1 files changed, 110 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/gpclip.c b/media/libstagefright/codecs/amrwbenc/src/gpclip.c
new file mode 100644
index 0000000..800b3f9
--- /dev/null
+++ b/media/libstagefright/codecs/amrwbenc/src/gpclip.c
@@ -0,0 +1,110 @@
+/*
+ ** Copyright 2003-2010, VisualOn, Inc.
+ **
+ ** Licensed under the Apache License, Version 2.0 (the "License");
+ ** you may not use this file except in compliance with the License.
+ ** You may obtain a copy of the License at
+ **
+ **     http://www.apache.org/licenses/LICENSE-2.0
+ **
+ ** Unless required by applicable law or agreed to in writing, software
+ ** distributed under the License is distributed on an "AS IS" BASIS,
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ ** See the License for the specific language governing permissions and
+ ** limitations under the License.
+ */
+
+/**************************************************************************
+*      File: gpclip.c                                                     *
+*                                                                         *
+*      Description:To avoid unstable synthesis on frame erasure, the gain *
+*      need to be limited(gain pitch < 1.0) when the following            *
+*      case occurs                                                        *
+*      a resonance on LPC filter(lp_disp < 60Hz)                          *
+*      a good pitch prediction (lp_gp > 0.95)                             *
+*                                                                         *
+***************************************************************************/
+#include "typedef.h"
+#include "basic_op.h"
+
+#define DIST_ISF_MAX    307                /* 120 Hz (6400Hz=16384) */
+#define DIST_ISF_THRES  154                /* 60     (6400Hz=16384) */
+#define GAIN_PIT_THRES  14746              /* 0.9 in Q14 */
+#define GAIN_PIT_MIN    9830               /* 0.6 in Q14 */
+#define M               16
+
+
+void Init_gp_clip(
+		Word16 mem[]                          /* (o) : memory of gain of pitch clipping algorithm */
+		)
+{
+	mem[0] = DIST_ISF_MAX;
+	mem[1] = GAIN_PIT_MIN;
+}
+
+
+Word16 Gp_clip(
+		Word16 mem[]                          /* (i/o) : memory of gain of pitch clipping algorithm */
+	      )
+{
+	Word16 clip = 0;
+	if ((mem[0] < DIST_ISF_THRES) && (mem[1] > GAIN_PIT_THRES))
+		clip = 1;
+
+	return (clip);
+}
+
+
+void Gp_clip_test_isf(
+		Word16 isf[],                         /* (i)   : isf values (in frequency domain)           */
+		Word16 mem[]                          /* (i/o) : memory of gain of pitch clipping algorithm */
+		)
+{
+	Word16 dist, dist_min;
+	Word32 i;
+
+	dist_min = vo_sub(isf[1], isf[0]);
+
+	for (i = 2; i < M - 1; i++)
+	{
+		dist = vo_sub(isf[i], isf[i - 1]);
+		if(dist < dist_min)
+		{
+			dist_min = dist;
+		}
+	}
+
+	dist = extract_h(L_mac(vo_L_mult(26214, mem[0]), 6554, dist_min));
+
+	if (dist > DIST_ISF_MAX)
+	{
+		dist = DIST_ISF_MAX;
+	}
+	mem[0] = dist;
+
+	return;
+}
+
+
+void Gp_clip_test_gain_pit(
+		Word16 gain_pit,                      /* (i) Q14 : gain of quantized pitch                    */
+		Word16 mem[]                          /* (i/o)   : memory of gain of pitch clipping algorithm */
+		)
+{
+	Word16 gain;
+	Word32 L_tmp;
+	L_tmp = (29491 * mem[1])<<1;
+	L_tmp += (3277 * gain_pit)<<1;
+
+	gain = extract_h(L_tmp);
+
+	if(gain < GAIN_PIT_MIN)
+	{
+		gain = GAIN_PIT_MIN;
+	}
+	mem[1] = gain;
+	return;
+}
+
+
+