[FFmpeg-user] Configure says it can't find openssl

Moritz Barsnick barsnick at gmx.net
Mon Aug 12 16:30:31 EEST 2019

On Mon, Aug 12, 2019 at 14:47:27 +0200, Reindl Harald wrote:
> Am 12.08.19 um 14:30 schrieb Simon Brown:
> > I run the following configure script using the latest ffmpeg pulled from
> > github.

> you don't say which version of ffmpeg you try to build [...]

Simon did say so.

> [...] and your openssl as well as your compiler are old

I build quite successfully with much older gcc and openssl. (I
shouldn't, but I do.)

> gcc -march=armv7-a -Wl,--as-needed -Wl,-z,noexecstack -o
> /tmp/ffconf.wZNnjr13/test /tmp/ffconf.wZNnjr13/test.o -lssl -lcrypto
> /usr/lib/gcc/arm-angstrom-linux-gnueabi/4.9.3/../../../libssl.so: error:
> undefined reference to 'sk_free'

This looks like libcrypto.so isn't providing the symbols it is supposed
to. My guess is that /usr/lib/libcrypto.so is broken. (Or is
accidentally version 1.1.0, where the symbols were renamed, and which
therefore wouldn't fit to libssl.so 1.0.1.)

Actually, with 1.0.1, you shouldn't be getting this far, because those
quoted lines are the check for OPENSSL_init_ssl we see here:

> /tmp/ffconf.wZNnjr13/test.o:test.c:function check_OPENSSL_init_ssl:
> error: undefined reference to 'OPENSSL_init_ssl'
> /tmp/ffconf.wZNnjr13/test.o:test.c:function check_OPENSSL_init_ssl:
> error: undefined reference to 'OPENSSL_init_ssl'
> collect2: error: ld returned 1 exit status

This check should fail in compilation (OPENSSL_init_ssl not being
defined in the headers), not in linking.

The subsequent test for SSL_library_init on the other hand should
succeed with 1.0.1, but it fails in your log (in compilation).

This hints at that you, Simon, may have the openssl headers for 1.1.x,
but the libraries for 1.0.x (or even mixed libraries). It looks a bit
broken, sorry. Did you compile openssl yourself? Did you first install
1.0.x, then 1.1.x, or vice versa, and failed to clean up inbetween?


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