Post by TheoHave you tried sending a Unirast file to an Airprint printer?
Ah, according to:
https://wiki.debian.org/CUPSAirPrint
I can get some information out of my printer:
('xxxx' redacts some serial numbers)
$ avahi-browse -rt _ipp._tcp
+ wlp0s20f3 IPv6 Brother HL-L8260CDW series Internet
Printer local
+ wlp0s20f3 IPv4 Brother HL-L8260CDW series Internet
Printer local
= wlp0s20f3 IPv6 Brother HL-L8260CDW series Internet
Printer local
hostname = [BRWD46A6Axxxx.local]
address = [192.168.1.3]
port = [631]
txt = ["mopria-certified=1.3" "print_wfds=T"
"UUID=e3248000-80ce-11db-8000-xxxx" "PaperMax=legal-A4"
"kind=document,envelope,label,postcard"
"URF=SRGB24,W8,CP1,IS19-1,MT1-3-4-5-8-11,OB10,PQ4,RS600,V1.4,DM1"
"TBCP=F" "Transparent=T" "Binary=T" "PaperCustom=T" "Scan=F" "Fax=F"
"Duplex=T" "Copies=T" "Color=T" "usb_CMD=PJL,PCL,PCLXL,URF"
"usb_MDL=HL-L8260CDW series" "usb_MFG=Brother" "priority=25"
"adminurl=http://BRWD46A6xxxx.local./net/net/airprint.html"
"product=(Brother HL-L8260CDW series)" "ty=Brother HL-L8260CDW series"
"note=" "rp=ipp/print"
"pdl=application/octet-stream,image/urf,image/jpeg,image/pwg-raster"
"qtotal=1" "txtvers=1"]
= wlp0s20f3 IPv4 Brother HL-L8260CDW series Internet
Printer local
hostname = [BRWD46A6Axxxx.local]
address = [192.168.1.3]
port = [631]
txt = ["mopria-certified=1.3" "print_wfds=T"
"UUID=e3248000-80ce-11db-8000-xxxx" "PaperMax=legal-A4"
"kind=document,envelope,label,postcard"
"URF=SRGB24,W8,CP1,IS19-1,MT1-3-4-5-8-11,OB10,PQ4,RS600,V1.4,DM1"
"TBCP=F" "Transparent=T" "Binary=T" "PaperCustom=T" "Scan=F" "Fax=F"
"Duplex=T" "Copies=T" "Color=T" "usb_CMD=PJL,PCL,PCLXL,URF"
"usb_MDL=HL-L8260CDW series" "usb_MFG=Brother" "priority=25"
"adminurl=http://BRWD46A6Axxxx.local./net/net/airprint.html"
"product=(Brother HL-L8260CDW series)" "ty=Brother HL-L8260CDW series"
"note=" "rp=ipp/print"
"pdl=application/octet-stream,image/urf,image/jpeg,image/pwg-raster"
"qtotal=1" "txtvers=1"]
so it can take URF, as well as JPEG and PWG. Perhaps, if the client
discovers that, it can choose to send via any supported format.
I would assume that iOS would send URF as the lowest common denominator?
[time passes]
It appears that I can run Wireshark on my wifi, but it can only see
traffic destined for the machine running Wireshark - it can't see the chat
between my phone and the printer. To do that I'd need to put both the phone
and printer on an open wifi network that I can sniff. That will be a task
for another day...
Theo