jpeg 交叉编译以及接口的使用

使用jpeg版本：jpegsrc.v9a.tar.gz

configure参数：./configure --prefix=/usr/local/jpeglib_arm/ --host=arm-none-linux-gnueabi

之后make； make install

调用jpeg接口

/*将bgr数据转换为jpg图像存储filename: 生成的jpg文件名width height:传入bmp file 的宽和高pBGRBuffer:传入bgr数据*/int convert_to_jpg(char *filename, int width, int height, unsigned char *pBGRBuffer){FILE *fJpg;struct jpeg_compress_struct cinfo;struct jpeg_error_mgr jerr;JSAMPROW row_pointer[1];int row_stride;cinfo.err = jpeg_std_error(&jerr);jpeg_create_compress(&cinfo);fJpg = fopen(filename, "wb");if(fJpg == NULL){debugE("Cannot open file %s\n", filename);return -1;}jpeg_stdio_dest(&cinfo, fJpg);cinfo.image_width = width;cinfo.image_height = height;cinfo.input_components = 3;cinfo.in_color_space = JCS_RGB;jpeg_set_defaults(&cinfo);jpeg_set_quality(&cinfo, 30, TRUE);jpeg_start_compress(&cinfo, TRUE);row_stride = cinfo.image_width * 3;/* JSAMPLEs per row in image_buffer */while (cinfo.next_scanline < cinfo.image_height) {/* jpeg_write_scanlines expects an array of pointers to scanlines. * Here the array is only one element long, but you could pass * more than one scanline at a time if that's more convenient. *///row_pointer[0] = & pBMPBuffer[cinfo.next_scanline * row_stride];row_pointer[0] = &pBGRBuffer[row_stride*(cinfo.image_height - cinfo.next_scanline - 1)];(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);}jpeg_finish_compress(&cinfo);jpeg_destroy_compress(&cinfo);fclose(fJpg);return 0;}