vfwcap: Add fallback define for HWND_MESSAGE

Some obsolete versions of the MinGW32 runtime (<4.0.0) lack the definition.
vc1: Fix the skip condition

As written in the comment above, skip must be added only if a
start code is found.
mpeg: Write H264 streams at offset 2

It hints that the content is H264 according to HD-DVD.
configure: update libvpx_vp9_encoder check

Required to add support for the aq_mode setting.
Any libvpx snapshot prior to 1.3.0 is not recommended for vp9 encoding for that matter.

Reviewed-by: James Zern <jzern@google.com>
Signed-off-by: James Almer <jamrial@gmail.com>
Merge commit 'ab56fabe6294524e99815451ad01e4ff50c6d734'

* commit 'ab56fabe6294524e99815451ad01e4ff50c6d734':
  vfwcap: Add fallback define for HWND_MESSAGE

The merged commit reverts the HWND_MESSAGE removial, and adds a #ifndef around
    commit 8bc52dbd9dffb1b2fa4a6aeed2d298d036b619b2
        vfwcap: Drop fallback VfW defines
        The defines were added long ago when MinGW still lacked them.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'a4d3c20035946cbc1509aec2dc28d51c2a2f9a8e'

* commit 'a4d3c20035946cbc1509aec2dc28d51c2a2f9a8e':
  vc1: Fix the skip condition

Conflicts:
	libavcodec/vc1_parser.c

See: ede411dd03950b91c6346f2a3ae0e7546555f42f
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '4e9e6fa99f3ff83cedbf6c378d62065ae419a3b9'

* commit '4e9e6fa99f3ff83cedbf6c378d62065ae419a3b9':
  mpeg: Write H264 streams at offset 2

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/snowenc: remove out-commented assert

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/nsvdec: fix out-commented asserts so the function names exist

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/utils: remove assert that tests the same condition as the if() directly above

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
os_support: Adjust an outdated #endif comment
doc: fix a typo

Signed-off-by: Diego Biurrun <diego@biurrun.de>
libxvid: K&R formatting cosmetics

Signed-off-by: Diego Biurrun <diego@biurrun.de>
h264: fully check cropping amount from sps

Even if sps.crop is true, the cropping amount may be zero.
Fixes a sample with a valid but broken container cropping.
libx264: fix -b_qfactor and -chromaoffset

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/rtpdec_h261: Fix sanity checks

Fixes mbap and quant

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '4c8bd8ddb049950347a5018fecbca7ee25d48c44'

* commit '4c8bd8ddb049950347a5018fecbca7ee25d48c44':
  os_support: Adjust an outdated #endif comment

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '56a721f020273d69daa8dcb0d99e42a43a0a0d4d'

* commit '56a721f020273d69daa8dcb0d99e42a43a0a0d4d':
  doc: fix a typo

Conflicts:
	doc/APIchanges

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '0a024268261d05ccdcf7e03c85fb78d22037a464'

* commit '0a024268261d05ccdcf7e03c85fb78d22037a464':
  libxvid: K&R formatting cosmetics

Conflicts:
	libavcodec/libxvid.c
	libavcodec/libxvid_rc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'e87f5e4e5f2e2e36b0b7826d708cda7049877af0'

* commit 'e87f5e4e5f2e2e36b0b7826d708cda7049877af0':
  h264: fully check cropping amount from sps

Conflicts:
	libavcodec/h264_slice.c

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