1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/interpolate_samples.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/interpolate_samples.c
new file mode 100644
index 0000000000..6dddd6fb86
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/interpolate_samples.c
@@ -0,0 +1,53 @@
+/*
+ *  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_InterpolateSamples.c
+
+******************************************************************/
+
+#include "modules/audio_coding/codecs/ilbc/interpolate_samples.h"
+
+#include "modules/audio_coding/codecs/ilbc/constants.h"
+#include "modules/audio_coding/codecs/ilbc/defines.h"
+
+void WebRtcIlbcfix_InterpolateSamples(
+    int16_t *interpSamples, /* (o) The interpolated samples */
+    int16_t *CBmem,   /* (i) The CB memory */
+    size_t lMem    /* (i) Length of the CB memory */
+                                      ) {
+  int16_t *ppi, *ppo, i, j, temp1, temp2;
+  int16_t *tmpPtr;
+
+  /* Calculate the 20 vectors of interpolated samples (4 samples each)
+     that are used in the codebooks for lag 20 to 39 */
+  tmpPtr = interpSamples;
+  for (j=0; j<20; j++) {
+    temp1 = 0;
+    temp2 = 3;
+    ppo = CBmem+lMem-4;
+    ppi = CBmem+lMem-j-24;
+    for (i=0; i<4; i++) {
+
+      *tmpPtr++ = (int16_t)((WebRtcIlbcfix_kAlpha[temp2] * *ppo) >> 15) +
+          (int16_t)((WebRtcIlbcfix_kAlpha[temp1] * *ppi) >> 15);
+
+      ppo++;
+      ppi++;
+      temp1++;
+      temp2--;
+    }
+  }
+
+  return;
+}