ENOTSUP is not defined on some systems

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Luma slices in YUV420 colourspace should have height in multiple of two since
they have the same line of chrominance data corresponding to pair of them.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This fixes false positives of has_codec_delay_been_guessed() for
streams where not every input picture generates an output picture,
such as interlaced H264.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Restore behavior of identifying files with huge id3 tags as
mp3 at AVPROBE_SCORE_MAX/4. This was broken in r25378 and subsequently
removed in r25929.

This only encourages our users to put id3v2 tags on non-mp3 files to opt
into extension based probing.

Locking the decoder against channel config changes in
parse_adts_frame_header() seems to be unnecessary and
streams with channel config changes are reported.

The sample in http://roundup.libav.org/issue999 still works.
Signed-off-by: Janne Grunau <janne-libav@jannau.net>

This avoids having to convert all input data from int16 to float, which is used
internally for encoding.

instead just print a warning

avoids silently truncating the output

Fix segfault on emu edge, to reproduce

make fate-vsynth1-snow
avplay -flags emu_edge tests/data/vsynth1/snow.avi
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

this allows for checking against the actual output size instead of max size.

Also fix some undefined unsigned/signed conversions.