dsputil: remove unused functions copy_block{2, 4, 8, 16}.
mpegvideo: Do REBASE_PICTURE with byte pointers

REBASE_PICTURE (more specifically, this half of it) takes a Picture
pointer that points into one larger struct, finds the offset of
that Picture within the struct and finds the corresponding field
within another instance of a similar struct.

The pointer difference "pic - (Picture*)old_ctx" is a value given
in sizeof(Picture) units, and when applied back on
(Picture*)new_ctx gets multiplied back with sizeof(Picture). Many
compilers seem to optimize out this division/multiplication, but
not all do.

GCC 4.2 on OS X doesn't seem to remove the division/multiplication,
therefore the new pointer didn't turn out to point to exactly
the right place in the new struct since it only had sizeof(Picture)
granularity (and the Picture is not aligned on a sizeof(Picture)
boundary within the encompassing struct). This bug has been present
before 47318953d as well - with H264, pointers to h->ref_list[0][0]
pointed to 88 bytes before h->ref_list[0][0] after the rebase. After
shrinking Picture, the difference ended up even larger, making
writes via such a Picture pointer overwrite other fields at random
in H264Context, ending up in crashes later.

This fixes H264 multithreaded decoding on OS X with GCC 4.2.

Signed-off-by: Martin Storsjö <martin@martin.st>
avisynth: Change demuxer name to avoid conflicts with AVS
configure: Add a comment indicating why uclibc is checked before glibc
configure: Move newlib libc check before mingw libc check

On Cygwin systems MinGW headers can be present if the corresponding
packages have been installed. Since the MinGW libc is checked for
first, this results in newlib getting misdetected as MinGW libc.
x86: hpel: Move {avg,put}_pixels16_sse2 to hpeldsp
Merge commit 'a5ba798c16d0614d982a76755fdd72b37d437170'

* commit 'a5ba798c16d0614d982a76755fdd72b37d437170':
  dsputil: remove unused functions copy_block{2, 4, 8, 16}.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'a65f965c04bfa27adedc0409c14cc05903f483d0'

* commit 'a65f965c04bfa27adedc0409c14cc05903f483d0':
  mpegvideo: Do REBASE_PICTURE with byte pointers

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '29f1fa74225e9fdbab6d590857edbecb51cf74da'

* commit '29f1fa74225e9fdbab6d590857edbecb51cf74da':
  configure: Move newlib libc check before mingw libc check
  avisynth: Change demuxer name to avoid conflicts with AVS

Conflicts:
	configure

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  x86: hpel: Move {avg,put}_pixels16_sse2 to hpeldsp
  configure: Add a comment indicating why uclibc is checked before glibc

Merged-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/bufferqueue: add ff_bufqueue_is_full().
lavfi/af_amerge: check for buffer queue overflows.

Without that test, ff_bufqueue_add silently discards the
oldest buffer, that leaves in[i].nb_samples inconsistent,
and causes later a segfault.
lavfi/af_amerge: set outbuf->audio->channels.

The value is lost because of avfilter_copy_buffer_ref_props().

Fix trac ticket #2217.
lavfi/buffersrc: forward filter_frame errors.

Note: The ret variable was unused.
doc/indevs: itemize examples for the v4l2 device
doc/indevs: document v4l2 options

Reviewed-By: Giorgio Vazzana <mywing81@gmail.com>
vc1dec: fix block_off

Fixes corruption of motion_val

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
vc1dec: fieldtx is only valid for interlaced frames

the fieldtx_plane is not cleared for interlaced fields

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