media/rc/rc-protos.rst

9 IR is encoded as a series of pulses and spaces, using a protocol. These
10 protocols can encode e.g. an address (which device should respond) and a
12 across different devices for a given protocol.
14 Therefore out the output of the IR decoder is a scancode; a single u32
17 Other things can be encoded too. Some IR protocols encode a toggle bit; this
22 Some remotes have a pointer-type device which can used to control the
29 rc-5 (RC_PROTO_RC5)
32 This IR protocol uses manchester encoding to encode 14 bits. There is a
41    * - rc-5 bit
65    * - 5
73      - 0 to 5
77 There is a variant of rc5 called either rc5x or extended rc5
81 done to keep it compatible with plain rc-5 where there are two start bits.
83 rc-5-sz (RC_PROTO_RC5_SZ)
85 This is much like rc-5 but one bit longer. The scancode is encoded
88 .. flat-table:: rc-5-sz bits scancode mapping
91    * - rc-5-sz bits
123      - 0 to 5
127 rc-5x-20 (RC_PROTO_RC5X_20)
130 This rc-5 extended to encoded 20 bits. The is a 3555 microseconds space
133 .. flat-table:: rc-5x-20 bits scancode mapping
136    * - rc-5-sz bits
160    * - 5
174      - 0 to 5
185 The scancode is a 16 bits value, where the address is the lower 8 bits
191 The sony protocol is a pulse-width encoding. There are three variants,
203    * - 5
218 The sony protocol is a pulse-width encoding. There are three variants,
245 The sony protocol is a pulse-width encoding. There are three variants,
257    * - 5
282 As a check, the nec protocol sends the address and command twice; the
285 A plain nec IR message has 16 bits; the high 8 bits are the address
291 Extended nec has a 16 bit address and a 8 bit command. This is encoded
292 as a 24 bit value as you would expect, with the lower 8 bits the command
305 The scancode has a somewhat unusual encoding.
356 The scancode is the exact 16 bits as in the protocol. There is also a
359 rc-6-6a-20 (RC_PROTO_RC6_6A_20)
362 This is the rc-6 in mode 6a, 20 bits. rc-6 is described here
365 as in the protocol. There is also a toggle bit.
367 rc-6-6a-24 (RC_PROTO_RC6_6A_24)
370 This is the rc-6 in mode 6a, 24 bits. rc-6 is described here
373 as in the protocol. There is also a toggle bit.
375 rc-6-6a-32 (RC_PROTO_RC6_6A_32)
378 This is the rc-6 in mode 6a, 32 bits. rc-6 is described here
388 This is the rc-6 in mode 6a, 32 bits. The upper 16 bits are the vendor,
397 This is a protocol used by Sharp VCRs, is described here
398 https://www.sbprojects.net/knowledge/ir/sharp.php. There is a very long
402 There is a 5 bit address and a 8 bit command. In the scancode the address is
415 This is not an IR protocol, this is a protocol over CEC. The CEC
454 device decodes the protocol. There is a BPF decoder available in v4l-utils.