Instead of a linked list constructed at av_register_all(), store them
in a constant array of pointers.
Since no registration is necessary now, this removes some global state
from lavf. This will also allow the urlprotocol layer caller to limit
the available protocols in a simple and flexible way in the following
commits.
This can later be extended to support other AES bit sizes,
encryption, other crypto algorithms, reading the key from a URL, etc.
In order to use it, the key and initialization vector has to be
passed via AVOptions. Since such options can't be passed to
protocols from the command line, the protocol is currently
only for libavformat internal use.
Signed-off-by: Martin Storsjö <martin@martin.st>
