Webcams and video formats
Choosing the right codec and resolution
From version 1.6, OptoGait offers the possibility to use Logitech C920 webcams instead of the previous QuickCam 9000 Pro.
The advantage of the new webcams is that it supports hardware video compression, resulting in a much smaller data flow to the PC (especially if two webcams are used simultaneously).
Without compression, the stream at 640x480 30fps reaches approximately 230 Mb/s. Therefore, with two webcams - as well as the OptoGait hardware - the USB 2.0 bandwidth (480 Mb/s) could easily be used up.
The following video formats are supported:
Logitech Brio 4k Pro (not Stream Edition)
|
Format |
Resolution |
Frame rate |
|
MJPG |
1920 x 1080 |
30/60 fps |
|
MJPG |
1280 x 720 |
30/60/90 fps |
|
MJPG |
800 x 600 |
30 fps |
|
MJPG |
640 x 480 |
30/60/90 fps |
|
ASF |
640 x 480 |
30 fps |
|
ASF |
320 x 240 |
30 fps |
Logitech C920
|
Format |
Resolution |
Frame rate |
|
MJPG |
1920 x 1080 |
30 fps |
|
MJPG |
800 x 600 |
30 fps |
|
MJPG |
640 x 480 |
30 fps |
|
ASF |
640 x 480 |
30 fps |
|
ASF |
320 x 240 |
30 fps |
QuickCam 9000 PRO
|
Format |
Resolution |
Frame rate |
|
ASF |
640 x 480 |
30 fps |
|
ASF |
320 x 240 |
30 fps |
On some PCs, even though they have several USB ports, they are managed by one single bus, causing possible blocks or program errors. If two webcams are used simultaneously, it is recommended to use the MP JG format for the C920/Brio webcam and a resolution of 320x240 for the QuickCam 9000.