Description
It seems that sane-airscan is not able to show the live progress of a scan as it progresses. On both an ET-2650 and an ET-2820, running
$ scanimage -d "airscan:e0:<hostname>" -vvv -p -o /tmp/scan.png
scanimage: scanning image of size 2550x3510 pixels at 24 bits/pixel
scanimage: acquiring RGB frame
causes the process to just wait here until the entire scan has finished, after which a progress indicator briefly appears and flies straight from 0% to 100%. This is also evident in graphical scanning applications such as simple-scan, where the image only appears after the scan has finished (when the progress breezes from 0% to 100%). Finally, the following is printed:
scanimage: min/max graylevel value = 211/255
scanimage: read 26851500 bytes in total
Running with SANE_DEBUG_DLL=255, I can see that the progress blocks at the first
[16:11:20.264073] [dll] sane_read(handle=0x56039bd3a5e0,data=0x56039bd5dfc0,maxlen=32768,lenp=0x7ffdf4d9005c)
until the scan is finished, after which all of the rest of the sane_read calls are printed in quick succession. However, when monitoring the network activity, I can see the scanner streaming data during the entire scan. What prevents live progress reporting in airscan, since it works with, e.g., the epson2 backend?