libvpx: Compiling simple encoder example

Question

I am trying to compile Googles libvpx encoder example which can be found here:

http://www.webmproject.org/docs/vp8-sdk/example__simple__encoder.html

Unfortunately libvpx seems to miss dependencies:

/usr/local/lib/libvpx.a(rdopt.c.o): In function `vp8_initialize_rd_consts':
(.text+0x3519): undefined reference to `pow'
/usr/local/lib/libvpx.a(onyx_if.c.o): In function `vp8_create_compressor':
(.text+0x34a8): undefined reference to `log'
/usr/local/lib/libvpx.a(psnr.c.o): In function `vp8_mse2psnr':
(.text+0x1f): undefined reference to `log10'
/usr/local/lib/libvpx.a(postproc.c.o):(.text+0xa4): undefined reference to `exp'
/usr/local/lib/libvpx.a(postproc.c.o): In function `vp8_gaussian':
(.text+0x11d2): undefined reference to `exp'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0x539): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0x5b6): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0x8cb): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0xb52): undefined reference to `sqrt'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0xca3): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_init_second_pass':
(.text+0x22b2): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_init_second_pass':
(.text+0x2376): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x26c6): undefined reference to `log'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x26df): undefined reference to `log'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x26f6): undefined reference to `log'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x2f39): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x300e): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x3790): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x387d): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x3c6d): undefined reference to `pow'
/usr/local/lib/libvpx.a(firstpass.c.o):(.text+0x486f): more undefined references to `pow' follow
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x7208): undefined reference to `sqrt'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x7264): undefined reference to `sqrt'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x72b8): undefined reference to `sqrt'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x7330): undefined reference to `sqrt'
/usr/local/lib/libvpx.a(firstpass.c.o): In function `vp8_second_pass':
(.text+0x73c1): undefined reference to `sqrt'

I'm using Fedora 18 x64 and have built libvpx from source (make + make install), so everything should be in place. Anybody else who ran into this problem?

Answer 1

You're missing to link the math library, -lm

Answer 2

Are you linking with libvpx statically? You can just use -lvpx to link dynamically. I didn't run into this problem (ubuntu 12.10, x64, vpx built from sources, gcc 4.7.2).

At any rate, pow, exp, sqrt, etc, are part of libm, the maths library that comes with the compiler, so just add -lm to you linker flags and those errors should go away.