Over a dozen small performance optimizations
* Memoization for linspace generation
* Removed unnecessary copies
* Limited the rate at which information is printed. Excessive `print()` output was causing issues for some SSH users
Zero pads the audio time samples until the length is equal to the next largest power of two. This improves the algorithmic complexity of the FFT calculations.
Initialized the Hamming window when the module is loaded instead of every loop.
Replaced a call to numpy.roll() with direct array index manipulation.
* Resolved an issue with the ESP8266 where gamma correction would be
performed twice. Changed GAMMA_CORRECTION to SOFTWARE_GAMMA_CORRECTION
to make a distinction between software and firmware gamma correction.
The ESP8266 does firmware gamma correction and dithering, while the
Raspberry Pi uses slightly more inferior software gamma correction.
Changed the software gamma table to match the gamma table used in the
ESP8266 firmware.
* Improved the spectrum visualization by using one of the color channels
to visualize the absolute value of the temporal derivative of the
spectrum. Also added a feature to reject the "common mode" spectral
components, which is analogous to the spectral DC component.
* Signficantly improved the GUI and added a frequency adjustment slider.
Adjusting the frequency range has a big impact on the visualization
output. Recommend using a high frequency range (something like 4 kHz -
10 kHz) when running the scrol visualization.
This commit adds support for the Raspberry Pi, which allows users to
create a completely standalone music visualization system. The Raspberry
Pi should be connected directly to a ws2812b LED strip. A PWM-capable
GPIO pin should be connected to the data line of the LED strip. A USB
audio input device should be connected to one of the Raspberry Pi's USB
ports.
It is recommended that the GUI and FPS output be disabled when running
the visualization on the Raspberry Pi. These features can degrade
performance on the already computationally limited Raspberry Pi.
Fixed a bug where the GUI ComboBox value would sometimes not match the
effect being displayed. This bug sometimes occurs when the GUI is first
initialized. This change now ensures that the ComboBox value is
correctly initialized.
Added a ComboBox to the GUI to allow the user to change the
visualization effect without having to restart Python. The user can now
select from one of the following visualizations using the GUI: 'Scroll
effect', 'Spectrum effect', 'Energy effect'
Fixed some bugs that occurred in Python 3.5 but were not present in
Python 2.7. Most compatiblity issues were caused by incompatible type
casting of numpy arrays.
