lavc: remove the extended_data workarounds.

All decoders should now handle it properly.
lavc: use buf[0] instead of data[0] as the indicator of an allocated frame

data[0] may be NULL for valid frames with hwaccel pixel formats.
lavc: remove a pointless check in decode_audio4()

av_frame_unref() works fine on unallocated frames.
lavc/decode_video(): always unref the frame if there is no output in decode_video

Not just on failure. This is the same thing that is done in the audio
path and should prevent leaks in decoders that allocate a frame, but
then end up not writing into it.
frame: copy flags in av_frame_copy_props()

Flags can be considered metadata (at least those that are defined now).
frame: cosmetics, reindent
lavc: rework handling of refcounted_frames=0

Use only proper AVFrame API (no assigning of whole frames, since that
hardcodes sizeof(AVFrame) into lavc).

Make a copy of the side data, so the caller can use av_frame_unref/free
on non-refcounted frames, eliminating the need for
avcodec_get_frame_defaults()/avcodec_free_frame().
ac3dec: make drc_scale exponentially

The a52 spec suggests that "partial compression" should scale the
drc value in this manner.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dv: use AVFrame API properly
avcodec: Use av_reallocp where suitable

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: detect Solaris libc

Add preprocessor flags for API availability as necessary.

Signed-off-by: Diego Biurrun <diego@biurrun.de>
configure: Prefix libc-related variables with "libc_"

Simplifies host/target libc detection splitting.
Merge commit 'e5419709f50593769037ab77d7102f82d9260784'

* commit 'e5419709f50593769037ab77d7102f82d9260784':
  lavc: remove the extended_data workarounds.

Conflicts:
	libavcodec/utils.c

One hunk is not merged as not all codecs are updated yet

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avframe: add codec-independent stereoscopic metadata
h264: parse frame packing arrangement SEI messages and save relevant stereo3d information
libx264: set frame packing information when relevant information is found
mpeg12dec: parse frame packing arrangement user_data and save relevant stereo3d information
mpeg12enc: set frame packing information when relevant metadata is found
hevc: parse frame packing arrangement SEI messages and save relevant stereo3d information
Merge commit 'd4f0f2d1e80b76260eb6b9cdde472ac069dfda56'

* commit 'd4f0f2d1e80b76260eb6b9cdde472ac069dfda56':
  lavc: use buf[0] instead of data[0] as the indicator of an allocated frame

Conflicts:
	libavcodec/utils.c

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