--- a/.hgignore	Wed May 08 05:32:27 2024 +0000
+++ b/.hgignore	Wed May 08 23:03:28 2024 +0000
@@ -9,6 +9,7 @@
 ^amrconv/gsm-amr2efr$
 ^amrconv/gsm-efr2amr$
 
+^amrefr/amrefr-tseq-dec$
 ^amrefr/amrefr-tseq-enc$
 
 ^amrtest/twamr-tseq-dec$

--- a/amrefr/Makefile	Wed May 08 05:32:27 2024 +0000
+++ b/amrefr/Makefile	Wed May 08 23:03:28 2024 +0000
@@ -1,18 +1,28 @@
 CC=	gcc
 CFLAGS=	-O2
-PROGS=	amrefr-tseq-enc
+PROGS=	amrefr-tseq-dec amrefr-tseq-enc
 LIBEFR=	../libgsmefr/libgsmefr.a
 LIBAMR=	../libtwamr/libtwamr.a
+LIBS=	${LIBEFR} ${LIBAMR}
 INSTBIN=/opt/freecalypso/bin
 
 all:	${PROGS}
 
-amrefr-tseq-enc:	tseq-enc.o tseq-enc-common.o ${LIBEFR} ${LIBAMR}
+amrefr-tseq-dec:	tseq-dec.o tseq-bit-rd.o tseq-pcm-out.o ${LIBS}
+	${CC} ${CFLAGS} -o $@ $^
+
+amrefr-tseq-enc:	tseq-enc.o tseq-enc-common.o ${LIBS}
 	${CC} ${CFLAGS} -o $@ $^
 
+tseq-bit-rd.o:	../efrtest/etsi-bit-rd.c
+	${CC} ${CFLAGS} -c -o $@ $<
+
 tseq-enc-common.o:	../efrtest/etsi-enc-common.c
 	${CC} ${CFLAGS} -c -o $@ $<
 
+tseq-pcm-out.o:	../efrtest/etsi-pcm-out.c
+	${CC} ${CFLAGS} -c -o $@ $<
+
 install:
 	mkdir -p ${INSTBIN}
 	install -c ${PROGS} ${INSTBIN}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/amrefr/tseq-dec.c	Wed May 08 23:03:28 2024 +0000
@@ -0,0 +1,94 @@
+/*
+ * amrefr-tseq-dec is a test program for our libtwamr-based "alternative EFR"
+ * decoder: it functions just like gsmefr-etsi-dec, but uses libtwamr as
+ * the decoder engine instead of libgsmefr.  Libgsmefr functions are still
+ * used for frame unpacking, but not for actual decoding.  Note that there is
+ * no DTX support in this version, and the *.dec test sequence being decoded
+ * must have SID=0 in every frame.  As a simplification, we also require BFI=0:
+ * while it is possible to feed BFI=1 frames to libtwamr decoder (convert to
+ * RX_SPEECH_BAD), such support is not needed for decoding the test sequences
+ * in amr122_efr.zip, hence we've omitted it for simplicity.
+ *
+ * The byte order is LE by default or BE with -b option.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include "../libgsmefr/gsm_efr.h"
+#include "../libtwamr/tw_amr.h"
+#include "../efrtest/etsi.h"
+
+main(argc, argv)
+	char **argv;
+{
+	int big_endian;
+	char *infname, *outfname;
+	FILE *inf, *outf;
+	struct amr_decoder_state *state;
+	unsigned frame_no;
+	uint8_t input_bits[ETSI_DEC_NWORDS], efr_frame[EFR_RTP_FRAME_LEN];
+	struct amr_param_frame amr_frame;
+	int16_t pcm[160];
+	int rc;
+
+	if (argc == 3 && argv[1][0] != '-') {
+		big_endian = 0;
+		infname = argv[1];
+		outfname = argv[2];
+	} else if (argc == 4 && !strcmp(argv[1], "-b")) {
+		big_endian = 1;
+		infname = argv[2];
+		outfname = argv[3];
+	} else {
+		fprintf(stderr, "usage: %s [-b] input.dec output.out\n",
+			argv[0]);
+		exit(1);
+	}
+	inf = fopen(infname, "r");
+	if (!inf) {
+		perror(infname);
+		exit(1);
+	}
+	outf = fopen(outfname, "w");
+	if (!outf) {
+		perror(outfname);
+		exit(1);
+	}
+	state = amr_decoder_create();
+	if (!state) {
+		perror("amr_decoder_create()");
+		exit(1);
+	}
+	amr_frame.type = RX_SPEECH_GOOD;
+	amr_frame.mode = 0x87;
+	for (frame_no = 0; ; frame_no++) {
+		rc = read_etsi_bits(inf, big_endian, input_bits,
+				    ETSI_DEC_NWORDS, infname);
+		if (!rc)
+			break;
+		if (input_bits[0]) {
+			fprintf(stderr,
+			"error in %s frame #%u: BFI != 0 not supported\n",
+				infname, frame_no);
+			exit(1);
+		}
+		bits2frame(input_bits + 1, efr_frame, infname, frame_no);
+		if (input_bits[245]) {
+			fprintf(stderr,
+			"error in %s frame #%u: SID != 0 not supported\n",
+				infname, frame_no);
+			exit(1);
+		}
+		EFR_frame2params(efr_frame, amr_frame.param);
+		amr_decode_frame(state, &amr_frame, pcm);
+		if (big_endian)
+			write_pcm_be(outf, pcm);
+		else
+			write_pcm_le(outf, pcm);
+	}
+	fclose(outf);
+	exit(0);
+}