lavfi/cropdetect: export cropdetect info to frame metadata

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/blackdetect: support 2 more pixels formats

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/delogo: option show shouldn't affect band

Options "show" and "band" are unrelated and should thus be
independent. However, setting "show" to 1 currently resets "band" to
its default value of 4. While this is documented, this still
surprising and confusing IMHO.

Change this behavior and make "show" and "band" independent from each
other. Update the documentation accordingly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/delogo: band width must be at least 1

We need at least one pixel around the logo to use as known points to
interpolate from. So properly declare the band/t attribute has having
a minimum value of 1.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>