lavfi/overlay: add enable expression
authorStefano Sabatini <stefasab@gmail.com>
Mon, 8 Apr 2013 10:22:48 +0000 (12:22 +0200)
committerStefano Sabatini <stefasab@gmail.com>
Wed, 10 Apr 2013 11:11:27 +0000 (13:11 +0200)
commit006e20bd3655443e2d709dfbee468af2805a994a
treeb5528eebdf3d61a5fc236b56ec22716c7be401d5
parentcc3edd99a678b9ecfe70cb3632029cb8db40e7f9
lavfi/overlay: add enable expression

This expression is useful to enable/disable overlaying on the fly.

Note that this can't be easily done relying on the filtergraph structure,
since this implies caching issues or a null frame overlaying in the best
case, which is better avoided for performance and convenience reasons.
doc/filters.texi
libavfilter/version.h
libavfilter/vf_overlay.c