I have checked out the latest version of ffmpeg from Git repository and for the last week when I try to compile it I get ERROR: opencv not found If you think configure made a mistake, make sure you are using the latest version from Git. If the latest version fails, report the problem to the ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net. Include the log file "config.log" produced by configure as this will help solve the problem. I have the opencv libraries installed. The error comes from the following: BEGIN /tmp/ffconf.N7phMWii.c 1 #include <opencv2/core/core_c.h> 2 #include <stdint.h> 3 long check_cvCreateImageHeader(void) { return (long) cvCreateImageHeader; } 4 int main(void) { int ret = 0; 5 ret |= ((intptr_t)check_cvCreateImageHeader) & 0xFFFF; 6 return ret; } END /tmp/ffconf.N7phMWii.c gcc -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600 -DPIC -I/usr/include/opencl-utils -std=c11 -fomit-frame-pointer -fPIC -pthread -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/opencv -c -o /tmp/ffconf.JalceQGi.o /tmp/ffconf.N7phMWii.c gcc -L/usr/local/lib64 -Wl,--as-needed -Wl,-z,noexecstack -I/usr/include/opencv -o /tmp/ffconf.Fy5RqLpT /tmp/ffconf.JalceQGi.o -lopencv_shape -lopencv_stitching -lopencv_superres -lopencv_videostab -lopencv_aruco -lopencv_bgsegm -lopencv_bioinspired -lopencv_ccalib -lopencv_cvv -lopencv_dnn -lopencv_dpm -lopencv_fuzzy -lopencv_hdf -lopencv_line_descriptor -lopencv_optflow -lopencv_plot -lopencv_reg -lopencv_saliency -lopencv_stereo -lopencv_structured_light -lopencv_rgbd -lopencv_surface_matching -lopencv_tracking -lopencv_datasets -lopencv_text -lopencv_face -lopencv_video -lopencv_ximgproc -lopencv_calib3d -lopencv_features2d -lopencv_flann -lopencv_xobjdetect -lopencv_objdetect -lopencv_ml -lopencv_xphoto -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_photo -lopencv_imgproc -lopencv_core -lopencore-amrwb -lopencore-amrnb -lmp3lame -lgsm -lass -lcrystalhd -lm -llzma -lbz2 -lz -pthread /tmp/ffconf.JalceQGi.o: In function `cvPointFrom32f': ffconf.N7phMWii.c:(.text+0x5ca): undefined reference to `cvRound' ffconf.N7phMWii.c:(.text+0x5e2): undefined reference to `cvRound' /tmp/ffconf.JalceQGi.o: In function `cvReadInt': ffconf.N7phMWii.c:(.text+0xf00): undefined reference to `cvRound' collect2: error: ld returned 1 exit status This is from config.log. I don't know what the exact change is, but this code needs to be compiled with g++ not gcc. Any assistance is appreciated. Paolo