Chris Craik | ca2bf81 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 1 | /*- pngtopng |
| 2 | * |
| 3 | * COPYRIGHT: Written by John Cunningham Bowler, 2011. |
| 4 | * To the extent possible under law, the author has waived all copyright and |
| 5 | * related or neighboring rights to this work. This work is published from: |
| 6 | * United States. |
| 7 | * |
| 8 | * Read a PNG and write it out in a fixed format, using the 'simplified API' |
| 9 | * that was introduced in libpng-1.6.0. |
| 10 | * |
| 11 | * This sample code is just the code from the top of 'example.c' with some error |
| 12 | * handling added. See example.c for more comments. |
| 13 | */ |
| 14 | #include <stddef.h> |
| 15 | #include <stdlib.h> |
| 16 | #include <string.h> |
| 17 | #include <stdio.h> |
| 18 | |
| 19 | /* Normally use <png.h> here to get the installed libpng, but this is done to |
| 20 | * ensure the code picks up the local libpng implementation: |
| 21 | */ |
| 22 | #include "../../png.h" |
Matt Sarett | 9ea7569 | 2016-01-08 13:00:42 -0500 | [diff] [blame^] | 23 | #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && \ |
| 24 | defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) |
Chris Craik | ca2bf81 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 25 | |
| 26 | int main(int argc, const char **argv) |
| 27 | { |
| 28 | int result = 1; |
| 29 | |
| 30 | if (argc == 3) |
| 31 | { |
| 32 | png_image image; |
| 33 | |
| 34 | /* Only the image structure version number needs to be set. */ |
| 35 | memset(&image, 0, sizeof image); |
| 36 | image.version = PNG_IMAGE_VERSION; |
| 37 | |
| 38 | if (png_image_begin_read_from_file(&image, argv[1])) |
| 39 | { |
| 40 | png_bytep buffer; |
| 41 | |
| 42 | /* Change this to try different formats! If you set a colormap format |
| 43 | * then you must also supply a colormap below. |
| 44 | */ |
| 45 | image.format = PNG_FORMAT_RGBA; |
| 46 | |
| 47 | buffer = malloc(PNG_IMAGE_SIZE(image)); |
| 48 | |
| 49 | if (buffer != NULL) |
| 50 | { |
| 51 | if (png_image_finish_read(&image, NULL/*background*/, buffer, |
| 52 | 0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */)) |
| 53 | { |
| 54 | if (png_image_write_to_file(&image, argv[2], |
| 55 | 0/*convert_to_8bit*/, buffer, 0/*row_stride*/, |
| 56 | NULL/*colormap*/)) |
| 57 | result = 0; |
| 58 | |
| 59 | else |
| 60 | fprintf(stderr, "pngtopng: write %s: %s\n", argv[2], |
| 61 | image.message); |
| 62 | |
| 63 | free(buffer); |
| 64 | } |
| 65 | |
| 66 | else |
| 67 | { |
| 68 | fprintf(stderr, "pngtopng: read %s: %s\n", argv[1], |
| 69 | image.message); |
| 70 | |
| 71 | /* This is the only place where a 'free' is required; libpng does |
| 72 | * the cleanup on error and success, but in this case we couldn't |
| 73 | * complete the read because of running out of memory. |
| 74 | */ |
| 75 | png_image_free(&image); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | else |
| 80 | fprintf(stderr, "pngtopng: out of memory: %lu bytes\n", |
| 81 | (unsigned long)PNG_IMAGE_SIZE(image)); |
| 82 | } |
| 83 | |
| 84 | else |
| 85 | /* Failed to read the first argument: */ |
| 86 | fprintf(stderr, "pngtopng: %s: %s\n", argv[1], image.message); |
| 87 | } |
| 88 | |
| 89 | else |
| 90 | /* Wrong number of arguments */ |
| 91 | fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n"); |
| 92 | |
| 93 | return result; |
| 94 | } |
Matt Sarett | 9ea7569 | 2016-01-08 13:00:42 -0500 | [diff] [blame^] | 95 | #endif /* READ && WRITE */ |