lavc/exr: use size_t instead of int for sizes.

Fix a segfault on 64-bits archs.
lavf: rescale duration for chained muxers.

Fix trac ticket #2300 because the duration of the segments
was computed using the timestamp of the last packet plus its
duration using the 1/90000 default time base instead of using
the chained muxer time base.
lavfi/af_aresample: fix layout consistency check.

If the channel layout is unknown, lswr will internally use
the default one for the corresponding number of channels.
lavfi/af_aresample: fix info log for unknown layouts.
lavf/avio: check for : in filenames for protocols.

If the first "special" character in a filename is a comma,
it can introduce protocol options, but only if there is a
colon at the end. Otherwise, it is just a filename with a
comma.

Fix trac ticket #2303.
exr: track channels properties

Needed for proper decoding of channels with subsampling
and also for remaining compression methods.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
exr: s/bits_per_color_id/pixel_type

Previous naming was misleading.

Also fix wrong message about missing
support for 32-bit unsigned int pixel type.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
exr: fix error message when pixel type is not set

This only happens with missing chlist attribute from header.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
exr: pxr24 decompression

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avformat/lavfi: force probesize to cover at least 30 frames

This ensures that fps and other values are estimated correctly,
the probesize also is intended to limit disk/protocol reads which
does not apply to lavfi inputs at all.

Fixes Ticket1051

Something similar could be usefull to other input devices

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