[sane-devel] Fwd: book scanner recognized as v4l device

[netukar201409+sane at mailbox.org]

---------- Ursprüngliche Nachricht ----------
Von: Michael Dittmer
An: "sane-devel at alioth-lists.debian.net" 
<sane-devel at alioth-lists.debian.net>
Datum: 23.08.2020 12:00
Betreff: book scanner recognized as v4l device

I bought a book scanner

JOURIST BT16

from a german dealer

looks like: 
http://www.scanner.expert/de/images/products/buchscanner/description/5_JOURIST_Buchscanner_BS16_Standalone.jpg 


It takes photos from the pages with a camera like a CZUR book scanner. 
My bookscanner camera also can be opened by

guvcview

It has maximum resolution of

4608x3456

pixels for A3 scan (resolution can be selected by gucview and is shown 
later when starting xsane).

When I plug it onto a usb port, several devices are recognized (dmesg 
output)

[ 1377.446137] usb 1-5: new high-speed USB device number 8 using xhci_hcd
[ 1377.467545] usb 1-5: New USB device found, idVendor=2b19, 
idProduct=0200, bcdDevice= 1.50
[ 1377.467551] usb 1-5: New USB device strings: Mfr=1, Product=2, 
SerialNumber=3
[ 1377.467554] usb 1-5: Product: JY-VP216
[ 1377.467557] usb 1-5: Manufacturer: YHW
[ 1377.467560] usb 1-5: SerialNumber: 35060591
[ 1377.646815] uvcvideo: Found UVC 1.00 device JY-VP216 (2b19:0200)
[ 1377.654409] uvcvideo: UVC non compliance - GET_DEF(PROBE) not 
supported. Enabling workaround.
[ 1377.656783] uvcvideo 1-5:1.2: Entity type for entity Processing 3 was 
not initialized!
[ 1377.656789] uvcvideo 1-5:1.2: Entity type for entity Extension 2 was 
not initialized!
[ 1377.656795] uvcvideo 1-5:1.2: Entity type for entity Camera 1 was not 
initialized!
[ 1377.662373] input: YHW JY-VP216 as 
/devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5:1.4/0003:2B19:0200.0008/input/input24
[ 1377.722925] hid-generic 0003:2B19:0200.0008: input,hidraw0: USB HID 
v1.10 Keyboard [YHW JY-VP216] on usb-0000:00:14.0-5/input4

All book scanner manufacturers seem to deliver only twain drivers. So I 
tried to handle the scanner as an generic v4l device

My linux mint 19.3 (based on Ubuntu 18.04) distribution has a sane 
backend package (1.0.27) without compiled v4l backend.
After compiling current 1.0.30 sources with v4l-dev libraries I obtained 
the v4l backend

scanimage --list-devices
device `v4l:/dev/video3' is a Noname JY-VP216: JY-VP216 virtual device

but xsane and scanimage are not able to perform scan ("illegal argument")

SANE_DEBUG_SANEI_USB=4 scanimage -v -d v4l:/dev/video3 --format tiff 
 >output.tif scanimage: ignored request to set inactive option br-x
scanimage: ignored request to set inactive option br-y
scanimage: sane_start: Invalid argument

Another program

simple scan

from Ubuntu distribution is able to scan into pdf with 1600x1200 pixel 
but not with maximum resolution.

It seems for me that the v4l backend has to support higher resolutions, 
like 4608x3456 e.g.