diff doc/Calypso-TCH-downlink @ 180:62c0359ff2a8

doc/Calypso-TCH-downlink: document use of tools on voice memos
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 30 Dec 2022 07:46:58 +0000
parents 486e19acc66f
children 2254fa16ec5f
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line diff
--- a/doc/Calypso-TCH-downlink	Fri Dec 30 07:23:24 2022 +0000
+++ b/doc/Calypso-TCH-downlink	Fri Dec 30 07:46:58 2022 +0000
@@ -109,3 +109,11 @@
   gsmx and calling library functions directly, and thus there is no FR1
   counterpart to gsmefr-dlcap-dec - just use gsmfr-dlcap-gsmx followed by
   gsmfr-decode or gsmfr-decode-r.
+
+* In addition to TCH DL capture files, gsmfr-dlcap-parse also accepts the hex
+  output from fc-vm2hex, originating from TCS211 voice memo recordings,
+  including fc-vm2hex output in the case of VM recordings made in DTX mode.
+  However, if the objective is to play that VM recording and not just look at
+  parsed bits, the correct approach is to convert the VM file to gsmx with
+  fc-vm2gsmx, and then decode with gsmfr-decode.  Using fc-vm2hex followed by
+  gsmfr-dlcap-gsmx instead of fc-vm2gsmx won't work!