Monday, June 15th, 2009
I have been trying to get a sense of how much video processing my computer can do. A 2.2Ghz Intel Core 2 Duo can capture 640 x 480 @ 30 fps from a Logitech Vision Pro webcam while simultaneously playing four previously captured clips encoded with H.264 and AAC mono audio. Capturing video while playing more than four videos results in dropped frames.
This plot shows a pretty linear falloff in captured framerate as the number of video files being played during capture is incremented.
Sunday, June 14th, 2009
I needed to know the geometry of some common LCD panels for a project I’m working on. I couldn’t find a convenient chart, so I am contributing this one to the Internet. I worked out the X and Y values with some simple trig. An alternative estimation based on resolution multiplied by pixel pitch yields similar results ±0.125”.
| H” | X” | Y” | AR | X res | Y res | a° | b° |
|---|---|---|---|---|---|---|---|
| 15 | 12.0 | 9.0 | 4:3 (1.33) | 1024 | 768 | 53.13 | 36.87 |
| 17 | 13.27 | 10.62 | 5:4 (1.25) | 1280 | 1024 | 51.34 | 38.66 |
| 19 | 14.84 | 11.87 | 5:4 (1.25) | 1280 | 1024 | 51.34 | 38.66 |
| 18.5 | 16.13 | 9.07 | 16:9 (1.77) | 1366 | 768 | 60.65 | 29.35 |
| 15.4 | 13.06 | 8.16 | 8:5 (1.6) | 1440 | 900 | 57.99 | 32.01 |
| 17 | 14.42 | 9.01 | 8:5 (1.6) | 1440 | 900 | 57.99 | 32.01 |
| 19 | 16.11 | 10.07 | 8:5 (1.6) | 1440 | 900 | 57.99 | 32.01 |
| 20.1 | 16.08 | 12.06 | 4:3 (1.33) | 1600 | 1200 | 53.13 | 36.87 |
| 19 | 16.11 | 10.07 | 8:5 (1.6) | 1680 | 1050 | 57.99 | 32.01 |
| 20 | 16.96 | 10.60 | 8:5 (1.6) | 1680 | 1050 | 57.99 | 32.01 |
| 22 | 18.66 | 11.66 | 8:5 (1.6) | 1680 | 1050 | 57.99 | 32.01 |
| 21.5 | 18.74 | 10.54 | 16:9 (1.77) | 1920 | 1080 | 60.64 | 29.36 |
| 23 | 20.05 | 11.28 | 16:9 (1.77) | 1920 | 1080 | 60.64 | 29.36 |
| 24 | 20.35 | 12.72 | 8:5 (1.6) | 1920 | 1200 | 57.99 | 32.01 |
| 25.5 | 21.62 | 13.52 | 8:5 (1.6) | 1920 | 1200 | 57.99 | 32.01 |
| 30 | 25.44 | 15.90 | 8:5 (1.6) | 2560 | 1600 | 57.99 | 32.01 |
