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