Building against ffmpeg libraries from jessie-backports causes version conflict warnings

[Matt]

I'm trying to build against libavformat-dev, libavcodec-dev, and
libavutil-dev from jessie-backports. When I build, I get these
warnings: 

/usr/bin/ld: warning: libavcodec.so.56, needed
by //usr/lib/x86_64-linux-gnu/libchromaprint.so.0, may conflict with
libavcodec.so.57

/usr/bin/ld: warning: libavutil.so.54, needed
by //usr/lib/x86_64-linux-gnu/libchromaprint.so.0, may conflict with
libavutil.so.55

It looks like this is the issue:
- In jessie-backports, libavcodec-dev depends on libavcodec57, and
libavutil-dev depends on libavutil55
- In jessie-backports, libavformat-dev depends on libavformat57, which
depends on libchromaprint0 from jessie, which depends on libavcodec56
and libavutil54. Thus, libavcodec56 and libavutil54 conflict with
libavcodec57 and libavutil55.

It seems like the most obvious fix would be backporting libchromaprint0
from stretch, as it correctly depends on libavcodec57 and libavutil55 in
stretch.