| |
| /* pngread.c - read a png file |
| |
| libpng 1.0 beta 3 - version 0.89 |
| For conditions of distribution and use, see copyright notice in png.h |
| Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| May 25, 1996 |
| */ |
| |
| #define PNG_INTERNAL |
| #include "png.h" |
| |
| /* Create a png structure for reading, and allocate any memory needed. */ |
| png_structp |
| png_create_read_struct(png_const_charp user_png_ver, voidp error_ptr, |
| png_error_ptr warn_fn, png_error_ptr error_fn) |
| { |
| png_structp png_ptr; |
| |
| if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL) |
| { |
| return (png_structp)NULL; |
| } |
| |
| if (setjmp(png_ptr->jmpbuf)) |
| { |
| png_large_free(png_ptr, png_ptr->zbuf); |
| png_free(png_ptr, png_ptr->zstream); |
| png_destroy_struct(png_ptr); |
| return (png_structp)NULL; |
| } |
| |
| png_set_error_fn(png_ptr, error_ptr, warn_fn, error_fn); |
| |
| if (user_png_ver == NULL || strcmp(user_png_ver, png_libpng_ver)) |
| { |
| if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0]) |
| { |
| png_error(png_ptr, "Incompatible libpng versions"); |
| } |
| else |
| { |
| png_warning(png_ptr, "Different libpng versions"); |
| } |
| } |
| |
| /* initialize zbuf - compression buffer */ |
| png_ptr->zbuf_size = PNG_ZBUF_SIZE; |
| png_ptr->zbuf = png_large_malloc(png_ptr, png_ptr->zbuf_size); |
| |
| png_ptr->zstream = (z_stream *)png_malloc(png_ptr, sizeof (z_stream)); |
| png_ptr->zstream->zalloc = png_zalloc; |
| png_ptr->zstream->zfree = png_zfree; |
| png_ptr->zstream->opaque = (voidpf)png_ptr; |
| |
| switch (inflateInit(png_ptr->zstream)) |
| { |
| case Z_OK: /* Do nothing */ break; |
| case Z_MEM_ERROR: |
| case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break; |
| case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break; |
| default: png_error(png_ptr, "Unknown zlib error"); |
| } |
| |
| png_ptr->zstream->next_out = png_ptr->zbuf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size; |
| |
| png_set_read_fn(png_ptr, NULL, NULL); |
| |
| png_ptr->do_free |= PNG_FREE_STRUCT; |
| |
| return (png_ptr); |
| } |
| |
| |
| /* initialize png structure for reading, and allocate any memory needed */ |
| /* This interface is depreciated in favour of the png_create_read_struct() */ |
| void |
| png_read_init(png_structp png_ptr) |
| { |
| jmp_buf tmp_jmp; /* to save current jump buffer */ |
| |
| /* save jump buffer and error functions */ |
| png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| |
| /* reset all variables to 0 */ |
| png_memset(png_ptr, 0, sizeof (png_struct)); |
| |
| /* restore jump buffer */ |
| png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); |
| |
| /* initialize zbuf - compression buffer */ |
| png_ptr->zbuf_size = PNG_ZBUF_SIZE; |
| png_ptr->zbuf = png_large_malloc(png_ptr, png_ptr->zbuf_size); |
| |
| png_ptr->zstream = (z_stream *)png_malloc(png_ptr, sizeof (z_stream)); |
| png_ptr->zstream->zalloc = png_zalloc; |
| png_ptr->zstream->zfree = png_zfree; |
| png_ptr->zstream->opaque = (voidpf)png_ptr; |
| |
| switch (inflateInit(png_ptr->zstream)) |
| { |
| case Z_OK: /* Do nothing */ break; |
| case Z_MEM_ERROR: |
| case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break; |
| case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break; |
| default: png_error(png_ptr, "Unknown zlib error"); |
| } |
| |
| png_ptr->zstream->next_out = png_ptr->zbuf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size; |
| |
| png_set_read_fn(png_ptr, NULL, NULL); |
| } |
| |
| /* read the information before the actual image data. */ |
| void |
| png_read_info(png_structp png_ptr, png_infop info) |
| { |
| png_byte chunk_start[8]; |
| png_uint_32 length; |
| |
| png_read_data(png_ptr, chunk_start, 8); |
| if (!png_check_sig(chunk_start, 8)) |
| { |
| if (!png_check_sig(chunk_start, 4)) |
| png_error(png_ptr, "Not a PNG file"); |
| else |
| png_error(png_ptr, "PNG file corrupted by ASCII conversion"); |
| } |
| |
| while (1) |
| { |
| png_uint_32 crc; |
| |
| png_read_data(png_ptr, chunk_start, 8); |
| length = png_get_uint_32(chunk_start); |
| png_reset_crc(png_ptr); |
| png_calculate_crc(png_ptr, chunk_start + 4, 4); |
| if (!png_memcmp(chunk_start + 4, png_IHDR, 4)) |
| png_handle_IHDR(png_ptr, info, length); |
| else if (!png_memcmp(chunk_start + 4, png_PLTE, 4)) |
| png_handle_PLTE(png_ptr, info, length); |
| else if (!png_memcmp(chunk_start + 4, png_IDAT, 4)) |
| { |
| 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"); |
| |
| png_ptr->idat_size = length; |
| png_ptr->mode |= PNG_HAVE_IDAT; |
| break; |
| } |
| else if (!png_memcmp(chunk_start + 4, png_IEND, 4)) |
| png_error(png_ptr, "No image in file"); |
| #if defined(PNG_READ_gAMA_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_gAMA, 4)) |
| png_handle_gAMA(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_sBIT_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_sBIT, 4)) |
| png_handle_sBIT(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_cHRM_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_cHRM, 4)) |
| png_handle_cHRM(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_tRNS_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_tRNS, 4)) |
| png_handle_tRNS(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_bKGD_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_bKGD, 4)) |
| png_handle_bKGD(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_hIST_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_hIST, 4)) |
| png_handle_hIST(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_pHYs_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_pHYs, 4)) |
| png_handle_pHYs(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_oFFs_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_oFFs, 4)) |
| png_handle_oFFs(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_tIME_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_tIME, 4)) |
| png_handle_tIME(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_tEXt_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_tEXt, 4)) |
| png_handle_tEXt(png_ptr, info, length); |
| #endif |
| #if defined(PNG_READ_zTXt_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_zTXt, 4)) |
| png_handle_zTXt(png_ptr, info, length); |
| #endif |
| else |
| { |
| if (chunk_start[4] < 41 || chunk_start[4] > 122 || |
| (chunk_start[4] > 90 && chunk_start[4] < 97) || |
| chunk_start[5] < 41 || chunk_start[5] > 122 || |
| (chunk_start[5] > 90 && chunk_start[5] < 97) || |
| chunk_start[6] < 41 || chunk_start[6] > 122 || |
| (chunk_start[6] > 90 && chunk_start[6] < 97) || |
| chunk_start[7] < 41 || chunk_start[7] > 122 || |
| (chunk_start[7] > 90 && chunk_start[7] < 97)) |
| { |
| char msg[45]; |
| |
| sprintf(msg, "Invalid chunk type 0x%02X 0x%02X 0x%02X 0x%02X", |
| chunk_start[4], chunk_start[5], chunk_start[6], chunk_start[7]); |
| png_error(png_ptr, msg); |
| } |
| |
| if ((chunk_start[4] & 0x20) == 0) |
| { |
| char msg[40]; |
| |
| sprintf(msg, "Unknown critical chunk %c%c%c%c", |
| chunk_start[4], chunk_start[5], chunk_start[6], chunk_start[7]); |
| png_error(png_ptr, msg); |
| } |
| |
| png_crc_skip(png_ptr, length); |
| } |
| png_read_data(png_ptr, chunk_start, 4); |
| crc = png_get_uint_32(chunk_start); |
| if (((crc ^ 0xffffffffL) & 0xffffffffL) != (png_ptr->crc & 0xffffffffL)) |
| png_error(png_ptr, "Bad CRC value"); |
| } |
| } |
| |
| /* optional call to update the users info structure */ |
| void |
| png_read_update_info(png_structp png_ptr, png_infop info) |
| { |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| png_read_transform_info(png_ptr, info); |
| } |
| |
| /* initialize palette, background, etc, after transformations |
| are set, but before any reading takes place. This allows |
| the user to obtail a gamma corrected palette, for example. |
| If the user doesn't call this, we will do it ourselves. */ |
| void |
| png_start_read_image(png_structp png_ptr) |
| { |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| } |
| |
| void |
| png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) |
| { |
| int ret; |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| |
| #if defined(PNG_READ_INTERLACING_SUPPORTED) |
| /* if interlaced and we do not need a new row, combine row and return */ |
| if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| switch (png_ptr->pass) |
| { |
| case 0: |
| if (png_ptr->row_number & 7) |
| { |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 1: |
| if ((png_ptr->row_number & 7) || png_ptr->width < 5) |
| { |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 2: |
| if ((png_ptr->row_number & 7) != 4) |
| { |
| if (dsp_row && (png_ptr->row_number & 4)) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 3: |
| if ((png_ptr->row_number & 3) || png_ptr->width < 3) |
| { |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 4: |
| if ((png_ptr->row_number & 3) != 2) |
| { |
| if (dsp_row && (png_ptr->row_number & 2)) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 5: |
| if ((png_ptr->row_number & 1) || png_ptr->width < 2) |
| { |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 6: |
| if (!(png_ptr->row_number & 1)) |
| { |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| } |
| } |
| #endif |
| |
| if (!(png_ptr->mode & PNG_HAVE_IDAT)) |
| png_error(png_ptr, "Invalid attempt to read row data"); |
| |
| png_ptr->zstream->next_out = png_ptr->row_buf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->irowbytes; |
| do |
| { |
| if (!(png_ptr->zstream->avail_in)) |
| { |
| while (!png_ptr->idat_size) |
| { |
| png_byte buf[4]; |
| png_uint_32 crc; |
| |
| png_read_data(png_ptr, buf, 4); |
| crc = png_get_uint_32(buf); |
| if (((crc ^ 0xffffffffL) & 0xffffffffL) != |
| (png_ptr->crc & 0xffffffffL)) |
| png_error(png_ptr, "Bad CRC value"); |
| |
| png_read_data(png_ptr, buf, 4); |
| png_ptr->idat_size = png_get_uint_32(buf); |
| png_reset_crc(png_ptr); |
| |
| png_crc_read(png_ptr, buf, 4); |
| if (png_memcmp(buf, png_IDAT, 4)) |
| png_error(png_ptr, "Not enough IDATs for image"); |
| } |
| 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_ptr->zstream->avail_in); |
| png_ptr->idat_size -= png_ptr->zstream->avail_in; |
| } |
| ret = inflate(png_ptr->zstream, Z_PARTIAL_FLUSH); |
| if (ret == Z_STREAM_END) |
| { |
| if (png_ptr->zstream->avail_out || png_ptr->zstream->avail_in || |
| png_ptr->idat_size) |
| png_error(png_ptr, "Extra compressed data"); |
| png_ptr->mode |= PNG_AT_LAST_IDAT; |
| png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
| 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); |
| |
| png_ptr->row_info.color_type = png_ptr->color_type; |
| png_ptr->row_info.width = png_ptr->iwidth; |
| png_ptr->row_info.channels = png_ptr->channels; |
| png_ptr->row_info.bit_depth = png_ptr->bit_depth; |
| png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; |
| png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * |
| (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); |
| |
| png_read_filter_row(png_ptr, &(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->prev_row + 1, |
| (int)(png_ptr->row_buf[0])); |
| |
| png_memcpy(png_ptr->prev_row, png_ptr->row_buf, (png_size_t)png_ptr->rowbytes + 1); |
| |
| if (png_ptr->transformations) |
| png_do_read_transformations(png_ptr); |
| |
| #if defined(PNG_READ_INTERLACING_SUPPORTED) |
| /* blow up interlaced rows to full size */ |
| if (png_ptr->interlaced && |
| (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| if (png_ptr->pass < 6) |
| png_do_read_interlace(&(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->pass); |
| |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| if (row) |
| png_combine_row(png_ptr, row, |
| png_pass_mask[png_ptr->pass]); |
| } |
| else |
| #endif |
| { |
| if (row) |
| png_combine_row(png_ptr, row, 0xff); |
| if (dsp_row) |
| png_combine_row(png_ptr, dsp_row, 0xff); |
| } |
| png_read_finish_row(png_ptr); |
| } |
| |
| /* read a one or more rows of image data. If the image is interlaced, |
| and png_set_interlace_handling() has been called, the rows need to |
| to contain the contents of the rows from the previous pass. If |
| the image has alpha or transparency, and png_handle_alpha() has been |
| called, the rows contents must be initialized to the contents of the |
| screen. row holds the actual image, and pixels are placed in it |
| as they arrive. If the image is displayed after each pass, it will |
| appear to "sparkle" in. display_row can be used to display a |
| "chunky" progressive image, with finer detail added as it becomes |
| available. If you do not want this "chunky" display, you may pass |
| NULL for display_rows. If you do not want the sparkle display, and |
| you have not called png_handle_alpha(), you may pass NULL for rows. |
| If you have called png_handle_alpha(), and the image has either an |
| alpha channel or a transparency chunk, you must provide a buffer for |
| rows. In this case, you do not have to provide a display_rows buffer |
| also, but you may. If the image is not interlaced, or if you have |
| not called png_set_interlace_handling(), the display_row buffer will |
| be ignored, so pass NULL to it. */ |
| |
| void |
| png_read_rows(png_structp png_ptr, png_bytepp row, |
| png_bytepp display_row, png_uint_32 num_rows) |
| { |
| png_uint_32 i; |
| png_bytepp rp; |
| png_bytepp dp; |
| |
| rp = row; |
| dp = display_row; |
| for (i = 0; i < num_rows; i++) |
| { |
| png_bytep rptr; |
| png_bytep dptr; |
| |
| if (rp) |
| rptr = *rp; |
| else |
| rptr = NULL; |
| if (dp) |
| dptr = *dp; |
| else |
| dptr = NULL; |
| png_read_row(png_ptr, rptr, dptr); |
| if (row) |
| rp++; |
| if (display_row) |
| dp++; |
| } |
| } |
| |
| /* read the image. If the image has an alpha channel or a transparency |
| chunk, and you have called png_handle_alpha(), you will need to |
| initialize the image to the current image that png will be overlaying. |
| We set the num_rows again here, in case it was incorrectly set in |
| png_read_start_row() by a call to png_read_update_info() or |
| png_start_read_image() if png_set_interlace_handling() wasn't called |
| prior to either of these functions like it should have been. You only |
| need to call this function once. If you desire to have an image for |
| each pass of a interlaced image, use png_read_rows() instead */ |
| void |
| png_read_image(png_structp png_ptr, png_bytepp image) |
| { |
| png_uint_32 i; |
| int pass, j; |
| png_bytepp rp; |
| |
| pass = png_set_interlace_handling(png_ptr); |
| |
| png_ptr->num_rows = png_ptr->height; /* Make sure this is set correctly */ |
| |
| for (j = 0; j < pass; j++) |
| { |
| rp = image; |
| for (i = 0; i < png_ptr->height; i++) |
| { |
| png_read_row(png_ptr, *rp, NULL); |
| rp++; |
| } |
| } |
| } |
| |
| /* read the end of the png file. Will not read past the end of the |
| file, will verify the end is accurate, and will read any comments |
| or time information at the end of the file, if info is not NULL. */ |
| void |
| png_read_end(png_structp png_ptr, png_infop info) |
| { |
| png_byte chunk_start[8]; |
| png_uint_32 length; |
| png_uint_32 crc; |
| |
| png_read_data(png_ptr, chunk_start, 4); |
| crc = png_get_uint_32(chunk_start); |
| if (((crc ^ 0xffffffffL) & 0xffffffffL) != |
| (png_ptr->crc & 0xffffffffL)) |
| png_error(png_ptr, "Bad CRC value"); |
| |
| do |
| { |
| png_read_data(png_ptr, chunk_start, 8); |
| length = png_get_uint_32(chunk_start); |
| png_reset_crc(png_ptr); |
| png_calculate_crc(png_ptr, chunk_start + 4, 4); |
| |
| if (!png_memcmp(chunk_start + 4, png_IHDR, 4)) |
| { |
| png_error(png_ptr, "Invalid IHDR after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_PLTE, 4)) |
| { |
| png_error(png_ptr, "Invalid PLTE after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_gAMA, 4)) |
| { |
| png_error(png_ptr, "Invalid gAMA after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_sBIT, 4)) |
| { |
| png_error(png_ptr, "Invalid sBIT after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_cHRM, 4)) |
| { |
| png_error(png_ptr, "Invalid cHRM after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_tRNS, 4)) |
| { |
| png_error(png_ptr, "Invalid tRNS after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_bKGD, 4)) |
| { |
| png_error(png_ptr, "Invalid bKGD after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_hIST, 4)) |
| { |
| png_error(png_ptr, "Invalid hIST after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_IDAT, 4)) |
| { |
| if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) |
| png_error(png_ptr, "Too many IDAT's found"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_pHYs, 4)) |
| { |
| png_error(png_ptr, "Invalid pHYs after IDAT"); |
| } |
| else if (!png_memcmp(chunk_start + 4, png_oFFs, 4)) |
| { |
| png_error(png_ptr, "Invalid oFFs after IDAT"); |
| } |
| #if defined(PNG_READ_tIME_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_tIME, 4)) |
| { |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| |
| if (info) |
| png_handle_tIME(png_ptr, info, length); |
| else |
| png_crc_skip(png_ptr, length); |
| } |
| #endif |
| #if defined(PNG_READ_tEXt_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_tEXt, 4)) |
| { |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| |
| if (info) |
| png_handle_tEXt(png_ptr, info, length); |
| else |
| png_crc_skip(png_ptr, length); |
| } |
| #endif |
| #if defined(PNG_READ_zTXt_SUPPORTED) |
| else if (!png_memcmp(chunk_start + 4, png_zTXt, 4)) |
| { |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| |
| if (info) |
| png_handle_zTXt(png_ptr, info, length); |
| else |
| png_crc_skip(png_ptr, length); |
| } |
| #endif |
| else if (!png_memcmp(chunk_start + 4, png_IEND, 4)) |
| { |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| png_ptr->mode |= PNG_AFTER_IEND; |
| } |
| else |
| { |
| if (chunk_start[4] < 41 || chunk_start[4] > 122 || |
| (chunk_start[4] > 90 && chunk_start[4] < 97) || |
| chunk_start[5] < 41 || chunk_start[5] > 122 || |
| (chunk_start[5] > 90 && chunk_start[5] < 97) || |
| chunk_start[6] < 41 || chunk_start[6] > 122 || |
| (chunk_start[6] > 90 && chunk_start[6] < 97) || |
| chunk_start[7] < 41 || chunk_start[7] > 122 || |
| (chunk_start[7] > 90 && chunk_start[7] < 97)) |
| { |
| png_error(png_ptr, "Invalid chunk type"); |
| } |
| |
| if ((chunk_start[4] & 0x20) == 0) |
| png_error(png_ptr, "Unknown critical chunk"); |
| |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| png_crc_skip(png_ptr, length); |
| } |
| png_read_data(png_ptr, chunk_start, 4); |
| crc = png_get_uint_32(chunk_start); |
| if (((crc ^ 0xffffffffL) & 0xffffffffL) != (png_ptr->crc & 0xffffffffL)) |
| png_error(png_ptr, "Bad CRC value"); |
| } while (!(png_ptr->mode & PNG_AFTER_IEND)); |
| } |
| |
| /* free all memory used by the read */ |
| void |
| png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, |
| png_infopp end_info_ptr) |
| { |
| png_structp png_ptr = NULL; |
| png_infop info_ptr = NULL, end_info = NULL; |
| |
| if (png_ptr_ptr) |
| png_ptr = *png_ptr_ptr; |
| |
| if (info_ptr_ptr) |
| info_ptr = *info_ptr_ptr; |
| |
| if (end_info_ptr) |
| end_info = *end_info_ptr; |
| |
| png_read_destroy(png_ptr, info_ptr, end_info); |
| |
| if (info_ptr) |
| { |
| png_destroy_struct((voidp)info_ptr); |
| *info_ptr_ptr = (png_infop)NULL; |
| } |
| |
| if (end_info) |
| { |
| png_destroy_struct((voidp)end_info); |
| *end_info_ptr = (png_infop)NULL; |
| } |
| |
| if (png_ptr) |
| { |
| png_destroy_struct((voidp)png_ptr); |
| *png_ptr_ptr = (png_structp)NULL; |
| } |
| } |
| |
| /* free all memory used by the read (old) */ |
| void |
| png_read_destroy(png_structp png_ptr, png_infop info, png_infop end_info) |
| { |
| int i; |
| jmp_buf tmp_jmp; |
| png_error_ptr error_fn; |
| png_error_ptr warning_fn; |
| png_voidp error_ptr; |
| |
| if (info) |
| { |
| #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) |
| for (i = 0; i < info->num_text; i++) |
| { |
| png_large_free(png_ptr, info->text[i].key); |
| } |
| |
| png_large_free(png_ptr, info->text); |
| #endif |
| png_memset(info, 0, sizeof(png_info)); |
| } |
| |
| if (end_info) |
| { |
| #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) |
| for (i = 0; i < end_info->num_text; i++) |
| { |
| png_large_free(png_ptr, end_info->text[i].key); |
| } |
| |
| png_large_free(png_ptr, end_info->text); |
| #endif |
| png_memset(end_info, 0, sizeof(png_info)); |
| } |
| |
| png_large_free(png_ptr, png_ptr->zbuf); |
| png_large_free(png_ptr, png_ptr->row_buf); |
| png_large_free(png_ptr, png_ptr->prev_row); |
| #if defined(PNG_READ_DITHER_SUPPORTED) |
| png_large_free(png_ptr, png_ptr->palette_lookup); |
| png_large_free(png_ptr, png_ptr->dither_index); |
| #endif |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| png_large_free(png_ptr, png_ptr->gamma_table); |
| #endif |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| png_large_free(png_ptr, png_ptr->gamma_from_1); |
| png_large_free(png_ptr, png_ptr->gamma_to_1); |
| #endif |
| if (png_ptr->do_free & PNG_FREE_PALETTE) |
| png_large_free(png_ptr, png_ptr->palette); |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_bKGD_SUPPORTED) |
| if (png_ptr->do_free & PNG_FREE_TRANS) |
| png_large_free(png_ptr, png_ptr->trans); |
| #endif |
| #if defined(PNG_READ_hIST_SUPPORTED) |
| if (png_ptr->do_free & PNG_FREE_HIST) |
| png_large_free(png_ptr, png_ptr->hist); |
| #endif |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| if (png_ptr->gamma_16_table) |
| { |
| for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) |
| { |
| png_large_free(png_ptr, png_ptr->gamma_16_table[i]); |
| } |
| } |
| #endif |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| png_large_free(png_ptr, png_ptr->gamma_16_table); |
| if (png_ptr->gamma_16_from_1) |
| { |
| for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) |
| { |
| png_large_free(png_ptr, png_ptr->gamma_16_from_1[i]); |
| } |
| } |
| png_large_free(png_ptr, png_ptr->gamma_16_from_1); |
| if (png_ptr->gamma_16_to_1) |
| { |
| for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) |
| { |
| png_large_free(png_ptr, png_ptr->gamma_16_to_1[i]); |
| } |
| } |
| png_large_free(png_ptr, png_ptr->gamma_16_to_1); |
| #endif |
| |
| inflateEnd(png_ptr->zstream); |
| png_free(png_ptr, png_ptr->zstream); |
| #ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
| png_large_free(png_ptr, png_ptr->save_buffer); |
| #endif |
| |
| /* Save the important info out of the png_struct, in case it is |
| * being used again. |
| */ |
| png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| |
| error_fn = png_ptr->error_fn; |
| warning_fn = png_ptr->warning_fn; |
| error_ptr = png_ptr->error_ptr; |
| |
| png_memset(png_ptr, 0, sizeof (png_struct)); |
| |
| png_ptr->error_fn = error_fn; |
| png_ptr->warning_fn = warning_fn; |
| png_ptr->error_ptr = error_ptr; |
| |
| png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); |
| } |
