Avoid a race condition between seeking and stopping.
Re-init avcodec context on seeks with DXVA too.
Remove write-only bDXVA variable
Move hwaccel_context cleanup into the AVCodecContext cleanup
Refactor playback init checks into an event instead of a critical section

Its enough to wait for the action to finish, we don't need to lock code
execution.
Wait for the seek to finish before returning to the caller.
Lock the allocator when re-initing the DXVA2 decoder

This avoids a race condition with the allocator being decommited while the
decoder creation is still in progress.
Revert "Wait for the seek to finish before returning to the caller."

This reverts commit 5d444eac2fb31fccefa41fcf35ee3613537bc3c4.

Locking the main thread of several players while the graph is in motion
may result in bad locks, so it should be avoided.
Remove H264RandomAccess class and rely on avcodec instead
Remove stdint.h in favor of Visual Studio official stdint.h

As of Visual Studio 2010, Microsoft provides their own stdint.h, so this
replacement version is long obsolete.
Disable MPEG-TS H.264 to AVC1 conversion by default

The conversion is not required for any competent decoders. However for
compat reasons still send a AVC1 type as a second media type for legacy
decoders.
Remove entry which was previously forgotten.
Fix handling of WMVA video with the DMO decoder
Only flush the avcodec decoder from the DXVA2 Allocator, not recreate it.

This avoids a crash in some situations when directly after a seek a new
media type occurs as well.
Detect support for DXVA2ExtendedFormat, instead of only supporting madVR
Use  m_bDXVAExtFormatSupport as a proper boolean.
LAV Audio: Fix a deadlock when changing bitstreaming settings when paused.
Move plane/stride calculation out of the individual pixfmt converters
Support different image height/buffer height during pixfmt conversions
Do not send dwControlFlags for only the MPEG2 Chroma Location info

MPEG2 chroma location is the default for 4:2:0, and the information
is as such not really useful, and not worth the extra reconnection cycle.