Posts

Plan 9: Network Printer (HP Deskjet Ink Advantage 3545)

Image
Internet Printing Protocol Printing with  Internet Printing Protocol (IPP)  involves sending a Unirast   Format (URF) image with appropriate protocol headers to port 631. It is the basis for standards like  Windows Mopria Alliance , Apple   AirPrint , and IPP Everywhere .  It is also called  Driverless Printing   since this doesn't involve installing any printer specific driver. On Plan 9, printing involves three steps: Convert the document to PDF using lp Convert the PDF to URF using  gs  (use urfgray, urfrgb or urfcmyk device) Send the request to the printer using hget IPP header ( req.bin in the below script) contains page output options like paper size, margins etc. This is generated   using ippenc.c .        #!/bin/rc HOST=$1 FILE=$2 TFILE=/tmp/a.pdf URL=( http://$HOST:631/ipp/print/ ) if (! ~ $#* 2)    echo 'Usage: $0 <printer-ip> <file>'     lp -d stdout $FILE > $TFILE...
Post a Comment
Read more

Plan 9: Audio-Video Pipeline

Image
Video pipeline in action Two important points about videos: A video is a series of images. RGB format is used for display. YUV format is used for storage and transmission.  Recording   ──────────────────────────────────────────────────────── [Video Source] → [Frame Processing] → [Video Encode] ┐                                                                                                      ├→ [Mux] → [Container Stream] [Audio Source] → [Audio Processing] → [Audio Encode] ┘ Playback   ──────────────────────────────────────────────────────── [Container Stream] → [Demux] → [Video Decode] → [Video Sink]                                   ...
Post a Comment
Read more

Plan 9: Real Time Streaming

Image
Stream a single window or the whole screen via Real Time Streaming Protocol (RTSP). This uses MJPEG stream over TCP-interleave . Plan 9 /dev/screen and /dev/window produces RGBA byte stream with Plan 9 headers. This is converted to JPEG using tojpg and streamed using RTSP. In the video, host port 12554 port is being forwarded to 554 in the Plan 9 VM.  ffplay -rtsp_transport tcp rtsp://localhost:12554/ stream1       Code https://gitlab.com/atamariya/plan9front/-/blob/dev/sys/src/cmd/rtsp/server.c https://gitlab.com/atamariya/plan9front/-/blob/dev/sys/src/cmd/jpg/tojpg.c https://gitlab.com/atamariya/plan9front/-/blob/dev/sys/src/cmd/jpg/writejpg.c ( Update 16/03/2026 : server.c is moved to /sys/src/cmd/stream/rtsp/)   Youtube Live Use Real-Time Messaging Protocol ( RTMP ) to feed into Youtube / Twitch Live. video/hj264 -f 25 /dev/screen | video/rtmp -a /dev/audio rtmp://.... rtmp://...         Note:   The encoder and the publisher pr...
Post a Comment
Read more

Plan 9: WiFi Protected Setup

Image
  Demo of Wifi router connection using WiFi Protected Setup (WPS). WiFi Protected Setup (WPS) allows you to connect to an Access Point (router) via Push Button Control (PBC) or a temporary PIN.   Authentication Flow   Direction Message / Contents Phase / Purpose Supplicant → AP Authentication Request 802.11 Authentication Supplicant ← AP Authentication Response Supplicant → AP Association Request 802.11 Association Supplicant ← AP Association Response Supplicant → AP EAPOL-Start EAP Initiation Supplicant ← AP EAP-Request Identity Supplicant → AP EAP-Response Identity (Identity: “WFA-SimpleConfig-Registrar-1-0”) Supplicant ← AP WSC Start Enrollee → Registrar (M1) N1 || Descripti...
Post a Comment
Read more

Plan 9: Share Media Content with TV via UPnP

Image
  Share media content with UPnP / DLNA capable players. This is a proof-of-concept of network programming  (TCP and UDP)  in Plan 9. For information, man udp is a useful place to get started.   Device Quirks VLC VLC looks for "urn:schemas-upnp-org:service:ContentDirectory:1" instead of "urn:schemas-upnp-org:device:MediaServer:1" during M-SEARCH.   LG WebOS TV   LG WebOS TV needs the services "urn:schemas-upnp-org:service:ConnectionManager:1" and "urn:microsoft.com:service:X_MS_MediaReceiverRegistrar:1" in addition to "urn:schemas-upnp-org:service:ContentDirectory:1" in device.xml.   It also seems to remember the UUIDs for a particular IP address. If you change the UUID of our application and it doesn't appear in the TV, restarting the TV might help.  Code https://gitlab.com/atamariya/plan9front/-/blob/dev/sys/src/cmd/upnp/server.c  
Post a Comment
Read more

Plan 9: Password Management

 An authentication server manages users credentials in a Plan 9 grid. However, if you are just getting started, probably it would be a better idea to directly use factotum for managing credentials for various services. Create a file keys  with the following content.  key proto=pass        service= ftp server=10.0.2.2 user=anand !password=<password> key proto= wpapsk service= wpa essid=Tomato24 !password=<password>   Load the keys in factotum.  read -m keys > /mnt/factotum/ctl   # Verify cat  /mnt/factotum/ctl   Now you can log into the services without manually entering the password. ftpfs 10.0.2.2 aux/wpa -s Tomato24 /net/ether1  Finally, you can add the command to $home/lib/profile so that it will be executed automatically during bootup. If you have the authentication server configured, you can use the following commands to manage your credentials. (Secstore files are stored at "/adm/secstore/use...
Post a Comment
Read more

Plan 9: Intel Wireless 3165

Intel Wireless 3165 internal PCI card works with Plan 9. You'll need firmware blob /lib/firmware/ iwlwifi-7265D-29 .ucode from Linux as /lib/firmware/ iwlwifi-7265D-29  in Plan 9. Detect hardware on Linux  lspci -nn 02:00.0 Network controller [0280]: Intel Corporation Wireless 3165 [ 8086:3165 ] (rev 81)      # slot_info=0000:02:00.0 # vendor_id=8086 # device_code=3165   Detect firmware on Linux  sudo dmesg | grep -i iwlwifi | grep -i firmware [    6.062085] iwlwifi 0000:02:00.0: loaded firmware version 29.f2390aa8.0 7265D-29.ucode op_mode iwlmvm Apply the following patch to etheriwl.c and rebuild kernel (cd  /sys/src/9/pc64 && mk install). The kernel should be copied to /n/9fat (9fat partition - use 9fs 9fat ) . @@ -4509,6 +4512,10 @@ iwlpci(void)              family = 9000;              fwname = "iwm-9260-34";           ...
Post a Comment
Read more