New Additions

Linux Command Line Guitar Tuner using FFMPEG and MPLAYER

 # ffmpeg -f lavfi -i "sine=f=440:d=7"   -ac 2 440.wav

 ffmpeg -f lavfi -i "sine=f=82.41:d=7"  -ac 2 E2.wav
 ffmpeg -f lavfi -i "sine=f=110:d=7"    -ac 2 A2.wav
 ffmpeg -f lavfi -i "sine=f=146.83:d=7" -ac 2 D3.wav
 ffmpeg -f lavfi -i "sine=f=196:d=7"    -ac 2 G3.wav
 ffmpeg -f lavfi -i "sine=f=246.94:d=7" -ac 2 B3.wav
 ffmpeg -f lavfi -i "sine=f=329.63:d=7" -ac 2 E4.wav

mplayer E2.wav   A2.wav D3.wav   G3.wav B3.wav E4.wav


ffmpeg -f concat -i tunerlist.txt  guitar-tuner.mp3

tunerlist.txt

file E2.wav
file A2.wav 
file D3.wav
file G3.wav 
file B3.wav 
file E4.wav

Wine Bottling Math

2 gallons = 9 liters = 12 bottles = 1 case

 * assuming 1 imperial gallon == 4.54 liters  
 * assuming 1 wine bottle     == 0.75 liters == 750 ml == 26 Fluid Ounces

X-Rite Color Chart Clones

"Real" X-Rite color charts ($80) are used by professionals for color management on monitors, cameras and printers.

I put these pdf's put on a USB stick and printed them off at Staples on their high end printers and paper. I printed 10 consecutive in a row, so I have a cheap color reference. It does not replace pro stuff, but it is more than enough for my image processing development work.

X-Rite Color Chart Clone in PDF

X-Rite Color Chart Clone in PDF With Color Names & RGB Values

These 2 clones pages can be also be used as a calibration chart for photogrammetry.

The color blocks are 1.25" x 1.25" squares with a 0.125" space between the blocks.
The entire chart is 8.625" x 5.875".

Accurate Scaled Gothic Arch Drawing

There are many videos on youtube on building the gothic arches for a gothic arch greenhouse, but none have links to drawings.

So, I drew a diagram with dimensions to scale and labels in PDF file format.

PDF allows the accurate printing of lengths, so if you print it at exactly 100% scale, you can use a metric ruler to read off dimensions.

DNS

Domain Name System Developer Notes

Software Defined Radio Notes

Receiving, decoding and displaying weather data from a WT440 Wireless Weather Transmitter

C code for Cairo Text Justification

No more tears. Place text exactly.