Fixes ticket #1218

Fixes rare race condition leading to null pointer dereferences.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This should fix build (include is necessary for ff_get_buffer).

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

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

Successfully opening a device altered the ret variable, making the function
not cleanup properly and return an incorrect value for errors that happened
afterwards.
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

samples created with

"cjpeg -grayscale -sample 1x3 / 1x4 / 3x1 / 3x3 / 4x1 / 4x3 / 4x4"

http://www.datafilehost.com/download-d828329d.htmlSigned-off-by: Michael Niedermayer <michaelni@gmx.at>

Core I7 (Sandy Bridge) 135 to 107 cycles
Core i5 (Arrandale) 162 to 142 (Thanks to Christophe Gisquet for testing)
Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

* qatar/master:
  golomb: use unsigned arithmetics in svq3_get_ue_golomb()
  x86: float_dsp: fix loading of the len parameter on x86-32
  takdec: fix initialisation of LOCAL_ALIGNED array
  takdec: fix initialisation of LOCAL_ALIGNED array

Conflicts:
	libavcodec/rv30.c
	libavcodec/svq3.c
	libavcodec/takdec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

* commit '57231e4d':
  tak: demuxer, parser, and decoder

Not merged as requested by Author and Maintainer of tak in FFmpeg.
I just merged a few typo fixes and minor cosmetic improvments.

Conflicts:
	Changelog
	libavcodec/Makefile
	libavcodec/allcodecs.c
	libavcodec/avcodec.h
	libavcodec/tak.c
	libavcodec/tak.h
	libavcodec/tak_parser.c
	libavcodec/takdec.c
	libavcodec/version.h
	libavformat/takdec.c
	libavformat/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Justin's version has more features but is otherwise equivalent from the
point of view of the syntax.

Spotted by ubitux.

* commit '096abfa1':
  parser: fix large overreads
  bitstream: add get_bits64() to support reading more than 32 bits at once
  arm: detect cpu features at runtime on Linux

Conflicts:
	libavcodec/parser.c
	libavformat/mpegts.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

Renaming because of name conflict
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'b3267559':
  arm: rename ARMVFP config symbol to VFP
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '637606de':
  configure: arm: make _inline arch ext symbols depend on inline_asm
  arm: use HAVE*_INLINE/EXTERNAL macros for conditional compilation

Conflicts:
	configure
	libavcodec/arm/dca.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '7f2b3dca':
  configure: arm: check inline and external asm support for extensions
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'c6ebc9fa':
  configure: add check_insn function
  configure: clean up check_inline_asm and check_as functions
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'f0fe245b':
  configure: arm: set fast_clz and fast_unaligned in cpuflags section
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '1234c66a':
  configure: arm: detect toolchain default arch version
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '9ebd45c2':
  configure: do not bypass cpuflags section if --cpu not given
  dct-test: arm: indicate required cpu features for optimised funcs
  snow: fix build after 594d4d5d
  arm: fix use of uninitialised value in ff_fft_fixed_init_arm()
  avpicture: Don't assume a valid pix fmt in avpicture_get_size

Conflicts:
	libavcodec/avpicture.c
	libavcodec/snow.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

This prevents undefined behaviour of signed left shift if the coded
value is larger than 2^31. Large values are most likely invalid and
caused errors or by feeding random.

Validate every use of svq3_get_ue_golomb() and changed the place there
the return value was compared with negative numbers. dirac.c was clean,
fixed rv30 and svq3.

Triggered by the sample for trac ticket #1726.