doc: add a tutorial for writing filters.
configure: s/solving/solve

Signed-off-by: Lou Logan <lou@lrcd.com>
doc/ffmpeg: note that -t is also an input option

Signed-off-by: Lou Logan <lou@lrcd.com>
MAINTAINERS: add Trac maintainers

Signed-off-by: Lou Logan <lou@lrcd.com>
avformat: move default for max_analyze_duration into utils.c

this way we can do better tha a single fixed constant value

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: set max analyze duration depending on the circumstances

Fixes Ticket3673

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>