--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/EFR-testing	Sun Dec 11 05:12:02 2022 +0000
@@ -0,0 +1,14 @@
+When it comes to codec libraries, testing for correctness is essential, and EFR
+is no exception.  There is a set of EFR encoder and decoder test sequences
+published by ETSI in ts_100725v050200p0.zip (GSM 06.54), and our suite of tools
+includes gsmefr-etsi-enc and gsmefr-etsi-dec test programs that operate on the
+representation formats used by these test sequences.  Because these test
+programs are based on libgsmefr EFR_encode_frame() and EFR_decode_frame()
+functions, seeing gsmefr-etsi-enc produce output that matches official ETSI
+*.cod files proves that libgsmefr encoder is correct, and seeing gsmefr-etsi-dec
+produce output that matches official ETSI *.out files proves that libgsmefr
+decoder is correct.
+
+For debugging, we also have gsmefr-cod-parse and gsmefr-dec-parse utilities that
+parse ETSI *.cod and *.dec file formats and dump their content in human-readable
+form.