--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgsmefr/dtx_defs.h	Sat Dec 10 02:25:20 2022 +0000
@@ -0,0 +1,19 @@
+/*
+ * The definitions contained in this header file originally lived in
+ * dtx.c; they are being factored out into a new header file as part of
+ * splitting of dtx.c code into common, encoder-only and decoder-only
+ * parts.
+ */
+
+/* Inverse values of DTX hangover period and DTX hangover period + 1 */
+
+#define INV_DTX_HANGOVER (0x7fff / DTX_HANGOVER)
+#define INV_DTX_HANGOVER_P1 (0x7fff / (DTX_HANGOVER+1))
+
+#define NB_PULSE 10 /* Number of pulses in fixed codebook excitation */
+
+/* Constant DTX_ELAPSED_THRESHOLD is used as threshold for allowing
+   SID frame updating without hangover period in case when elapsed
+   time measured from previous SID update is below 24 */
+
+#define DTX_ELAPSED_THRESHOLD (24 + DTX_HANGOVER - 1)