A simple audio oscilloscope with variable time scale, triggering, cursors and numeric readout in LV2 plugin format.
The minimum grid resolution is 50 micro-seconds - or a 32 times oversampled signal. The maximum buffer-time is 15 seconds.
Currently variants up to four channels are available.
For documentation please see http://x42.github.io/sisco.lv2/
Compiling this plugin requires the LV2 SDK, gnu-make, a c-compiler, libpango, libcairo and openGL (sometimes called: glu, glx, mesa).
git clone git://github.com/x42/sisco.lv2.git cd sisco.lv2 make submodules make sudo make install PREFIX=/usr
Note to packagers: The Makefile honors
DESTDIR variables as well
OPTIMIZATIONS (additions to
see the first 10 lines of the Makefile.
You really want to package the superset of x42-plugins.
# Just run the stand-alone jack app x42-scope # Some info man x42-scope
Oscilloscope vs Waveform Display
This project was created to test and exemplify LV2 Atom-Vector communication and demonstrate the short-comings of LV2 thread synchronization and LV2Atoms for visualization UIs:
LV2Atom messages are written into a ringbuffer in the LVhost in the DSP-thread.
This ringbuffer is sent to the UI in another thread (jalv and ardour use
g_timeout() usually at 40ms ~ 25fps), and finally things are painted in the
Accurate (low-latency, high-speed) visualization is a valid use-case for LV2 instance access in particular if visual sync to v-blank is of importance. This is not the case for a scope. A ringbuffer using message-passing is sufficient since signal acquisition is usually perform on a trigger condition and subject to hold-off times.
The basic structure of this plugin is now available as eg05-scope example plugin from the official lv2plug.in repository.
Compared to the example, this plugin goes to some length to add features in order to make it use-able beyond simple visualization and make it useful for scientific measurements. It is however still rather simple compared to a fully fledged oscilloscope. See the TODO file included with the source.