qt中处理jpeg [复制链接]

videocapture.cpp:(.text+0x190): undefined reference to `jpeg_std_error(jpeg_error_mgr*)'
videocapture.cpp:(.text+0x1a8): undefined reference to `jpeg_CreateCompress(jpeg_compress_struct*, int, unsigned int)'
videocapture.cpp:(.text+0x1d0): undefined reference to `jpeg_set_defaults(jpeg_compress_struct*)'
videocapture.cpp:(.text+0x1e0): undefined reference to `jpeg_set_quality(jpeg_compress_struct*, int, int)'
videocapture.cpp:(.text+0x1ec): undefined reference to `jpeg_start_compress(jpeg_compress_struct*, int)'
videocapture.cpp:(.text+0x200): undefined reference to `jpeg_write_scanlines(jpeg_compress_struct*, unsigned char**, unsigned int)'
videocapture.cpp:(.text+0x22c): undefined reference to `jpeg_finish_compress(jpeg_compress_struct*)'
videocapture.cpp:(.text+0x250): undefined reference to `jpeg_destroy_compress(jpeg_compress_struct*)'
videocapture.cpp:(.text+0x278): undefined reference to `jpeg_destroy_compress(jpeg_compress_struct*)'

-ljpeg也加了 ，so文件也有，总是这样提示编不过去，qt要怎么用ligjpeg啊？

当时编译时加了-system-jpeg  选项 ，用pixmap可以打开个jpeg图片，正不正确？？ 工具链也可以编译一个bmp转jpeg的c程序。

貌似编译QT库时没有编译libjpeg模块