format = V4L2_PIX_FMT_YUYV; break; 可知指定 -y后格式是V4L2_PIX_FMT_YUYV 线程函数cam_thread中有调用如下图像格式转换函数 /* * If capturing in YUV mode convert to JPEG now. * This compression requires many CPU cycles, so try to avoid YUV format. * Getting JPEGs straight from the webcam...