WinTV USB support?

[sysreq93]

Hello, I'm trying to capture teletext data from VHS through a WinTV USB device, model 40214; I'm doing that with GraphEdit under 32 bit Windows (Linux's usbvision driver doesn't create the /dev/vbiX device) and the result is the file attached here. The device produces 704 samples per line, and with vbiview I can see that the teletext data is definitely there, but somehow "off-centered", and I can't deconvolve anything.
I also own a WinTV PCI card, and using the same Windows software for capture I can get good results (though I had to set "line_length" to 2000 and "field_lines" to 18 in vbi/config.py) but I would like to use the USB one because it gets a cleaner video signal, and has S-Video input. Could you please have a look to my data and help me to fix the USB capture?
Thanks in advance.

Sample from USB: https://drive.google.com/file/d/14c7Rz65DmjCCjJxFcpMaysbRKn8DlbYZ/view
Sample from PCI: https://drive.google.com/file/d/1MeGCUrUARYyrA9FGw7SpCVvD98N0uK3e/view