--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/trau-decode/parse-amr.c	Sat Feb 08 06:22:45 2025 +0000
@@ -0,0 +1,53 @@
+/*
+ * This module contains a bit of code that has been factored out of
+ * trau-parse program; it handles AMR frames.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+static unsigned
+bits_to_num(bits, nbits)
+	uint8_t *bits;
+	unsigned nbits;
+{
+	unsigned accum;
+	unsigned n;
+
+	accum = 0;
+	for (n = 0; n < nbits; n++) {
+		accum <<= 1;
+		if (*bits)
+			accum |= 1;
+		bits++;
+	}
+	return accum;
+}
+
+void
+print_amr_frame(frame_bits)
+	uint8_t *frame_bits;
+{
+	unsigned c6_11;
+
+	c6_11 = bits_to_num(frame_bits + 22, 6);
+	printf("  C6-C11: %u\n", c6_11);
+	printf("  RIF=%u C13=%u Config_Prot=%u%u%u Msg_No=%u%u\n",
+		frame_bits[28], frame_bits[29], frame_bits[30],
+		frame_bits[31], frame_bits[33], frame_bits[34],
+		frame_bits[35]);
+	printf("  DTXd=%u TFOE=%u FClass=%u%u CMI/CMR=%u%u%u\n",
+		frame_bits[36], frame_bits[37], frame_bits[38],
+		frame_bits[39], frame_bits[40], frame_bits[41],
+		frame_bits[42]);
+	if (!frame_bits[38] && !frame_bits[39])
+		printf("  No_Spch_Class=%u%u%u CMI=%u%u%u CMR=%u%u%u\n",
+			frame_bits[76], frame_bits[77], frame_bits[78],
+			frame_bits[79], frame_bits[81], frame_bits[82],
+			frame_bits[83], frame_bits[84], frame_bits[85]);
+	printf("  T1=%u T2=%u T3=%u T4=%u\n", frame_bits[316],
+		frame_bits[317], frame_bits[318], frame_bits[319]);
+}