x42 Convo.lv2

convoLV2 is a LV2 plugin to convolve audio signals with zero latency.

It is a very basic plugin: Currently the only parameter is the Impulse-Response file and hence it is robust and efficient convolver.

The plugin comes in three variants:

  • Mono: 1 channel in, 1 channel out. Mono IR file
  • Mono To Stereo: 1 channel in, 2 channel out. Stereo IR file. (L, R)
  • True Stereo: 2 in, 2 out. 4 channel IR file (L -> L, R -> R, L -> R, R -> L)

Excess channels in an IR file are ignored. If an IR file has insufficient channels for the required configuration, channel-assignment wraps around (modulo file channel count).

convoLV2's main use-case is cabinet-emulation and generic signal processing where latency matters.

For fancy reverb applications, see also IR.lv2

libzita-convolver is used to perform the convolution, libsndfile to read the impulse-response and libsamplerate to resample the IR if necessary.

convoLV2 was written to demonstrate new features of LV2 1.2.0 (back in 2012):

It since serves as example code for those LV2 extensions.

While the convolution engine supports pre-delay, channel-mapping and per-channel gain settings, these parameters are currently not exposed in the LV2 interface (hack tip: they are supported in the LV2 DSP and saved as text in the plugin-state which can be directly edited).

Software type
LV2 plugin
Platform
GNU/Linux
macOS
Windows
Software features
Audio FX
Reverb
Colvolution
Software language
C
License
GPL-2
Developer(s)
Robin Gareus (rgareus/x42)

x42 Balance.lv2

Balance.lv2 is an audio-plugin for stereo balance control with optional per channel delay.

balance.lv2 facilitates adjusting stereo-microphone recordings (X-Y, A-B, ORTF). But it also generally useful as "Input Channel Conditioner". It allows for attenuating the signal on one of the channels as well as delaying the signals (move away from the microphone). To round off the feature-set channels can be swapped or the signal can be downmixed to mono after the delay.

It features a Phase-Correlation meter as well as peak programme meters according to IEC 60268-18 (5ms integration, 20dB/1.5 sec fall-off) for input and output signals.

Software type
LV2 plugin
Platform
GNU/Linux
macOS
Windows
Software features
Audio input
Audio mixing
Software language
C
License
GPL-2
Developer(s)
Robin Gareus (rgareus/x42)

x42 Meter Collection

meters.lv2 is a collection of audio-level meters with GUI in LV2 plugin format.

It includes needle style meters (mono and stereo variants)

  • IEC 60268-10 Type I / DIN
  • IEC 60268-10 Type I / Nordic
  • IEC 60268-10 Type IIa / BBC
  • IEC 60268-10 Type IIb / EBU
  • IEC 60268-17 / VU

Stereo & Mono variants of bar-graph meters:

  • 30 Band 1/3 octave spectrum analyzer IEC 61260
  • Digital True-Peak Meter (4x Oversampling), Type II rise-time, 13.3dB/s falloff.
  • True-Peak (4x Oversampling) + RMS (600ms integration time) combined with numeric readout
  • K-12, K-14, K-20 / RMS type K-Meters according to the K-system introduced by Bob Katz
  • DR-14 (crest factor / loudness range measurement method)

and the following stereo plugins:

  • EBU R128 Meter with Histogram and History
  • Stereo Phase Correlation Meter (Needle Display)
  • BBC Mid/Side M-6 (Needle Display)
  • Goniometer (Stereo Phase Scope)
  • Phase/Frequency Wheel
  • Stereo/Frequency Monitor

as well as a mono:

  • Signal Distribution Histogram
  • Bitmeter
Software type
LV2 plugin
Platform
GNU/Linux
Software features
Audio input
Analysis
Software language
C
License
GPL-2
Developer(s)
Robin Gareus (rgareus/x42)