# HG changeset patch
# User Mychaela Falconia <falcon@freecalypso.org>
# Date 1683863299 0
# Node ID 6ac547f0b90384bd4df8e64e9799b978dcabf253
# Parent  56d3fbacd115310c6be1975d0c9f97ade1bd6881
libgsmfrp: yet another invalid SID logic change, for 1.0.2

diff -r 56d3fbacd115 -r 6ac547f0b903 libgsmfrp/Makefile
--- a/libgsmfrp/Makefile	Fri May 12 02:04:42 2023 +0000
+++ b/libgsmfrp/Makefile	Fri May 12 03:48:19 2023 +0000
@@ -1,7 +1,7 @@
 CC=	gcc
 CFLAGS=	-O2
 OBJS=	bad_frame.o comfort_noise.o good_frame.o prng.o sidclass.o \
-	silence_frame.o state.o
+	silence_frame.o state.o xmaxc_mean.o
 HDRS=	gsm_fr_preproc.h internal.h
 LIB=	libgsmfrp.a
 
diff -r 56d3fbacd115 -r 6ac547f0b903 libgsmfrp/bad_frame.c
--- a/libgsmfrp/bad_frame.c	Fri May 12 02:04:42 2023 +0000
+++ b/libgsmfrp/bad_frame.c	Fri May 12 03:48:19 2023 +0000
@@ -94,6 +94,8 @@
 
 void gsmfr_preproc_invalid_sid(struct gsmfr_preproc_state *st, gsm_byte *frame)
 {
+	int mute;
+
 	switch (st->rx_state) {
 	case NO_DATA:
 		memcpy(frame, &gsmfr_preproc_silence_frame, sizeof(gsm_frame));
@@ -105,17 +107,16 @@
 		 */
 		st->rx_state = COMFORT_NOISE;
 		memcpy(st->sid_prefix, &st->speech_frame, 5);
-		st->sid_xmaxc = ((st->speech_frame[27] & 0x1F) << 1) |
-				(st->speech_frame[28] >> 7);
+		st->sid_xmaxc = gsmfr_preproc_xmaxc_mean(st->speech_frame);
 		gsmfr_preproc_gen_cn(st, frame);
 		return;
 	case SPEECH_MUTING:
-		/* same as above, but set the state to CN_MUTING */
-		st->rx_state = CN_MUTING;
-		memcpy(st->sid_prefix, &st->speech_frame, 5);
-		st->sid_xmaxc = ((st->speech_frame[27] & 0x1F) << 1) |
-				(st->speech_frame[28] >> 7);
-		gsmfr_preproc_gen_cn(st, frame);
+		/* ignore invalid SID in this state and act as if we got BFI */
+		mute = reduce_xmaxc(st->speech_frame);
+		memcpy(frame, &st->speech_frame, sizeof(gsm_frame));
+		random_grid_pos(st, frame);
+		if (mute)
+			st->rx_state = NO_DATA;
 		return;
 	case COMFORT_NOISE:
 	case LOST_SID:
diff -r 56d3fbacd115 -r 6ac547f0b903 libgsmfrp/internal.h
--- a/libgsmfrp/internal.h	Fri May 12 02:04:42 2023 +0000
+++ b/libgsmfrp/internal.h	Fri May 12 03:48:19 2023 +0000
@@ -33,3 +33,4 @@
 				      gsm_byte *frame);
 extern uint16_t gsmfr_preproc_prng(struct gsmfr_preproc_state *state,
 				   uint16_t no_bits);
+extern uint8_t gsmfr_preproc_xmaxc_mean(const gsm_byte *frame);
diff -r 56d3fbacd115 -r 6ac547f0b903 libgsmfrp/xmaxc_mean.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgsmfrp/xmaxc_mean.c	Fri May 12 03:48:19 2023 +0000
@@ -0,0 +1,100 @@
+/*
+ * The function implemented in this module computes a mean Xmaxc
+ * for comfort noise generation from the 4 subframe Xmaxc parameters
+ * extracted from an input frame.
+ */
+
+#include <stdint.h>
+#include "gsm_fr_preproc.h"
+#include "internal.h"
+
+static const uint16_t dequant_table[64] = {
+	  0,   1,   2,   3,   4,   5,   6,   7,
+	  8,   9,  10,  11,  12,  13,  14,  15,
+	 16,  18,  20,  22,  24,  26,  28,  30,
+	 32,  36,  40,  44,  48,  52,  56,  60,
+	 64,  72,  80,  88,  96, 104, 112, 120,
+	128, 144, 160, 176, 192, 208, 224, 240,
+	256, 288, 320, 352, 384, 416, 448, 480,
+	512, 576, 640, 704, 768, 832, 896, 960,
+};
+
+static const uint8_t requant_table[1024] = {
+	 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+	16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
+	24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27,
+	28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31,
+	32, 32, 32, 32, 32, 32, 32, 32, 33, 33, 33, 33, 33, 33, 33, 33,
+	34, 34, 34, 34, 34, 34, 34, 34, 35, 35, 35, 35, 35, 35, 35, 35,
+	36, 36, 36, 36, 36, 36, 36, 36, 37, 37, 37, 37, 37, 37, 37, 37,
+	38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39,
+	40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
+	41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
+	42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
+	43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43,
+	44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44,
+	45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45,
+	46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46, 46,
+	47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47,
+	48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
+	48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
+	49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49,
+	49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49,
+	50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50,
+	50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50,
+	51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51,
+	51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51,
+	52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52,
+	52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52,
+	53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53,
+	53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53,
+	54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54,
+	54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54,
+	55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55,
+	55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55,
+	56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56,
+	56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56,
+	56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56,
+	56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56,
+	57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57,
+	57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57,
+	57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57,
+	57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57,
+	58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
+	58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
+	58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
+	58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
+	59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59,
+	59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59,
+	59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59,
+	59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59,
+	60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
+	60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
+	60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
+	60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
+	61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61,
+	61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61,
+	61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61,
+	61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61,
+	62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62,
+	62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62,
+	62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62,
+	62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62,
+	63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
+	63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
+	63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
+	63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
+};
+
+uint8_t gsmfr_preproc_xmaxc_mean(const gsm_byte *frame)
+{
+	unsigned sub, xmaxc, sum;
+
+	sum = 0;
+	for (sub = 0; sub < 4; sub++) {
+		xmaxc = ((frame[sub*7+6] & 0x1F) << 1) | (frame[sub*7+7] >> 7);
+		sum += dequant_table[xmaxc];
+	}
+	xmaxc = requant_table[sum >> 2];
+	return xmaxc;
+}