAL_SUPPORTED
383 else if (!png_memcmp(chunk_name, png_sCAL, 4))
384 png_handle_sCAL(png_ptr, info_ptr, length);
387 #ifdef PNG_READ_pHYs_SUPPORTED
388 else if (!png_memcmp(chunk_name, png_pHYs, 4))
389 png_handle_pHYs(png_ptr, info_ptr, length);
392 #ifdef PNG_READ_sBIT_SUPPORTED
393 else if (!png_memcmp(chunk_name, png_sBIT, 4))
394 png_handle_sBIT(png_ptr, info_ptr, length);
397 #ifdef PNG_READ_sRGB_SUPPORTED
398 else if (!png_memcmp(chunk_name, png_sRGB, 4))
399 png_handle_sRGB(png_ptr, info_ptr, length);
402 #ifdef PNG_READ_iCCP_SUPPORTED
403 else if (!png_memcmp(chunk_name, png_iCCP, 4))
404 png_handle_iCCP(png_ptr, info_ptr, length);
407 #ifdef PNG_READ_sPLT_SUPPORTED
408 else if (!png_memcmp(chunk_name, png_sPLT, 4))
409 png_handle_sPLT(png_ptr, info_ptr, length);
412 #ifdef PNG_READ_tEXt_SUPPORTED
413 else if (!png_memcmp(chunk_name, png_tEXt, 4))
414 png_handle_tEXt(png_ptr, info_ptr, length);
417 #ifdef PNG_READ_tIME_SUPPORTED
418 else if (!png_memcmp(chunk_name, png_tIME, 4))
419 png_handle_tIME(png_ptr, info_ptr, length);
422 #ifdef PNG_READ_tRNS_SUPPORTED
423 else if (!png_memcmp(chunk_name, png_tRNS, 4))
424 png_handle_tRNS(png_ptr, info_ptr, length);
427 #ifdef PNG_READ_zTXt_SUPPORTED
428 else if (!png_memcmp(chunk_name, png_zTXt, 4))
429 png_handle_zTXt(png_ptr, info_ptr, length);
432 #ifdef PNG_READ_iTXt_SUPPORTED
433 else if (!png_memcmp(chunk_name, png_iTXt, 4))
434 png_handle_iTXt(png_ptr, info_ptr, length);
438 png_handle_unknown(png_ptr, info_ptr, length);
441 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
443 /* Optional call to update the users info_ptr structure */
445 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
447 png_debug(1, "in png_read_update_info");
452 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
453 png_read_start_row(png_ptr);
457 "Ignoring extra png_read_update_info() call;"
458 " row buffer not reallocated");
460 png_read_transform_info(png_ptr, info_ptr);
463 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
464 /* Initialize palette, background, etc, after transformations
465 * are set, but before any reading takes place. This allows
466 * the user to obtain a gamma-corrected palette, for example.
467 * If the user doesn't call this, we will do it ourselves.
470 png_start_read_image(png_structp png_ptr)
472 png_debug(1, "in png_start_read_image");
477 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
478 png_read_start_row(png_ptr);
481 "Ignoring extra png_start_read_image() call;"
482 " row buffer not reallocated");
484 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
486 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
488 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
491 #ifdef PNG_READ_INTERLACING_SUPPORTED
492 PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
494 PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
501 png_debug2(1, "in png_read_row (row %lu, pass %d)",
502 (unsigned long)png_ptr->row_number, png_ptr->pass);
504 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
505 png_read_start_row(png_ptr);
507 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
509 /* Check for transforms that have been set but were defined out */
510 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
511 if (png_ptr->transformations & PNG_INVERT_MONO)
512 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
515 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
516 if (png_ptr->transformations & PNG_FILLER)
517 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
520 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
521 !defined(PNG_READ_PACKSWAP_SUPPORTED)
522 if (png_ptr->transformations & PNG_PACKSWAP)
523 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
526 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
527 if (png_ptr->transformations & PNG_PACK)
528 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
531 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
532 if (png_ptr->transformations & PNG_SHIFT)
533 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
536 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
537 if (png_ptr->transformations & PNG_BGR)
538 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
541 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
542 if (png_ptr->transformations & PNG_SWAP_BYTES)
543 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
547 #ifdef PNG_READ_INTERLACING_SUPPORTED
548 /* If interlaced and we do not need a new row, combine row and return */
549 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
551 switch (png_ptr->pass)
554 if (png_ptr->row_number & 0x07)
557 png_combine_row(png_ptr, dsp_row,
558 png_pass_dsp_mask[png_ptr->pass]);
559 png_read_finish_row(png_ptr);
565 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
568 png_combine_row(png_ptr, dsp_row,
569 png_pass_dsp_mask[png_ptr->pass]);
571 png_read_finish_row(png_ptr);
577 if ((png_ptr->row_number & 0x07) != 4)
579 if (dsp_row != NULL && (png_ptr->row_number & 4))
580 png_combine_row(png_ptr, dsp_row,
581 png_pass_dsp_mask[png_ptr->pass]);
583 png_read_finish_row(png_ptr);
589 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
592 png_combine_row(png_ptr, dsp_row,
593 png_pass_dsp_mask[png_ptr->pass]);
595 png_read_finish_row(png_ptr);
601 if ((png_ptr->row_number & 3) != 2)
603 if (dsp_row != NULL && (png_ptr->row_number & 2))
604 png_combine_row(png_ptr, dsp_row,
605 png_pass_dsp_mask[png_ptr->pass]);
607 png_read_finish_row(png_ptr);
612 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
615 png_combine_row(png_ptr, dsp_row,
616 png_pass_dsp_mask[png_ptr->pass]);
618 png_read_finish_row(png_ptr);
625 if (!(png_ptr->row_number & 1))
627 png_read_finish_row(png_ptr);
635 if (!(png_ptr->mode & PNG_HAVE_IDAT))
636 png_error(png_ptr, "Invalid attempt to read row data");
638 png_ptr->zstream.next_out = png_ptr->row_buf;
639 png_ptr->zstream.avail_out =
640 (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
641 png_ptr->iwidth) + 1);
645 if (!(png_ptr->zstream.avail_in))
647 while (!png_ptr->idat_size)
649 png_crc_finish(png_ptr, 0);
651 png_ptr->idat_size = png_read_chunk_header(png_ptr);
652 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
653 png_error(png_ptr, "Not enough image data");
655 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
656 png_ptr->zstream.next_in = png_ptr->zbuf;
657 if (png_ptr->zbuf_size > png_ptr->idat_size)
658 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
659 png_crc_read(png_ptr, png_ptr->zbuf,
660 (png_size_t)png_ptr->zstream.avail_in);
661 png_ptr->idat_size -= png_ptr->zstream.avail_in;
664 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
666 if (ret == Z_STREAM_END)
668 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
670 png_benign_error(png_ptr, "Extra compressed data");
671 png_ptr->mode |= PNG_AFTER_IDAT;
672 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
677 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
678 "Decompression error");
680 } while (png_ptr->zstream.avail_out);
682 png_ptr->row_info.color_type = png_ptr->color_type;
683 png_ptr->row_info.width = png_ptr->iwidth;
684 png_ptr->row_info.channels = png_ptr->channels;
685 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
686 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
687 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
688 png_ptr->row_info.width);
690 if (png_ptr->row_buf[0])
691 png_read_filter_row(png_ptr, &(png_ptr->row_info),
692 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
693 (int)(png_ptr->row_buf[0]));
695 png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
697 #ifdef PNG_MNG_FEATURES_SUPPORTED
698 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
699 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
701 /* Intrapixel differencing */
702 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
707 if (png_ptr->transformations)
708 png_do_read_transformations(png_ptr);
710 #ifdef PNG_READ_INTERLACING_SUPPORTED
711 /* Blow up interlaced rows to full size */
712 if (png_ptr->interlaced &&
713 (png_ptr->transformations & PNG_INTERLACE))
715 if (png_ptr->pass < 6)
716 /* Old interface (pre-1.0.9):
717 * png_do_read_interlace(&(png_ptr->row_info),
718 * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
720 png_do_read_interlace(png_ptr);
723 png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]);
726 png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]);
733 png_combine_row(png_ptr, row, 0xff);
736 png_combine_row(png_ptr, dsp_row, 0xff);
738 png_read_finish_row(png_ptr);
740 if (png_ptr->read_row_fn != NULL)
741 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
743 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
745 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
746 /* Read one or more rows of image data. If the image is interlaced,
747 * and png_set_interlace_handling() has been called, the rows need to
748 * contain the contents of the rows from the previous pass. If the
749 * image has alpha or transparency, and png_handle_alpha()[*] has been
750 * called, the rows contents must be initialized to the contents of the
753 * "row" holds the actual image, and pixels are placed in it
754 * as they arrive. If the image is displayed after each pass, it will
755 * appear to "sparkle" in. "display_row" can be used to display a
756 * "chunky" progressive image, with finer detail added as it becomes
757 * available. If you do not want this "chunky" display, you may pass
758 * NULL for display_row. If you do not want the sparkle display, and
759 * you have not called png_handle_alpha(), you may pass NULL for rows.
760 * If you have called png_handle_alpha(), and the image has either an
761 * alpha channel or a transparency chunk, you must provide a buffer for
762 * rows. In this case, you do not have to provide a display_row buffer
763 * also, but you may. If the image is not interlaced, or if you have
764 * not called png_set_interlace_handling(), the display_row buffer will
765 * be ignored, so pass NULL to it.
767 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
771 png_read_rows(png_structp png_ptr, png_bytepp row,
772 png_bytepp display_row, png_uint_32 num_rows)
778 png_debug(1, "in png_read_rows");
785 if (rp != NULL && dp != NULL)
786 for (i = 0; i < num_rows; i++)
788 png_bytep rptr = *rp++;
789 png_bytep dptr = *dp++;
791 png_read_row(png_ptr, rptr, dptr);
795 for (i = 0; i < num_rows; i++)
797 png_bytep rptr = *rp;
798 png_read_row(png_ptr, rptr, NULL);
803 for (i = 0; i < num_rows; i++)
805 png_bytep dptr = *dp;
806 png_read_row(png_ptr, NULL, dptr);
810 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
812 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
813 /* Read the entire image. If the image has an alpha channel or a tRNS
814 * chunk, and you have called png_handle_alpha()[*], you will need to
815 * initialize the image to the current image that PNG will be overlaying.
816 * We set the num_rows again here, in case it was incorrectly set in
817 * png_read_start_row() by a call to png_read_update_info() or
818 * png_start_read_image() if png_set_interlace_handling() wasn't called
819 * prior to either of these functions like it should have been. You can
820 * only call this function once. If you desire to have an image for
821 * each pass of a interlaced image, use png_read_rows() instead.
823 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
826 png_read_image(png_structp png_ptr, png_bytepp image)
828 png_uint_32 i, image_height;
832 png_debug(1, "in png_read_image");
837 #ifdef PNG_READ_INTERLACING_SUPPORTED
838 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
840 pass = png_set_interlace_handling(png_ptr);
841 /* And make sure transforms are initialized. */
842 png_start_read_image(png_ptr);
846 if (png_ptr->interlaced && !(png_ptr->transformations & PNG_INTERLACE))
848 /* Caller called png_start_read_image or png_read_update_info without
849 * first turning on the PNG_INTERLACE transform. We can fix this here,
850 * but the caller should do it!
852 png_warning(png_ptr, "Interlace handling should be turned on when "
853 "using png_read_image");
854 /* Make sure this is set correctly */
855 png_ptr->num_rows = png_ptr->height;
858 /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
859 * the above error case.
861 pass = png_set_interlace_handling(png_ptr);
864 if (png_ptr->interlaced)
866 "Cannot read interlaced image -- interlace handler disabled");
871 image_height=png_ptr->height;
873 for (j = 0; j < pass; j++)
876 for (i = 0; i < image_height; i++)
878 png_read_row(png_ptr, *rp, NULL);
883 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
885 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
886 /* Read the end of the PNG file. Will not read past the end of the
887 * file, will verify the end is accurate, and will read any comments
888 * or time information at the end of the file, if info is not NULL.
891 png_read_end(png_structp png_ptr, png_infop info_ptr)
893 png_debug(1, "in png_read_end");
898 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
906 #ifdef PNG_READ_bKGD_SUPPORTED
909 #ifdef PNG_READ_cHRM_SUPPORTED
912 #ifdef PNG_READ_gAMA_SUPPORTED
915 #ifdef PNG_READ_hIST_SUPPORTED
918 #ifdef PNG_READ_iCCP_SUPPORTED
921 #ifdef PNG_READ_iTXt_SUPPORTED
924 #ifdef PNG_READ_oFFs_SUPPORTED
927 #ifdef PNG_READ_pCAL_SUPPORTED
930 #ifdef PNG_READ_pHYs_SUPPORTED
933 #ifdef PNG_READ_sBIT_SUPPORTED
936 #ifdef PNG_READ_sCAL_SUPPORTED
939 #ifdef PNG_READ_sPLT_SUPPORTED
942 #ifdef PNG_READ_sRGB_SUPPORTED
945 #ifdef PNG_READ_tEXt_SUPPORTED
948 #ifdef PNG_READ_tIME_SUPPORTED
951 #ifdef PNG_READ_tRNS_SUPPORTED
954 #ifdef PNG_READ_zTXt_SUPPORTED
957 png_uint_32 length = png_read_chunk_header(png_ptr);
958 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
960 if (!png_memcmp(chunk_name, png_IHDR, 4))
961 png_handle_IHDR(png_ptr, info_ptr, length);
963 else if (!png_memcmp(chunk_name, png_IEND, 4))
964 png_handle_IEND(png_ptr, info_ptr, length);
966 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
967 else if (png_handle_as_unknown(png_ptr, chunk_name))
969 if (!png_memcmp(chunk_name, png_IDAT, 4))
971 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
972 png_benign_error(png_ptr, "Too many IDATs found");
974 png_handle_unknown(png_ptr, info_ptr, length);
975 if (!png_memcmp(chunk_name, png_PLTE, 4))
976 png_ptr->mode |= PNG_HAVE_PLTE;
980 else if (!png_memcmp(chunk_name, png_IDAT, 4))
982 /* Zero length IDATs are legal after the last IDAT has been
983 * read, but not after other chunks have been read.
985 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
986 png_benign_error(png_ptr, "Too many IDATs found");
988 png_crc_finish(png_ptr, length);
990 else if (!png_memcmp(chunk_name, png_PLTE, 4))
991 png_handle_PLTE(png_ptr, info_ptr, length);
993 #ifdef PNG_READ_bKGD_SUPPORTED
994 else if (!png_memcmp(chunk_name, png_bKGD, 4))
995 png_handle_bKGD(png_ptr, info_ptr, length);
998 #ifdef PNG_READ_cHRM_SUPPORTED
999 else if (!png_memcmp(chunk_name, png_cHRM, 4))
1000 png_handle_cHRM(png_ptr, info_ptr, length);
1003 #ifdef PNG_READ_gAMA_SUPPORTED
1004 else if (!png_memcmp(chunk_name, png_gAMA, 4))
1005 png_handle_gAMA(png_ptr, info_ptr, length);
1008 #ifdef PNG_READ_hIST_SUPPORTED
1009 else if (!png_memcmp(chunk_name, png_hIST, 4))
1010 png_handle_hIST(png_ptr, info_ptr, length);
1013 #ifdef PNG_READ_oFFs_SUPPORTED
1014 else if (!png_memcmp(chunk_name, png_oFFs, 4))
1015 png_handle_oFFs(png_ptr, info_ptr, length);
1018 #ifdef PNG_READ_pCAL_SUPPORTED
1019 else if (!png_memcmp(chunk_name, png_pCAL, 4))
1020 png_handle_pCAL(png_ptr, info_ptr, length);
1023 #ifdef PNG_READ_sCAL_SUPPORTED
1024 else if (!png_memcmp(chunk_name, png_sCAL, 4))
1025 png_handle_sCAL(png_ptr, info_ptr, length);
1028 #ifdef PNG_READ_pHYs_SUPPORTED
1029 else if (!png_memcmp(chunk_name, png_pHYs, 4))
1030 png_handle_pHYs(png_ptr, info_ptr, length);
1033 #ifdef PNG_READ_sBIT_SUPPORTED
1034 else if (!png_memcmp(chunk_name, png_sBIT, 4))
1035 png_handle_sBIT(png_ptr, info_ptr, length);
1038 #ifdef PNG_READ_sRGB_SUPPORTED
1039 else if (!png_memcmp(chunk_name, png_sRGB, 4))
1040 png_handle_sRGB(png_ptr, info_ptr, length);
1043 #ifdef PNG_READ_iCCP_SUPPORTED
1044 else if (!png_memcmp(chunk_name, png_iCCP, 4))
1045 png_handle_iCCP(png_ptr, info_ptr, length);
1048 #ifdef PNG_READ_sPLT_SUPPORTED
1049 else if (!png_memcmp(chunk_name, png_sPLT, 4))
1050 png_handle_sPLT(png_ptr, info_ptr, length);
1053 #ifdef PNG_READ_tEXt_SUPPORTED
1054 else if (!png_memcmp(chunk_name, png_tEXt, 4))
1055 png_handle_tEXt(png_ptr, info_ptr, length);
1058 #ifdef PNG_READ_tIME_SUPPORTED
1059 else if (!png_memcmp(chunk_name, png_tIME, 4))
1060 png_handle_tIME(png_ptr, info_ptr, length);
1063 #ifdef PNG_READ_tRNS_SUPPORTED
1064 else if (!png_memcmp(chunk_name, png_tRNS, 4))
1065 png_handle_tRNS(png_ptr, info_ptr, length);
1068 #ifdef PNG_READ_zTXt_SUPPORTED
1069 else if (!png_memcmp(chunk_name, png_zTXt, 4))
1070 png_handle_zTXt(png_ptr, info_ptr, length);
1073 #ifdef PNG_READ_iTXt_SUPPORTED
1074 else if (!png_memcmp(chunk_name, png_iTXt, 4))
1075 png_handle_iTXt(png_ptr, info_ptr, length);
1079 png_handle_unknown(png_ptr, info_ptr, length);
1080 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1082 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1084 /* Free all memory used by the read */
1086 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1087 png_infopp end_info_ptr_ptr)
1089 png_structp png_ptr = NULL;
1090 png_infop info_ptr = NULL, end_info_ptr = NULL;
1091 #ifdef PNG_USER_MEM_SUPPORTED
1092 png_free_ptr free_fn = NULL;
1093 png_voidp mem_ptr = NULL;
1096 png_debug(1, "in png_destroy_read_struct");
1098 if (png_ptr_ptr != NULL)
1099 png_ptr = *png_ptr_ptr;
1100 if (png_ptr == NULL)
1103 #ifdef PNG_USER_MEM_SUPPORTED
1104 free_fn = png_ptr->free_fn;
1105 mem_ptr = png_ptr->mem_ptr;
1108 if (info_ptr_ptr != NULL)
1109 info_ptr = *info_ptr_ptr;
1111 if (end_info_ptr_ptr != NULL)
1112 end_info_ptr = *end_info_ptr_ptr;
1114 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1116 if (info_ptr != NULL)
1118 #ifdef PNG_TEXT_SUPPORTED
1119 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1122 #ifdef PNG_USER_MEM_SUPPORTED
1123 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1124 (png_voidp)mem_ptr);
1126 png_destroy_struct((png_voidp)info_ptr);
1128 *info_ptr_ptr = NULL;
1131 if (end_info_ptr != NULL)
1133 #ifdef PNG_READ_TEXT_SUPPORTED
1134 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1136 #ifdef PNG_USER_MEM_SUPPORTED
1137 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1138 (png_voidp)mem_ptr);
1140 png_destroy_struct((png_voidp)end_info_ptr);
1142 *end_info_ptr_ptr = NULL;
1145 if (png_ptr != NULL)
1147 #ifdef PNG_USER_MEM_SUPPORTED
1148 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1149 (png_voidp)mem_ptr);
1151 png_destroy_struct((png_voidp)png_ptr);
1153 *png_ptr_ptr = NULL;
1157 /* Free all memory used by the read (old method) */
1159 png_read_destroy(png_structp png_ptr, png_infop info_ptr,
1160 png_infop end_info_ptr)
1162 #ifdef PNG_SETJMP_SUPPORTED
1165 png_error_ptr error_fn;
1166 png_error_ptr warning_fn;
1167 png_voidp error_ptr;
1168 #ifdef PNG_USER_MEM_SUPPORTED
1169 png_free_ptr free_fn;
1172 png_debug(1, "in png_read_destroy");
1174 if (info_ptr != NULL)
1175 png_info_destroy(png_ptr, info_ptr);
1177 if (end_info_ptr != NULL)
1178 png_info_destroy(png_ptr, end_info_ptr);
1180 png_free(png_ptr, png_ptr->zbuf);
1181 png_free(png_ptr, png_ptr->big_row_buf);
1182 png_free(png_ptr, png_ptr->prev_row);
1183 png_free(png_ptr, png_ptr->chunkdata);
1185 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1186 png_free(png_ptr, png_ptr->palette_lookup);
1187 png_free(png_ptr, png_ptr->quantize_index);
1190 #ifdef PNG_READ_GAMMA_SUPPORTED
1191 png_free(png_ptr, png_ptr->gamma_table);
1194 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1195 png_free(png_ptr, png_ptr->gamma_from_1);
1196 png_free(png_ptr, png_ptr->gamma_to_1);
1199 if (png_ptr->free_me & PNG_FREE_PLTE)
1200 png_zfree(png_ptr, png_ptr->palette);
1201 png_ptr->free_me &= ~PNG_FREE_PLTE;
1203 #if defined(PNG_tRNS_SUPPORTED) || \
1204 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1205 if (png_ptr->free_me & PNG_FREE_TRNS)
1206 png_free(png_ptr, png_ptr->trans_alpha);
1207 png_ptr->free_me &= ~PNG_FREE_TRNS;
1210 #ifdef PNG_READ_hIST_SUPPORTED
1211 if (png_ptr->free_me & PNG_FREE_HIST)
1212 png_free(png_ptr, png_ptr->hist);
1213 png_ptr->free_me &= ~PNG_FREE_HIST;
1216 #ifdef PNG_READ_GAMMA_SUPPORTED
1217 if (png_ptr->gamma_16_table != NULL)
1220 int istop = (1 << (8 - png_ptr->gamma_shift));
1221 for (i = 0; i < istop; i++)
1223 png_free(png_ptr, png_ptr->gamma_16_table[i]);
1225 png_free(png_ptr, png_ptr->gamma_16_table);
1228 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1229 if (png_ptr->gamma_16_from_1 != NULL)
1232 int istop = (1 << (8 - png_ptr->gamma_shift));
1233 for (i = 0; i < istop; i++)
1235 png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1237 png_free(png_ptr, png_ptr->gamma_16_from_1);
1239 if (png_ptr->gamma_16_to_1 != NULL)
1242 int istop = (1 << (8 - png_ptr->gamma_shift));
1243 for (i = 0; i < istop; i++)
1245 png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1247 png_free(png_ptr, png_ptr->gamma_16_to_1);
1252 #ifdef PNG_TIME_RFC1123_SUPPORTED
1253 png_free(png_ptr, png_ptr->time_buffer);
1256 inflateEnd(&png_ptr->zstream);
1258 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1259 png_free(png_ptr, png_ptr->save_buffer);
1262 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1263 #ifdef PNG_TEXT_SUPPORTED
1264 png_free(png_ptr, png_ptr->current_text);
1265 #endif /* PNG_TEXT_SUPPORTED */
1266 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1268 /* Save the important info out of the png_struct, in case it is
1271 #ifdef PNG_SETJMP_SUPPORTED
1272 png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
1275 error_fn = png_ptr->error_fn;
1276 warning_fn = png_ptr->warning_fn;
1277 error_ptr = png_ptr->error_ptr;
1278 #ifdef PNG_USER_MEM_SUPPORTED
1279 free_fn = png_ptr->free_fn;
1282 png_memset(png_ptr, 0, png_sizeof(png_struct));
1284 png_ptr->error_fn = error_fn;
1285 png_ptr->warning_fn = warning_fn;
1286 png_ptr->error_ptr = error_ptr;
1287 #ifdef PNG_USER_MEM_SUPPORTED
1288 png_ptr->free_fn = free_fn;
1291 #ifdef PNG_SETJMP_SUPPORTED
1292 png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1298 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1300 if (png_ptr == NULL)
1303 png_ptr->read_row_fn = read_row_fn;
1307 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1308 #ifdef PNG_INFO_IMAGE_SUPPORTED
1310 png_read_png(png_structp png_ptr, png_infop info_ptr,
1316 if (png_ptr == NULL || info_ptr == NULL)
1319 /* png_read_info() gives us all of the information from the
1320 * PNG file before the first IDAT (image data chunk).
1322 png_read_info(png_ptr, info_ptr);
1323 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1324 png_error(png_ptr, "Image is too high to process with png_read_png()");
1326 /* -------------- image transformations start here ------------------- */
1328 #ifdef PNG_READ_16_TO_8_SUPPORTED
1329 /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
1331 if (transforms & PNG_TRANSFORM_STRIP_16)
1332 png_set_strip_16(png_ptr);
1335 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1336 /* Strip alpha bytes from the input data without combining with
1337 * the background (not recommended).
1339 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1340 png_set_strip_alpha(png_ptr);
1343 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1344 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1345 * byte into separate bytes (useful for paletted and grayscale images).
1347 if (transforms & PNG_TRANSFORM_PACKING)
1348 png_set_packing(png_ptr);
1351 #ifdef PNG_READ_PACKSWAP_SUPPORTED
1352 /* Change the order of packed pixels to least significant bit first
1353 * (not useful if you are using png_set_packing).
1355 if (transforms & PNG_TRANSFORM_PACKSWAP)
1356 png_set_packswap(png_ptr);
1359 #ifdef PNG_READ_EXPAND_SUPPORTED
1360 /* Expand paletted colors into true RGB triplets
1361 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1362 * Expand paletted or RGB images with transparency to full alpha
1363 * channels so the data will be available as RGBA quartets.
1365 if (transforms & PNG_TRANSFORM_EXPAND)
1366 if ((png_ptr->bit_depth < 8) ||
1367 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1368 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1369 png_set_expand(png_ptr);
1372 /* We don't handle background color or gamma transformation or quantizing.
1375 #ifdef PNG_READ_INVERT_SUPPORTED
1376 /* Invert monochrome files to have 0 as white and 1 as black
1378 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1379 png_set_invert_mono(png_ptr);
1382 #ifdef PNG_READ_SHIFT_SUPPORTED
1383 /* If you want to shift the pixel values from the range [0,255] or
1384 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1385 * colors were originally in:
1387 if ((transforms & PNG_TRANSFORM_SHIFT)
1388 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1390 png_color_8p sig_bit;
1392 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1393 png_set_shift(png_ptr, sig_bit);
1397 #ifdef PNG_READ_BGR_SUPPORTED
1398 /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
1399 if (transforms & PNG_TRANSFORM_BGR)
1400 png_set_bgr(png_ptr);
1403 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1404 /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
1405 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1406 png_set_swap_alpha(png_ptr);
1409 #ifdef PNG_READ_SWAP_SUPPORTED
1410 /* Swap bytes of 16 bit files to least significant byte first */
1411 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1412 png_set_swap(png_ptr);
1415 /* Added at libpng-1.2.41 */
1416 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1417 /* Invert the alpha channel from opacity to transparency */
1418 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1419 png_set_invert_alpha(png_ptr);
1422 /* Added at libpng-1.2.41 */
1423 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1424 /* Expand grayscale image to RGB */
1425 if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
1426 png_set_gray_to_rgb(png_ptr);
1429 /* We don't handle adding filler bytes */
1431 /* We use png_read_image and rely on that for interlace handling, but we also
1432 * call png_read_update_info therefore must turn on interlace handling now:
1434 (void)png_set_interlace_handling(png_ptr);
1436 /* Optional call to gamma correct and add the background to the palette
1437 * and update info structure. REQUIRED if you are expecting libpng to
1438 * update the palette for you (i.e., you selected such a transform above).
1440 png_read_update_info(png_ptr, info_ptr);
1442 /* -------------- image transformations end here ------------------- */
1444 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1445 if (info_ptr->row_pointers == NULL)
1449 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1450 info_ptr->height * png_sizeof(png_bytep));
1451 for (iptr=0; iptr<info_ptr->height; iptr++)
1452 info_ptr->row_pointers[iptr] = NULL;
1454 info_ptr->free_me |= PNG_FREE_ROWS;
1456 for (row = 0; row < (int)info_ptr->height; row++)
1457 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1458 png_get_rowbytes(png_ptr, info_ptr));
1461 png_read_image(png_ptr, info_ptr->row_pointers);
1462 info_ptr->valid |= PNG_INFO_IDAT;
1464 /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
1465 png_read_end(png_ptr, info_ptr);
1467 PNG_UNUSED(transforms) /* Quiet compiler warnings */
1471 #endif /* PNG_INFO_IMAGE_SUPPORTED */
1472 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1473 #endif /* PNG_READ_SUPPORTED */