游戲項目是基于cocos2d-x開發的，但線上發現一個bug就是玩家在設置完自定義頭像后直接閃退。凡是在設置該玩家頭像的地方，游戲就直接閃退。最終定位到的問題是圖片數據源有問題，我的機器是win7，圖片能預覽，但同事xp系統該圖片是無法預覽的，默認的系統自帶的圖片查看工具也無法顯示圖片。

把圖片拉到sublime text中，查看文件二進制，發現它并非一個完整的jpeg格式

沒有jpeg格式的結束標識0xff? 0xd9

?

我在windows下調試代碼，發現是在CCImageCommon_cpp.h中的_initWithJpgData方法調用jpeg_finish_decompress函數時程序直接退出了

bool CCImage::_initWithJpgData(void * data, int nSize, bool bNeedDecode /*= false*/)
{
??? int nRandomBytes = 0;
??? if (bNeedDecode) nRandomBytes = RANDOM_BYTES;

??? if (bNeedDecode)
??? {
??????? data = (unsigned?char *)data + nRandomBytes;
??????? nSize = nSize - nRandomBytes;
??? }

??? /* these are standard libjpeg structures for reading(decompression) */
??? struct jpeg_decompress_struct cinfo;
??? struct jpeg_error_mgr jerr;
??? /* libjpeg data structure for storing one row, that is, scanline of an image */
??? JSAMPROW row_pointer[1] = {0};
??? unsigned?long location = 0;
??? unsigned?int i = 0;

??? bool bRet = false;
??? do?
??? {
??????? /* here we set up the standard libjpeg error handler */
??????? cinfo.err = jpeg_std_error( &jerr );

??????? /* setup decompression process and source, then read JPEG header */
??????? jpeg_create_decompress( &cinfo );

??????? jpeg_mem_src( &cinfo, (unsigned?char *) data, nSize );

??????? /* reading the image header which contains image information */
??????? jpeg_read_header( &cinfo, true );

??????? // we only support RGB or grayscale
??????? if (cinfo.jpeg_color_space != JCS_RGB)
??????? {
??????????? if (cinfo.jpeg_color_space == JCS_GRAYSCALE || cinfo.jpeg_color_space == JCS_YCbCr)
??????????? {
??????????????? cinfo.out_color_space = JCS_RGB;
??????????? }
??????? }
??????? else
??????? {
??????????? break;
??????? }

??????? /* Start decompression jpeg here */
??????? jpeg_start_decompress( &cinfo );

??????? /* init image info */
??????? m_nWidth? = (short)(cinfo.image_width);
??????? m_nHeight = (short)(cinfo.image_height);
??????? m_bHasAlpha = false;
??????? m_bPreMulti = false;
??????? m_nBitsPerComponent = 8;
??????? row_pointer[0] = new?unsigned?char[cinfo.output_width*cinfo.output_components];
??????? CC_BREAK_IF(! row_pointer[0]);

??????? m_pData = new?unsigned?char[cinfo.output_width*cinfo.output_height*cinfo.output_components];
??????? CC_BREAK_IF(! m_pData);

??????? /* now actually read the jpeg into the raw buffer */
??????? /* read one scan line at a time */
??????? while( cinfo.output_scanline < cinfo.image_height )
??????? {
??????????? jpeg_read_scanlines( &cinfo, row_pointer, 1 );
??????????? for( i=0; i<cinfo.image_width*cinfo.output_components;i++)
??????????? {
??????????????? m_pData[location++] = row_pointer[0][i];
??????????? }
??????? }

??????? jpeg_finish_decompress( &cinfo );
??????? jpeg_destroy_decompress( &cinfo );
??????? /* wrap up decompression, destroy objects, free pointers and close open files */???????
??????? bRet = true;
??? } while (0);

??? CC_SAFE_DELETE_ARRAY(row_pointer[0]);
??? return bRet;
}

后面我用jpegtran(https://github.com/imagemin/jpegtran-bin)工具復制有問題的圖片時， 也提示錯誤了

?

參考文章：

[1] 小議libjpeg解壓損壞文件時的錯誤處理

[2] JPEG File Layout and Format

解決方案可以參考這篇文章：libjpeg解壓損壞文件時的錯誤處理

轉載于:https://www.cnblogs.com/meteoric_cry/p/3998425.html

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