The parameter was being passed as a pointer instead of being
dereferenced

The field orders of retro 2x and linear 2x deinterlace shaders were
inverted.  Note that yadif 2x does not act the same in this regard, its
field ordering is correct due to how it operates.

Set the starting browse path to the directory of the current file used
for the source.

Don't display the warning for using two software encoders at the same
time if the stream encoder is not x264

Warns users that two separate QSV encoders can't be active at the same
time.

This should be considered a temporary solution to two issues:
1.) Encoders need to be able to report these errors themselves
2.) If the QSV encoder is ever changed to allow more than one encoder at
    the same time this should be removed

Currently, multiple QSV encoders cannot be active at the same time
(otherwise it will crash).  This is a temporary solution to prevent
crashes from occurring when more than one QSV encoder tries to start up
at the same time.

Additionally, in the future there should be a way for encoders to be
able to communicate with the front-end when an error such as this
occurs.

There's no point in the filter continuing its processing if there's
nothing to draw.

If the parent source of a scroll filter has a 0 width or 0 height, the
scroll filter would do a division by zero on the size_i variable, which
would then cause the offset variable to perpetually have a non-finite
value, thus preventing the scroll filter from rendering properly after
that due to the non-finite offset value being uploaded to the shader.

(Note: this commit also modifies the obs-filters and test-input modules)

Changes the obs_source_process_filter_begin return type so that it
returns true/false to indicate that filter processing should or should
not continue (for example if the filter is bypassed or if there's some
other sort of issue that causes the filtering to fail)

Under certain circumstances (when there's no text and a filter is
applied for example) the freetype 2 text source would still draw.

On outputs that use already-active video/audio encoder, the audio
pruning to sync up audio packets with video packets doesn't always get
called (for example if the video pruning function was called).  Always
prune excess starting audio packets.

Specifies whether packets were pruned or not

libff: Fix a race condition crash when handling clocks

How to crash:
1. Use recent ffmpeg shared libraries.
2. Add a ffmpeg_source, a small static picture (e.g. jpeg) with loop
3. After a while of high cpu usage, it crashed. Seems reproduced more
easily on faster computer

Closes #533

Fixes issues with invalid textures causing huge output or large black
regions to be rendered.

Fixes a race condition during shutdown where the dialogs aren't deleted
before another render attempt occurs, by which time the sources are
already freed, resulting in a crash.

This is supposed to assign -1 to the sampler_id to indicate that no
sampler need be assigned for the texture, but instead it was leaving the
variable with uninitialized data, resulting in a crash when used.

From MSDN: "The behavior of the least significant bit of the return value
is retained strictly for compatibility with 16-bit Windows applications
(which are non-preemptive) and should not be relied upon."

This caused problems with hotkeys firing if the user pressed a hotkey key
in another application, followed by the modifier keys at any other time.
OBS would then think the hotkey key was just pressed based on the was_down
behavior and incorrectly trigger a hotkey event.

Fixes 0000443.

--collection [name] allows setting the starting scene collection
--profile [name] allows setting the starting profile

There's no need to duplicate the packet as the reference count will be 1
after the av_read_frame call. Duplicating causes heap corruption when a
synthetic clock packet is duplicated and assigned the buffer from the
stack-based temporary packet which is then double-freed by the decoder
thread.

To be able to use index buffers, they must also be bound to a vertex
array object along with the vertex buffers.

Ideally, if there are multiple index buffers for a vertex buffer,
separate VAOs should be created for each combination.

GL_ARRAY_BUFFER is for vertex buffers, GL_ELEMENT_ARRAY_BUFFER is for
index buffers.

The 'tier' parameter is used with the NVENC HEVC encoder, not with the
AVC encoder.

When using QSV is used on a windows 7 machine with a dedicated card, you
have to fake a monitor connection to your Intel graphics to be able to
use QSV.  If you do not, the initialization will fail with an error.
The error for that situation is not handled properly, and a variable
will be used while null.  Instead, the function should safely return
after that error is received.

Also, do not call ClearData in the destructor unless QSV has been
properly initialized (if m_pmfxENC is null).