Re: [sane-devel] escl backend and ippusbxd
Many thanks for your explanations. Rolf Am 20.03.20 um 12:38 schrieb Till Kamppeter: > On 20/03/2020 12:29, Thierry HUCAHRD wrote: >> Hi, >> No, this has nothing to do with eSCL. >> ippusbxd allows you to use escl backends on the usb. >> The problem is that sane doesn't detect the scanner on the usb >> anymore, so PIXMA can't be used anymore. >> I don't know if ippusbxd solved the problem? >> in any case if the device has a usb driver, ippusbxd is not necessary! > > On the other side if you have ippusbxd or ipp-usb running you do not > need one of the device-specific USB drivers like pixma, as > IPP-over-USB is designed for driverless operation of multi-function > devices and so every device which supports IPP-over-USB also supports > printing and scanning using manufacturer-independent standards, for > scanning currenly usually eSCL. So with an IPP-over-USB daemon > (ippusbxd or ipp-usb) running you are supposed to scan with an eSCL > backend (escl or airscan). This way multi-function devices which are > not from HP (HPLIP) or from Canon (pixma) scan with free software. > > Till > >
Re: [sane-devel] escl backend and ippusbxd
On 20/03/2020 12:29, Thierry HUCAHRD wrote: Hi, No, this has nothing to do with eSCL. ippusbxd allows you to use escl backends on the usb. The problem is that sane doesn't detect the scanner on the usb anymore, so PIXMA can't be used anymore. I don't know if ippusbxd solved the problem? in any case if the device has a usb driver, ippusbxd is not necessary! On the other side if you have ippusbxd or ipp-usb running you do not need one of the device-specific USB drivers like pixma, as IPP-over-USB is designed for driverless operation of multi-function devices and so every device which supports IPP-over-USB also supports printing and scanning using manufacturer-independent standards, for scanning currenly usually eSCL. So with an IPP-over-USB daemon (ippusbxd or ipp-usb) running you are supposed to scan with an eSCL backend (escl or airscan). This way multi-function devices which are not from HP (HPLIP) or from Canon (pixma) scan with free software. Till
Re: [sane-devel] escl backend and ippusbxd
Le 2020-03-20 12:04, Rolf Bensch a écrit : Hello, I've seen that some people need to purge ippusbxd before they can use their scanner with escl backend (e.g. https://gitlab.com/sane-project/backends/-/issues/256#note_307051019). Is this a fix rule? Then I'd like to add a break dependency to ippusbxd in my Ubuntu ppa. Hi, No, this has nothing to do with eSCL. ippusbxd allows you to use escl backends on the usb. The problem is that sane doesn't detect the scanner on the usb anymore, so PIXMA can't be used anymore. I don't know if ippusbxd solved the problem? in any case if the device has a usb driver, ippusbxd is not necessary! Thierry Cheers, Rolf
Re: [sane-devel] escl backend and ippusbxd
Rolf, please do not add a break dependency against ippusbxd. It is most probably only some models which cause problems. If you want to use eSCL via the network it does not matter whether ippusbxd is running or not. You only need to make sure to select the correct scanner entry in the client software. The selected entry should nowhere contain "USB". Principally eSCL scanning works also via IPP-over-USB, with the device connected via USB and either ippusbxd or ipp-usb running. ipp-usb is the more reliable of the two but it is rather new and does not have the wide penetration in Linux distributions therefore. It is also written in Go and some OS vendors (like Google with Chrome OS) refuse Go applications because of there larger memory footprint. To select scanning through this connection use entries with "USB" in your scanning client software. I am able to both print and scan via network and USB and with one of ippusbxd or ipp-usb permanently running, with both the "escl" and "airscan" backends. This I have tested on two HP devices, the HP DeskJet 2540 and the HP OfficeJet Pro 8730. To reach this state I have done a lot of debugging with the authors of the two SANE backends, Thierry and Alexander. I appreciate their great collaboration a lot and they will most probably help you, too, if your device does not work, independent whether you want to use it via network or USB. Please speak up on the list here or post an issue at the appropriate backend or IPP-over-USB daemon upstream. Naturally it can happen that things do not work for one or another hardware model, it already happens with the two eSCL/AirScan backends alone. So please report if you have a problem. Till On 20/03/2020 12:04, Rolf Bensch wrote: Hello, I've seen that some people need to purge |ippusbxd| before they can use their scanner with escl backend (e.g. https://gitlab.com/sane-project/backends/-/issues/256#note_307051019). Is this a fix rule? Then I'd like to add a break dependency to |ippusbxd| in my Ubuntu ppa. Cheers, Rolf
Re: [sane-devel] escl backend and ippusbxd
Hi, On 3/20/20 2:04 PM, Rolf Bensch wrote: I've seen that some people need to purge |ippusbxd| before they can use their scanner with escl backend (e.g. https://gitlab.com/sane-project/backends/-/issues/256#note_307051019). Is this a fix rule? Then I'd like to add a break dependency to |ippusbxd| in my Ubuntu ppa. ippusbxd has inherent problems that cannot be easily fixed: https://github.com/OpenPrinting/ippusbxd/issues/15 https://github.com/OpenPrinting/ippusbxd/issues/14 ippusbxd may occasionally work with escl backend or not, but in any case it will not work stable. There is a replacement free of these problems: https://github.com/OpenPrinting/ipp-usb Note, this software is only needed to connect IPP-over-USB enabled device using USB. It is not needed if network connection is in use. -- Wishes, Alexander Pevzner (p...@apevzner.com)
