* Visualizer: use log scale
- log scale frequency and gain
- Hamming windowing
- improve reading from fifo
* Fix Visualizer memory leaks
* Visualizer: use Blackman window
* Visualizer: support DFT zero padding
* Visualizer: support fractional height bars, fix fifo read
* Revert "Fix Visualizer memory leaks"
This reverts commit 5c6509d2b8ed985a4928f681217dc8616d053ace.
* Visualizer: fix fifo read again
* Visualizer: add cubic interpolation option
* Visualizer: Expose more config options, add docs for config options
* Visualizer: Use reverse video text for stereo visualizer smooth look
* Visualizer: use FormattedColor to for reverse-video
* Visualizer: change some config options for spectrum
* Fix build fftw disabled
* Visualizer: use [0,5] interval for dft_size config option
