cir - a new implementation of linux infrared tools

For Linux, there are tools for infrared: ir-ctl and ir-keytable. These tools can load simple infrared keymaps and load decoders, and transmit simple IR. The IR decoders and encoders are hardcoded. There is also the lirc daemon and its tools, which supports many more IR protocols but certainly not all.

This tool replaces all those tools, but with major new features:

• Pronto hex codes
• IRP support
• lircd.conf remote definition support
• daemon-less (using BPF)

Pronto hex codes are a fairly straightforward way of encoding raw IR, NEC, RC-5 and a few others.

IRP Notation is a DSL language which can express any IR protocol. We can parse IRP and compile a decoder to BPF using LLVM. So, any protocol can be supported directly.

List devices (cir list)

This gives you a list of infrared and CEC devices on your Linux system. It is the cir equivalent of both ir-keytable with no arguments combined with the lirc features from ir-ctl -f.

cir list

This gives you a list of the all the rc devices on the system.

rc0:
        Device Name             : Media Center Ed. eHome Infrared Remote Transceiver (1784:0008)
        Driver                  : mceusb
        Default Keymap          : rc-rc6-mce
        Input Device            : /dev/input/event12
        Input properties        : Permission denied (os error 13)
        LIRC Device             : /dev/lirc0
        LIRC Features           : Permission denied (os error 13)
        Supported Protocols     : rc-5 nec rc-6 jvc sony rc-5-sz sanyo sharp mce_kbd xmp imon rc-mm
        Enabled Protocols       : rc-6

Not all information is available, unless you run it as root.

rc0:
        Device Name             : Media Center Ed. eHome Infrared Remote Transceiver (1784:0008)
        Driver                  : mceusb
        Default Keymap          : rc-rc6-mce
        Input Device            : /dev/input/event10
        Bus                     : USB
        Vendor/product          : 1784:0008 version 0x0101
        Repeat                  : delay 500 ms, period 125 ms
        LIRC Device             : /dev/lirc0
        LIRC Receiver           : raw receiver
        LIRC Resolution         : 50 microseconds
        LIRC Timeout            : 125000 microseconds
        LIRC Timeout Range      : 50 to 1250000 microseconds
        LIRC Wideband Receiver  : yes
        LIRC Measure Carrier    : yes
        LIRC Transmitter        : yes
        LIRC Set Tx Carrier     : yes
        LIRC Set Tx Duty Cycle  : no
        LIRC Transmitters       : 2
        BPF protocols           :
        Supported Protocols     : rc-5 nec rc-6 jvc sony rc-5-sz sanyo sharp mce_kbd xmp imon rc-mm
        Enabled Protocols       :

Transmit/Send (cir transmit)

If you have a .lircd.conf file or .toml keymap, you can transmit with the following command:

cir transmit --keymap RM-Y173.lircd.conf --keycode KEY_CHANNELUP

Alternatively, you can send raw IR directly like so:

cir transmit --raw '+9000 -4500 +560'

You can also send files or linux kernel scancodes, using the same options like ir-ctl. This supports mode2 files or raw IR files.

cir transmit -f input-file -S nec:0xcafe

You can send pronto codes:

cir transmit --pronto '5000 0073 0000 0001 0001 0001'

Lastly you use IRP notation and set the parameters. This is great for experimenting with IRP; use the --dry-run (-n) to avoid sending.

cir transmit -n -a F=2 --irp '{40k,600}<1,-1|2,-1>(4,-1,F:8,^45m)[F:0..255]'

This will give the following output:

info: carrier: 40000Hz
info: rawir: +2400 -600 +600 -600 +1200 -600 +600 -600 +600 -600 +600 -600 +600 -600 +600 -600 +600 -32400

Decoding (cir decode)

Use this if have a .lircd.conf file or .toml keymap, and want to decode the IR. This does not change any configation.

cir decode --keymap foo.lircd.conf

This will infrared from the first lirc device. You can also decode IR on the command line or a file.

cir decode --keymap foo.lircd.conf -r '+9000 -4500 +560'

or

cir decode --keymap foo.lircd.conf -f input-file

If you wish to decode using IRP Notation that is possible too:

cir decode --irp '{40k,600}<1,-1|2,-1>(4,-1,F:8,^45m)[F:0..255]'

Like above the input can be from a lirc device (optionally specify the device with -d /dev/lirc1 or -s rc), on the command line (-r '+100 -200 +100') or a file (-f filename).

Loading of keymaps

This is the cir equivalent of ir-keytable -w, however cir can not just load keymaps, it can also load .lircd.conf files.

cir keymap -s rc0 foo.lircd.conf

This will generate a BPF decoder for foo.lircd.conf and load it.

On startup, ir-keytable -a -s rc0 read the correct keymap from /etc/rc_maps.cfg.

cir keymap -s rc0

Setting the auto-repeat parameters.

cir keymap -P 125 -D 500

Test configuration (cir test)

This is the cir equivalent of ir-keytable -t

cir test

Status

All the functionality is in place to load keymaps. More tests are needed, and more polish. The aim is to have this done by the end of 2024.

Building

On Linux, cir depends on llvm for BPF code generation. On Fedora you can install the dependencies (apart from rust) with:

sudo dnf install libstdc++-devel libstdc++-static libffi-devel llvm-devel

For Ubuntu:

sudo apt-get install llvm-dev g++

Once you have all the dependencies installed, you can build cir like so:

cargo install --git https://gitlab.freedesktop.org/linux-media/tools/cir cir

Tests

• The IRP encoder and decoder is compared against IrpTransmogrifier with a large set of inputs.
• The parsing, encoding and decoding of lircd.conf files is compared against lirc (see liblircd)
• The encoding of linux protocols is compared against ir-ctl (see libirctl)
• There are many more tests