On 10/30/2017 05:41 PM, Pali Rohár wrote: > On Monday 30 October 2017 17:30:53 Hans Verkuil wrote: >> Hi Pavel, >> >> On 10/28/2017 09:57 PM, Pavel Machek wrote: >>> Add support for simple SDL test application. Allows taking jpeg >>> snapshots, and is meant to run on phone with touchscreen. Not >>> particulary useful on PC with webcam, but should work. >> >> When I try to build this I get: >> >> make[3]: Entering directory '/home/hans/work/src/v4l/v4l-utils/contrib/test' >> CCLD sdlcam >> /usr/bin/ld: sdlcam-sdlcam.o: undefined reference to symbol 'log2@@GLIBC_2.2.5' >> //lib/x86_64-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line >> collect2: error: ld returned 1 exit status >> Makefile:561: recipe for target 'sdlcam' failed >> make[3]: *** [sdlcam] Error 1 >> make[3]: Leaving directory '/home/hans/work/src/v4l/v4l-utils/contrib/test' >> Makefile:475: recipe for target 'all-recursive' failed >> make[2]: *** [all-recursive] Error 1 >> make[2]: Leaving directory '/home/hans/work/src/v4l/v4l-utils/contrib' >> Makefile:589: recipe for target 'all-recursive' failed >> make[1]: *** [all-recursive] Error 1 >> make[1]: Leaving directory '/home/hans/work/src/v4l/v4l-utils' >> Makefile:516: recipe for target 'all' failed >> make: *** [all] Error 2 >> >> I had to add -lm -ldl -lrt to sdlcam_LDFLAGS. Is that correct? > > Is not for <<undefined reference to symbol 'log2@@GLIBC_2.2.5'>> needed > just -lm? log2 should be in mathematical library. > Sorry, I was unclear: after adding -lm I got an unresolved for dl_open, after adding -ldl I got an unresolved on shm_open. Only after using all three did it compile. Regards, Hans
