當我嘗試建立這個代碼,行struct my_error_mgr jerr;
給出了錯誤「變量具有不完全類型‘結構my_error_mgr’變量具有不完全類型「結構my_error_mgr」
#import "Engine.h"
#include "jpeglib.h"
@implementation Engine
+(void)test{
struct jpeg_decompress_struct cinfo;
struct my_error_mgr jerr;
FILE * infile;
if ((infile = fopen(filename, "rb")) == NULL) {
fprintf(stderr, "can't open %s\n", filename);
return 0;
}
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = my_error_exit;
if (setjmp(jerr.setjmp_buffer)) {
jpeg_destroy_decompress(&cinfo);
fclose(infile);
return 0;
}
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
(void) jpeg_read_header(&cinfo, TRUE);
jvirt_barray_ptr* coeffs_array;
coeffs_array = jpeg_read_coefficients(&cinfo);
BOOL done = FALSE;
for (int ci = 0; ci < 3; ci++)
{
JBLOCKARRAY buffer_one;
JCOEFPTR blockptr_one;
jpeg_component_info* compptr_one;
compptr_one = cinfo.comp_info + ci;
for (int by = 0; by < compptr_one->height_in_blocks; by++)
{
buffer_one = (cinfo.mem->access_virt_barray)((j_common_ptr)&cinfo, coeffs_array[ci], by, (JDIMENSION)1, FALSE);
for (int bx = 0; bx < compptr_one->width_in_blocks; bx++)
{
blockptr_one = buffer_one[0][bx];
for (int bi = 0; bi < 64; bi++)
{
blockptr_one[bi]++;
}
}
}
}
write_jpeg(output, &cinfo, coeffs_array); // saving modified JPEG to the output file
jpeg_destroy_decompress(&cinfo);
fclose(infile);
}
@end
當我嘗試註釋掉相關的所有行這個錯誤,然後我得到一個EXC_BAD_ACCESS
運行時錯誤的
(void) jpeg_read_header(&cinfo, infile);
我試圖修改已保存的JPEG圖像的DCT係數的iOS與創建一個JPEG隱寫應用程序的最終目標就行了。我有下面的代碼嘗試一個dd一個到每個DCT係數。我正在使用libjpeg庫。代碼是Objective-C和C的組合。
快速提示,變量文件名等於「/ Users/ScottBouloutian/Library/Application Support/iPhone Simulator/7.0.3/Applications/27A0450E-4685- 4C3E-AAC8-A0CC6C85359E/Crypsis.app/screen.jpg「,這是我嘗試修改的JPEG圖像的路徑。
我有什麼問題?它是否像我的文件路徑缺少包含或有問題一樣愚蠢?