lavfi/smptebars: fix invalid writes

Signed-off-by: Paul B Mahol <onemda@gmail.com>
bmpenc: get rid of BMPContext as it is unused

Signed-off-by: Paul B Mahol <onemda@gmail.com>
xwdenc: remove unused code

Signed-off-by: Paul B Mahol <onemda@gmail.com>
xbmenc: remove unused code

Signed-off-by: Paul B Mahol <onemda@gmail.com>
doc/filters: put separated geq variables in separate lines

Make clear that they are not aliases for the same variable.
doc/filters: fix erroneously truncated comment on a scale example
rtsp/rtp_read_header: Use RTP_MAX_PACKET_LENGTH instead of 1500

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
rtpdec: Increase max rtp packet size to 8192

Fixes Ticket2314
Fixes connecting to "Ceton InfiniTV4 PCIe & USB"

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