Updated IRSend RAW Encoding (markdown)

IRSend-RAW-Encoding.md

@@ -118,3 +118,10 @@ You need to take timing by pairs, again the first value is Mark (IR on), the sec
 
 So the first bits of the bitstream are: `101001...`
 
+## Pioneer IR enconding
+
+Pioneer IR encoding is very similar to NEC encoding for the bitstream. When capturing IR codes, they will easily be recognized as NEC codes. But they have subtle differences.
+
+First, the Frequency if 40KHz for Pioneer vs 38KHz for NEC. The number of IR pulses are the same, so all Pioneer timings are 5% shorter than Nec equivalent. Most Pioneer will tolerate the difference, but some won't. If you have a Pioneer device, prefer the `Pioneer` encoding.
+
+Second, Pioneer introduced 64 bits messages vs 32 bits for NEC. Most simple Pioneer commands still use 32 bits, but newer require 64 bits. 64 bits messages are actually sent as 2x 32 bits messages with a very short pause in between.