Yammer

Audio visualizer thing in guile scheme

Build

Dependencies

guile-sdl2, fftw

Compiling the library

You need to compile the yammer.c file because it has wrappers and stuff.

To disable FFTW, use export NO_FFTW=1

To disable PulseAudio, use export NO_PULSE=1

To enable debugging symbols, use export DEBUG=1

./compile.sh

You may need to adjust PKG_CONFIG_PATH if you use something like Guix System.

Configuration

Copy config.example.scm to ~/.config/yammer/config.scm

Below is a list of values and what they do

• using-fftw?: Was libyammer.so compiled using FFTW?

• using-pulse?: Was libyammer.so compiled using PulseAudio?

• source: The MPD fifo or PulseAudio source

• source-type: One of 'mpd or 'pulse

• pulse-latency: Latency to request from PulseAudio

• bitrate: The bitrate of the audio coming from the input

• sample-factor: Proportional to quality, may cause stuttering when >1.

• fps: Self explanatory

• resolution: Pixel width of bars

• scale: Bar height multiplier

• color: Bar color

• bgcolor: Background color

• queue-size: The size of the queue (minimum of 1), delays displaying bars by queue-size frames. Useful if desync is noticed

• fft: Whether or not to perform a fourier transform to show frequencies (like spectrum mode in most other visualizers)

• interpolation: Number of points to interpolate between values. <1 means disable

• smoothing: Smoothing mode. Possible values are:

  • #f: No smoothing or interpolation. Disregards interpolation
  • 'none: No smoothing
  • 'moving-average: Moving average
  • 'exponential: Simple (basic) exponential smoothing

• moving-average-block-size: Size of the moving average window. Higher is smoother.

• exponential-factor: Exponential smoothing factor, lower is more smooth.

Running

Either install .libs/libyammer.so, src/c/yammer.h, src/guile/yammer.scm, and src/guile/yammer to their respective systemwide locations, or do the following:

export LD_LIBRARY_PATH=.libs
export GUILE_LOAD_PATH=src/guile

Then, run yammer.

./yammer

Screenshots

Normal mode

FFT mode

Exponential

Moving Average

Wishlist

• Native PipeWire, ALSA, JACK, sndio sources
• More smoothing modes (one that actually works would be nice)
• Average over resolution
• Offload some calculations to the GPU
• Use more than one core lmao?

Known issues

• Sometimes the read gets misaligned and just becomes noise
• When MPD is paused or the program is sleeping for the next frame, the UI doesn't update so you can't exit
• The surface can't be transparent
• PulseAudio can be reeaaaaally behind