VIDEO_RANGE_DEFAULT uses partial range for YUV and full range for RGB.
Previous default was always partial.

VIDEO_RANGE_DEFAULT uses partial range for YUV and full range for RGB.
Previous default was always partial.

Cleans up obs-ffmpeg.c and separates all the logging code to a different
file, which can be enabled with ENABLE_FFMPEG_LOGGING.

This terrible boilerplate code is no longer necessary, as it is now
fixed by the previous commit.

The replay buffer was triggering on both button press and button
release, which is redundant.

Prevents automatic formatting with clang-format

Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed.  Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.

Someone mentioned this format preserves the most quality for a
particular capture card using V4L2.

Remove KSAUDIO_SPEAKER_2POINT1 because it is included in the Windows
SDK. (I'm guessing it wasn't before.)

Redefine 4POINT1 as KSAUDIO_SPEAKER_SURROUND|SPEAKER_LOW_FREQUENCY
instead of KSAUDIO_SPEAKER_QUAD|SPEAKER_LOW_FREQUENCY. See definitions:

FFmpeg 4.1: FL+FR+FC+LFE+BC
WASAPI QUAD: FL+FR+BL+BR (looks wrong)
WASAPI SURROUND: FL+FR+FC+BC
WASAPI LOW_FREQUENCY: LFE

Variable was never used. Clean up both C++ and shader code.

Shuts down browser panels early to ensure that cookie data doesn't
necessarily get lost.

(This commit also modifies the UI, obs-ffmpeg, and obs-output modules)

Fixes a long-time regression where the program would lock up if an
encode call fails.  Shuts down all outputs associated with the failing
encoder and displays an error message to the user.

Ideally, it would be best if a more detailed error could be displayed to
the user about the nature of the error, though the primary problem is
the encoder errors are typically not something the user would be able to
understand.  The current message is a bit of a generic error message;
improvement is welcome.

Another suggestion is to try to have the encoder restart seamlessly,
though it would take a significant amount of work to be able to make it
do something like that properly, and it sort of assumes that encoder
failures are sporadic, which may not necessarily be the case with some
hardware encoders on some systems.  It may be better just to use another
encoder in that case.  For now, seamless restart is ruled out.

Define MSG_NOSIGNAL even if CRYPTO is not defined.

This patch fixes QSV failing with new DCH graphics drivers. QSV is not
initializing under certain conditions when the graphics adapter 0 is not
set to iGFX due to outdated MSDK dispatcher. Updating to MSDK with new
dispatcher to enable proper initialization of QSV encoder with DCH
drivers.

This could happen if writing to a socket which was closed by the peer.

There are cases where alpha is multiplied unnecessarily. This change
attempts to use premultiplied alpha blending for composition.

To keep this change simple, The filter chain will continue to use
straight alpha. Otherwise, every source would need to modified to output
premultiplied, and every filter modified for premultiplied input.

"DrawAlphaDivide" shader techniques have been added to convert from
premultiplied alpha to straight alpha for final output. "DrawMatrix"
techniques ignore alpha, so they do not appear to need changing.

One remaining issue is that scale effects are set up here to use the
same shader logic for both scale filters (straight alpha - incorrectly),
and output composition (premultiplied alpha - correctly). A fix could be
made to add additional shaders for straight alpha, but the "real" fix
may be to eliminate the straight alpha path at some point.

For graphics, SrcBlendAlpha and DestBlendAlpha were both ONE, and could
combine together to form alpha values greater than one. This is not as
noticeable of a problem for UNORM targets because the channels are
clamped, but it will likely become a problem in more situations if FLOAT
targets are used.

This change switches DestBlendAlpha to INVSRCALPHA. The blending
behavior of stacked transparents is preserved without overflowing the
alpha channel.

obs-transitions: Use premultiplied alpha blend, and simplify shaders
because both inputs and outputs use premultiplied alpha now.

Fixes https://obsproject.com/mantis/view.php?id=1108

Logitech C920 web camera will output YUVJ420P which is not supported yet.

The initial DTS for non-fractional framerates was being incorrectly
calculated.  It assumed that the time base was in frames when it was
not.

Closes obsproject/obs-studio#1857

The workarounds were made because of conflicts with running multiple UI
threads at once on macOS, which macOS can't do very well, and would be
susceptible to crashes.  This would cause crashes not only on startup
but seemingly at random when using the browser source on macOS.  The
original "fix" was a hack to try to minimize UI code and browser UI code
from executing at the same time.  The macOS initial scene loading was
deferred until all Qt-related and main window initialization was
completed.  Although this worked to some extent to prevent conflicts, it
made it so that there was an initial period on startup where the entire
UI seemed "blank" for users, and it was still possible for the main UI
thread and the browser UI thread to clash, causing crashes seemingly at
random for users.

The external message pump method of CEF is the solution to the problem,
which is the method which allows the main UI thread to share events with
CEF.  To do this, all CEF operations need to be performed in the UI
thread (Qt's main thread), and CefDoMessageLoopWork() needs to be called
when CefApp::OnScheduleMessagePumpWork callback is triggered.  A number
of other issues had to be solved as well, such as CefBrowser references
getting "stuck" in the Qt event queue.

With this, macOS no longer needs to do the "deferred load" hack, and
browsers are now much more stable and no longer as susceptible to
seemingly random crashes, improving overall program stability when
browsers are used.

Instead of having ffmpeg-mux stored in a data directory, install it to
the primary binary directory.  On windows, this fixes ffmpeg-mux
potentially accessing the wrong FFmpeg libraries (some programs install
them to system32, foolishly), and instead ensures that it uses the ones
that come with the program.  On Linux, ensures that a binary is in its
appropriate directory (/usr/bin or /usr/local/bin rather than a subset
of /usr/share or /usr/local/share).

This changes all opacity scrollers for filters to sliders + scrollers.

Reference: obsproject/obs-studio#1827

The alpha value from the opacity slider was being overwritten.

Closes obsproject/obs-studio#1827

libobs: Add support for limited to full color range conversions when
using RGB or Y800 formats, and move RGB converison for Y800 formats to
the GPU.

decklink: Stop hiding color space/range properties for RGB formats, and
remove "YUV" from "YUV Color Space" and "YUV Color Range".

win-dshow: Remove "YUV" from "YUV Color Space" and "YUV Color Range".

UI: Remove "YUV" from "YUV Color Space" and "YUV Color Range".

Allows the ability to override and use partial range RGB with the
DirectShow and Decklink device sources when partial range RGB is
implemented.  Fixes certain cases where devices could capture RGB in
limited range via HDMI (per the HDMI specs).