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.
Add a new algorithm to calculate the true-peak. It implements the
Whittaker- Shannon interpolation from four samples to create 4
intermediate samples (5 x oversampling) inbetween the middle two
samples.
With 4 samples and 4 intermediate samples the algorithm can be
implemented as a 4x4 vector-matrix cross product, which is ideal for
SSE.
I've also replaced the sample-peak algorithm using SSE as well to
improve performance.
Closesobsproject/obs-studio#1189
The following features have been added to the audio-meters:
* Stereo PPM-level meter, with 40 dB/1.7s decay rate.
* Stereo VU-level meter, with 300 ms integration time.
* Stereo Peak-hold meter, with 20 second sustain.
* Input peak level color-squares in front of every meter.
* Minor-ticks for each dB.
* Major-ticks for every 5 dB.
* Meter is divided in sections at -20 dB and -9 dB.
The ballistic parameters chosen here where taken from:
* https://en.wikipedia.org/wiki/Peak_programme_meter (SMPTE RP.0155)
* https://en.wikipedia.org/wiki/VU_meter
In the rework I have removed any ballistic calculations from
libobs/obs-audio-controls.c making the calculations here a lot more
simple doing only MAX and RMS calculations for only the samples in
the current update. The actual ballistics are now done by just
the UI/volume-control.cpp because ballistics need to be updated
based on the repaint-rate of the user-interface.
The dB to pixel conversion has been moved from
libobs/obs-audio-controls.c to UI/volume-control.cpp as well to reduce
coupling between these two objects, especially when implementing the
major- and minor-ticks and the sections.
All colors and ballistic parameters are adjustable via QT style sheets.
There are slight differences in colors for each of the themes.
(Note: This commit also modifies UI)
Instead of using signals, use designated callback lists for audio
capture and audio control helpers. Signals aren't suitable here due to
the fact that signals aren't meant for things that happen every frame or
things that happen every time audio/video is received. Also prevents
audio from being allocated every time these functions are called due to
the calldata structure.
Add a property to the volume meter that specifies the length of the
interval in which the audio data should be sampled before the
audio_levels signal is emitted.
This adds a volume meter object to libobs that can be used by the GUI
or plugins to convert the raw audio level data from sources to values
that can easily be used to display the audio data.
The volume meter object will use the same mapping functions as the
fader object to map dB levels to a scale.
This adds a new library of audio control functions mainly for the use in
GUIS. For now it includes an implementation of a software fader that can
be attached to sources in order to easily control the volume.
The fader can translate between fader-position, volume in dB and
multiplier with a configurable mapping function.
Currently only a cubic mapping (mul = fader_pos ^ 3) is included, but
different mappings can easily be added.
Due to libobs saving/restoring the source volume from the multiplier,
the volume levels for existing source will stay the same, and live
changing of the mapping will work without changing the source volume.