codec: Implement proper 10 ms subframe synthesis

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

4 files changed, 73 insertions, 71 deletions

diff --git a/src/codec/ambe.c b/src/codec/ambe.c
index ea46b20..4aa0762 100644
--- a/src/codec/ambe.c
+++ b/src/codec/ambe.c
@@ -37,7 +37,7 @@ void
 ambe_decode_init(struct ambe_decoder *dec)
 {
 	memset(dec, 0x00, sizeof(struct ambe_decoder));
-	mbe_initMbeParms(&dec->mp_cur, &dec->mp_prev, &dec->mp_prev_enh);
+	mbe_initMbeParms(&dec->mp_prev);
 }
 
 void
@@ -62,6 +62,26 @@ ambe_classify_frame(const uint8_t *frame)
 	};
 }
 
+static void
+ambe_subframe_to_mbelib(mbe_parms *mp, struct ambe_subframe *sf)
+{
+	float unvc;
+	int i;
+
+	mp->w0 = sf->f0 * (2.0f * (float)M_PI);
+	mp->L  = sf->L;
+
+	unvc = 0.2046f / sqrtf(mp->w0);	/* ??? */
+
+	for (i=1; i<=mp->L; i++) {
+		int j = (int)((i-1) * 16.0f * sf->f0);
+		mp->Vl[i] = sf->v_uv[j];
+		mp->Ml[i] = powf(2.0, sf->Mlog[i-1]) / 6.0f;
+		if (!mp->Vl[i])
+			mp->Ml[i] *= unvc;
+	}
+}
+
 static int
 ambe_decode_speech(struct ambe_decoder *dec,
                    int16_t *audio, int N,
@@ -69,8 +89,7 @@ ambe_decode_speech(struct ambe_decoder *dec,
 {
 	struct ambe_raw_params rp;
 	struct ambe_subframe sf[2];
-	float unvc;
-	int i;
+	mbe_parms mp[2];
 
 	/* Unpack frame */
 	ambe_frame_unpack_raw(&rp, frame);
@@ -78,25 +97,18 @@ ambe_decode_speech(struct ambe_decoder *dec,
 	/* Decode subframe parameters */
 	ambe_frame_decode_params(sf, &dec->sf_prev, &rp);
 
-	/* Convert to mbelib's format */
-	dec->mp_cur.w0 = sf[1].f0 * (2.0f * (float)M_PI);
-	dec->mp_cur.L  = sf[1].L;
+	/* Convert both subframes to mbelib's format */
+	ambe_subframe_to_mbelib(&mp[0], &sf[0]);
+	ambe_subframe_to_mbelib(&mp[1], &sf[1]);
 
-	unvc = 0.2046f / sqrtf(dec->mp_cur.w0);	/* ??? */
+	/* Synthesize speech (using mbelib for now) */
+	mbe_spectralAmpEnhance(&mp[0]);
+	mbe_spectralAmpEnhance(&mp[1]);
 
-	for (i=1; i<=dec->mp_cur.L; i++) {
-		int j = (int)((i-1) * 16.0f * sf[1].f0);
-		dec->mp_cur.Vl[i] = sf[1].v_uv[j];
-		dec->mp_cur.Ml[i] = powf(2.0, sf[1].Mlog[i-1]) / 8.0f;
-		if (!dec->mp_cur.Vl[i])
-			dec->mp_cur.Ml[i] *= unvc;
-	}
+	mbe_synthesizeSpeech(audio,    &mp[0], &dec->mp_prev, 2);
+	mbe_synthesizeSpeech(audio+80, &mp[1], &mp[0],        2);
 
-	/* Synthesize speech (using mbelib for now) */
-	mbe_moveMbeParms(&dec->mp_cur, &dec->mp_prev);
-	mbe_spectralAmpEnhance(&dec->mp_cur);
-	mbe_synthesizeSpeech(audio, &dec->mp_cur, &dec->mp_prev_enh, 2);
-	mbe_moveMbeParms(&dec->mp_cur, &dec->mp_prev_enh);
+	mbe_moveMbeParms(&mp[1], &dec->mp_prev);
 
 	/* Save subframe */
 	memcpy(&dec->sf_prev, &sf[1], sizeof(struct ambe_subframe));
diff --git a/src/codec/mbelib.c b/src/codec/mbelib.c
index d6561f4..67b2455 100644
--- a/src/codec/mbelib.c
+++ b/src/codec/mbelib.c
@@ -26,35 +26,32 @@
 /*
  * Speech Synthesis Window 8k version
  */
-static const float Ws[321] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0,
-	0, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18,
-	0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38,
-	0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58,
-	0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78,
-	0.8, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, 0.94, 0.96, 0.98,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	0.98, 0.96, 0.94, 0.92, 0.9, 0.88, 0.86, 0.84, 0.82, 0.8,
-	0.78, 0.76, 0.74, 0.72, 0.7, 0.68, 0.66, 0.64, 0.62, 0.6,
-	0.58, 0.56, 0.54, 0.52, 0.5, 0.48, 0.46, 0.44, 0.42, 0.4,
-	0.38, 0.36, 0.34, 0.32, 0.3, 0.28, 0.26, 0.24, 0.22, 0.2,
-	0.18, 0.16, 0.14, 0.12, 0.1, 0.08, 0.06, 0.04, 0.02, 0,
-	0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+static const int N = 80;
+
+static const float Ws[161] = {
+	0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.02, 0.06, 0.10, 0.14, 0.18, 0.22, 0.26, 0.30,
+	0.34,
+	0.38, 0.42, 0.46, 0.50, 0.54, 0.58, 0.62, 0.66,
+	0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00,
+	0.98, 0.94, 0.90, 0.86, 0.82, 0.78, 0.74, 0.70,
+	0.66, 0.62, 0.58, 0.54, 0.50, 0.46, 0.42, 0.38,
+	0.34, 0.30, 0.26, 0.22, 0.18, 0.14, 0.10, 0.06,
+	0.02,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
+	0.00, 0.00, 0.00, 0.00
 };
 
 
@@ -109,26 +106,23 @@ mbe_useLastMbeParms (mbe_parms * cur_mp, mbe_parms * prev_mp)
 }
 
 void
-mbe_initMbeParms (mbe_parms * cur_mp, mbe_parms * prev_mp, mbe_parms * prev_mp_enhanced)
+mbe_initMbeParms (mbe_parms *mp)
 {
-
 	int l;
 
-	prev_mp->w0 = 0.09378;
-	prev_mp->L = 30;
-	prev_mp->K = 10;
-	prev_mp->gamma = (float) 0;
+	mp->w0 = 0.09378;
+	mp->L = 30;
+	mp->K = 10;
+	mp->gamma = (float) 0;
 	for (l = 0; l <= 56; l++)
 	{
-		prev_mp->Ml[l] = (float) 0;
-		prev_mp->Vl[l] = 0;
-		prev_mp->log2Ml[l] = (float) 0;   // log2 of 1 == 0
-		prev_mp->PHIl[l] = (float) 0;
-		prev_mp->PSIl[l] = (M_PI / (float) 2);
+		mp->Ml[l] = (float) 0;
+		mp->Vl[l] = 0;
+		mp->log2Ml[l] = (float) 0;   // log2 of 1 == 0
+		mp->PHIl[l] = (float) 0;
+		mp->PSIl[l] = (M_PI / (float) 2);
 	}
-	prev_mp->repeat = 0;
-	mbe_moveMbeParms (prev_mp, cur_mp);
-	mbe_moveMbeParms (prev_mp, prev_mp_enhanced);
+	mp->repeat = 0;
 }
 
 void
@@ -209,7 +203,7 @@ mbe_synthesizeSilencef (float *aout_buf)
 	float *aout_buf_p;
 
 	aout_buf_p = aout_buf;
-	for (n = 0; n < 160; n++)
+	for (n = 0; n < N; n++)
 	{
 		*aout_buf_p = (float) 0;
 		aout_buf_p++;
@@ -224,7 +218,7 @@ mbe_synthesizeSilence (short *aout_buf)
 	short *aout_buf_p;
 
 	aout_buf_p = aout_buf;
-	for (n = 0; n < 160; n++)
+	for (n = 0; n < N; n++)
 	{
 		*aout_buf_p = (short) 0;
 		aout_buf_p++;
@@ -246,8 +240,6 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
 	float qfactor;
 	float rphase[64], rphase2[64];
 
-	const int N = 160;
-
 	uvthresholdf = (float) 2700;
 	uvthreshold = ((uvthresholdf * M_PI) / (float) 4000);
 
@@ -475,7 +467,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
 void
 mbe_synthesizeSpeech (short *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp, int uvquality)
 {
-	float float_buf[160];
+	float float_buf[N];
 
 	mbe_synthesizeSpeechf (float_buf, cur_mp, prev_mp, uvquality);
 	mbe_floattoshort (float_buf, aout_buf);
@@ -493,7 +485,7 @@ mbe_floattoshort (float *float_buf, short *aout_buf)
 	again = 7;
 	aout_buf_p = aout_buf;
 	float_buf_p = float_buf;
-	for (i = 0; i < 160; i++)
+	for (i = 0; i < N; i++)
 	{
 		audio = again * *float_buf_p;
 		if (audio > 32760)
diff --git a/src/codec/mbelib.h b/src/codec/mbelib.h
index 1353bd1..601161b 100644
--- a/src/codec/mbelib.h
+++ b/src/codec/mbelib.h
@@ -40,7 +40,7 @@ typedef struct mbe_parameters mbe_parms;
 void mbe_printVersion (char *str);
 void mbe_moveMbeParms (mbe_parms * cur_mp, mbe_parms * prev_mp);
 void mbe_useLastMbeParms (mbe_parms * cur_mp, mbe_parms * prev_mp);
-void mbe_initMbeParms (mbe_parms * cur_mp, mbe_parms * prev_mp, mbe_parms * prev_mp_enhanced);
+void mbe_initMbeParms (mbe_parms *mp);
 void mbe_spectralAmpEnhance (mbe_parms * cur_mp);
 void mbe_synthesizeSilencef (float *aout_buf);
 void mbe_synthesizeSilence (short *aout_buf);
diff --git a/src/codec/private.h b/src/codec/private.h
index 193b44e..9edea03 100644
--- a/src/codec/private.h
+++ b/src/codec/private.h
@@ -83,9 +83,7 @@ struct ambe_decoder
 
 	struct ambe_subframe sf_prev;	/*!< \brief Previous subframe */
 
-	mbe_parms mp_cur;	/*!< \brief mbelib current frame */
 	mbe_parms mp_prev;	/*!< \brief mbelib previous frame */
-	mbe_parms mp_prev_enh;	/*!< \brief mbelib previous frame (enhanced) */
 };
 
 /* From ambe.c */