I need help learning how to interact with Epiphan capture software to acquire video. I cannot find a version of documentation that appears to apply to the software version I have downloaded and installed. My goal is to get the Epiphan VGA2USB LR and software to consistently display video from the attached device.
I want to configure the VGA2USB LR to capture and watch video originating from a piece of industrial test equipment, the HP 8753D network analyzer. The 8753D has an internal CRT color monitor (7 or 8 inches diagonal) and on the rear, 3 BNC connectors bearing red, green and blue (this device was built before VGA standard emerged). I am using a VGA to BNC cable. I believe the cable and hardware are working because the Epiphan device renders an occasional image, and usually returns then to “tuning capture parameters”.
The Epiphan software user interface is extremely slow - this is on an Intel I3 with 16MB RAM, no other application is slow, and the Epiphan software does not seem to be using an excess of CPU resource.
The video resolution and frame rate of the HP test equipment are not documented, however, given that the VGA2USB LR occasionally displays an image, I believe the resolution and frame rate are among those that the device and software are trying.
When all is connected (and software is in default configuration), the Epiphan device LED is flashing green with an occasional (every few seconds) red flash. The display window says “Tuning capture parameters”, however, every minute or so I see a single image of video (that looks OK), then it returns to tuning capture parameters. This cycle is not regular (that is, I can wait a long time, or a short time, to see an image.)
With very excellent support from George (epiphan person on chat duty today) I learned:
The windows (7) Epiphan shortcut must be set to “run as administrator” - without this, I was unable to save changes to the vga modes dialog.
The slowness in the user interface can be worked around by temporarily removing the video source while interacting with the software. Once a single video mode is located, the slowness disappears and further adjustments can be tried while video source is attached.
I was able to find a workable video mode and make needed adjustments.
FYI for future user interested in applying VGA2USB LR to HP 8753D:
720 x 410 pixels (720 x 400 cuts off bottom line of text on screen)
59.9 Hz “actual frequency”
Interlace de-selected (i.e., progressive scan)
The leftmost few pixels (about one character-width) remain invisible and changes to front/back porch do not affect this, however, the video image is steady and usable as-is.
Here’s an implementation of HP8753D network analyzer displaying on linux using VGA2USB LR and 32-bit xubuntu 16.04 (the machine is an old Atom N270 box, and linux version was selected to agree with an available driver). vlc is used for video playback. The binary utilities and driver for VGA2USB LR are from epiphan download page. vlc allows adjustment of aspect ratio to make smith chart circular on the LCD monitor in use (among many other features and capabilities that may be useful). Adjusted horizontal offset value from default to resolve missing pixels at left margin of original CRT display.
HP 8753D > BNC/VGA cable > VGA2USB LR > USB2 > Linux Box > Xubuntu 16.04 > video4linux > VLC (32-bit)