--- a/.hgignore	Sat Nov 26 18:58:56 2022 +0000
+++ b/.hgignore	Sat Nov 26 19:55:59 2022 +0000
@@ -9,6 +9,7 @@
 ^dev/gsm0611-silence-fr$
 ^dev/gsm0611-silence-fr\.out$
 
+^efrtest/gsmefr-etsi-dec$
 ^efrtest/gsmefr-rec2etsi$
 
 ^frtest/gsmfr-cvt-dlcap$

--- a/efrtest/Makefile	Sat Nov 26 18:58:56 2022 +0000
+++ b/efrtest/Makefile	Sat Nov 26 19:55:59 2022 +0000
@@ -1,12 +1,15 @@
 CC=	gcc
 CFLAGS=	-O2
-PROGS=	gsmefr-rec2etsi
+PROGS=	gsmefr-etsi-dec gsmefr-rec2etsi
 LIBEFR=	../libgsmefr/libgsmefr.a
 LIBTEST=../libtest/libtest.a
 INSTBIN=/opt/freecalypso/bin
 
 all:	${PROGS}
 
+gsmefr-etsi-dec:	etsi-dec.o ${LIBEFR}
+	${CC} ${CFLAGS} -o $@ etsi-dec.o ${LIBEFR}
+
 gsmefr-rec2etsi:	rec2etsi.o ${LIBTEST} ${LIBEFR}
 	${CC} ${CFLAGS} -o $@ rec2etsi.o ${LIBTEST} ${LIBEFR}
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/efrtest/etsi-dec.c	Sat Nov 26 19:55:59 2022 +0000
@@ -0,0 +1,164 @@
+/*
+ * gsmefr-etsi-dec is a test program for our EFR decoder: it reads ETSI's
+ * .dec format as input and writes raw 16-bit PCM (same as ETSI's *.out)
+ * as output, allowing our decoder to be tested with ETSI's official test
+ * sequences.
+ *
+ * ETSI input and output files are read and written in LE byte order,
+ * matching the official test sequences in ts_100725v050200p0.zip.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include "../libgsmefr/gsm_efr.h"
+
+#define	ETSI_DEC_NWORDS	247
+
+static int
+read_input(inf, bitvec, filename_for_errs)
+	FILE *inf;
+	uint8_t *bitvec;
+	char *filename_for_errs;
+{
+	uint8_t file_bytes[ETSI_DEC_NWORDS * 2], *sp;
+	int cc;
+	unsigned n;
+
+	cc = fread(file_bytes, 2, ETSI_DEC_NWORDS, inf);
+	if (cc == 0)
+		return 0;
+	if (cc != ETSI_DEC_NWORDS) {
+		fprintf(stderr, "error: short read from %s\n",
+			filename_for_errs);
+		exit(1);
+	}
+	sp = file_bytes;
+	for (n = 0; n < ETSI_DEC_NWORDS; n++) {
+		if (sp[1]) {
+			fprintf(stderr,
+		"error in %s: non-zero in what should be LE upper byte\n",
+				filename_for_errs);
+			exit(1);
+		}
+		bitvec[n] = sp[0];
+		sp += 2;
+	}
+	return 1;
+}
+
+static void
+bits2frame(input_bits, frame, filename_for_errs, frame_no)
+	uint8_t *input_bits, *frame;
+	char *filename_for_errs;
+	unsigned frame_no;
+{
+	uint8_t bits[248], *sp, *dp;
+	unsigned nb, byte, mask;
+
+	bits[0] = 1;
+	bits[1] = 1;
+	bits[2] = 0;
+	bits[3] = 0;
+	bcopy(input_bits, bits + 4, 244);
+	sp = bits;
+	dp = frame;
+	for (nb = 0; nb < EFR_RTP_FRAME_LEN; nb++) {
+		byte = 0;
+		for (mask = 0x80; mask; mask >>= 1) {
+			if (*sp > 1) {
+				fprintf(stderr,
+					"error in %s frame #%u: data bit > 1\n",
+					filename_for_errs, frame_no);
+				exit(1);
+			}
+			if (*sp)
+				byte |= mask;
+			sp++;
+		}
+		*dp++ = byte;
+	}
+}
+
+static void
+write_pcm_le(outf, pcm)
+	FILE *outf;
+	int16_t *pcm;
+{
+	uint8_t bytes[320], *dp;
+	int16_t samp;
+	unsigned n;
+
+	dp = bytes;
+	for (n = 0; n < 160; n++) {
+		samp = pcm[n];
+		*dp++ = samp & 0xFF;
+		*dp++ = (samp >> 8) & 0xFF;
+	}
+	fwrite(bytes, 2, 160, outf);
+}
+
+main(argc, argv)
+	char **argv;
+{
+	FILE *inf, *outf;
+	struct EFR_decoder_state *state;
+	unsigned frame_no;
+	uint8_t input_bits[ETSI_DEC_NWORDS], frame[EFR_RTP_FRAME_LEN];
+	int16_t pcm[160];
+	int rc;
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s input.dec output.out\n", argv[0]);
+		exit(1);
+	}
+	inf = fopen(argv[1], "r");
+	if (!inf) {
+		perror(argv[1]);
+		exit(1);
+	}
+	outf = fopen(argv[2], "w");
+	if (!outf) {
+		perror(argv[2]);
+		exit(1);
+	}
+	state = EFR_decoder_create();
+	if (!state) {
+		perror("EFR_decoder_create()");
+		exit(1);
+	}
+	for (frame_no = 0; ; frame_no++) {
+		rc = read_input(inf, input_bits, argv[1]);
+		if (!rc)
+			break;
+		if (input_bits[0] > 1) {
+			fprintf(stderr, "error in %s frame #%u: BFI > 1\n",
+				argv[1], frame_no);
+			exit(1);
+		}
+		bits2frame(input_bits, frame, argv[1], frame_no);
+		if (input_bits[245] > 2) {
+			fprintf(stderr, "error in %s frame #%u: SID > 2\n",
+				argv[1], frame_no);
+			exit(1);
+		}
+		if (input_bits[246] > 1) {
+			fprintf(stderr, "error in %s frame #%u: TAF > 1\n",
+				argv[1], frame_no);
+			exit(1);
+		}
+		rc = EFR_sid_classify(frame);
+		if (input_bits[245] != rc) {
+			fprintf(stderr,
+"warning: frame #%u has mismatching SID (file says %u, analysis yields %d)\n",
+				frame_no, input_bits[245], rc);
+		}
+		EFR_decode_frame(state, frame, input_bits[0], input_bits[246],
+				 pcm);
+		write_pcm_le(outf, pcm);
+	}
+	fclose(outf);
+	exit(0);
+}