If ffmpeg is compiled WITH_RTMP it links with multiple versions of openssl causing problems. I have only seen this issue since upgrading to openssl 1.0.1 recently.

When building multimedia/rtmpdump it warns about finding multiple openssl versions to link against.

From the rtmpdump build --
/usr/bin/ld: warning: libssl.so.6, needed by /usr/local/lib/librtmp.so, may conflict with libssl.so.8
/usr/bin/ld: warning: libcrypto.so.6, needed by /usr/local/lib/librtmp.so, may conflict with libcrypto.so.8

When ffmpeg is compiled it brings in both versions -- 
cd /usr/ports/multimedia/ffmpeg
make WITH_RTMP=yes
find work -name libavformat.so | xargs ldd | grep ssl
	libssl.so.8 => /usr/local/lib/libssl.so.8 (0x8025f4000)
	libssl.so.6 => /usr/lib/libssl.so.6 (0x805f8f000)
find work -name libavformat.so | xargs ldd | grep crypto
	libcrypto.so.6 => /lib/libcrypto.so.6 (0x8061e0000)
	libcrypto.so.8 => /usr/local/lib/libcrypto.so.8 (0x80657c000)

When this build of ffmpeg is then used to build graphics/blender it causes blender to crash when a python script tries to use ssl.

How-To-Repeat: cd /usr/ports/multimedia/ffmpeg
make WITH_RTMP=yes
find work/ -name libavformat.so | xargs ldd | grep ssl
find work/ -name libavformat.so | xargs ldd | grep crypto

The only way I know to prove it causes problems is build graphics/blender with ffmpeg enabled and when run enable an addon that uses ssl such as network render or renderfarm.fi