API break in commit 83937c6

In 83937c6, the signature of `oapvm_create()` was changed. This broke ffmpeg build when liboapv is enabled.

What version check or guard can I use when patching ffmpeg to avoid this?

Thanks.

Start by comparing the oapvm_create() signature before and after commit 83937c6, then inspect the ffmpeg integration path used when liboapv is enabled. Determine what version check or compatibility guard can distinguish the signatures, and confirm that the proposed ffmpeg patch builds against the affected liboapv versions.

Written by the indexing model from the issue text.