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-rw-r--r--third_party/libwebrtc/modules/audio_coding/codecs/ilbc/comp_corr.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/comp_corr.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/comp_corr.c
new file mode 100644
index 0000000000..452bc78e3b
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/comp_corr.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+/******************************************************************
+
+ iLBC Speech Coder ANSI-C Source Code
+
+ WebRtcIlbcfix_CompCorr.c
+
+******************************************************************/
+
+#include "modules/audio_coding/codecs/ilbc/comp_corr.h"
+
+#include "modules/audio_coding/codecs/ilbc/defines.h"
+
+/*----------------------------------------------------------------*
+ * Compute cross correlation and pitch gain for pitch prediction
+ * of last subframe at given lag.
+ *---------------------------------------------------------------*/
+
+void WebRtcIlbcfix_CompCorr(
+ int32_t *corr, /* (o) cross correlation */
+ int32_t *ener, /* (o) energy */
+ int16_t *buffer, /* (i) signal buffer */
+ size_t lag, /* (i) pitch lag */
+ size_t bLen, /* (i) length of buffer */
+ size_t sRange, /* (i) correlation search length */
+ int16_t scale /* (i) number of rightshifts to use */
+ ){
+ int16_t *w16ptr;
+
+ w16ptr=&buffer[bLen-sRange-lag];
+
+ /* Calculate correlation and energy */
+ (*corr)=WebRtcSpl_DotProductWithScale(&buffer[bLen-sRange], w16ptr, sRange, scale);
+ (*ener)=WebRtcSpl_DotProductWithScale(w16ptr, w16ptr, sRange, scale);
+
+ /* For zero energy set the energy to 0 in order to avoid potential
+ problems for coming divisions */
+ if (*ener == 0) {
+ *corr = 0;
+ *ener = 1;
+ }
+}