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.
Remove three instances of unnecessary double-buffering. They are not
needed to avoid stalls, and cause increased memory traffic when
measured on Intel HD 530, presumably because texture data will remain
in cache if sampled immediately after write.
(Note: GPU timings from Intel GPA are volatile.)
NV12, 3 Draws:
RGBA -> UYVX: 628 us -> 543 us
UYVX -> Y: 522 us -> 507 us
UYVX -> UV: 315 us -> 187 us
Total, Duration: 1594 us -> 1153 us
Total, GTI Read Throughput: 25.2 MB -> 15.9 MB
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
Fixes handling of the `obs_source_frame::full_range` member variable,
which is often set to false by default by many plugins even when using
RGB, which would cause RGB to be marked as "partial range". This change
is crucial for when partial range RBG support is implemented.
Adds `obs_source_frame2` structure that replaces the `full_range` member
variable with a `range` variable, which uses the `video_range_type` enum
to allow handling default range values. This member variable treats
VIDEO_RANGE_DEFAULT as full range if the format is RGB, and partial
range if the format is YUV.
Also adds `obs_source_output_video2` and `obs_source_preload_video2`
functions which use the `obs_source_frame2` structure instead of the
`obs_source_frame` structure.
When using the original `obs_source_frame`, `obs_source_output_video`,
and `obs_source_preload_video` functions, RGB will always be full range
by default for backward compatibility purposes.
This new scale filter computes pixels by weighing the coverage area of
source pixels over the target pixel. This algorithm works well for both
upsampling and downsampling, but was mainly designed to upscale
high-quality low-resolution sources like RGB/HDMI retro consoles. I've
heard of people using odd workarounds like scaling up to very high
resolutions before scaling back down to preserve pixel shartpness. This
algorithm directly addresses this use-case in a much more direct
fashion.
The Area scale filter does a better job of preserving the thickness of
thin features than the Point filter.
The Area scale filter does not look at source pixels that lie outside
of the target pixel, leading to a much sharper image than Bilinear,
Bicubic, and Lanczos filters.
This filter should interpolate pixels in linear space, but OBS is not
equipped to do that at the moment.
libobs: Add GPU effect, and wire up scene serialization.
obs-filters: Add Area as an option for scale_filter.
UI: Add Area as an option for both scene items, and canvas downscaling.
Previously only sources would receive a load signal, but sources and
filters would receive a save signal. This meant that filters that had
a save signal to store something on disk would never receive a load
signal to load it from disk.
With this both sources and filters will now receive save and load
signals, allowing both to work the same way.
This actually isn't necessary because the graphics subsystem technically
automatically frees effects, but that could change, so call this just to
be safe.
Allows the ability to encode by passing NV12 textures. This uses a
separate thread for texture-based encoders with a small queue of
textures. An output texture with a keyed mutex shared texture is locked
between OBS and each encoder. A new encoder callback and capability
flag is used to encode with textures.
(This commit also modifies UI)
Adds a universal function for determining whether video output is
currently active, rather than having to use video_output_active() on the
value returned by obs_get_video().
This paves the way for plugins to have access to the argc/argv used
when spawning OBS. Notably, this will allow a patch to obs-browser that
passes through command line arguments on macOS to CEF.
(This commit also modifies UI)
Changes groups to their own independent type, "group". This allows them
to be used like other regular types, and allows the ability to reference
groups in multiple scenes. Before, a group would always be linked to
the scene it was in. This made it cumbersome for users to modify groups
if they had a similar group in multiple scenes (they would have to
modify each group in each scene). Making groups like other source types
makes more sense to solve this issue so they can be referenced in
multiple scenes at once. This also removes a significant amount of
group-specific handling code required for implementing groups in the
front-end.
One limitation however: due to the way sub-items of groups are
seamlessly modifiable and sortable as part of the whole scene, the user
cannot have multiple references to the same group within one scene.
This function returns a char *, so it should not be const (the value is
set from a function which also returns a char *, so there is no real
reason for this to be const).
Due to the ability to track creation of scenes via the "source_created"
global signal, the callback parameter of obs_load_sources has become
somewhat obsolete. This change allows the ability to pass NULL to the
callback parameter in case the callback is not needed.
Adds obs_add_raw_video_callback() and obs_remove_raw_video_callback()
functions which allow the ability to get raw video frames without
necessarily needing to create an output.
Reduces GPU usage when encoding is not active. Does not perform color
conversion, frame staging, or frame downloading unless encoding is
explicitly active.
The "obs" global variable can still be accessed by functions during
shutdown. To prevent access to the variable during shutdown, move the
pointer to a temporary function variable, and set the "obs" global
variable to NULL before shutting down.
(Note: This commit also modifies UI and test)
This makes it so that main preview panes are rendered with the main
output texture rather than re-rendering the main view. The view will
render all objects again, whereas the output texture will be a single
texture render of the same exact thing.
Also fixes some abnormal artifacting when scaling the main preview pane.
This is to prevent confusion with video_thread in
libobs/media-io/video-io.c, which is used exclusively for video
encoding/output. Also prevents confusion in the profiler log data.
Some plugins are using the OBS_VERSION macro obs-config.h to specify the
current version, which will bake the string in to the plugin, making it
so that if the plugin is not replaced for a patch, it could potentially
have the incorrect version. This makes it so that a plugin/frontend can
get the current version string that's baked in to libobs itself.
Originally, obs_get_video_info would recreate the obs_video_info
structure that was originally passed to it from obs_reset_video. This
changes that to just store a copy of the obs_video_info when calling
obs_reset_video, and then copying that to the parameter of
obs_get_video_info when called.
This change prevents source flags from being incorrectly overwritten and
set to 0. Eventually flags need to be separated from source settings
and this should be reverted, but for now this solves an issue where
buffering would be enabled on async video sources regardless of whether
the user disabled it or not on the source.
