lavu: Add a fate test for the HMAC API

Signed-off-by: Martin Storsjö <martin@martin.st>
lavf: Add a fate test for the SRTP functions

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: Make the new srtp protocol depend on the rtp protocol

Signed-off-by: Martin Storsjö <martin@martin.st>
srtp: Mark a few variables as uninitialized

This squelches false positive warnings (with gcc) about them being
used uninitalized.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec_mpeg4: Check the return value from malloc

Signed-off-by: Martin Storsjö <martin@martin.st>