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1 /* readpng.c
2  *
3  * Copyright (c) 2013 John Cunningham Bowler
4  *
5  * Last changed in libpng 1.6.1 [March 28, 2013]
6  *
7  * This code is released under the libpng license.
8  * For conditions of distribution and use, see the disclaimer
9  * and license in png.h
10  *
11  * Load an arbitrary number of PNG files (from the command line, or, if there
12  * are no arguments on the command line, from stdin) then run a time test by
13  * reading each file by row.  The test does nothing with the read result and
14  * does no transforms.  The only output is a time as a floating point number of
15  * seconds with 9 decimal digits.
16  */
17 #include <stdlib.h>
18 #include <stdio.h>
19 #include <string.h>
20 
21 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
22 #  include <config.h>
23 #endif
24 
25 /* Define the following to use this test against your installed libpng, rather
26  * than the one being built here:
27  */
28 #ifdef PNG_FREESTANDING_TESTS
29 #  include <png.h>
30 #else
31 #  include "../../png.h"
32 #endif
33 
34 static int
read_png(FILE * fp)35 read_png(FILE *fp)
36 {
37    png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
38    png_infop info_ptr = NULL;
39    png_bytep row = NULL, display = NULL;
40 
41    if (png_ptr == NULL)
42       return 0;
43 
44    if (setjmp(png_jmpbuf(png_ptr)))
45    {
46       png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
47       if (row != NULL) free(row);
48       if (display != NULL) free(display);
49       return 0;
50    }
51 
52    png_init_io(png_ptr, fp);
53 
54    info_ptr = png_create_info_struct(png_ptr);
55    if (info_ptr == NULL)
56       png_error(png_ptr, "OOM allocating info structure");
57 
58    png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0);
59 
60    png_read_info(png_ptr, info_ptr);
61 
62    {
63       png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
64 
65       /* Failure to initialize these is harmless */
66       row = malloc(rowbytes);
67       display = malloc(rowbytes);
68 
69       if (row == NULL || display == NULL)
70          png_error(png_ptr, "OOM allocating row buffers");
71 
72       {
73          png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
74 #        ifdef PNG_READ_INTERLACING_SUPPORTED
75             int passes = png_set_interlace_handling(png_ptr);
76 #        else /* !READ_INTERLACING */
77             int passes = png_get_interlace_type(png_ptr, info_ptr) ==
78                PNG_INTERLACE_ADAM7 ? PNG_INTERLACE_ADAM7_PASSES : 1;
79 #        endif /* !READ_INTERLACING */
80          int pass;
81 
82          png_start_read_image(png_ptr);
83 
84          for (pass = 0; pass < passes; ++pass)
85          {
86             png_uint_32 y = height;
87 
88 #           ifndef PNG_READ_INTERLACING_SUPPORTED
89                if (passes == PNG_INTERLACE_ADAM7_PASSES)
90                   y = PNG_PASS_ROWS(y, pass);
91 #           endif /* READ_INTERLACING */
92 
93             /* NOTE: this trashes the row each time; interlace handling won't
94              * work, but this avoids memory thrashing for speed testing.
95              */
96             while (y-- > 0)
97                png_read_row(png_ptr, row, display);
98          }
99       }
100    }
101 
102    /* Make sure to read to the end of the file: */
103    png_read_end(png_ptr, info_ptr);
104    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
105    free(row);
106    free(display);
107    return 1;
108 }
109 
110 int
main(void)111 main(void)
112 {
113    /* Exit code 0 on success. */
114    return !read_png(stdin);
115 }
116